Emerging Topics

Asymptomatic carrier ratio estimation and asymptomtic transmission are becoming critical concerns in control of COVID-19 pandemic especially in consideration of re-opening.

Asymptomatic and Pre-Symptomatic Infection

Several studies have documented SARS-CoV-2 infection in patients who never develop symptoms (asymptomatic) and in patients not yet symptomatic (pre-symptomatic).1,2 Since asymptomatic persons are not routinely tested, the prevalence of asymptomatic infection and detection of pre-symptomatic infection is not well understood. One study found that as many as 13% of RT-PCR-confirmed cases of SARS-CoV-2 infection in children were asymptomatic.3 Another study of skilled nursing facility residents infected with SARS-CoV-2 from a healthcare worker demonstrated that half were asymptomatic or pre-symptomatic at the time of contact tracing evaluation and testing.4 Patients may have abnormalities on chest imaging before the onset of symptoms. Some data suggest that pre-symptomatic infection tended to be detected in younger individuals and was less likely to be associated with viral pneumonia.5,6

Asymptomatic and Pre-Symptomatic Transmission

Epidemiologic studies have documented SARS-CoV-2 transmission during the pre-symptomatic incubation period5, and asymptomatic transmission has been suggested in other reports.7,8 Virologic studies have also detected SARS-CoV-2 with RT-PCR low cycle thresholds, indicating larger quantities of viral RNA, and cultured viable virus among persons with asymptomatic and pre-symptomatic SARS-CoV-2 infection.9 The exact degree of SARS-CoV-2 viral RNA shedding that confers risk of transmission is not yet clear. Risk of transmission is thought to be greatest when patients are symptomatic since viral shedding is greatest at the time of symptom onset and declines over the course of several days to weeks.10 However, the proportion of SARS-CoV-2 transmission in the population due to asymptomatic or pre-symptomatic infection compared to symptomatic infection is unclear.11


  1. Chan JF, Yuan S, Kok KH, et al. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster. Lancet 2020;395:514-23.
  2. Lu X, Zhang L, Du H, et al. SARS-CoV-2 Infection in Children. N Engl J Med 2020;382:1663-5.
  3. Dong Y, Mo X, Hu Y, et al. Epidemiology of COVID-19 Among Children in China. Pediatrics 2020.
  4. Kimball A, Hatfield KM, Arons M, et al. Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility – King County, Washington, March 2020. MMWR Morb Mortal Wkly Rep 2020;69:377-81.
  5. Hu Z, Song C, Xu C, et al. Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing, China. Sci China Life Sci 2020;63:706-11.
  6. Wang Y, Liu Y, Liu L, Wang X, Luo N, Ling L. Clinical outcome of 55 asymptomatic cases at the time of hospital admission infected with SARS-Coronavirus-2 in Shenzhen, China. J Infect Dis 2020.
  7. Pan X, Chen D, Xia Y, et al. Asymptomatic cases in a family cluster with SARS-CoV-2 infection. Lancet Infect Dis 2020;20:410-1.
  8. Bai Y, Yao L, Wei T, et al. Presumed Asymptomatic Carrier Transmission of COVID-19. JAMA 2020.
  9. Kam KQ, Yung CF, Cui L, et al. A Well Infant with Coronavirus Disease 2019 (COVID-19) with High Viral Load. Clin Infect Dis 2020.
  10. Zou L, Ruan F, Huang M, et al. SARS-CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients. N Engl J Med 2020;382:1177-9.
  11. Li R, Pei S, Chen B, et al. Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2). Science 2020;368:489-93.

(Courtesy of CDC https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html)

September 28, 2020

Ontario reverses the policy on asymptomatic testing due to limited testing capacity

Until recently, the Canadian province of Ontario had been offering free COVIDUntil recently, the Canadian province of Ontario had been offering free COVID-19 testing to anyone. However, the demand for testing exceeded the province’s testing capacity of about 50,000 tests per day. Waitlines up to seven hours were reported in some places. As of now, however, only people who have symptoms and identified to be at risk by contact tracing or planning to visit a relative in long-term care facility will be allowed to take a test.

September 25, 2020

New study finds no significant difference in viral loads between symptomatic and asymptomatic COVID-19 patients

A new study published in Thorax journal had compared the viral loads in symptomatic versus asymptomatic COVID-19 carriers. 213 people from an early outbreak in Daegu City, South Korea were tested several times during the disease progression to measure the levels of SARS-CoV-2 in the nose and throat. About 20% never developed any symptoms. Nonetheless, their the viral loads were similar to symptomatic patients.

September 24, 2020

Ontario to offer free asymptomatic COVID-19 testing at 60 pharmacies

Canadian province of Ontario will offer free COVID-19 testing for anyone at 60 pharmacies across the province. This move is associated with re-surging of COVID-19 cases in the province; there have beeen 400 new cases per day at the end of September compared to less than 100 new cases per day a month ago.

September 23, 2020

Many unwitting COVID-19 spreaders are presymptomatic rather than asymptomatic

New study published today in PLOS medicine suggests that the number of truly asymptomatic people may be closer to 20%, much less than was previously assumed. Many people who are asymptomatic at the time of testing do develop COVID-19 symptoms later. Truly asymptomatic people may be less likely to spread the virus than presymptomatic ones. Regardless of the definitions, vast majority of people who know they are infected take steps to lower the chances of infecting others, whereas people who are unaware of being sick continue their normal activities thus spreading the virus. From this point of view asymptomatic vs. presymptomatic is a distinction without a difference.

September 22, 2020

Specificity vs. cost vs. speed: what kind of COVID-19 test is best against the epidemic?

Researchers from Massachusetts General Hospital had compared different testing strategies and quality of tests in order to understand the best approach to population testing. According to the model with current cost of testing, the most cost effective testing strategy is to test people with any indications that they have COVID-19. Testing the whole population once a month results in a 60% reduction in infections and a 40% reduction in deaths, but requires 66x increase in testing volume. The model suggests that a modest sensitivity, low-cost test is the most desirable type both from human and monetary perspective. The frequency of tests should be higher in surging epidemic scenarios and can be decreased in slowing scenarios.

September 21, 2020

Mathematics helps to make asymptomatic COVID-19 testing cheaper

The main obstacle for finding asymptomatic COVID-19 carriers is the necessity to test large number of individuals to find a single COVID-19 infected person. Contrast this with testing of symptomatic individuals and it is easy to understand the reluctance of authorities and insurance companies to pay for asymptomatic tests – vast majority of them will come back negative. Israeli scientists proposed the use of a mathematical approach to decrease the number of tests by using a pooling approach. 48 patient samples are pooled and analyzed together. Each individual sample participates in six separate pools. Many pools come out negative and some come out positive. By comparing pools and knowing which samples comprise each pool, an algorithm reveals which individual samples come from infected patients. This approach allows to cut down the overall number of tests by 8x.

September 18, 2020

Asymptomatic testing study helps to explain a silent spread of COVID-19

In order to assess the risk of the spread of COVID-19 by asymptomatic carriers, scientists from University of California, Santa Barbara asked volunteers self-identified as students to take a COVID-19 test. The first series of 732 tests was performed in late May and early June when stay-at-home orders were in place. A second series of 1,076 tests was performed in late June – early July when the order was lifted. Among the first group, no individuals have tested positive for COVID-19. In the second group, nine RT-PCR tests returned positive results. Most of these individuals would be unlikely to seek testing; they would continue to unknowingly transmit COVID-19. The Center for Disease Control currently estimates that 40% of COVID-19 infections occur via people who show no symptoms.

September 17, 2020

Asymptomatic COVID-19 carriers may experience ‘happy hypoxia’

When the lungs don’t provide enough oxygen people normally experience shortness of breath. However, some asymptomatic COVID-19 patients may now feel it due to damaged nerves. The brain cannot recognize the dangerous conditions. The patient can have visible signs of hypoxia such as bluish coloration of the lips and fingertips. This is a dangerous condition that requires hospitalization.

September 16, 2020

Transmission risk in late stages of asymptomatic COVID-19 may be low.

Prolonged shedding of virus had been previously reported in asymptomatic COVID-19 patients. However, the presence of viral RNA does not prove the presence of living virus. The researchers from Yonsei University College of Medicine had studied the recovery process of 48 asymptomatic and mildly symptomatic patients. They traced the presence of virus both by RT PCR and by infecting the human cells grown in vitro with samples collected from patients. A later test was aimed to detect the presence of viable virus. The results had shown that RT PCR continues to show the presence of viral RNA long after the viable virus had disappeared. It appears that in asymptomatic and mildly symptomatic patients, the transmission risk of COVID-19 is minimal in later stages of the disease. However, the authors advise caution in interpreting of their results.

September 15, 2020

Indonesia will isolate asymptomatic COVID-19 patients.

Indonesia had seen a steady increase of COVID-19 cases trough the summer. In response, Indonesian government had mandated that asymptomatic and mildly symptomatic patients will be isolated in specially designated quarantine centers instead of self-isolating at home. “It is important because self-isolation at home could result in the virus being transmitted to family members”, said the President Joko Widodo during the cabinet meeting on Monday. A number of one to three star hotels will be converted to isolation centers. Indonesia, population 267 million, had 222,000 coronavirus infections since the beginning of COVID-19.

September 14, 2020

New CDC data shows the spread of COVID-19 by children

Researchers from the CDC analyzed the data from 184 people associated with COVID-19 outbreaks in three daycare facilities in Salt Lake County, Utah. According to the CDC, two of the outbreaks began with staff members who had contact with COVID-19 at home and the went to work. Researchers found that 12 children, with the average age of 7, had contracted the virus and spread it to 12 additional people – mostly the member of their households. Two of the children had remained asymptomatic.

September 11, 2020

Children as asymptomatic carriers of COVID-19

Children are much less likely to experience severe symptoms of COVID-19. However it does not mean that they are less likely to get infected or that they are less contagious than adults. Risk of spreading the COVID-19 by asymptomatic children is real. This is especially true for low-income multi-generational families where vulnerable adults often share the crowded household with children. “Kids are a possible source of spreading this virus, and this should be taken into account in the planning stages for reopening schools”, said Alessio Fasano, a professor of Pediatrics at Harvard Medical School.

September 10, 2020

Asymptomatic transmission slows down South Korea recovery from COVID-19

Sporadic outbreaks of COVID-19 continue to be an obstacle to complete recovery from COVID-19 in South Korea. 156 new cases were reported on September 9 wotj only 12 of them caused by people coming from abroad. Authorities were able to trace only 22% of cases, meaning that the majority of infections came from unknown asymptomatic carriers. New clusters show up in offices, call centers, restaurants, religious facilities, sales events, hospitals and nursing homes. Since January 3, the country has carried out 2,082,234 COVID-19 tests.

September 9, 2020

Asymptomatic COVID-19 increases the risk of premature birth

Pregnant woman infected with COVID-19 are typically asymptomatic – 80% have no symptoms. However, the recent study from Spain, where pregnant woman are universally tested for COVID-19 had found that the rate of premature birth among pregnant woman who have COVID-19 is 14% versus 7% in non-infected group.

September 8, 2020

Asymptomatic COVID-19 patients often develop heart problems studies suggest

The common perception of COVID-19 is that children and young people are at low risk. This is based of very low mortality rates in young adults and especially in children. Most of them are either asymptomatic or, at worst, have mild symptoms. However, recent studies had revealed less optimistic picture. First evidence came from a Penn State doctor who discovered that one-third of Penn State athletes who had COVID-19 have myocarditis – a silent disease which can years later lead to heart failure. A second study was around the heart muscle cells grown in vitro, which had shown that SARS-CoV-19 can attack these cells directly. This is not unexpected, since heart muscle cells have the same ACE-2 receptor that COVID-19 uses to attack the lung cells. A third piece of evidence came from an observation that many COVID-19 patients have no lung damage, but still have abnormally low levels of oxygen in their blood. This very common phenomenon may be due to improper functioning of the heart. The public has to be made aware of hidden risks of asymptomatic COVID-19 patients.

September 4, 2020

Many people never exposed to SARS-CoV-2 show strong immune response to it, new study found.

Researchers from La Jolla Institute for Immunology have found that 40-60% of people who have never been exposed to SARS-CoV-2 have strong immune reaction to it. Scientists attribute this phenomenon to earlier exposure to other viruses, including other species of coronavirus. Another study found that many blood samples collected before 2020 display strong immune reaction to SARS-CoV-2 as well as to four other coronaviruses causing the common cold. This can, in part, explain the high percentage of asymptomatic COVID-19 patients. However, not everyone who had the common cold is immune to COVID-19. Genetic and environmental factors may play a role in the severity of COVID-19 infection as well.

September 3, 2020

Contact tracing of an early COVID-19 cluster in Japan shows that more that half of transmission cases originate from asymptomatic people.

Epidemiologists from Japan analyzed the cluster of 108 COVID-19 cases linked to four live music clubs in Osaka, Japan. The cluster was one of the earliest clusters in Japan (early February) and the infection from the unknown source outside the music clubs is very unlikely. Therefore, virus transmissions can be attributed to contacts withing the music club and in many cases can be conclusively traced to a single visit to a club. Out of such cases, 23 patients became infected by contacting people who had symptoms. Another 38 people contracted COVID-19 from people who were asymptomatic at the time of contact.

September 2, 2020

USA still lacks coherent strategy for asymptomatic testing

From state to state and county to county there are various strategies and guidelines dictating who has to take a COVID-19 test. The decisions are often made by people who know little about the virus, and many of them wonder why people who feel fine need to be tested at all. COVID-19 testing has two distinctly different purposes: firstly, understood by all, is the health of the person. As a general rule, infected people need to be treated. However, people without symptoms and mild COVID-19 symptoms usually don’t need treatment. Such people sometimes hear their doctor’s say: “If your symptoms are mild, don’t bother taking test, my recommendations will be the same regardless of the result”. Secondly, and equally important, is the protection of the community. People who ‘feel fine’ may still carry and spread the virus. Politicians and community leaders need to be educated on the importance of mild-symptomatic and asymptomatic testing. More importantly, there must be unified strategy regarding who gets to be tested – and how – for COVID-19.

September 1, 2020

Evidence of asymptomatic COVID-19 transmission on the airplane

Conclusively demonstrating transmission of COVID-19 from asymptomatic people is difficult because almost always there is an alternative possibility of contracting COVID-19 from some unknown symptomatic person. The South Korean case of airplane passengers evacuated from Italy to South Korea in March of 2020 provides the controlled environment where the transmission source can be identified with near certainty. A 28 years old healthy woman had been wearing a mask and was seated, like the rest of passengers, 6 feet or more away from anyone else on the plane. Yet she had developed COVID-19 symptoms while in 14-day quarantine after the plane landed in South Korea. The most likely source of infection was an asymptomatic COVID-19 passenger who visited the toilet before her; she removed her N-95 mask when she used the toilet. The infection may have occurred either through contact with contaminated surfaces or through the contaminated air.

August 31, 2020

Wastewater testing at University of Arizona helps to identify asymptomatic COVID-19 carriers

The University of Arizona is conducting wastewater testing of campus dorms in order to prevent the spread of COVID-19. Last week, the test of one of the dormitories indicated the presence of COVID-19. All 300 residents of the dorm were consequently tested and two cases of asymptomatic COVID-19 had been found. Two students were immediately isolated. “If we had waited until [infected students] had been symptomatic or if they had stayed in that dorm for days or week or a whole incubation period, how many other people would have been infected” – said Richard Carmona, director of UofA reentry task force.

August 28, 2020

Many ‘asymptomatic’ COVID-19 patients have atypical COVID-19 symptoms

When SARS-CoV-2 virus lands in the upper respiratory tract, it uses ACE2 receptors present on the surface of the epithelial cell as a gateway to the patients’ bodies. ACE2 receptors are also found in lungs, the main target of COVID-19. However the same receptors are found in heart, gut and other organs. “Asymptomatic” patients may also have sometimes severe to other organs. The first United STates patient who died of COVID-19 on February 6th had only mild lung symptoms; she died of a heart attack. There is long list of atypical COVID-19 symptoms that gets updated every day – some of ‘symptoms’ proven to be red herrings, other added to the list. This broad diversity of type and severity of symptoms, in combination the with lack of gold standard COVID-19 test, makes it very difficult to know for sure whether someone has COVID-19.

August 27, 2020

Why some people have asymptomatic COVID-19? The answer is more complicated than “they just have strong immune system”

Asymptomatic COVID-19 people are known to have virus levels similar to people with mild COVID-19 symptoms. Therefore we are dealing with disease tolerance – not disease resistance – as most people have assumed. Disease tolerance is the ability of an individual to tolerate the same levels of pathogens in their bodies that makes other people sick. This is a very well known phenomenon – 90% of people infected with tuberculosis don’t get sick. One theory of animal disease tolerance suggests that zero tolerance policy toward the invader is not the best strategy in 100% of cases – it is costly and may cause the damage to the animal itself. Animals may have developed a flexible strategy to respond to the invasions of foreign biological agents. A growing number of experts agree that disease tolerance can have a profound implication for dealing with epidemics.

August 25, 2020

Pooling decreases the cost of asymptomatic testing

Researchers at National Institute for Biotechnology in The Negev, Israel had shown that pooling samples can help to save the money and labor on screening for COVID-19. Samples are pooled in a special pattern and then the test is run on each pool. If any of the pools turn out to be positive, an algorithm can then identity the infected individual(s). Mathematically, the method works best when 1% or less of the tested individuals are infected. The pooling method had been successfully used on the personal of Soroka University Medical Center.

August 24, 2020

By March 13 there may have been 100,000 of unknown COVID-19 cases in US

On March 13, the national emergency was declared due to COVID-19 epidemic. The number of confirmed cases a day earlier was 1514. Now scientists say that that actual number of infected people at that day may have been around 100,000. This number of unobserved infections may be due to combination of factors. Until February 27, the testing was allowed only for those who had close contacts with confirmed cases and people who recently came from China. Lack of testing, combined with asymptomatic and presymptomatic transmission may have contributed to this disparity. The number of 100,000 is based on simulation ran by epidemiologist Alex Perkins from the University of Notre Dame and his colleagues. “By the time we got to February, the problem had grown so big, containing the virus wasn’t possible” says Perkins.

August 21, 2020

Asymptomatic vs. mildly symptomatic COVID-19: a comparative study

A group of 70 SARS-CoV-2 infected people who remained asymptomatic throughout the disease course were compared with a mildly symptomatic group. On average, the time until the virus clearance, confirmed by negative RT-PCR test, is shorter for asymptomatic patients (14 days) compared to mildly symptomatic ones (18 days). However, there is a great deal of variability in both groups; many asymptomatic patients remain COVID-19 positive for weeks.

August 20, 2020

Kids have much higher levels of SARS-CoV-2 than adults, study suggests.

Researchers at Massachusetts General Hospital have studied 49 children infected by SARS-CoV-2. They have found that kids with COVID-19 often have have symptoms that ‘overlap’ with other illnesses, which makes it harder to diagnose. Another finding was that children carry much more virus in their upper respiratory tract than adults. “These kids had viral loads that were higher, significantly higher, than patients who were hospitalized for COVID,” said Dr. Lael Yonker, director of the Cystic Fibrosis Center at MGH.

August 19, 2020

Princeton University will test all students, staff and employees who spend time on campus

Princeton University has announced a new policy stating anyone who spends at least eight hours a week on campus must be tested for COVID-19. For this purpose, a safe distancing clinic has been set up at Princeton University Stadium. The saliva-based RNA test in not invasive and results are ready in 48-72 hours.

August 18, 2020

Young asymptomatic people are driving the pandemic is some regions, WHO says

In some regions of the world, including countries like Vietnam, France and Spain where COVID-19 was under control, there is a resurgence of COVID-19 cases. WHO believes that the driving force behind the uptick is young, asymptomatic people who do not follow social distancing rules.

August 17, 2020

Wearing masks can increase the number of asymptomatic COVID-19 cases

Evidence emerges that the severity of COVID-19 infection may depend, among other things, on the amount of virus that enters the body during an infection event. The differences between outbreaks on two cruise ships reveals that wearing masks on one of two ships may be a reason for the increase of asymptomatic cases from 18% to 81%. This dose dependency is not unique for COVID-19. For example, it was experimentally shown on volunteers infected with Influenza A virus.

August 14, 2020

Four theories on why many people with COVID-19 are asymptomatic

The article discusses the possible reasons why so many people infected with COVID-19 have no symptoms. Lack of symptoms may be due to immunity previously developed against other species of coronaviruses, some of which cause common cold. Alternatively, immunity may be due to childhood vaccinations against pneumonia and polio. Another possibility is differences in biology, specifically in nucleotide sequence of the ACE2 gene, which regulates blood pressure and inflammation. SARS-CoV-2 virus uses the ACE2 receptor to enter the cell. Finally there is some evidence that getting a smaller dose of the virus, for example due to protection of a mask, increases the chance to stay asymptomatic.

August 13, 2020

Asymptomatic’ care home residents have atypical symptoms

518 care home residents from New Norfolk were tested for COVID-19. Only 37% of 103 residents who tested positive had typical COVID-19 symptoms, such as coughing, fever and loss of sense of smell. Many appear to be asymptomatic. However, many of the latter group had told the questioners about “feeling unwell” without being able to pinpoint specific problem. Dr. Paul Everden of Norwich Medical School points out that lack of typical symptoms makes it more challenging to recognize COVID-19 cases, especially in elderly people.

August 12, 2020

Asymptomatic COVID-19 infection is not always harmless

Lack of telltale COVID-19 symptoms and feeling healthy may lead people with asymptomatic COVID-19 to believe that they are not infected. However, the reality is more complex and nuanced. CT scans of lungs of asymptomatic patients often show same ‘ground glass’ opacities that symptomatic people have. These opacities are characteristic of lung damage done by COVID-19. Weather this damage is permanent and how much it will affect the health of the patients for the rest their lives remains unclear. There is also damage to the heart: some of recovered asymptomatic COVID-19 patients can’t exercise as vigorously as before. More research is needed on long term effects of asymptomatic COVID-19 infection. Valentina Puntmann, MD and researcher at the Uiversity Hospital Frankfurt, Germany says,”Who knows what other organs are being affected? We don’t know.”

August 11, 2020

A massive study of asymptomatic patients from South Korea

The data from Korean National Health Insurance Service database on 10,273 COVID-19 patients was analyzed in respect to the presence of the symptoms. At the time of the test, approximately 60% of the people had no symptoms. The percentage of asymptomatic people is lowest for people between 30 and 60 years old, with higher percentage of asymptomatic COVID-19 in younger and older people. Older males are more frequently asymptomatic than same aged females. The study explains why the reliance of symptom-based testing and isolation is a failed strategy. Instead, population-wide testing and contact tracing should be employed to stop the spread of the disease.

August 10, 2020

Asymptomatic COVID-19 patients may be less likely to infect family members than symptomatic ones

The analysis of cases reported in literature allows scientists and researchers to estimate the secondary attack rate (SAR) of COVID-19 for household members. SAR is the probability of family members to get sick when someone in the house is already infected. Meta-analysis of 40 studies shows that the overall SAR for in-household contact is fairly high, averaging 20%. Some studies that included asymptomatic attack rate show that it is significantly lower than symptomatic SAR – between 0 to 5% in three available studies. Some studies included tests of all family members while others tested symptomatic family members only.

August 7, 2020

South Korean research confirms asymptomatic transmission

The medical team from South Korea had compared 193 symptomatic and 110 asymptomatic people who were isolated at a community treatment center. The samples were collected from all patients, symptomatic or not, during the whole time they stayed at the center. The data shows that symptomatic and asymptomatic patients have similar levels of SARS-CoV-2 virus through most of the infection period, except asymptomatic people tend to clear the infection sooner. Since about 40% of people never develop any symptoms, this finding strongly suggests that asymptomatic transmission is not only possible but very common.

August 6, 2020

Asymptomatic COVID-19 patients are just as likely to infect family members as mildly symptomatic ones

Monitoring 265 patients in Wuhan province, China has revealed that asymptomatic and symptomatic patients share many similarities. For example, both categories frequently have pneumonia detected by CT scans, albeit asymptomatic patients are less likely to have one (50%) than mildly symptomatic ones (75%). According to the same study, both categories of patients are equally likely to infect their family members with a 60% probability.

August 5, 2020

Children of all ages are susceptible to COVID-19: evidence from Georgia summer camp emerges.

The COVID-19 outbreak in a Georgia summer camp, when nearly half of its 597 residents became infected, is still under investigation. Preliminary results suggest that children are nearly as likely to be infected by COVID-19 as adults. “Children of all ages are susceptible to SARS-CoV-2 infection and, contrary to early reports, might play an important role in transmission,” said Christine M. Szablewski from the Georgia Department of Public Health.

August 4, 2020

St. Luke’s medical director: “children seem to transmit it quite effectively just like they do other viruses”

Young children rarely become ill from COVID-19. However, they may be more likely to spread it to others. Dr. Kenny Bramwell, a Medical Director for St. Luke’s Children’s hospital, is planning to send his 16 year old to school this fall. Older children are able to take precautionary measures required by school, he says. His concern in younger children, who do the “stuff we don’t typically do as adults”, and are not likely to follow the social distancing rules. Dr Bramwell had emphasized that young children very rarely get sick from COVID-19, much less need to go to the hospital. But, “they certainly seem to get it and they certainly seem to be really efficient asymptomatic spreaders.”

August 3, 2020

Massive testing, including air and surface sampling is needed to stop COVID-19

Asymptomatic and mildly symptomatic COVID-19 patients are likely to be as contagious as symptomatic ones. In China, government keeps track of asymptomatic patients; in the United States and Europe, this aspect of pandemic response hasn’t received enough attention. Another important aspect is sampling of air and surfaces in buses, aircraft cabins and other public places for COVID-19 contamination in order to find and predict the hotspots of virus transmission.

July 31, 2020

Younger children may have higher viral loads

Researchers from Northwestern University and Lurie Children’s Hospital have studied 145 COVID-19 patients with mild to moderate symptoms, including 46 children under age five. The viral loads were measured by Amplification Cycle Threshold (CT) values. The study indicates that young, symptomatic children have a 10 to 100 times greater amount of SARS-CoV-2 in their upper respiratory tract. Young children, therefore, can be important drivers of COVID-19 spread. The SARS-CoV-2 situation may be similar to respiratory syncytial virus (RSV) where children have higher viral loads and are more likely to transmit.

July 30, 2020

Children and asymptomatic transmission of COVID-19

Reported number of COVID-19 deaths of children under the age 18 is less than 1%, whereas the percentage of children under 18 in United States is 22%. Children are less likely to be infected than adults and, when infected, are much less likely to have COVID-19 symptoms. In short, children are much more resistant to COVID-19 than adults. However, the data suggests that children, while themselves being asymptomatic or mildly symptomatic, can transmit COVID-19 to adults. The frequency and extent of the child-to-adult transmission remains unclear. Several studies suggest that asymptomatic and mildly symptomatic children have viral loads similar to adults, which can mean that they transmit COVID-19 at the same level as asymptomatic adults. One study from South Korea indicates that there is a gradient of transmissibility from young children to older children when younger children are less likely to transmit COVID-19, whereas older children have transmission rates similar to adults. Counties that had opened schools did not see the jump in COVID-19 cases; however these countries, unlike United States, have the overall level of COVID-19 under control.

July 29, 2020

Ventilation system design is critical in reducing the risks of COVID-19

The researchers from the Department of Mechanical Engineering, University of Minnesota have used the ultrasound-based video and Digital Inline Holographic imaging to measure the sizes and 3D trajectories of aerosol particles produced in the process of breathing and speaking. They then combined experimental measurements with fluid dynamic simulations, finding that the effectiveness of ventilation system in removing the virus does not solely depend on the strength of the air flow. Researchers had created recommendations for the better design of ventilation systems.

July 28, 2020

Mathematical models of COVID-19 transmission via breathing and coughing

COVID-19 is frequently transmitted without direct contact by inhaling the air containing the virus-filled microdroplets. Swiss scientists from the University of Zurich built a mathematical model of production of microdroplets by those infected by COVID-19. Data from swab samples was used to estimate the viral load in the liquid of respiratory broncheoles. Distribution of microdroplet sizes were obtained from published experimental data. Small microdroplets can stay airborne for a long time, and models suggests that sharing space within a poorly ventilated room with highly contagious individuals is likely to lead to infection — even with proper physical distance. Some of such super-spreading events are reported to have infection rate of 75%. On the other hand, super-spreaders – individuals with high viral loads – are not common in the population.

July 27, 2020

Comparison of antibody levels in asymptomatic patients and patients with COVID-19 pneumonia

Levels of neutralizing antibodies were measured in COVID-19 patients with severity ranging from asymptomatic to COVID-19 pneumonia. The majority of infected people have COVID-19 neutralizing antibodies. However, about 20% of asymptomatic people with infections confirmed by nucleic acid tests don’t have COVID-19 antibodies. The levels of antibodies generally correlate with the severity of the disease.

July 24, 2020

There is a reservoir of this virus in healthy people

Contact tracing shows that coronavirus clusters often originate from young asymptomatic people. A recent study looked at more that 3000 infected people in Japan. Cases were traced down to 22 people who started the clusters. Half of them were between 20 and 29 years old. The majority of sick people at the time were in their 50s and 60s. Dr. Monica Gandhi, Professor of Medicine at the University of California, says that almost universal failure to prevent the spread of COVID-19 can only be explained by the presence of ‘reservoir of this virus in healthy people’.

July 23, 2020

Is the asymptomatic transmission of COVID-19 ‘very rare’?

At the June 8 conference, the World Health Organization official suggested that asymptomatic transmission of the coronavirus is “very rare.” WHO later has added many qualifiers to the statement. Nevertheless, the “message many people heard was that the virus doesn’t spread when people don’t have symptoms” – notes the author of the post. This was the message “some politicians and those on social media seized upon as evidence that certain public health measures were not necessary”. FactCheck attempts to summarize what is known about asymptomatic transmission.

July 22, 2020

Chinese clinicians describe confirmed case of asymptomatic transmission from January, 2020

This case is important because it occurred so early that the transmission can be traced with certainty. Patient-case-1, an asymptomatic 22 year old male, returned via high-speed train from Wuhan to Anhui Province, China, four days before the Wuhan quarantine began. In the following days he closely contacted 22 people. The article provides details of contact, including dining together, attending and singing at a karaoke party and sharing food. Patient-index-1 had experienced his first symptom (itchy eyes) as of January 22. The same day he heard about the emergency in Wuhan and checked himself into the hospital. The estimated COVID-19 attack rate (ratio of infected people to total close contacts) is about 40%.

July 21, 2020

As many as two thirds of transmissions may come from COVID-19 infected people without symptoms

The authors of the online article cite several studies that suggest ‘silent’ COVID-19 transmission, where the COVID-19 carrier is asymptomatic and likely is not aware of being infected. Further, this may be common and even prevalent in the spread of COVID-19. This has severe implications for COVID-19 policies, such as reopening or wearing masks.

July 20, 2020

Most of COVID-19 transmissions come from young asymptomatic people

According to Brett Giroir, assistant secretary for health at Department of Health and Human Services, most of cases of COVID-19 infections come from asymptomatic people who will never develop the symptoms of disease. “Just feeling like you want to go get a test is really not the best strategy … so you have to cast a wide net.” In an interview with Facebook CEO Mark Zuckerberg, Dr. Fauci, Director of the National Institute of Allergy and Infectious Diseases, said, “There’s as much virus in the nose of a person who’s asymptomatic as there is in a symptomatic person.”

July 17, 2020

54% of people tested positive for COVID-19 don’t know how they got infected

CDC survey shows that 46% of people who tested positive for COVID-19 reported contact with someone who is sick. The rest don’t know how they got infected. They could be infected by passer by who coughed near them in a grocery store. Or, it could be a coworker or friend who are asymptomatic COVID-19 carrier. Or, it could be even a chance encounter with asymptomatic person. There is a consensus that the large percentage of COVID-19 infected people are asymptomatic. The point of hot debate is how contagious asymptomatic people are, compared to sick people. So far, we can only rely on anecdotal evidence in this regard. But perhaps this is precisely why, for now, we have to assume that asymptomatic people are nearly as contagious as symptomatic ones.

July 16, 2020

CDC admits that asymptomatic transmission is possible, but says more evidence is needed to tell how common it is

Three authors from Center for Disease Control and Prevention had analyzed the existing literature on transmission of COVID-19 from the patients who, at the moment of transmission, had no symptoms. They describe the epidemiological, virological and modeling evidence that supports the idea. However, their conclusion is that currently it is impossible to assess the extent of asymptomatic transmission.

July 15, 2020

Politicians pushed back against the evidence of asymptomatic transmission for months

Traditional strategies for stopping epidemics had failed against COVID-19. The New York Times article by Matt Apuzzo, Selam Gebrekidan and David D. Kirkpatrick describes how politicians and health authorities around the world had for months resisted the idea of asymptomatic transmission. From a practical perspective, it is irrelevant whether the person spreading the virus is presymptomatic or asymptomatic. What really matters is that apparently healthy people, not aware of being contagious, continue their normal activities and keep infecting other people. To admit that this happens on large scale means the need of dramatic changes in traditional anti-epidemic policies. Such measures include enforcing social distancing, widespread testing and mask wearing — regardless of symptoms. These are very costly and unpopular measures. Even in early June, W.H.O had stated that transmission from asymptomatic patients is ‘very rare’. Later the agency said it was misunderstanding. Only now the consensus seem to emerge that asymptomatic transmission – that is, transmission from people who have to symptoms, regardless of weather they will develop them later – plays a major role in the spread of COVID-19.

July 14, 2020

“Asymptomatic” COVID-19 infected people still have symptoms

The evidence is mounting that a large portion of COVID-19 transmissions originate from people who are not aware of being sick; that is, those who are either pre-symptomatic or asymptomatic. Despite the term, the ‘asymptomatic’ COVID-19 patients frequently display some symptoms; however, these symptoms are mild and hard to differentiate from allergies or a common cold. But difficult does not mean impossible. “If you ask the right questions, you’ll find symptoms.” says Dr. Robin Trotman, an infectious disease specialist.

July 13, 2020

Testing and isolating, regardless of symptoms is the key to controlling COVID-19 outbreaks: Italian town experience

The small Italian town of Vo went into quarantine in February, 2020. The majority of the residents were tested for COVID-19. Tests revealed that 40% of infected people were asymptomatic but had the viral load comparable to sick people. They were unaware of any problem and were likely to continue their normal activities; for many of them that involved contact with lots of people. Isolation based on test results, rather than on the presence of symptoms, had allowed to quickly block the spread of infection.

July 10, 2020

Study of rooms of asymptomatic patients shows extensive contamination

Negative pressure rooms are designed to assure that the virus cannot escape the room. Chinese doctors analyzed hundreds of samples taken from various surfaces in such rooms in order to measure the amount of virus shed by the patients. Rooms of patients with symptoms ranging from negative to mild were found to be ‘extensively contaminated’ with COVID-19. However, the virus was not found in any of the air samples.

July 9, 2020

Silent transmission raises questions about efficiency of traditional symptom-based COVID-19 policies

Many countries, including United States, struggle to contain the spread of coronavirus. Silent transmission of coronavirus is the transmission from the people who, at the time of transmission, are asymptomatic. The paper by Canadian and American scientists discusses the share of silent transmission in the spread of COVID-19 and the implications of silent transmission for the formulation of the most effective strategy to combat the pandemic. The results suggest that as many as 50% of infections originate from presymptomatic and asymptomatic people. Therefore, relying on traditional symptom-based interventions is not a plausible strategy. Extensive contact tracing and the widespread COVID-19 testing is required to stop the pandemic.

July 8, 2020

Asymptomatic doesn’t always mean no damage

The paper published in Nature Medicine addresses the possible damage to lungs that occurs in patients that don’t ever experience symptoms and are not aware of being infected. These patients are truly asymptomatic, as opposed to the presymptomatic people who will eventually develop symptoms. The study shows that more than half of truly asymptomatic people have signs of inflammation in their lungs characteristic of COVID-19. Asymptomatic people do shed the virus; however to what extent, if any, they contribute to the spread of COVID-19 remains unclear.

July 7, 2020

Meta-analysis of 67 studies of asymptomatic COVID-19

Researchers from the Biomedical Research Center of Qatar University have analyzed 67 published studies of asymptomatic COVID-19 cases. While the percentage of asymptomatic patients vary from study to study, certain trends are apparent. Antibody tests show higher rates of asymptomatic patients than PCR-based tests. Young children rarely show any signs of the disease and remain asymptomatic, while continuing to shed the virus. Many adult patients who are initially asymptomatic eventually develop the symptoms. The most important question, how much the truly asymptomatic patients contribute to the spread of COVID-19, remains unanswered.

July 6, 2020

Antibody study of Geneva population reveals much broader exposure to COVID-19

2000 individuals were randomly selected from the healthy population of Geneva and analyzed for the presence of anti-COVID-19 antibodies. The presence of antibodies indicated the presence of past COVID-19 infection. A five week study from April to May revealed the increase in positive tests from 5% to 11%. This is a much larger porportion of the population than the one based on the number of officially confirmed cases. On the other hand, the majority of the population remains unexposed to COVID-19, which means that the ‘herd immunity’ effect can’t stop the spread of the virus.

July 2, 2020

What does asymptomatic really means?

The article in News Medicine, published on June 18, addresses the important question of the meaning of the term ‘asymptomatic’ when applied to COVID-19 infection. It seems that ‘asymptomatic’ usually means the lack of complains by the patient who can continue hers of his normal life, despite the ongoing COVID-19 infection. They may be either unaware of any abnormalities in their body or consider the symptoms they experience trivial, for example tiredness or a headache. Studies show that under closer examination the majority of the asymptomatic patients have abnormalities in their lungs. About 80% of them have anti -SARS-CoV-2 antibodies. Many have some mild symptoms of infection.

July 1, 2020

Confirmed case of asymptomatic transmission in China

Between March 11 and April, 9 there were no reported new cases of COVID-19 in Heilongjiang Province, China. Therefore when the new cases started to appear the authorities were able to trace their origins. It turned out that a single person, named A0 had originated a cluster of 71 sick people. A0 had returned from the USA, self-isolated for 14 days, showed no symptoms and tested negatively both for COVID-19 nucleic acids and antibodies. Despite all this, the downstairs neighbor who used the same elevator (not at the same time) was infected and started the chain reaction of infections. This is one of the rare cases when the infection from truly asymptomatic person was confirmed.

June 30, 2020

Mathematics of testing asymptomatic people for COVID-19: cost-benefit analysis

Doing more testing seems like a straightforward answer to pandemic, but including RT-PCR based tests are far from ideal: they produce large fractions of both false positive and false negative results. Currently, we don’t have a ‘gold standard’ to measure the quality of tests since a significant portion of people remains asymptomatic and there is no way to know for sure if they had ever been infected. Testing large pools of populations will lead to large number of false positive results. Mathematical modeling shows that with lower-end quality tests, as many as 20 uninfected people may have to be isolated in order to prevent one infection. This fraction sharply declines with the increase of the quality of the test. More accurate tests would provide an enormous health and economic benefit.

June 29, 2020

Testing of health care workers in Germany reveals larger that expected percentage of asymptomatic cases

Presence of anti-COVID-19 antibodies in blood indicates that an individual is either currently infected or was infected in the past. Hameln-Pyrmont, the rural and sparsely populated region in Germany, reported an antibody-based COVID-19 rate of 0.889 per thousand, much less than that overall in Germany (1.99 per thousand). However, only 2.8 percent of the Hameln-Pyrmont population was tested for antibodies, which means that people who had no symptoms or mild symptoms were likely not counted. Doctors from Hannover Medical School set up the study of healthcare workers who were in frequent contact with COVID-19 patients in order to estimate the incidence of asymptomatic cases. They have found that 2.9 percent of staff have anti COVID-19 antibodies, indicating infection at some point of time, past or present. Only 36% of test-positive staff had experienced flu-like symptoms. The authors conclude that the real incidence of COVID-19 in the area is much higher than reported due to high incidence of people who are now aware of being infected. For that reason, the real mortality rate of COVID-19 is lower than reported.

June 26, 2020

Olfactory test may reveal COVID-19 infection before any other symptoms appear

Team of researchers from New York and Ohio was able to find the signs of COVID-19 infection in asymptomatic or presymtomatic volunteer students from small private college in Iowa. The researchers used the n-butanol sensitivity threshold test and so call Hedonics test (liking/disliking of various odors) for early detection of the changes in sense of smell. Participants who later developed COVID-19 symptoms had shown greatest changes in test results, even though they were not subjectively aware of any changes in their olfactory perception. Study demonstrates that olfactory test is superior to self-reporting of the same symptoms in early detection of COVID-19.

June 25, 2020

Longitudinal study of asymptomatic workers at several skilled care facilities in Colorado

Long-term care facilities account for disproportionally large percentage of COVID-19 related deaths. Protecting the elderly living at these facilities requires vigilant monitoring of infections as well as better understanding of COVID-19 transmission, including asymptomatic transmission, specifically in cases when the elderly person is on the receiving end of transmission. Presymptomatic and asymptomatic workers are potential source of unrecognized COVID-19 transmissions. Scientists from Colorado State University and University of Colorado performed longitudinal surveillance of workers at skilled care facilities. The results of the study emphasize the importance of identifying and removing asymptomatic and presymptomatic workers from vulnerable populations.

June 24, 2020

Asymptomatic/Presymptomatic transmission gives viruses an evolutionary advantage

Asymptomatic transmission is not uncommon among viruses. For example, the common flu virus can be transmitted from patients with no symptoms. Princeton scientists used mathematical modeling to demonstrate that asymptomatic transmission confers the evolutionary advantage to the virus, allowing it to spread ‘below the radar’. Symptomatic patients tend to self-isolate, for example, by staying at home while asymptomatic people continue to behave normally, coming into contact with more people. The researchers evolved their model by including patients who are mildly symptomatic and may or may not consider themselves sick. The researches had found that the most successful evolutionary strategy for a virus is to create a mix of asymptomatic, mildly symptomatic and symptomatic patients at early stages of the infection.

June 23, 2020

Monitoring 1573 health care workers provides a glimpse into asymptomatic COVID-19 infection

1573 healthcare workers, including physicians, nurses, healthcare technicians and clerical workers from University Hospital, Milan were monitored for the presence of SARS-CoV-2 infection. 139 of them eventually became infected. Out of 139 infected workers, only 17 had remained strictly asymptomatic, whereas the rest had developed some symptoms. Among the symptoms, the most indicative of COVID-19 were loss of taste and smell with fever being distant second.

June 22, 2020

Low risk of asymptomatic COVID-19 transmission is shown for 9 confirmed asymptomatic patients

Doctors from several Wuhan hospitals had monitored nine confirmed asymptomatic patients for the period of 85 days. During the study period none of the family members who lived in the close proximity of infected patients had become positive for COVID-19. Doctors propose that viral shedding may be less dangerous in the absence of sneezing and coughing. Also, patients and their cohabitants knew about the infection and presumably took steps to avoid the transmission.

June 19, 2020

Deeper look into asymptomatic patients: are they capable of COVID-19 transmission?

Asymptomatic transmission remains a difficult challenge to address. Can all the cases of apparent asymptomatic transmission be attributed to transmission from the patients who develop COVID-19 symptoms a few days later? Is all ‘asymptomatic’ transmission really a presymptomatic transmission? The paper published in Nature Medicine takes a deeper look into the condition of asymptomatic patients. The study shows the presence of virus in nasopharyngeal swabs and urine samples of asymptomatic patients for many days, which means that these patients likely remain infectious.

June 18, 2020

Prevalence of asymptomatic cases of COVID-19 in Indianapolis area

The 3120 volunteers without self-reported COVID-19 symptoms from the Indianapolis metropolitan area were systematically tested by RT-PCR for the presence of COVID-19. About 3% of volunteers tested positive for COVID-19. Further detailed questionnaires revealed the presence of nonspecific symptoms in a fraction of the study group; for example, 10% had reported headaches. Other common nonspecific symptoms included muscle aches and shortness of breath. Overall, 72% of patients had remain asymptomatic while 28% had eventually developed some symptoms. The limitation of the study is that subjects were self-selected.

June 17., 2020

Medscape expert weighs in in on asymptomatic transmission

Asymptomatic transmission is perhaps the most popular topic of discussion around COVID-19. Dr. Natalie E. Dean explains why asymptomatic transmission is extremely difficult to detect in comparison to transmission detection from symptomatic COVID-19 patients. The very definition of ‘asymptomatic’ is unclear: people who appear to be fine can develop symptoms later, but there is no doubt presymptomatic people can transmit the disease. In regard to truly asymptomatic patients, Dr. Dean still advises caution: despite uncertainty, it is better to assume that asymptomatic transmission does occur.

June 15, 2020

Is 14-day quarantine period enough for asymptomatic patients?

The article presents the case of an asymptomatic patient who remained COVID-19 positive for 24 days under strict isolation conditions. Authors suggest that the period of COVID-19 related quarantine may need to be longer that 14 days.

June 12, 2020

Superspreading can cause the domino effect leading to explosion in COVID-19 cases: a hypothesis

Doctor Pablo M. Beldomenico suggests that propensity to become a COVID-19 superspreader may depend on the initial viral load: being infected with a large amount of the virus may cause the patient to produce more virus and become a superspreader. This domino effect may lead to an explosion of COVID-19 cases. While this is only a hypothesis, it may explain the dramatic differences in the rates of spreading of COVID-19 between countries and even within the same country at different times and locations.

June 11, 2020

How to protect health care workers from asymptomatic COVID-19 transmission

Canadian clinicians discuss the steps that can be taken to decrease the risk of COVID-19 asymptomatic transmission to healthcare workers. Authors conclude that the risk of asymptomatic transmission is real. They outline the 5-level plan that includes switching to safer medical procedures, improving ventilation and using better personal protective equipment.

June 10, 2020

Asymptomatic ‘speech super-emitters’ may play significant role in the spread of COVID-19

Doctor Chris Kenyon from Belgian Institute of Tropical Medicine argues that ‘super spreaders’, a small fraction of asymptomatic patients who shed high amounts of virus, play crucial role in COVID-19 infection. One prominent case identifies one person possibly causing 3900 infections. The study suggests re-thinking return to work strategies to emphasize the obligation to wear masks and avoiding gatherings in poorly ventilated areas.

June 9, 2020

Truly asymptomatic COVID-19 patients present lesser risk of disease transmission.

Dr. Maria Van Kerkhove, the technical lead for coronavirus response at WHO, stated today that truly asymptomatic patients present relatively little risk of transmitting the disease. Many people who appear to be asymptomatic in fact do have mild symptoms or will develop a mild case of disease in a few days. Infected individuals may be able to transmit the disease two or tree days before showing any symptoms. Babak Javid, a principal investigator at Tsinghua University School of Medicine in Beijing, spoke to the distinction between asymptomatic and presymptomatc cases, “Other data available confirming that presymptomatic transmission does occur would suggest that being well does not necessarily mean one cannot transmit SARS-CoV-2.”

June 8, 2020

Asymptomatic transmission is is the “Achilles Heel” of the fight against the pandemic.

According to Prof Neil Hall, head of the Earlham Institute “Asymptomatic cases may be the ‘dark matter’ of the COVID-19 epidemic. As lockdown measures are eased, the importance of population-wide testing increases. Population needs to be made aware of dangers of asymptomatic transmission and the importance of following strict rules of social distancing.

June 5, 2020

Review of isolated cohorts of patients reveal high percentage of asymptomatic cases

Analysis of cases when COVID-19 had spread among isolated populations demonstrates that the incidence of asymptomatic people infected with SARS-CoV-2 is, by most conservative estimate, 30%. It was revealed that some people can feel no discomfort but still have noticeable damage to their lungs; others have no discernible damage. Both types seem to shed the virus and can infect others. The accumulated data suggests that testing only symptomatic people is a faulty strategy. Authors recommend increasing the number of tests by at least one order of magnitude compared to exiting level.

June 4, 2020

Subtle loss of hearing of high frequency noises can be sign of asymptomatic COVID-19

Scientists from Egypt have discovered a new symptom of COVID-19 that my be present in asymptomatic patients: a subtle loss of high frequency hearing. By measuring the audiological profiles of patients it’s possible to discover any damage to cochlear hair cells.

June 3, 2020

CDC weighs in on asymptomatic transmission on COVID-19

CDC had summarized available evidence on the existence of asymptomatic and pre-symptomatic transmission of COVID-19, including epidemiological evidence, virological evidence and evidence from modeling studies. The paper discusses public health implications of asymptomatic and pre-symptomatic transmission

June 2, 2020

Asymptomatic people play a major role in the transmission of COVID-19

Mounting body of evidence suggests that the main reason of why COVID-19 has spread with such speed, compared to other infections may be that people without the disease symptoms but infected by SARS-CoV-2 play a major role in spreading the disease. The paper suggests that symptom-based approach to testing must be replaced with mass testing, especially in nursing homes where concentration of vulnerable population is high.

June 1, 2020

Virginia hospitals testing reveals the percentage of asymptomatic COVID-19 cases.

As hospitals in Virginia begin re-opening for scheduled procedures many started testing all incoming patients, for example expecting mothers and people coming for elective surgery. The data sheds light on how many people in the general population are asymptomatic. Among pregnant women, the percentage of expecting mothers having COVID-19 was 1.6%; among people coming for surgery it was 1.8%. 

May 29, 2020

Mounting evidence suggests that asymptomatic patients can transmit disease with high probability


Evaluating the degree at which asymptomatic patients can spread COVID-19 disease is complicated task; however there are known cases when infection was traced back to asymptomatic people. In some known cases one person who had no symptoms had infected several people. This presents unique challenge in stopping the COVID-19.

May 28, 2020

4 out of 5 people infected with SARS-CoV-2 on cruise ship  were asymptomatic


The cruise ship departed from Argentina had 217 people on board. Out of 217 people 128 eventually got infected wish SARS-CoV-2; One person has died. 8 people (6.2%) required medical evacuation, 19,2% had symptoms. The majority, 81% were asymptomatic. For the first 28 days of the trip the ship, traveling near Antarctica, had no outside human contact.

May 25, 2020

The Time Scale of Asymptomatic Transmission Affects Estimates of Epidemic Potential in the COVID-19 Outbreak


This work described a mathematic model using generation interval of asymptomatic transmission to assess overall reproduction number.

May 22, 2020

Viral Dynamics in Asymptomatic Patients With COVID-19


This study found that in 31 patients virologically confirmed but were asymptomatic at time of admission, 22 presented symptoms afterwards. The rest 9 remained asymptomatic during hospitalization. Those 9 patients had low viral load but might still be capable of viral shedding and transmission.

May 19, 2020

Over 90% of Covid-19 cases in Michigan treatment center are asymptomatic


At two children’s treatment center in Michigan, 41 out of 44 residents who were tested positive for COVID-19 didn’t show symptoms. Another site none of 19 people with positive test results showed any symptom.

May 16, 2020

Cats With No Symptoms Spread Coronavirus to Other Cats, Lab Test Suggests


Researchers in University of Wisconsin School of Veterinary Medicine infected three cats with coronavirus from a human patient. Cats to Cats infection was also observed. But CDC said that based on the limited information, chance for pet to human transmission is considered to be low.

April 26, 2020

Most Americans Who Carry the Coronavirus Don’t Know It


An serological test indicated that as many as 2.7 million New Yorkers may have been infected without realizing it. This result was backed by several other observations in the world.

Artificial intelligence (AI) in the past 10 years gained a mainstream status as a technology. Today AI has become an important ally in the fight against coronavirus epidemic. There are several distinct areas where artificial intelligence has a potential to help in the fight against COVID-19.

Development of drugs and vaccines. Testing of new drug candidates is a tedious and expensive process that involves testing millions of chemical substances for their ability to inhibit the SARS-CoV-2 infection. Today, a significant part of searching for drugs can be done in silico, using computational modeling of the physical process of binding of the drug molecule to its target. AI is relatively new to this field, but significant progress has been made in this area. Based on examples of existing drugs that work against other diseases, AI can learn to recognize the chemical features of existing drugs that make the drug effective. Based on the ‘knowledge’ AI gains from the data describing existing drugs and the proteins they bind to, AI then can ‘look’ at new drug candidates and predict whether or not the candidate drug will work against COVID-19. To date, the accuracy of prediction has not been perfect, but using AI helps to prioritize the drug candidates for further testing in the laboratory.

Prediction of individual susceptibility to the virus. It is well known that many people infected with COVID-19 are asymptomatic, and showing immunity to the virus. Some have only mild symptoms, while others will develop severe – and sometimes fatal – symptoms. Overall about 80 percent of those infected have either mild symptoms or no symptoms at all. Presently we don’t have a clear picture to explain the vast difference in severity of infection. Being able to predict who is immune to the disease or would tolerate it with minimal symptoms would be enormously important. We could send some people right back to work or even recruit them to roles where they would be exposed to the virus. At the same time, we would be able to let the vulnerable part of the population stay home and wait until the epidemic is over or vaccines become available. Recently we have learned about the role of the ACE2 gene which encodes the protein responsible for the maintenance of the blood pressure. It appears that some mutations in the ACE2 gene, previously harmless and shared by many people worldwide, could facilitate the binding of SARS-CoV-2 to epithelial cells, making individuals carrying such mutations much more susceptible to the infection. There are most likely other genes that affect the susceptibility to the virus. Several large-scale studies are underway that aim to predict the susceptibility to SARS-CoV-2 by analyzing the individual genomes of the people.

Detection of infected individuals, contact tracing, hot spot identification. Artificial intelligence is capable of combining the information coming from different sources, such as self-reported symptoms, thermal imaging and other sources of data to estimate the probability that an individual has SARS-CoV-2 infection. Some countries, for example Israel, South Korea, Taiwan and United Kingdom utilize movement data from cell phones and video feed from street cameras or drones to track the spread of the disease. There is also substantial data coming from social media platforms. AI software is looking for posts about people experiencing symptoms, conversations about plans to get tested, or sharing the test results with friends and relatives. The AI can  then analyze the stream of data and accurately predict emerging geographical hot spots of the disease. If used correctly the use of AI can alert the authorities of dangerous development and thus significantly decrease the number of infections and deaths by coronavirus.

Easing the load on healthcare professionals. The COVID-19 pandemic has created a worldwide shortage of healthcare personnel. AI can help to ease the load on doctors, nurses and other medial personnel by taking over some tasks that traditionally are performed by people. Remote monitoring devices continuously gather the information from the patients. AI processes the information and alerts the healthcare workers if the condition of the patient has changed. An additionalbenefit of remote monitoring is that it lessens the exposure of medial personnel to the infected patients who can spread the virus.


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September 28, 2020

Parexel and Innoplexus are building a unified interface to access multiple COVID-19 data sources

American pharmaceutical company Paraxel has partnered with German AI company Innoplexus to build COVID Clearinghouse, a unified open access to 22,853 datasets, 65,602 publications, 5,173 clinical trials and 229,738 news articles related to COVID-19. Datasets are available with to researchers, physicians, patients and the general public.

September 25, 2020

AI helps to identify the mechanisms of severe COVID-19

Pathophysiology of COVID-19 remains a mystery. Very slow onset is sometimes followed by ‘cytokine storm’, an overzealous immune response which can be fatal. Researchers from Scrippts Institute and University of California, San Diego had analyzed 45,000 transcriptomic datasets. They selected 166 genes that are related to ACE2 gene, which encodes for protein that plays a central role in SARS-CoV-2 infection. Researchers used machine learning to look for genes that are involved in the aberrant immune response. Their findings point to a set of 20 genes, particularly IL15 interleukin and its receptor that may be involved in the genesis of the cytokine storm.

September 24, 2020

DOD and Pentagon to begin mass-testing of RATE device

The Pentagon has partnered with Philips to develop a device for Rapid Analysis of Threat Exposure, or RATE. RATE is a wearable device that monitors temperature, pulse, blood oxygen levels and other parameters in order to identify early signs of COVID-19. The build-in AI model was trained on 36,782 COVID-19 patients and 256,320 controls. The DOD is planning to start mass-testing of the device: 5,000 units will be produced in coming weeks.

September 23, 2020

COVID-19 had started AI transformation of radiology, but the process will continue beyond COVID.

COVID-19 had forced radiologists to rethink old practices, but AI will stay after COVID-19 pandemic is over. Radiologists are frequently allowed to work from home, the practice that was previously frowned upon. This, in turn, had prompted the use of AI to better organize the image repositories. On the image interpretation front AI is now being used not only to find COVID and is used not only on lung images. AI can locate fractures, intracranial hemorrhages, determine the age of bones. Moreover AI can combine image data with other medical information. As an example, AI can identify and even predict the stroke with 70% accuracy.

September 22, 2020

Study claims to identify COVID with 90% accuracy based on retina images.

Researchers at Shanghai Public Health Clinical Centre had proposed using retina images taken by high-resolution cameras to diagnose COVID-19. The preliminary data shows over 90% accuracy. These amazing results, however, need to be taken with a grain of salt: the cohort of 303 patients from a single hospital and 136 healthy individuals may be too small to contain unrecognized confounding factors. On the other hand, retina images are unique for each individual – much more so than fingerprints – and potentially contain valuable information. It is not impossible that COVID-19 causes characteristic changes in the eye that are picked up by AI. Retina imaging is not invasive and extremely cheap, so the approach needs to be investigated further.

September 21, 2020

Role of AI in drug repurposing

Artificial intelligence had been successfully used to repurpose existing drugs against COVID-19. Repurposing allows to skip lengthy and costly safety testing trials since existing drugs had been already tested for safety. However, the efficacy of AI is limited by the quantity and quality of input data. Authors argue for broadened inclusion of diverse clinical, physiological, biochemical and genetic data into the process of repurposing existing drugs. Unaccounted genetic differences between patients may explain the contradictory results in testing antimalarial drugs, such as chloroquine. Predicting which cocktail of COVID-19 inhibitors will be effective in treatment is impossible without information about cellular pathways. On the other hand AI algorithms, themselves, may need to be improved to better handle heterogeneous input data.

September 18, 2020

COVID-19 “proximity index” promotes safe behaviour

Non-profit organization Parkland Health & Hospital Systems in Dallas, Texas created the machine learning system that calculates the ‘proximity index’ for each location in Dallas based on density of COVID-19 carriers and other factors that determine the likelihood of infection. Proximity index can help vulnerable individuals to avoid high-risk locations. People living in high-risk neighborhoods receive messages advising them to use extra caution.

September 17, 2020

South Korean telecom giant introduces the food server robot

KT Corporation, the largest South Korea telecommunication company, had introduced an AI driven robotic food server. The robot moves with a speed up to 1.5 meters per second carrying four trays of food with very low level of vibration. It uses a 3D map to navigate the environment. KT is planning to deploy robots nationwide to decrease the number of person to person contact.

September 16, 2020

Detecting COVID-19 by sounds of patient’s coughing

Wadhwani Institute for Artificial Intelligence in India had secured a U.S. patent for detecting the COVID-19 infection based on sounds of patients’ coughing. AI system trained on multiple recorded sounds of cough by COVID-19 infected people and people without COVID-19 is able to predict the presence of COVID-19 based on the sound of the cough alone. “After months of hard work, we are proud to present our patented Cough against Covid AI tool that can identify both symptomatic and asymptomatic individuals,” said Dr. Rahul Panicker, Chief Research and Innovation Officer.

September 15, 2020

AI helps the country to keep COVID-19 under control.

Greece, a country with a population of 11 million, normally hosts 33 million tourist per year. The tourism accounts for 20% of the country’s GDP. Due to the COVID-19 epidemic, the country had placed restriction on travel; U.S. tourists, for example, are banned from entering Greece. The average hotel occupancy had dropped to 25%. However, even a quarter of 33 million is still a lot of people. How does Greece manage to keep infection rates at a very low level? One of the answers is the EVA platform developed by scientists from University of Southern California and The Wharton School of the University of Pennsylvania. EVA is an AI- based COVID-19 risk assessment platform. Before departing to Greece, visitors fill out an online “passenger locator form”, providing the information about their place or residence, age, gender and other details. Once visitors arrive at the border they are issued the QR code generated by EVA that is scanned by border security. Based on the QR code, some visitors are asked to take a COVID-19 test. If the test is positive, individuals must quarantine for 14 days. Otherwise, visitors are allowed to continue their journey. EVA was operational since July and so far Greece has managed to keep the levels of COVID-19 well below 500 new cases per day.

September 14, 2020

Gary Markus: COVID-19 has laid bare the shortcomings of AI

Speaking at Intelligent Health AI conference, entrepreneur and author Gary Markus had argued that the COVID-19 crisis had revealed several problems associated with AI. The first problem is the focus on areas that don’t really help the world in meaningful ways. We want AI “to be able to guide robots to keep humans out of dangerous situations, care for the elderly, deliver packages to the door,” he said. Another problem is excessive focus on deep learning at the expense of other types of AI. He pointed out the dependence of deep learning AI on big data and its inability to create abstractions. Markus had emphasized the role of AI in helping to organize all accumulated knowledge about COVID-19: “With better AI, we might have computers that can read, digest, filter, and synthesize all the vast growing literature,” he said.

September 11, 2020

Multi-objective AI identifies new COVID-19 drug candidates

In order to succeed, a new drug must meet multiple requirements, including non-toxicity, stability and lack of major side effects. However, AI-based drug design platforms typically use single-objective optimization strategies, aiming to select the substances with strongest predicted binding to their biological target. Trying to optimize for multiple objectives is counter-intuitive since such a strategy seems to require a compromise between objectives. However, multiobjective optimization forces AI to explore of the broader search space, sometimes pushing the search off the beaten path. A research team from University of Bari Aldo Moro in Italy has employed multi-objective recurrent neural network to search for new inhibitors of several human proteins including SARS-CoV-2 main protease. Selected compounds were verified by in silico docking. Python implementation of the algorithm is freely available on GitHub.

September 10, 2020

New AI platform aims to predict the outcomes of COVID-19 clinical trials

Opyl, an Australian artificial intelligence company, is working on the Artificial Intelligence application that predicts the outcomes of clinical trials. Their algorithm that is still in the development stage was tested on past clinical trials and had outperformed the competition. When applied to ongoing COVID-19 trials, the algorithm has predicted that antibody-based therapies are the most promising direction in development of COVID-19 treatments.

September 9, 2020

COVIDomic, a cloud-based multi-omics COVID-19 bioinformatics platform.

Insilico Medicine, an artificial intelligence company had developed a versatile cloud-based AI platform that uses multiple data sources, including clinical and genomic data to identify risk factors associated with severe COVID-19 progression. ““COVIDomics is an open access tool to stratify risk and severity from multimodal data sets, including multi-omics data”, said Alex Zhavoronkov, PhD, Founder and CEO of Insilico Medicine.

September 8, 2020

AI helps to tap unto medical records from COVID-19 patients as a source for COVID-19 research

Clinical researchers prefer to work with experimental evidence obtained in clinical trials. Clinical trial is a controlled environment, where random external factors affecting the outcomes are reduced to a minimum. In real hospital settings outside of the clinical trials no two patients are treated in the same way. Therefore, analyzing real word evidence (RWE) from hospitals treating COVID-19 patients requires comparing apples to oranges. On the other hand, millions of records contain incredible amounts of information that can be used to combat the virus. Artificial intelligence can be utilized to make sense of RWE. A recent example is a study of 212,000 cancer patients, some of whom also had COVID-19. The study had shown that cancer patients with COVID-19 have a 16X higher mortality risk. Despite the ever-increasing amount of COVID-19 related medical records, RWE remains an under-utilized resource for COVID-19 data analytics research.

September 4, 2020

AI-selected COVID-19 drug cocktail is remarkably better than Remdesivir in animal tests.

Syntekabio, a Korean Big Data and AI drug discovery company, reports remarkable success. Using DeepMatcher, an AI-powered selection software running on supercomputer, researchers had selected 30 candidates predicted to to bind 3CL hydrolase, an enzyme encoded by SARS-CoV-2 genome. All candidates were already approved by FDA for treatment of other diseases and thus were already thoroughly tested for safely in humans. The combination of the two selected drugs had been proven remarkably effective against COVID-19: it shows 94% of lung pathogenicity recovery rate vs. 44% of Remdesivir.

September 3, 2020

AI helps to decrease X-ray radiation dose during CT scan

CT scans are used to detect abnormalities in the body. Recently millions of CT scans have been performed to assess the lung damage in the course of COVID-19 diagnosis and treatment. Exposure of the patient to X-ray radiation is a concern. In order to decrease the dose of X-ray, researchers from Switzerland and Iran have collaborated to develop an AI model that can identify the COVID-19 on low-energy CT scans. Using AI to denoise the low-energy images allowed for a reduction of the level of X-ray exposure by 89%.

September 2, 2020

MilliporeSigma and University of Michigan team up to address the shortages of chemicals needed for COVID-19 drugs

A team of medical chemists searched for alternative routes to make building blocks for promising antiviral drugs that are being investigated for treatment of COVID-19. Once the drug is approved, very large quantities of the drug need to be made. This places a heavy burden on supply chains, which normally can handle relatively small quantities of chemicals. Drug and chemical manufacturers will have to find alternative ways to quickly boost the production of drug components. This is why MilliporeSigma approached Tim Cernak, a researcher at University of Michigan. Cernak and his team had used the AI software Synthia to find alternative chemical routes to compounds that are needed to make 12 drugs, which are either approved (remdesivir) or are under revision process by FDA for COVID-19 treatment.

September 1, 2020

Identity management problems in the age of remote: AI to the rescue.

Authentication is at the core of today’s society, from shopping and banking to healthcare and national security. The present identity management systems rely heavily on in-person interactions. In response to pandemic when most of interactions became remote, businesses and governments had turned to a disjointed array of tools from passwords to biometrics to address the potential gaps in security. Artificial Intelligence can help to improve the identity management process to include recognizable patterns of an individual’s behavior, including subconscious ones. “You’d have to kind of replicate someone’s subconsciousness for the identity, and this is a little bit futuristic, but identity management is one of the areas that really has the potential”, said Combiz Abdolrahimi, a digital security expert.

August 31, 2020

‘Baby brain’ AI can detect COVID-19 with high accuracy

Scientists at Princeton University have developed a smartwatch-like device that is capable of monitoring COVID-19 status of the wearer and sounds an alarm when the warning signs of infection show up. The device constantly monitors skin temperature, sweat gland activity, pulse and blood oxygen levels. When warning signs appear, the person is asked to complete a questionnaire regarding other symptoms. All of the data is analyzed by AI that decides on infection status. The creators of the device claim it can predict the infection with 95% accuracy. At the heart of the system is a new type if AI invented at Princeton. Traditional deep learning systems contain fixed number of neurons, arranged in layers. Princeton AI adds and removes neurons and inter-neuron connections in the process of learning, much like human brain does. A number of connections in the human brain peak at the age of three. From this point on the connections continue to be removed, leaving about half of them in an adult brain. AI models built by the process of adding and removing connections are much more compact than traditional AI – so much so that they can fit into a smart watch.

August 28, 2020

Pandemic and job loss: AI replacing hotel workers, lawyers, journalists

The COVID-19 pandemic has dramatically accelerated the trend of replacing workers with robots, the process that was already underway before 2020. COVID-19 created additional incentive for companies to automate all kinds of tasks formerly performed by humans. By 2025 robots can replace 2,000,000 workers in manufacturing alone. White collar jobs are also not immune. At JP Morgan, AI is reviewing commercial-loan agreements replacing 360,000 hours of lawyers’ time per year. Microsoft laid off many journalists at MSN, replacing them with AI. In the past, government sponsored education programs helped people to find new jobs. Today the situation may be different, since the demand for new high-tech workers is far less than the number of jobs lost to automation.

August 27, 2020

RoboRXN, IBM’s automatic drug discovery platform

RoboRXN for Chemistry is a combination of AI and automated chemistry lab that aims to make the discovery of drugs for COVID-19 quicker and less expensive. Chemists can remotely access the RoboRXN and submit the drug molecules they come up with using an application running in a web browser. RoboRXN will now only help evaluate the compound, but suggests the best way to make it from commercially available reagents and can even build it in automated chemical lab. Normally it takes 10 years and at least $10M for a new drug to reach the market. RoboRXN aims to cut these numbers down to 1 year and $1M.

August 25, 2020

Collective of AI models casts votes do diagnose COVID-19

Ensemble methods involving multiple models working on the same set of data are not uncommon in Artificial Intelligence. However, neural networks are typically too large and computation-heavy to employ ensembles of them. Researchers from Bethesda, Cambridge (USA) and St. Louis found the way to use ensembles of deep learning models. They have trained multiple models on the same training image dataset. They then used the method called ‘pruning’ to remove ‘lazy’ neurons that contribute almost nothing to the outcome of the model. Pruning makes models computationally ‘lean’ as well as more robust. Pruned models were asked to evaluate the images and cast their votes on the presence of COVID-19. This ‘democratic’ method had shown the accuracy of 94-97%.

August 24, 2020

AI may be able to detect COVID-19 by phone. Voice sampling is being tested as diagnostics tool.

Patients who develop COVID-19 are frequently having breathing problems. The new diagnostics app, developed by Israel startup company asks the suspected patient to count from 50 to 70. The AI algorithm will analyze a voice pattern and deliver the diagnostic result in 30 seconds. The obvious advantages of the system are speed, extremely low cost, nearly universal accessibility and non invasiveness. Positive results still have to be verified by RT-PCR test.

August 21, 2020

Performance of COVID-19 detection models trained on collection of chest CT images from three countries

CT scans from the same hospital done on the same equipment have a tendency to have a technical bias which makes the model trained on such data less universal. To mitigate this bias, the doctors and engineers from Italy, China and Japan pooled their images to develop more robust AI model for COVID-19 diagnostics. The model had shown sensitivity of 85 and specificity of 90% on the data from a new source.

August 20, 2020

Vaxign-ML, a machine learning tool helps to develop COVID-19 vaccine

Vaccines are designed to induce strong immune responses to viruses without exposing the person to the virus itself. This is done by injecting the human body with harmless fragments of the virus, which, nonetheless, cause the immune system to produce antibodies against the virus. Researchers from University of Michigan have used machine learning to predict which parts of SARS-CoV-2 virus are most likely to induce the robust immune response. They have identified three proteins, including spike protein, as best candidates for vaccine development.

August 19, 2020

AI predicts inflow of COVID-19 to South Korea

Korea Advanced Institute of Science and Technology (KAIST) has developed an AI application that predicts the inflow of COVID-19 cases into South Korea. Since official COVID-19 statistics coming from governments depend on level of testing, the application also estimates the number of COVID-19 cases in each country based on COVID-19 searches originating from that country. Influx prediction model developed by KAIST has 35% better accuracy than other models.

August 18, 2020

Machine learning is used to predict required hospital capacity

Researchers from Cedars-Sinai medical center in Los Angeles have developed a machine learning tool that predicts the number of beds that will be needed for COVID-19 patients in the future. The platform uses historical hospitalization volumes, rate of COVID-19 cases in the area and the condition of current patients to predict the future need for beds, protective equipment, ventilators and staff.

August 17, 2020

AI is used to analyse public perceptions of COVID-19

Artificial intelligence analysis of over 1000,000 tweets originating from the US was used to capture some aspects of public perception of the COVID-19 pandemic. Analysis revealed five prominent topics: healthcare environment, emotional support, economy, social change and psychological stress. On average, positive attitudes outnumbered negative ones as 1.57 : 1. However, there was significant variability in this ratio between states

August 14, 2020

A CEO of AI company discusses problems and perspectives of AI in healthcare

AJ Abdallat, CEO of Beyond Limits, an AI company developing COVID-19 related applications, outlines the challenges in adoption of AI solutions by patients and medical professionals. Patients and doctors are hesitant to entrust treatment decisions to AI – something they don’t know much about, let alone understand. Developing not only efficient, but explainable and accountable AI with clear, straightforward interface goes a long way toward broader adoption of AI in healthcare.

August 13, 2020

UCADI: AI without borders

AI has potential to recognize COVID-19 on CT chest scans at least as well as the best radiologists. However, to properly train an AI model, large quantities of image data are required; the quality of the model continues to improve as the amount of training data increases. This calls for data sharing, but there are multiple obstacles, including patient privacy concerns. In 2016, researchers at Google proposed the method of federated learning. Unlike traditional learning where all data is shared, in federated learning, only the model parameters are shared. Training occurs in parallel in many locations, each having its own set of data. Using this approach researchers at Stanford had built publicly available AI learning framework called Unified CT-COVID AI Diagnostic Initiative (UCADI). Trained on a variety of sources UCADI performs as well as centralized models, especially on the CT images coming from sources previously unknown to the model.

August 12, 2020

New AI drug design tool combines deep learning with with automatic 3D modeling

Researchers from Lanzhou University, China built an AI system that combines the two main approaches to in silico drug design: artificial intelligence and molecular docking. First, AI selects the promising candidates from millions of chemical compounds. Then selected candidates are tested by molecular docking – fitting in-silico models of drugs to in-silico models of target proteins. Both steps of analysis are fully automated. The drug candidates for SARS-CoV-2 are made publicly available.

August 11, 2020

AI-powered personalized treatment reduces COVID-19 death rate by 50%

An AI system that gives personalized recommendations for the treatment of COVID-19 patients has been employed at the Hospital Clinic Barcelona since April. It was trained on a trillion anonymized data points to predict which patients are likely to develop complications and require more attention. It can predict the trajectory the disease will take with 90% accuracy. The use of the system has helped reduce the mortality rate at the hospital by 50%. The system is now being expanded to other hospitals in Spain.

August 10, 2020

AI helps to make cheaper COVID-19 drugs

Drug synthesis is closely guarded secret. This knowledge gives an advantage to the original drug producer even after the patent has expired. University of Michigan chemist Timothy Cernak and colleagues used Synthia, a drug synthesis AI-based program, to find ways the synthesize 12 drugs now being tested for COVID-19, including remdesivir. A good synthesis path leading from widely available components to a drug makes the drug more available. “If you are going to supply a drug to the world, your starting materials have to be cheap and as available as sugar,” noted Danielle Schultz, a scientist at Merck & Co.

August 7, 2020

Harvard and Google provide public 14 day COVID-19 forecast

Experts at Google and Harvard collaborated in creating a public portal showing the 14-day COVID-19 AI-based forecast at state and local level. According to Dr. Thomas Tsai, a surgeon and assistant professor in health policy and management at the Harvard Chan School of Public Health, the model “provides actionable insights at the local, county level”, predicting what will happen provided no action is taken by federal and local authorities.

August 6, 2020

Wireless wearable sensors to monitor and catch early warning signs in COVID-19 patients

Zenzium, Ltd, in collaboration with Manchester University have begun clinical trials for AI-based monitoring of the COVID-19 patients in hospital settings. Wearable sensors constantly collect information about the condition of the patients. 10% to 20% of the patients will eventually need intensive care. The AI system monitoring the sensors can recognize the early warning signs of the worsening of the patient’s condition and alert medical staff.

August 5, 2020

A success story of halicin is an inspiration for using AI in drug discovery. Can AI deliver a COVID-19 vaccine?

Halicin, an antibiotic effective against most drug-resistant strains of bacteria, was the first drug discovered with help of AI. This success story, published in February 2020, had inspired many AI researchers to try to apply similar techniques in search of COVID-19 vaccines. However, vaccines are very different from antibiotics in many respects. Vaccines and antibiotics both protect the body from infections, but have very different mechanisms of action. Vaccines are much larger molecules that imitate parts of the virus to teach the body to produce the right antibodies. One cannot mechanistically copy the antibiotic prediction AI models in hope that they will work for vaccine discovery.

August 4, 2020

An automated AI system can accurately identify symptomatic COVID-19 infection based on CT scans

Dutch engineers have developed CO-RADS, a fully automated image analysis system to diagnose COVID-19. Trained on data from a single hospital, CO-RADS can predict COVID-19 based on chest X-ray tomography images with an accuracy of 88%. The creators of the system believe that the system accuracy can be improved by federated learning – distributing the interconnected CO-RADS nodes among multiple hospitals and allowing them to learn from each other.

August 3, 2020

Artificial Neural Network predicts the COVID-19 mortality rate at the admission time

Artificial Neural Network (ANN) was trained on the patient data available at and before the time of hospital admission in combination with retrospective mortality information. AI engineers used the data from the COVID-19 patients from the teaching hospital in West London. Based on current symptoms as well as patient’s medical history – chronic respiratory disease, hypertension, diabetes, ischaemic heart disease, congestive cardiac failure, hepatic cirrhosis, chronic kidney disease etc. – ANN predicts the mortality with an accuracy of 85%. Knowing mortality risks helps to allocate more resources to the patients with higher risk of dying.

July 31, 2020

Customer behavior during pandemic: a challenge and an opportunity for AI

Consumer behavior has changed dramatically during the pandemic, and panic buying can result in depleted warehouses. AI models that had been trained on customer behavior data collected during normal times are unprepared for black swan events and make wrong predictions. AI scientists must adapt to make AI models less fragile. There is great potential for learning from the changing patterns of consumer behavior during emergency times in order to prepare an adequate response.

July 30, 2020

COVID-19 Insights Partnership announced on July, 28, 2020

Sharing the data and computational resources is essential for COVID-19 bioinformatics research. On July 28, the Department of Health and Human Services and Veterans Affairs announced the COVID-19 Insights Partnership to consolidate artificial intelligence and high performance computing resources. The National COVID Cohort Collaborative, or N3C, will be collecting the clinical data from health care providers and place it into secure cloud location where it will be made accessible to data scientists and bioinformaticians.

July 29, 2020

MIT  introduces an AI platform for peptide vaccine design

Researchers from MIT have developed OptiVax, a machine learning platform designed to assist in developing a peptide COVID-19 vaccine. Peptide vaccines contain small fragments of COVID-19 proteins, specifically those fragments that are most exposed in the living virus. Antibodies induced by peptide vaccines will attack these exposed parts of the virus, which could potentially make them better weapons against COVID-19. By mixing multiple versions of peptides, researchers hope to induce the immune response in people with diverse genetic background, thus boosting the overall levels of immunity in the population.

July 28, 2020

Generated CT scan images used to train Deep Learning model

Deep Learning algorithms tend to be ‘data-hungry’ – they perform better and better as the amount of training data increases. Increasing the number of CT scan images of COVID-19 patients to train the Deep Learning models improves the performance. However, individual hospitals often have very limited number of images; sharing of images is impeded by privacy laws and the private ownership of the data. A group of researchers from Egypt and China had employed Convolutional Generative Adversarial Network (CGAN) to enhance the training set with artificial images generated from the existing ones by CGAN. The use of fake images during the training had improved the model’s performance on the real CT images. Neural networks trained on the mix of real and fake images had shown a 4 to 8 percent improvement on real data, compared to traditional Deep Learning models.

July 27, 2020

What AI can and cannot do in a pandemic

At the beginning of the pandemic, many expected AI to be at the front and center of COVID-19 fight. However, AI has under-performed in several important areas. One example is AI-based predictions of the spread of the virus, which were not better than educated guesses. The apparent reason for this was wrong assumptions that went into models: COVID-19 is unique in the sense that the infections we know about are only the tip of the iceberg – most carriers of COVID-19 are asymptomatic. Another example is drug development. Despite the excitement around it, quantum computing is yet to deliver any results that can help to design the drug or vaccine against COVID-19. Finally, in many ways COVID-19 turned out to be mostly a human problem. AI cannot make people wash hands, follow social distancing rules and wear masks.

July 24, 2020

Why did AI fail to deliver in predicting of COVID-19 spread?

In the United States there were several failed attempts to predict incidence or severity of the COVID-19 infections based on aggregated electronic health records. Dr. Isaac Kohane, chair of the Department of Biomedical Informatics at Harvard Medical School, attributes it to the lack of high quality data. “Most of the data that was being shared for the first three months was literally just case counts and death counts,” he said. “We did not have a real collective intelligence.” Artificial intelligence is only as good as the data it receives. Biases and pre-conceived notions existing among medical professionals can seep into the data and distort the results. Dr. Karen DeSalvo, Chief Health Officer at Google Health, says that this is a continued concern among AI developers.

July 23, 2020

Novel type of convolutional neural network shows superior performance in recognizing COVID-19 on CT scans

Image recognition by neural network typically begins with so called convolution – extracting small, commonly occurring basic elements of images. The neural network then looks at how these small pieces are combined together to recognize the object on the image. With traditional convolution these basic elements are continuous, much like the pieces of puzzle, capturing small fragments of the image. This technique works very well for recognizing typical things that surround us, like people, animals, furniture or cars. When dealing with CT scans, the situation is somewhat different: some ‘puzzle-piece’ characteristics of COVID-19 are compacted, whereas others are diffused and thus remain unnoticed by regular convolution. The researchers from Bangladesh, in addition to the traditional convolution that captures compact features, used a special kind of convolution that is able to capture diffused, non-local features of COVID-19 infection. This led to a better success rate in recognition of COVID-19.

July 22, 2020

Knowledge graph analysis predicts COVID-19 drug candidates

Authors of the paper present a new methodology for identifying potential drug candidates for COVID-19 treatment. They have built a knowledge graph containing 16 million edges, signifying 36 types of relationships between drugs, diseases, genes, anatomies, pharmacologic classes, gene/protein expression and other biological entities. By analyzing this graph they were able to make a list of COVID-19 drug candidates. The list includes anti-inflammatory agents, estrogen receptor modulators and antiparasitics (Hydroxychloroquine).

July 21, 2020

xDNN, a new kind of Deep Neural Network can teach humans to recognize COVID-19 on CT scans

Explainable Deep Neural Network or xDNN is a new kind of neural network. Unlike the typical neural networks, it uses five types of neuron layers, arranged in pre-defined order. Each type of layer has clearly defined role in xDNN model, and functions according to it’s own math rules.  xDNN was tested on several standard image recognition datasets as well as on COVID-19 chest tomography datasets. In all cases xDNN demonstrated excellent performance. However the major advantage of xDNN is that it is able to provide a clear ‘explanation’ of why the given image was classified as COVID-19 positive. This is in contrast to ‘traditional’ Deep Learning that produce millions parameters that  are meaningless to humans.

July 20, 2020

AI model developed by Chinese clinicians can successfully predict the sudden deterioration of COVID-19 patients

Sudden worsening condition of COVID-19 patients is a serious concern. Rapid and effective prediction of the course of the disease is crucial for proper treatment and efficient allocation of hospital resources. The COVID-19 disease has shown a worrying trend of sudden progression in 6.5% of people, with a high mortality rate. Chinese clinicians did a retrospective study of the large cohort of COVID-19 patients to see if the sudden progression of the disease can be predicted with the help of deep learning. The model was tested on independent cohort of patients with wide geographic coverage. The model was able to predict severe illness with success rate of about 80%.

July 17, 2020

Scripps Research Institute and Repurpose.AI team up to develop COVID-19 drug

Scripps Research Institute has partnered with Repurpose.AI, a company with a successful record in drug discovery to search for anti COVID-19 drugs. “Our goal is to move therapeutics from the computer to the clinic in a fraction of the time typically required to discover and bring new drugs to market”, said Dr. Daniel Haders II, Executive Chairman at Repurpose.AI.

July 16, 2020

AI gets B minus in COVID-19 fight

‘Wired magazine interviewed Kai-Fu Lee, a chairman on a Chinese technology venture capital company. AI got a passing grade because it continues to help with replacing people in dangerous jobs with AI-driven robots and, in countries like China, with contact tracing. On the other hand, in Lee’s opinion AI had not delivered in drug and vaccine research. Also, there are some areas where AI could help, but so far had not attracted the attention of AI engineers, for example distance learning. When asked how AI and new technologies can be used to improve the coronavirus situation in the United States, Kai-Fu Lee’s answered, ‘everyone has to wear mask’

July 15, 2020

‘Emergency ML’ is needed to risk-stratify the COVID-19 patients

Machine-learning models can help to risk-stratify the people diagnosed with COVID-19. Identifying low-risk patients would allow to switch them to telehealth and virtual care, to avoid unnecessary hospital admissions. This would allow to dedicate more resources to approximately 15% of patients who require more intensive treatment. There is now a demand for ‘Emergency ML’ that can assist doctors in assessing the patients with COVID-19, especially in the regions where epidemic is getting worse.

July 14, 2020

The ‘Science of where’ in the age of pandemic: geospacialy-aware AI helps to find solutions for connected world

During the pandemic, the locations of people, goods and events have become more important than ever. Location analytics – the ‘Science of where’ – had provided information to policymakers as well as to the broad population that is absolutely essential for comprehending the facts on the ground during the COVID-19 pandemic. Geospacialy-aware data collection and processing requires broad cooperation between people, institutions and counties.

July 13, 2020

Medics propose an AI-based model to inform COVID-19 related hospitalization decisions

Hospitals use ad hoc scoring systems to make decisions about hospitalizations of COVID-19 patients. The group of doctors from Netherlands, China, Italy, Belgium and France had proposed a simple machine learning-based method to inform the decisions about hospitalization. The method, which is designed by radiologists, is based on age, combination of lab results and verbal descriptions of CT scan results, is accessible online for doctors around the world.

July 10, 2020

AI system helps to avoid mistakes in diagnosis of COVID-19

It is important to accurately differentiate the bacterial pneumonia from COVID-19 pneumonia. Engineers from Qassim University in Saudi Arabia used adversarial neural networks to teach the AI to make a distinction between the two. One of the networks, called ‘generator,’ creates fake chest X-Ray images based on bacterial pneumonia trying to fool the other network, called ‘discriminator,’ into classifying them as COVID-19 images. Discriminator’s goal is to make the correct diagnosis. Gradually, discriminator learns to pay attention to features characteristic of COVID-19 only, which improves the overall accuracy of the AI system.

July 9, 2020

Use of AI to track COVID-19 raises privacy concerns

AI based technologies are essential for extracting the real-time information about the coronavirus pandemic. At the same time, the widespread use of AI in combination with extensive surveillance measures raises privacy concerns. As an example, public transportation systems in China reportedly employ thermal scanning cameras in combination with face recognition to identify and track people with fever. The US CARES Act allocates $500 million to the development of public health surveillance and data collection systems. The Organization for Economic Co-operation and Development (OECD) had released the guidelines to help governments assure that privacy rights of citizens are not violated.

July 8, 2020

Using AI to measure public attitudes toward social distancing and face masks

Researchers from Singapore created the Health Believe Model to obtain quantitative metrics of public attitudes toward the measures that Singapore authorities had imposed to curtail the spread of COVID-19, such as wearing masks and physical distancing. Deep learning-based text classifiers were able to classify the posts into four categories with accuracy over 90%. Analysis of Facebook posts revealed that relative frequency of comments in support of measures versus comments opposing measures change over time. The Singapore timeline showed two peaks when the number of relevant posts increased dramatically. The first peak corresponded to certain measures taken by Singapore authorities. The vast majority of posts were supportive of state-imposed policies. The second peak, a much larger one, had no clear origin and contained many posts complaining about restrictions. However, the overall attitudes of Singapore populations toward COVID-19 measures remain positive.

July 7, 2020

Amazon AI-based ‘Distance Assistant’ helps to enforce social distancing rules at workplace

Amazon has unveiled the AI based monitoring tool that gives employees a real time warning about violating social distancing rules. Amazon likens this to radar speed check that gives drivers feedback on their driving. The Amazon tool, called Distance Assistant will guard against inadvertent or careless violations of six-feet distancing rules. Many had raised the concern that the employer gets the whole map of employee movements during the day, which then can be used for purposes unrelated to COVID-19 pandemic. Amazon plans to open-source this software.

July 6, 2020

Robots help to address the shortage of medical staff in China

Robots can replace humans in situations where the environment is dangerous to human life: on battlefields,nuclear disaster zones and terrorist threat situations. Increasingly, robots are used to perform tasks where there is high risk for exposure to COVID-19. Such tasks include the cleaning jobs in hospitals and places with high human traffic, the deliveries of food and medicines to sick people and the taking of vitals of COVID-19 patients. Simple task robots are relatively inexpensive: while the da Vinci surgical robot cost $3.5 million, the cost of disinfecting robots for hospitals is $30,000 to $80,000. In China, such simple-task robots are used to address the shortages of medical workers.

July 2, 2020

US government to use AI to counter COVID-19 disinformation

The US Department of State is responsible for carrying out US foreign policies and managing international relations. The COVID-19 pandemic created specific challenges for their function; one of them is the abundance of incomplete and outright false information about COVID-19. In response, the State Department is building a cloud-based AI platform called “Disinfo Cloud” to counter propaganda and misinformation.

July 1, 2020

Anomaly detection helps to identify new COVID-19 outbreaks

Delays in detection of COVID-19 outbreaks are due to the combination of factors. One of the confounding factors is that the symptoms of COVID-19 overlap with other diseases such as influenza. A sophisticated AI system based on so called anomaly detection addresses this problem. While the symptoms may be similar on individual level, the frequencies of symptoms in population differ between COVID-19 and influenza. The AI is capable to detect the COVID-19 outbreak even it it overlaps with seasonal influenza outbreak.

June 30, 2020

AI answers questions about COVID-19 in real time

There are currently 67,000 scientific papers about COVID-19. This this number is rapidly increasing and, as a result, getting answers to even simple questions is becoming a burdensome task. With this in mind, researchers from The Hong Kong University of Science and Technology in cooperation with World Health Organization’s Health Emergency Information and Risk Assessment Department have developed a publicly available AI-based question-answering system called CAiRE-COVID. In response to free from questions such as, ‘What are the risk factors for COVID-19?’ the system brings up relevant passages from multiple scientific papers. It also generates a brief summary to give users a concise answer to the question.

June 29, 2020

AI-driven cleaning robot helps to prevent spread of COVID-19

Door handles are contact points that are likely to be contaminated by the virus. Frequent cleaning of door handles helps to prevent the spread of COVID-19. To this end, engineers from Singapore University of Technology and Design and the University of Ontario have developed Human Support Robot with a customized cleaning module. The deep learning-based AI system helps the robot to recognize all kinds of door handles. After locating the handle, the robot uses liquid spray and a cleaning brush to clean up the handle. The tobot is equipped with the LiDAR (Light Detection and Ranging) system to navigate in the changing environment.

June 26, 2020

Some FDA approved drugs may be re-purposed to treat COVID-19

Unlike millions of other compounds discovered by chemists, FDA approved drugs had been already extensively tested for safety, which make them attractive candidates for fast-track development of anti COVID-19 drugs. Two AI algorithms were used to predict the binding of 2657 FDA approved drugs to ACE2, the protein that serves as a gateway for SARS-CoV-2 entry. Besides known ACE2 inhibitors the software had identified the drug involved in glucose homeostasis and the drug used against cystic fibrosis (a hereditary lung disfuntion) as anti COVID-19 candidates. Other candidates included drugs used for treatment of autoimmune diseases, obesity, hepatitis C and HIV.

June 25, 2020

Images of cell lines infected by SARS-CoV-2 analyzed by AI to measure the protective effect of drugs

Researchers from University of Michigan and Boston University measured protective effects of 1,425 drugs previously approved by FDA for treatment of various diseases. To measure the protective effect of drugs they used human cells grown in vitro as a model subject. They trained the Random Forest classifier to identify SARS-CoV-2 infected cells among millions of cells on tens of thousands of images. 660 unique features allowed AI software to identify and count infected cells on the images and thus to measure and compare the protective effect of drugs. Researchers had identified 132 drugs as having potential do protect human cells from being destroyed by SARS-CoV-2. The selected set includes some drugs previously indicated as promising by unrelated studies, for example remdesivir. These drugs are candidates for further investigation involving human subjects.

June 24, 2020

AI-selected drug shows promise in treatment of COVID-19

The drug combining antiviral and immunodepressant activities could be a powerful tool to fight COVID-19. Artificial Intelligence had predicted that baricitinib, an inhibitor of Janus kinase, can be effective against COVID-19. Since the drug was previously approved for rheumatoid arthritis, scientists had received the authorization to test it on four COVID-19 patients with bilateral pneumonia, one of them on ventilator. Within days, all four patients had improved, with both their viral loads and IL-6 levels (reflecting degree of inflammation) decreased. A much larger study, involving about 1000 patients, in underway.

June 23, 2020

Correcting for the biases present in data when doing AI research

Predictions made my AI are only as good as the available data. Data collection processes are not perfect and, as a result, minority groups can be either under-represented or over-represented in the data sets, which could lead to erroneous policy decisions. The article provides several examples of possible biases inherent in COVID-19 related data that can potentially lead policymakers in the wrong direction.

June 22, 2020

AI outperforms two trained radiologists in diagnosis of COVID-19 from CT scans

COVID-19 infection does not always result in visible changes in lungs, especially at early stages of infection. Despite that, CT scans remain to be a valuable diagnostic tool with a relatively small percentage of false positive results. It is fast and available in the majority of hospitals. The paper published in Nature Medicine shows that the accuracy of CT scan-based diagnostics can be improved by using Artificial Intelligence. In this study the performance of AI systems were compared to that of two trained radiologists. Two out of three AI system outperformed both radiologists in recognizing the COVID-19 infection on CT scans. The best performing AI model had combined CT scan images with clinical information.

June 19, 2020

Big Data analytics in the age of pandemics: promises and hurdles

There is an indisputable connection between big data analytics and the fight against pandemics, as pandemic response generates large amounts of data from the millions of patients. However, in practice the picture is much less clear. The first obstacle is the private ownership of the data. Medical institutions are interested in the results of big data analytics, but have little incentive to contribute their own data to common pools. There are also risks associated with potential breaches of the patient confidentiality. The second obstacle is the private ownership of the software. The creators of algorithms have little incentive to share the knowledge with the competitors. New approaches, both political and technological, are needed to overcome these obstacles.

June 18, 2020

Using AI to evaluate effect of isolation policies on the rate of COVID-19 infections

The specifics of COVID-19 isolation policies differ between countries. Authors use three different AI algorithms to predict the future spread of COVID-19 in three countries (United States, Canada and Sweden) based on stringency of COVID-19 isolation policies. Models predict the possibility of a second wave of COVID-19 infection to impact the U.S. in New England and the Mountain states.

June 17, 2020

Tsunami of COVID-19 publications makes using AI a necessity

With more than 5000 COVID-19 publications weekly, keeping track of ongoing research is becoming an extremely difficult task. This is serious problem because new research is built on foundation of previous research. However, AI systems can be used to filter the literature and deliver more refined sets of publications tailored to fit the interests of individual researchers. SciSight, for example, is a free online tool that takes a sample paper and an input to display a browsable map or similar papers as an output.

June 16, 2020

Federated training helps to overcome lack of data sharing

The difficulties in data sharing such as privacy concerns and private ownership of the data is one of the biggest obstacles in applying the machine learning to biomedical domain. Federated learning, is the family of algorithms which can use decentralized data sources; the training occurs on separate data set and only intermediate results of training, but not the data is shared between participants. Several teams of scientists from China, Thailand and USA have build the AI application that recognizes COVID-19 on series of chest CT scans from different hospitals. Images themselves were not shared; instead the sets weights of the neural networks were averaged in synchronized learning cycles. The federated network performance was similar to the control performance on aggregated data

June 15, 2020

AI selects the best candidates for peptide-based COVID-19 vaccine.

In order to develop immunity to the virus, the chunks of viral proteins must be first ‘presented’ to the immune system by special types of blood cells carrying so-called MHC receptors of their surface. Different chunks of viral proteins (called peptides) have a very different propensity to be captured and presented by MHC; therefore, predicting which peptides have a chance to induce strong immunity is important for developing a vaccine. Peptides causing the robust immune response can be mass-produced by the bio-pharma industry and made into efficient vaccines. An AI tool developed by scientists at MIT and Duke University had analyzed 150,000 peptides and selected 19 peptides to be synthesized in the laboratory for developing a vaccine against COVID-19.

June 12, 2020

Clinical data confirms effectiveness of Baricitinib against COVID-19 predicted by AI

Clinical data had confirmed that Baricitinib, a drug previously approved for treatment of rheumatoid arthritis, is effective against COVID-19. Earlier, this drug was proposed as a candidate for COVID-19 treatment by the researchers at Benevolent AI, a London startup specializing in AI. 

June 11, 2020

Explainable AI teaches humans the signs of COVID-19 on CT scans

A team of AI scientists from several US universities used the popular YOLO convolutional neural network to separate CT scans of COVID-19 patients from CT scans of patients with unrelated pulmonary diseases. The model had an accuracy of 97% and a sensitivity of 98%. The YOLO algorithm is able to highlight the features on CT scans that it had found to be characteristic of COVID-19 infection, which is important for understanding the pathology of COVID-19.

June 10, 2020

Machine learning used to shed light on SARS-CoV-2 origins

Taxonomic classification and elucidation of the origin of the virus is relevant to fight against COVID-19 pandemic. The researchers from the University of Western Ontario used novel, alignment free approach to produce highly accurate classification of 5000 viral genomes, including 29 SARS-CoV-2 genomes. The method, based on unsupervised machine learning helps to discover relationships of SARS-CoV-2 to other virus species.

June, 9, 2020

Combining Artificial Intelligence with traditional protein structure prediction tools to build 3D models of SARS-CoV-2 proteome

3D structures of some of SARS-CoV-2 proteins are not available from experiments, making it difficult to predict these structures using traditional 3D prediction models based on homology. Researchers from Michigan State University used machine learning tools trRosetta and AlphaFold in combination with molecular dynamics simulations to predict 3D structures of SARS-CoV-2 proteins.

June 5, 2020

Q-learning helps in drug discovery process

Q-Learning, the algorithm that was used to build AI capable of playing computer games, turned out to be useful for drug design. Researches at Pucho Technology Information in Bangalore, India, have developed an AI system that can learn to ‘build’ the new drug candidates from groups of atoms much the same way as AI learns the right sequence moves in the game by trial and error. Combining AI with traditional physical modeling of drugs seems to be promising in creating new drugs against COVID-19.

June 4, 2020

Mobil app uses AI to predict severity of the COVID-19 disease

A team of scientists at New York University created a mobile app that uses a combination of a patient’s medical history and blood tests to predict the severity of COVID-19 infection. The levels of certain factors in blood, such as C-reactive protein, myoglobin, procalcitonin and cardiac troponin, as well as data from electronic health records calculate a risk score ranging from 0 to 100. The instrument for quick analysis of blood factors – similar to an insulin measurement device – is being developed.

June 3, 2020

AI may help to evaluate COVID-19 research

A team from Northwestern university has built an AI system that they believe can be trained to recognize promising high-quality research on COVID-19. The suggest it may be used in addition to human expert panels to allocate the societal resources for the fight against pandemic.

June 2, 2020

Exploring Knowledge Graph to find new COVID-19 drug candidates

Knowledge graphs have become a popular way to capture the knowledge about the issue in a way that it can be explored by artificial intelligence. Benevolent AI, a London startup, has built the COVID-19 knowledge graph that encompasses much of what we know today about the SARS-CoV-2 virus. Based on this body of knowledge they were able to suggest that certain drug, known to medical professionals as janus kinase inhibitor baricitinib can be beneficial for treatment of COVID-19.

June 1, 2020

AI can provide some foresight into the future of COVID-19 epidemic

Data-driven predictions about the future course of COVID-19 epidemic are far from perfect, Errors in perdition may be due to unexpected events such as strengthening of restrictions in Singapore or protests in USA. Data science is, at it’s best, only as good as the data available; however, data driven predictions are better than any alternative.

May 29, 2020

A startup Diveplane is building a ‘parallel database’ of people’s contacts that masks the private information, but still enables the disease tracing

Diveplane, an AI startup aims to solve the problem of tracing the people movement and spreading of COVID-19 without violating their privacy. At the core of their technology is ‘masking’ peoples identities by creating the ‘parallel database’ that contains all contact information but hides peoples identities, This database can be explored to study the spread of COVID-19 while protecting civil liberties.

May 28, 2020

AI gave an early warning on the cluster  of unknown disease in December 2019


ProMED is a global disease monitoring system winch captures information on unexplained cases of the disease. On December 30, 2019 based on the analysis of social media it picked up a cluster of unusual pneumonia cases. Simultaneously, a disease surveillance system HealthMap collected the media alert about unknown respiratory illness.  This illustrates that AI systems can be used successfully to identify and monitor the outbreaks of infectious diseases. 

May 27, 2020

Chinese researchers built an AI model predicting the spread of COVID-19 based on the population flow from Wuhan province

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Researchers team from China and Sweden had analysed over 14,000,000 data points related to the population movement from Wuhan to 296 prefectures in 31 provinces of China collected based on phone location records. They used machine learning to build the model that can accurately predict the spread of the virus based on the movement of population and the quarantine measures imposed by the state.

May 26, 2020

Models predict that age-based targeted lockdown may work better

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It is a known fact that age is a major factor in COVID-19 fatality. Older people at at much higher risk of severe infection and death. It would logically follow that it is possible that the targeted isolation policy may work better that uniform isolation policy. However, it is not clear of exactly how such targeted isolation policy should be applied across different age group. It is very difficult to come up with clear cut guidelines for such policy, not to mention that it is not clear whether targeted isolation will work better than uniform isolation. In order to evaluate possible advantages of targeted isolation the scientists at National Bureau or Economic Research build a computational model that aims to predict infection rates, hospitalization and fatality rates under different lockdown scenarios – both uniform and age-targeted. They had shown that under some conditions the targeted lockdown works better than uniform lockdown. Of course the larger issue is how to enforce the targeted lockdown, given a fact that authorities have hard time enforcing even a uniform lockdown.

May 25, 2020

Artificial Intelligence-Enabled Rapid Diagnosis of Patients With COVID-19


This worked used AI to diagnose COVID-19 using CT scan and other clinical data. The method’s CT performance was as good as experienced senior thoracic radiologist and it was able to identify patients that had been tested negative using nucleic acid kit alone.

May 22, 2020

Researchers use AI to re-purpose drugs against COVID-19

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Many drugs are found to be useful against more than one disease. This observation has led to the drug development strategy called repurposing. Existing drugs have been already tested for safety and lack of severe side-effects. This makes the path to finding drugs for new disease much shorter. Therefore often it makes sense to begin with testing the set of existing drugs before venturing into the unknown territory of new substances. The group of scientist from the Institute of Biotechnology and Pharmaceutical Research, Taiwan, trained neural network to recognize drugs that work on feline coronavirus based on data that had been collected in the past. The trained network was then used to predict the drugs that will work on SARS-CoV-2, which is similar to feline coronavirus. Neural network had identified 8 candidate drugs that are currently used against cancer, tuberculosis and other diseases as potential candidates for COVID-19 treatment.

May 21, 2020

Covid Scholar helps to search COVID-19 papers

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Scientists spend 23 percent of their time reading papers or searching for papers. Ever increasing volume of information requires new advanced tools that help scientists to find the relevant papers. Group of AI researchers at Lawrence Berkeley National Laboratory developed Covid Scholar, an online tool to explore scientific papers related to COVID-19. Instead of relying on papers containing same words AI looks for deeper connections between publications, for example when papers mention drugs with similar chemical structure. So far AI researchers amassed the collection of 60,000 papers, growing every day. The tool allows the lab scientists to find hidden gems that were missed by traditional PubMed searches.

May 20, 2020

AI used to accelerate the design of T-cell vaccine

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Inducing T-cell immune response is very desirable for efficient vaccine. While T-cell immunity does not prevent virus entry into the cell it helps the body to recognize and destroy infected cells before virus has a chance to reproduce. T-cell response involves so call ‘presentation’ where parts of virus proteome in form of short peptides are presented on the surface of the T-cell. This is the mechanism by which the body can recognize the alien proteins and develop immune response to them. The peptides comprising virus proteome are not equal in their ability to be presented and to induce immune response. Some are poorly bind to the MHC (‘handles’ that presents them), others, when attached, do not induce sufficient immune response. Researchers from Norway and Germany used Artificial Intelligence to analyze the SARS-CoV-2 proteome and to calculate so called Antigen Presentation Score (APS) for each of the peptides. The peptides with highest APS were selected as candidates for the vaccine development.

May 19, 2020

Urban monitoring predicts infection spread hot spots


Combining Artificial Intelligence with various sources of information ranging from aerial photography to smart phone ping data, commercial transactions data and social networks allows to measure peoples movements patterns throughout the city. This, in turn, allows to predict the infection hot spots where virus transmission is most likely to occur.

May 18, 2020

AI helps with remote monitoring of COVID-19 patients


A team led by MIT professor Dina Katabi has developed the AI-based system called Emerald. AI system analyses electromagnetic signals generated by people’s motion and is able to analyse breathing patterns. System is able to monitor patients located in separate hospital room of at remote location which greatly reduces risk to medical personnel and reduces the workload on doctors.

Transmission Control 

Social distancing and good hygiene go a long way in an epidemic. According to the CDC, limiting face to face contact with others is the most effective way to reduce the transmission of corona virus disease 2019 (COVID-19). The practice of physical or social distancing refers to keeping space between yourself and others outside of your immediate household. In addition to distancing, proper hygiene can reduce the spread of and avoid exposure to the infectious virus.  

Social Distancing  

Social or physical distancing refers to minimizing the physical contact between individuals, especially between yourself and those outside of your household. Social distancing interrupts the possibility of transmission of infectious diseases, which are easily spread through contact or respiratory passages.1,3At the public level, avoiding large gatherings, crowded places and trying to stay at least six feet from other people reduces the chances of spreading the virus between carriers to non-carriers of the live infectious virus. Avoid close contact with people who are sick, even inside your home. Other measures such as the closure of educational institutions and workplaces can prevent further spreading of the disease. 

Good Hygiene 

An essential first step in avoiding any infection is proper handwashing.  Wash hands with soap and clean water for at least 20 seconds, especially after you have been in a public place, or after blowing your nose, coughing, or sneezing.  If soap and water are not readily available, using alcohol-based sanitizer (containing at least 70 percent alcohol) is recommended.2,3 Its also encouraged to avoid touching your eyes, nose and mouth with unwashed hands. 

Clean and Disinfect 

Cleaning with soap and water reduces number of germs, dirt and impurities on the surface. 4 Disinfecting kills germs on surfaces. Practice routine cleaning of frequently touched surfaces, especially high touch surfaces such as doorknobs, light switches, countertops and phones. Follow the labeled instructions on disinfectants to ensure safe and effective use. 

Face Masks 

Care should be taken to cover the nose and mouth while coughing or sneezing to prevent the spread of droplets and reduce the chance of infecting infection to others. Everyone should wear a cloth face cover when they go out in public, for example to the grocery store or to pick up other necessities. The cloth face cover is meant to protect other people in case you are infected and is not a substitute for social distancing.5 

1.Mal PR, Suneel P, Shomeeta P. Social distancing: A non-pharmacological intervention for COVID-19. J Pak Med Assoc. 2020;70(Suppl 3)(5):S21‐S24. doi:10.5455/JPMA.05 

2.Pankajakshan A, Prasannan A, Chaudhary S. COVID-19: What have we learnt, and plan for the future. J Pak Med Assoc. 2020;70(Suppl 3)(5):S30‐S33. doi:10.5455/JPMA.07 

3.Verma M, Aydin H. Personal prophylaxis against COVID-19: A compilation of evidence based recommendations. J Pak Med Assoc. 2020;70(Suppl 3)(5):S15‐S20. doi:10.5455/JPMA.04 

4. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/disinfecting-your-home.html 

5. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html 

September 28, 2020 

COVID-19 Diagnostics, Tools, and Prevention

An overview of the preventive tools and measures that can decrease the likelihood of virus transmission are presented to highlight the proper use of personal protective equipment (PPE), including face masks, face shields, gloves and ventilators. The authors begin with suggesting rapid diagnosis of COVID-19, such as anti-body tests over the previously used RT-PCR method. Adequate masks should be used in public venues and people should be more aware of possible seasonal transmission of the virus. In a healthcare setting where the supply of proper face shields is low, DIY and 3-D printed solutions provide a good alternative. In the case of masks, the authors suggest masks be limited to high risk healthcare workers or those specifically taking care of infected family members. Proper hand washing should suffice.

September 25, 2020 

To mask or not to mask children to overcome COVID-19

Universal use of face masks in addition to hand hygiene and safety distance seems to be effective to reduce the role of asymptomatic individuals transmitting COVID-19. Protecting healthy children with masks can be difficult due to many challenges. Adult sized masks may not fit properly and children may simply remove the masks or spread the virus by touching their face when adjusting or removing masks. Children under the age of two should not wear masks due to suffocation risks. Schools and parents must educate children on the proper use and fitment of masks as well as general hygiene.

September 24, 2020 

The first eight months of Sweden’s COVID-19 strategy and the key actions and actors that were involved

The authors reviewed the eight-month period following the COVID-19 pandemic outbreak, specifically detailing how Sweden flattened the curve, protected at risk groups and ensured continuity of health and medical resources during that timeline. Compared to other countries, Sweden’s response to COVID-19 has been less invasive with no general lockdown. Bars, restaurants, public spaces, kindergartens and schools continued to operate throughout the pandemic. Quarantines for infected households were not enforced and physical distancing was recommended and only mandatory for specific settings. Wearing facemasks was not recommended except for healthcare workers. Sweden had a multi-pronged approach to flatten the curve with mitigation rather than suppression. The strategy focused on protecting the at risk 70 year and above age group. Schools remained open and health/medical services never ceased. Sweden’s COVID-19 strategy has been controversial: the mortality per capita was higher in Sweden than in neighboring countries but lower than that of several other European countries that had applied a general lockdown.

September 23, 2020 

COVID-19 Transmission and Children: The Child Is Not to Blame

Coronavirus disease (COVID-19) presents arguably the greatest public health crisis in living memory having not only widespread impact to health but also global economy. One surprising aspect of this pandemic is that children appear to be infected by SARS-CoV-2 far less frequently than adults and with milder symptoms. The authors reviewed data to determine the extent to which children and young people are responsible for SARS-CoV-2 transmission. Through contact tracing, 39 households with reverse-transcription polymerase chain reaction–confirmed cases from Geneva, Switzerland were studied. Data suggests that children are not significant drivers of the COVID-19 pandemic and are more likely to contract the disease from adults than transmitting it to them.

September 22, 2020 

Role of children in the transmission of the COVID-19 pandemic: a rapid scoping review

There is currently insufficient information on the child population and their role in transmitting COVID-19. Initial mitigation strategies such as school closures were employed based on previous epidemics where children were the main transmitters. The authors searched PubMed to review if children were more contagious than adults. This rapid scoping study determined that children are not transmitters to a greater extent than adults. Children are equally susceptible, though may present less severe symptoms than the adult/elderly population.

September 21, 2020 

Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients

There is currently substantial controversy on whether live infectious SARS-CoV-2 virus can be transmitted through aerosols. The most common air samplers have a tendency to inactivate the virions through their harsh collection processes. The authors take advantage of a newer air sampling technology that operates using a water-vapor condensation mechanism with less invasiveness. Air samples were collected in a room that was part of a designated ward with COVID-19 patients. Viable (infectious) SARS-CoV-2 was present in aerosols within the hospital room of COVID-19 patients as determined rRT-qPCR.

September 18, 2020 

Could masks curtail the post-lockdown resurgence of COVID-19 in the US?

The community lock down measures implemented in the United States from late March to late May of 2020 resulted in a significant reduction in the community transmission of the COVID-19 pandemic throughout the country. However, a number of US states are currently experiencing an alarming post-lock down resurgence of the pandemic, triggering fears for a devastating second pandemic wave. The authors developed a new mathematical Kermack–Mckendrick epidemic model to address the question of whether or not universal face masks alone could curtail the post-lock down resurgence of COVID-19 in the US. The study highlights the fact that widespread random testing contributes in detecting, tracing and isolating asymptomatic cases that would otherwise be spreading the virus in the community. The simulation results also demonstrate the importance of combining early implementation of the lock down measures with increased face mask usage during the community lockdown.

September 17, 2020 

College campuses and COVID-19 mitigation: clinical and economic value

The authors conducted a model-based evaluation of the impact of COVID-19 mitigation strategies on college campuses and the surrounding communities. Social distancing and mask-wearing policies as well as the use of routine laboratory testing of asymptomatic students and faculty were assessed. It was determined that most infections among students were from other students and that most infections among faculty members were not from students. Implementing extensive social distancing and mandatory mask-wearing policies would enable higher education institutions to have the biggest impact in reducing COVID-19 infections among students and faculty. Routine laboratory testing would further reduce infections but would require less costly tests coupled with markedly increased capacity to be feasible for many colleges.

September 16, 2020 

COVID‐19: Face masks and human‐to‐human transmission

The authors present a case of face masks being used to prevent the transmission of COVID-19 while using public transportation. Contact tracing was used following a small outbreak by public transportation exposure. Five of 39 passengers tested positive after sharing a coach bus with an unmasked rider unaware that he was infected with COVID-19. Upon arrival, the patient donned a face mask prior to transferring to a small minibus with 14 other passengers. No passengers riding the minibus were infected after a 14-day observation period.

September 15, 2020 

COVID-19 in children: the link in the transmission chain

Young children and infants are usually at high risk for admission to hospital after respiratory tract infection with viruses. Therefore, the absence of pediatric patients with COVID-19 has perplexed scientific community. It is noteworthy that infants and children have not been featured prominently in COVID-19 case statistics. The authors studied a cohort of patients with results suggesting that may children have specific mechanisms regulating the interaction between the immune system and respiratory network, which could be contributing to milder disease.

September 14, 2020 

Face Masks are Beneficial Regardless of the Level of Infection in the Fight Against COVID-19

It is crucial that measures be implemented to decrease the spread of COVID-19 from person to person. The widespread implementation of wearing face masks by the general population has faced challenges due to a variety of factors. The authors review data to evaluate the efficacy of universal masking in the public. The extensive use of cloth masks in conjunction with other preventative measures such as social distancing and handwashing can potentially reduce the risk of transmission of COVID-19. The authors are also suggesting that current distancing practices should be re-evaluated and possible extended beyond the suggested two meters.

September 11, 2020 

COVID-19 and its Modes of Transmission

The authors review various modes of SARS-CoV-2 transmission and propose measures to reduce the risk of spread within the population and operating personnel. Broadly, two modes of transmission of COVID-19 exist—direct and indirect. The direct mode includes bodily fluid, secretions such as saliva, feces, tears as well as related aerosols. Contaminated surfaces and fomites from infected individuals contribute to the indirect methods. Several of these modes may be underestimated and can lead to further spread of the virus among the community. More studies are required to assess other potential modes of transmission. For more effective mitigation strategies, samples from a bigger and more diverse population are needed to gain adequate details on transmission as well as duration and source of viral shedding.

September 10, 2020 

SARS-CoV-2 infections in children and young people

It currently remains unclear whether children and young people (CYP) significantly contribute to community SARS-CoV-2 transmission. General symptoms  show milder presentations in children as compared to adults, raising the question of whether age-related characteristics may protect from the development of clinical disease. Possible reasons for mild presentations in childhood include frequent contact to seasonal coronaviruses and, as a result, the presence of cross-reactive antibodies. Further potential age-related factors include recent vaccinations and associated heterologous immune responses, and a more diverse memory T cell repertoire when compared to the elderly. More research is required to determine if whether CYP constitute a significant source of transmission.

September 09, 2020 

Potential of Ocular Transmission of SARS-CoV-2: A Review

Understanding methods of transmission of SARS-CoV-2 is critical to controlling the pandemic. Current data and literature pertaining to the ophthalmological community was reviewed to better understand the mechanisms of SARS-CoV-2 on a molecular scale. The authors assessed if ocular secretions contained live virus, the ocular inoculation of virus result in systemic infection and effective mitigation strategies. Analysis of the literature, as well as the analysis of gene involved in viral infection in ocular tissues, suggest that both direct infection of the ocular surface or transmission of the virus through tears down the nasolacrimal duct to infect the nasal epithelium are both plausible.

September 08, 2020 

An Examination on the Transmission of COVID-19 and the Effect of Response Strategies: A Comparative Analysis

The authors evaluated COVID-19 transmission trends among six countries: China, Korea, Japan, Italy, the United States, and Brazil. Specifically, the pandemic severity, mortality rate, and mitigation effectiveness were compared. Overall, Korea and China had relatively higher mitigation effectiveness and lower pandemic severity, while the United States and Brazil had the opposite. This paper suggests that viral testing, together with contact tracing, strict implementation of lockdown, and public cooperation play important roles in achieving a reduction in COVID-19 transmission.

September 04, 2020 

Preventing SARS-CoV-2 transmission in rehabilitation pools and therapeutic water environments

Most outbreaks related to contaminated recreational waters are caused by oral–fecal transmission of enteric viruses. The authors assessed the risk of SARS-CoV-2 transmission in rehabilitation pools and therapeutic water environments in order to provide specific recommendations to control the spread of SARS-CoV-2. The first line of prevention of SARS-CoV-2 transmission is based on barrier measures including hand hygiene, physical distancing, and respiratory hygiene. However, these precautions are difficult or impossible to apply in patients when bathing. The authors propose maintaining usual pool disinfection standards, together with appropriate individual hygiene practices in and out of the pool should be sufficient to prevent a risk of waterborne transmission of SARS-CoV-2. These guidelines may be extended to public and private swimming pools.

September 03, 2020 

Safety testing improvised COVID‐19 personal protective equipment based on a modified full‐face snorkel mask

While COVID-19 continues to spread across the globe, supplies of PPE and N95 masks are being exhausted. As a result, improvised PPE designs have circulated online to provide solutions. One such design consists of commercially available full-face snorkel masks outfitted with filters. In the authors’ single combination of mask, adapter and filter on a single user quantitative fit-testing failed. Submerged snorkel masks are designed to fit properly when the higher outside pressure and fitment security may be compromised with no such pressure differential. The authors emphasize the need to properly test fit these masks to ensure efficacy.

September 02, 2020 

Modifying a Full-Face Snorkel Mask to Meet N95 Respirator Standards for Use With Coronavirus Disease 2019 Patients

Healthcare workers are at high risk for contracting COVID-19, especially anesthesiologists, respiratory therapists, and intensive care physicians who manage the airways of COVID-19 patients. The supply of proper personal protective equipment, specifically N95 masks, is becoming exhausted with the increasing number of corona virus cases. The authors modified and tested commercially available full-face snorkel masks outfitted with airway breathing circuit filters.  The modified masks satisfy OSHA N95 standards to protect front line health care providers from pathogen aerosol exposure such as the novel SARS-CoV-2 virus.

September 01, 2020 

Shedding of SARS-CoV-2 in feces and urine and its potential role in person-to-person transmission and the environment-based spread of COVID-19

The fecal-oral route has been suggested in its spreading of COVID-19 do to shedding of SARS-COV-2 RNA in bodily fluids such as feces or urine. Millions of cases of COVID-19 have occurred globally, yet exposure to wastewater has not been implicated as a transmission vector. The biggest risk of transmission will occur in clinical and care home settings where secondary handling of people and urine/fecal matter occurs. The authors evaluated evidence of gastrointestinal (GI) symptoms, the quantity and infectivity of SARS-CoV-2 in feces and urine, and whether these pose an infection risk in wastewater and sewage networks. Analysis suggests the likelihood of infection due to contact with sewage-contaminated water or food is extremely low based on very low predicted abundances and limited environmental survival of SARS-CoV-2.

August 31, 2020 

Swimming Pool safety and prevention at the time of Covid-19: a consensus document from GSMS-SItI

Swimming Pools play an important role in society by providing a  source of aerobic exercise for people of different ages and conditions. This is especially true during  a pandemic when many activities may not be available due to social distancing practices.  The possible transmission of SARS-COV-2  in swimming pools is still debatable due to limited knowledge. No evidence demonstrating SARS-COV-2 contamination or outbreaks from swimming pools as sources has been found.  The authors recommend a structured re-opening protocol with proper monitoring and disinfection.

August 28, 2020 

COVID-19: Limiting the Risks for Eye Care Professionals

In general, mucosal membranes of the mouth, eyes and tears are potential sources of microbial transmission. By nature of their interaction with patients, ophthalmic healthcare professionals are at higher risk of contracting the virus. Preliminary data suggests that COVID-19 may be transmitted by tears and the ophthalmic pathway, even though the risk may be low. Negative PCR report in ocular samples does not fully exclude the risk of transmission of the virus. The authors propose a comprehensive approach that includes a physical barrier that may be implemented in an ophthalmic care facility to protect healthcare personnel, as well as patients, from contracting the virus.

August 27, 2020 

Comprehensive review of mask utility and challenges during the COVID-19 pandemic

Government agencies across the globe have recommended and even mandated universal mask-wearing in public. The authors compare the features, benefits and drawbacks of various masks available. The four types of masks researched include Powered Air-Purifying Respirators (PAPRs), N95 respirators, surgical masks as well as cloth masks. Due to the limited supply of certain PPE, the authors also propose a strategy for the reuse and sterilization of masks. It is important to couple mask-wearing with adequate social distancing and proper hygiene.

August 26, 2020 

Infection control in non‐clinical areas during the COVID‐19 pandemic

Large numbers of healthcare workers have contracted COVID‐19 in the workplace. The authors believe non-clinical common areas are potentially high risk for transmission and are likely neglected by prevention and control protocols. The authors recommend extending proper cleaning and control protocols to communal and office areas. Adding plexiglass dividers in office and break areas and making commonly contacted surfaces easily cleanable are also suggested.

August 25, 2020 

Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis

The authors systematically reviewed and performed  a meta-analysis of 172 studies from across 16 countries to investigate optimum person-to person distance and to assess  face masks and eye protection to reduce transmission of COVID-19. Physical distancing of greater than 1 meter was associated with a much lower risk of infection. The use of eye protection in addition to the use of faces masks also lowers risk.

August 24, 2020 

Physical distancing, face masks, and eye protection for prevention of COVID-19

Governments and health organizations have recommended and mandated social/physical distancing as well as the wearing of face masks in public. There still remains a lack of agreement on the efficacy of certain types of mask materials and respirators. The discrepancy reflects uncertain evidence and no consensus about the transmission mode of severe acute respiratory syndrome coronavirus 2(SARS­CoV­2). For eye protection, data is even less certain. After reviewing data in hospitals, the authors determined that eye protection reduced infection rate by 78%.

August 21, 2020 

Universal masking during COVID-19 pandemic: Can textile engineering help public health? Narrative review of the evidence

Governments across the globe are recommending universal precautions such as hand washing and physical distancing in order to slow down the transmission of COVID-19. In addition to proper hygiene, cloth masks may be helpful, especially with shortages of filtering or surgical masks. The authors review the uses of various textiles and make suggestions to improve the quality of cloth masks for the general public. Masks should have the following properties: good filtration for microorganisms, low breathing resistance, hypoallergenic, washable as well as being comfortable, and affordable.

August 20, 2020 

Indirect Virus Transmission in Cluster of COVID-19 Cases, Wenzhou, China, 2020

An outbreak of COVID-19 cases emerged in association with a Wenzhou, China shopping center. The authors monitored and traced contacts in order to determine the modes of transmission of the outbreak. After the first employee working at the mall tested positive, seven coworkers were also later confirmed for COVID-19. Within two days, the mall was shut down and the Wenzhou center for Disease Control and Prevention traced and tested contacts. The authors acknowledge the unknown asymptomatic carriers but their findings indicate that the virus spreads indirectly and though brief contact.

August 19, 2020 

Universal use of face masks for success against COVID-19: evidence and implications for prevention policies9

Extreme forms of social distancing such as city/nation wide lock downs are not sustainable in the long run and can be devastating to the economy.  The practice of universal masking in addition to good hygiene practice can compliment social distancing to reduce the transmission of COVID-19. The authors provide data to  support the use of cloth faces masks in light of the shortages of surgical masks that should be reserved for healthcare workers.

August 18, 2020 

Identifying airborne transmission as the dominant route for the spread of COVID-19

Various measures have been implemented to reduce the spread of COVID-19, including mandatory mask-wearing and social distancing. The authors analyzed data and trends measured at the three COVID-19 epicenters in New York, Italy, and Wuhan. Results show that the airborne contagion route is highly virulent and the primary method of COVID-19 transmission. Understanding the virus transmission allows for the recommendation of the most effective means of prevention or control of the spread of the disease.

August 17, 2020 

Protecting Breastfeeding during the COVID-19 Pandemic

There is incomplete understanding of the transmission potential of COVID-19 through human breast milk and the negative health and emotional implications of maternal-baby separation must be weighed before recommending isolation of COVID-19 positive mothers from their newborns. Considering the benefits of breastfeeding and available data suggesting an insignificant role of human milk in the transmission of SARS-CoV-2, the authors maintain that mothers suspected of or confirmed with COVID-19 can directly breastfeed with appropriate precautions.

August 14, 2020 

Infection Control in Dental Practice During the COVID-19 Pandemic

Authors outline transmission routes of coronavirus in the dental field and propose practical advice to reduce transmission of COVID-19. Those working in dental practices are at high risk due to exposure to saliva, blood and body fluids. The authors discuss patient side screening and PPE use as well as enhanced protective measures for the dental workers.

August 13, 2020 

Interrupting COVID-19 transmission by implementing enhanced traffic control bundling: Implications for global prevention and control efforts

Traditional Traffic Control Bundling (TCB) proved to be effective during the 2003 SARS outbreak by ensuring that healthcare workers and patients were protected from contact, fomite and droplet transmission within hospitals. The authors propose an enhanced TCB (eTCB) modified to address the new challenges from COVID-19. ETCB introduces enhanced disinfection checkpoints, PPE deployment and additional quarantine zones.

August 12, 2020 

Back to Normal: An Old Physics Route to Reduce SARS-CoV-2 Transmission in Indoor Spaces

Current social distancing, hygiene practices and facial masks have limited efficacy, especially within indoor spaces. The authors suggest UV-C light as an economically viable measure to help reduce SARS-CoV-2 transmission. UV-C radiation integrated within current air circulation/ventilation systems could be deployed with no optical path to humans. Smaller interior areas and surfaces could be exposed to high intensity UV-C radiation when unoccupied. Further investigation to employ such measures effectively is needed.

August 11, 2020 

COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020

An outbreak of novel COVID-19 involved 10 people from three families dining at an air conditioned restaurant in Guangzhou, China. The authors detail the potential transmission route beginning with patrons that recently traveled from Wuhan, China. The three families were seated at tables within close proximity and downstream from the recent Wuhan travelers that were closest to the air conditioning vents. The key factor for the infection was the direction of the airflow relative to the patrons. The authors recommend increasing distance between tables, improving ventilation and strengthening temperature monitoring of patrons.

August 10, 2020 

Vertical Transmission of Coronavirus Disease 19 (COVID-19) from Infected Pregnant Mothers to Neonates: A Review

At this time very little is known about the transmission of SARS Cov-19-2 between pregnant mothers to their infants. The authors reviewed data from published articles or official websites from January to March of 2020, documenting 31 infected mothers with COVID-19. Although infected mothers may be at higher respiratory risk for complications, there was no evidence for intrauterine transmission of COVID-19 from infected mothers to their fetuses.

August 7, 2020 

Back to Normal: An Old Physics Route to Reduce SARS-CoV-2 Transmission in Indoor Spaces

Social distancing, hygiene practices and face masks have limited the efficacy of COVID019, especially within indoor spaces. The authors suggest UV-C light as an economically viable measure to help reduce SARS-CoV-2 transmission. UV-C radiation integrated within current air circulation/ventilation systems could be deployed with no optical path to humans. Smaller interior areas and surfaces could be exposed to high intensity UV-C radiation when unoccupied. Further investigation to employ such measures effectively is needed.

August 6, 2020 

Can indoor sports centers be allowed to re-open during the COVID-19 pandemic based on a certificate of equivalence?

Physical exercise is an important aspect of mental and physical well being , especially during periods of quarantine. Indoor exercise facilities and gyms have been the last to be permitted to reopen by government authorities and face many challenges due to the high opportunities of both direct and indirect infection transmission. There are challenges presented to exercise facilities operators, employees and visitors, such as limiting the occupancy or requiring reservations. The authors elaborate on three particular areas to improve upon: increased building ventilation, HEPA filtration and development of sports face masks in addition to current measures to reduce the transmission of COVID-19 infectious agents.

August 5, 2020 

How can airborne transmission of COVID-19 indoors be minimised?

Microdroplets or aerosols is a potential source of airborne transmission of SARS-CoV-2. Several hospital  studies have shown positive samples of SARS-CoV-2 genome within air quality samples using PCR testing.  The authors suggest that improving engineering controls such as ventilation, filtration and disinfection should be prioritized to aid in reducing indoor transmission of COVID-19 related airborne pathogens.

August 4, 2020 

Airborne Transmission Route of COVID-19: Why 2 Meters/6 Feet of Inter-Personal Distance Could Not Be Enough

The World Health Organization has recommended maintaining a social distance of at least 2 meters or approximately 6 feet to minimize the transmission of infectious agents between people. The authors have identified other research showing that the airborne persistence and viability of the SARS-COV-2 necessitates additional measures to prevent infection. The authors also suggest the mandatory adoption of face masks to be used during and after lockdown periods and to limit gathering sizes, especially indoors.

August 3, 2020 

Reducing Transmission of SARS-CoV-2

A Large proportion of the transmission of COVID-19 appears to result from aerosol transmission from asymptomatic individuals during breathing and speaking. Measures such as universal masking, designed to reduce aerosol transmission, should be implemented. In addition, efforts should be made to increase testing in order to identify and ultimately isolate asymptomatic individuals.

July 31, 2020 

COVID-19 Transmission in Dental Practice: Brief Review of Preventive Measures in Italy

Authors outline transmission routes of coronavirus in the dental field, especially since dental services are deemed a necessary service.  Those working in dental practices are at high risk due to exposure of body fluids and unavoidable proximity to patients’ mouths. The authors discuss various prophylactic methods and increased cleaning and PPE.

July 30, 2020 

Biosafety at Home: How to Translate Biomedical Laboratory Safety Precautions for Everyday Use in the Context of COVID-19

Social distancing measures to reduce the spread of COVID-19 have only been loosely followed by the general public and what may have worked to flatten the curve initially is likely not as effective as during the initial stages of the pandemic. As a response, a group of scientists have developed a protocol that translates laboratory biosafety precautions to fit outside of the lab. This protocol is targeted to healthcare workers and those working or living in high exposure environments. Household and work areas have been divided into segregated areas with directional one-way traffic and de-gowning areas to minimize contamination of “clean” areas.

July 29, 2020 

Risk of SARS-CoV-2 transmission by aerosols, the rational use of masks, and protection of healthcare workers from COVID-19

The two main types of masks available to healthcare workers are surgical masks (intended to protect the patients) and filtering face piece masks (intended to protect the wearer). The authors review the epidemiology of COVID-19 among healthcare workers and compare the effectiveness of different mask types. More important than the comparative type of mask is the proper donning of the mask in addition to appropriate hygiene.

July 28, 2020 

Expanding frontiers of risk management: care safety in nursing home during COVID-19 pandemic

Nursing homes face added complexity when trying to control the spread of SAR-CoV-2. The authors emphasize the need for every nursing facility to elect a properly trained individual to spearhead the efforts to prevent and control infections. Risk management for residential nursing facilities differs from  that of standard hospitals and requires a modified approach.

July 16, 2020 

Absence of apparent transmission of SARS-CoV-2 from two stylists after exposure at a hair salon with a universal face covering policy 

The authors document a case study involving two hair stylists that both tested positive for SARS-COV-2. The stwo stylists developed symptoms within three days of each other but continued to work respectively for at least 8 days before seeking testing. 139 clients were serviced by the two SARS-COV-2 positive stylists from the time symptoms developed until they took leave. It should be noted that both stylists and the clients wore face masks and through contract tracing, no symptomatic secondary cases were reported.

July 15, 2020 

Progression of confirmed COVID-19 cases after the implementation of control measures 

The authors observed the progression COVID-19 cases in regions that implemented control measures to reduce transmission or SARS-CoV-2. Nine countries were observed and data was compared once the selected country reached 50 positive cases per day. The authors hope that by reviewing the infection curves, countries are able to adopt the most effective methods to slow infection. 

July 14, 2020 

Absence of in-flight transmission of SARS-CoV-2 likely due to use of face masks on board 

The authors describe a 14 hour flight of 11 passengers and four crew members that included two SAR-COV-2 positive passengers. The flight crew were instructed to wear filtering facepiece masks with one-way valves while all passengers were instructed to have surgical masks replacing them every three hours. All passengers were found to be negative on six consecutive tests during the 14 day arrival quarantine. The authors suggest the with proper masking, there is low risk of transmission during flights even with the close proximity.

July 13, 2020 

Clinical Characteristics and Results of Semen Tests Among Men With Coronavirus Disease 2019 

Direct transmission of respiratory droplets and contact transmission of mucosal membranes are the most common transmission routes of COVID-19. However, little is known about the transmission of SARS-CoV- 2 in human sperm. In a cohort study of 38 subjects, the authors found that SARS-CoV-2 can be present in the semen of patients with COVID-19, and SARS-CoV-2 may still be detected in the semen of recovering patients.

Herd immunity is based on the protection of susceptible (uninfected) people from being infected with a certain disease due to a large percentage of immune people in the population. Immunity could result from infection recovery or from vaccination (which is not currently available for COVID-19) (Randolph et al., 2020). Once a certain percentage of the population is immune, the spread of the disease should decline as infected people are less likely to encounter susceptible people. This herd immunity threshold is estimated with the equation (1 – 1/R0) where R0 is the reproductive number of the disease (i.e. how many secondary infections are caused on average per infected person) (Plans-Rubió 2012).

For COVID-19, R0 has been estimated in the range 2-6 and has likely varied by region (Randolph et al., 2020). With an R0 of 3, herd immunity would be reached at about 67%. Due to a lack of consistent testing, estimates of the case fatality rate (CFR) and infection fatality rate (IFR) have varied widely. Assuming an approximate IFR of 1% for COVID-19 (Okell et al., 2020), reaching 67% herd immunity solely by infections and not vaccinations could lead to deaths for 0.67% of a population (over 50 million people globally).

Regional immunity

The herd immunity concept assumes a homogeneous mixture of the population. The percent of immune people may likely vary by region, so small outbreaks could still occur even after the threshold is reached (Randolph et al., 2020). The CDC recently reported analysis of over 11,000 specimens from 6 U.S. sites tested for SARS-CoV-2 antibodies (Havers et al., 2020). The seroprevalence showed higher numbers than reported confirmed cases by a factor of 6 in Connecticut to 24 in Missouri. Seroprevalence was reported as 6.9% in New York City, 1.9% in south Florida, 4.9% in Connecticut, 2.7% in Missouri, 2.2% in Utah, and 1.1% in Washington (near Puget Sound).

Pollán et al. recently reported a serological study of over 61,000 households in Spain to measure SARS-CoV-2 by regions. They gathered data with surveys about COVID-19 related symptoms and risk factors, point-of-care antibody tests, and immunoassay (if participants agreed). Seroprevalence was about 5% overall with higher values in regions such as Madrid. Approximately one-third of positive participants were asymptomatic, and only about 20% of symptomatic participants reported a previous PCR test (Pollán et al., 2020). The highest seroprevalence by region in Spain was <15% which is far from herd immunity.

Immunity duration

Even if the herd immunity threshold is reached in the future, the duration of immunity is not yet known (Kissler et al., 2020). Studies of other coronaviruses suggested immunity periods of up to 2 years for SARS-CoV-1 infection (Mo et al., 2006) and over 18 months for MERS (Alshukairi et al., 2016). Depending on the extent of immunity, there could be recurring waves of COVID-19 infections (such as annual or biennial waves) (Kissler et al., 2020). If secondary waves begin, restrictions could be periodically reinstated to slow the spread and prevent overwhelming healthcare systems (Kissler et al., 2020).


Alshukairi AN, Khalid I, Ahmed WA, Dada AM, Bayumi DT, Malic LS, Althawadi S, Ignacio K, Alsalmi HS, Al-Abdely HM, Wali GY. Antibody response and disease severity in healthcare worker MERS survivors. Emerging infectious diseases. 2016 Jun;22(6):1113.

Havers FP, Reed C, Lim TW, Montgomery JM, Klena JD, Hall AJ, Fry AM, Cannon DL, Chiang CF, Gibbons A, Krapiunaya I, et al. Seroprevalence of Antibodies to SARS-CoV-2 in Six Sites in the United States, March 23-May 3, 2020. medRxiv. 2020 June 26.

Kissler SM, Tedijanto C, Goldstein E, Grad YH, Lipsitch M. Projecting the transmission dynamics of SARS-CoV-2 through the postpandemic period. Science. 2020 May 22;368(6493):860-8.

Mo H, Zeng G, Ren X, Li H, Ke C, Tan Y, Cai C, Lai K, Chen R, Chan-Yeung M, Zhong N. Longitudinal profile of antibodies against SARS-coronavirus in SARS patients and their clinical significance. Respirology 11, 49–53. 2006.

Okell LC, Verity R, Watson OJ, Mishra S, Walker P, Whittaker C, Katzourakis A, Donnelly CA, Riley S, Ghani AC, Gandy A. Have deaths from COVID-19 in Europe plateaued due to herd immunity? Lancet. 2020 Jun 11.

Plans-Rubió P. The vaccination coverage required to establish herd immunity against influenza viruses. Preventive medicine. 2012 Jul 1;55(1):72-7.

Pollán M, Pérez-Gómez B, Pastor-Barriuso R, Oteo J, Hernán MA, Pérez-Olmeda M, et al. Prevalence of SARS-CoV-2 in Spain (ENE-COVID): a nationwide, population-based seroepidemiological study. The Lancet. Preprint. 2020 July 6.

Randolph HE, Barreiro LB. Herd Immunity: Understanding COVID-19. Immunity. 2020 May 19;52(5):737-41.

September 28, 2020

Seroprevalence study in dialysis patients in US reports less than 10% had COVID-19 antibodies

A large study of over 28,000 dialysis patients tested plasma samples from July 2020 for SARS-CoV-2 antibodies. The randomly sampled patients lived in 46 states and across 1013 US counties. Seroprevalence was 8% in the sampled group which is far from the herd immunity threshold. The authors estimated an 8.3% positive value after standardizing the results to reflect the US dialysis population and 9.3% after adjusting to the US adult population. In the US dialysis adjusted data, the values ranged from 3.5% in the west to 27.2% in the northeast region of the US. The study also estimates that only 9.2% of seropositive patients were diagnosed previously with COVID-19.

September 25, 2020

Study analyzed COVID-19 clusters and superspreading events in Hong Kong

A recent study used data from contact tracing of COVID-19 in Hong Kong to identify clusters of transmission and superspreading events. The researchers analyzed over 1,000 cases and estimated that 19% of cases caused 80% of COVID-19 transmission in Hong Kong. The researchers suggest implementing measures to prevent superspreading events such as venue closures, reduced capacity, and mask usage.

September 24, 2020

Study estimates that the city of Manaus, Brazil may have reached herd immunity through extensive COVID-19 epidemic

The city of Manaus, Brazil in the Amazon region had a large COVID-19 outbreak with many deaths in May 2020. The number of COVID-19 cases in the city of 1.8 million people decreased by mid-August. While the decrease could be from non-pharmaceutical interventions, a new pre-print study estimates that the city has reached herd immunity. Based on testing blood bank samples and their modeling results, the researchers estimate 44% to 66% of Manaus were infected. The city has a fairly young population, and the study estimates the IFR as 0.3%. The length of immunity for COVID-19 is unknown, so cases could increase again without precautions or a vaccine.

September 23, 2020

United States reached 200,000 COVID-19 deaths with increasing proportion in smaller cities

The US has had over 200,000 confirmed COVID-19 deaths. At the beginning of the pandemic, most COVID-19 deaths were occurring in large cities. Over time, the proportion of deaths in medium-sized cities and in small, rural areas has increased. By mid-September, about half of weekly deaths were in large cities. Hot spots in states such as Texas, Georgia, and Mississippi have had a high number of deaths per capita in small communities.

September 22, 2020

Weekly COVID-19 cases are decreasing in many African countries

The Africa CDC reported in a recent briefing that most regions in Africa are seeing a decrease in weekly cases of COVID-19. Africa has had almost 1.4 million COVID-19 cases at the time of the report and almost 33 thousand deaths (2.4% CFR). Only 5% of all globally reported cases were in Africa. The Northern region of Africa recently had an increase in cases. Over 70% of the recent COVID-19 cases were from Morocco, South Africa, Ethiopia, Libya, Tunisia, and Algeria. Overall, weekly cases across the continent have continued to be lower than the peak seen in July.

September 21, 2020

FDA approves first portable COVID-19 PCR test

As COVID-19 cases increase, several testing methods are being developed to detect infections. The startup company Visby Medical has developed a portable COVID-19 PCR test kit, and the test recently received an Emergency Use Authorization by the US FDA. The FDA approval is for the test kit to be used in clinical labs, but the company hopes to eventually make their product available to consumers at home. The small test kit requires a sample via nasal swab. Then, within 30 minutes, the test kit will reveal a positive or negative result for COVID-19.

September 18, 2020

Daily COVID-19 cases increasing in several European countries

Several countries in Europe are experiencing a second wave of COVID-19 cases. Albania, the Czech Republic, Denmark, France, Greece, Romania, and other countries have had record high daily COVID-19 cases in the past few weeks. Other countries, such as Italy and the UK, have had recent increases in confirmed cases, but their cases have not exceeded the peaks seen in spring.

September 17, 2020

Impact of COVID-19 on hospitalized pregnant women in the United States

As COVID-19 cases continue to increase, the CDC is continuing to monitor the impact of the virus on pregnant women and newborns. A recent report summarizes the outcomes of 598 pregnant women with COVID-19 who were hospitalized across 13 states. In this group, 55% were asymptomatic at the time of admission. In the symptomatic cases, 16% were admitted to the ICU, 8% required ventilation, and 0.7% of pregnant women died. The most common COVID-19 symptoms were fever or chills and cough. Pregnancy loss occurred in asymptomatic and symptomatic cases (2%). Pre-term delivery was reported for 23% of symptomatic and 8% of asymptomatic patients. Two live-born newborns died, and both had mothers who required mechanical ventilation. The study also suggests that pregnant women who are Hispanic or Black may have higher rates of COVID-19 hospitalization.

September 16, 2020

Longitudinal study of seasonal coronaviruses shows short-lived immunity

While the length of immunity against the novel SARS-CoV-2 is not yet known, researchers have studied other coronaviruses over time. Serum samples from ten healthy adult male subjects in Amsterdam were analyzed over a 35-year period to test for antibodies against seasonal coronaviruses. The four coronaviruses studied (HCoV-NL63, HCoV-229E, HCoV-OC43, and HCoV-HKU1) cause respiratory tract infections and can be asymptomatic. The researchers detected 3 to 17 coronavirus infections per patient over the course of the study. Time between reinfection varied from 6 to 105 months. Reinfection often occurred at 12 months, and infection rates were lowest in the summer months. The researchers did not study strain variation of the viruses.

September 15, 2020

Germany hopes to have widely available COVID-19 vaccine by mid-2021

The Federal Minister of Health in Germany reported plans for a voluntary vaccine program to reach herd immunity in Germany. The government is helping to fund three German firms with their vaccine development. They hope for a vaccine to be widely available by mid-2021. The vaccine would likely be prioritized to certain groups initially such as the elderly and frontline workers in Germany.

September 14, 2020

Study of T cell immune response against SARS-CoV-2

Researchers investigated T cell immunity in COVID-19 patients, specifically CD4+ ‘helper’ T cells and CD8+ ‘killer’ T cells against SARS-CoV-2. The study included 35 patients (18 who had COVID-19 and 17 healthy subjects). All of the COVID-19 patients seroconverted and had antibodies against SARS-CoV-2. The CD4+ T cell response levels were relatively similar to levels seen from other viruses; however, the CD8+ T cell response was not as high as the response seen for influenza or the Epstein-Barr virus. This study could help better understand the impact of SARS-CoV-2 on the immune system and guide vaccine development.

September 11, 2020

Sweden’s COVID-19 positive test rate recently reached new low record

Of more than 120,000 recent tests in Sweden, the number of positive COVID-19 cases was 1.2%. In spring 2020, the positive test rate was as high as 19% during the peak of the pandemic. The country has had few restrictions during the pandemic and no official lockdown. Sweden had more deaths than its neighboring countries throughout the pandemic, but recent hospitalization and death numbers are currently low in Sweden.

September 10, 2020

COVID-19 Cases Increase in France Particularly Among Younger Population

In France, the new daily confirmed cases recently reached 8,975 – higher than the previous peak of 7,578 in late March. The recent increase in cases is mainly among the younger population that tend to have less severe cases of COVID-19. Due to the lower age of those infected, hospitalizations and deaths are not as high as they were in spring 2020. However, hospitalizations are in fact increasing slowly and expected to continue to rise in the near future in a delayed response to the increase in cases.

September 9, 2020

COVID-19 Cases are Continuing to Increase in India

The total number of confirmed COVID-19 cases in India recently passed the total case numbers in Brazil. India now has the second highest cases of any country after the United States. The number of COVID-19 deaths are also rising in India. Currently, the United States, followed by Brazil, has the highest total deaths due to COVID-19 in the world.

September 8, 2020

COVID-19 Cases Reported Across U.S. Colleges & Universities

The New York Times has reported over 51,000 COVID-19 cases and at least 60 deaths across colleges and universities in the United States during the pandemic. They surveyed over 1,500 institutions and reported cases in over 1,020 locations. There have been recent increases in cases at dozens of schools that reopened for the fall semester. Some schools have responded to the increase in cases by switching to online learning or canceling large sports gatherings. These cases on campuses could lead to outbreaks in the local college or university communities or the students’ hometowns if they return home.

September 4, 2020

Study reports reduced mortality in critically ill COVID-19 patients treated with systemic corticosteroids

A meta-analysis of seven randomized trials assessed the effect of corticosteroids (dexamethasone, hydrocortisone, or methylprednisolone) on 28-day all-cause mortality in COVID-19 patients. Results from 1703 patients with a median age of 60 were included. In the corticosteroid group (total of 678 patients), 33% died. In the placebo or usual care group (total of 1025 patients) 41% died. As COVID-19 cases increase around the world, investigations such as this study will be valuable to helping reduce the fatal impact of SARS-CoV-2.

September 3, 2020

Large seroprevalence study in Iceland shows antibody response over time and estimates undetected cases of COVID-19

Researchers in Iceland measured antibodies against SARS-CoV-2 with multiple assays in over 30,000 people. Participants included those with a previously confirmed case, people that quarantined due to possible exposure, and people without any known exposure. In the recovered COVID-19 group, 91.1% were seropositive for the two pan-Ig tests used, and 95.1% were positive for at least 1 pan-Ig assay. Antibody titers were measured for up to 4 months after diagnosis. Antibodies increased over a 2-month period and then remained level. Additionally, 2.3% of people that quarantined were seropositive, and 0.3% of people with no known exposure were positive. The authors estimate 0.9% of Iceland’s population was infected with COVID-19 and that 44% of all cases were likely not detected by PCR testing.

September 2, 2020

Detecting COVID-19 cases in a community by testing municipal wastewater

Researchers in Bozeman, Montana showed that the concentration of SARS-CoV-2 RNA in the community wastewater correlated to COVID-19 prevalence in the area. Previous studies have shown that SARS-CoV-2 can be detected in the stool of COVID-19 patients. In this recent study, SARS-CoV-2 RNA was analyzed for 17 days throughout a 74-day period starting in late March. The samples tested positive in late March into early April and in late May, which corresponded to the first and second waves of COVID-19 cases in the community. By surveying COVID-19 patients retrospectively, the researchers reported that the wastewater RNA concentrations followed symptom onset by 5-8 days and preceded clinical test results by 2-4 days. They were also able to analyze the phylogenetic origins of the SARS-CoV-2 strains in their community with the wastewater samples. These methods could be used to monitor cases at the community level in different cities, especially if testing availability is low or to detect people that are asymptomatic and not tested.

September 1, 2020

CDC reports seroprevalence of SARS-CoV-2 among health care workers across multiple states

A study of healthcare workers across 13 medical centers from 12 states in the U.S. found that 6% of the 3,248 participants tested positive for SARS-CoV-2 antibodies. The samples were collected from April to June 2020. Of the positive test results, 29% were asymptomatic in the months prior to sample collection. Additionally, 44% reported that they did not think they had COVID-19, and 69% had not been diagnosed with COVID-19. The positive rate was lower for healthcare workers who reported always wearing a face covering. The positive rate varied by hospital from 0.8% at three hospitals to 31.2% at a medical center in New York. The study shows that many cases have gone undetected among healthcare workers in the U.S.

August 31, 2020

Characteristics of COVID-19 in children that tested positive in South Korea

A study reported the impact of COVID-19 on children in South Korea who tested positive in February or March 2020. Children under 19 years old were tested based on symptoms, contact tracing, recent travel, or other risks. Of the 91 positive patients, 22% were asymptomatic throughout the observation period. Of those with symptoms, 66% did not have detected symptoms before their diagnosis. Symptoms varied from fevers to gastrointestinal, respiratory, or other symptoms. Most children had been exposed from household contacts (63%). All patients recovered; most cases were mild, but two required oxygen. The mean duration of a positive PCR test for SARS-CoV-2 was 17.6 days overall or 14.1 days in asymptomatic patients. The study showed that even though most cases in children were mild, many cases could go undetected without sufficient testing and can last for over two weeks on average.

August 28, 2020

New COVID-19 test uses patient saliva for simpler sample collection and testing

The biotechnology company Fluidigm and Washington University School of Medicine in St. Louis collaborated on a new COVID-19 test that has been approved by the U.S. FDA. Patients can provide saliva samples for simpler collection than nasal swab tests. The sample can then be analyzed in a laboratory within a few hours. The researchers report that the test can detect low levels of SARS-CoV-2. Tests such as these could help increase testing capacity to diagnose patients quickly and improve transmission controls in a community.

August 27, 2020

US FDA approves fast, portable SARS-CoV-2 antigen test on a card

The U.S. FDA authorized Abbott’s BinaxNOW COVID-19 Ag Card that provides test results in 15 minutes. The test requires a nasal swab sample collected by a healthcare worker and application of a testing reagent. A positive or negative result is produced on the card without the use of any extra equipment. The test will be available in the U.S. in early October 2020 to rapidly detect COVID-19 cases.

August 26, 2020

Managing COVID-19 cases as the school year starts in Germany

As the new school year starts in many countries across the globe, there are concerns about how COVID-19 cases may increase in response. Different schools in Germany may have different policies for where masks and social distancing are required. In Berlin, 49 cases were recently confirmed among teachers or students across the city. Due to fast testing, contact tracing and quarantine for certain contacts, these cases have not been tied to large outbreaks at this time. Schools are hoping to avoid large outbreaks such as the one observed at a high school in Israel in May. As other countries in Europe or the United States reopen schools, many factors such as the local case numbers, testing and safety measures could determine if reopening will lead to increases in COVID-19 cases.

August 25, 2020

Network-based model of COVID-19 transmission may help explain why herd immunity has not been reached

A new scientific study of COVID-19 transmission used a network model to try to understand why many countries have had a linear increase in cumulative, confirmed cases and have not reached herd immunity. The authors describe how many countries have had a linear region in plots of cumulative cases (such as the USA, UK, and Sweden), while others have had a linear pattern followed by a slight leveling off (such as Italy, Germany, and Austria). This linear region can be hard to replicate in traditional epidemiological models (i.e. SIR models) that have sensitive parameters such as the reproductive number of the disease. The authors use a Poissonian small-world network to model US and Austrian COVID-19 cases. The authors suggest traditional models work well for rapid transmission scenarios with exponential growth, but below a critical social contact number, their network model works well with less fine-tuning of parameters.

August 24, 2020

COVID-19 study in Kentucky finds lower prevalence in health care workers than the general population

The Co-Immunity Project in Louisville, KY has been testing health care workers and people in the general population for COVID-19 using nasal and blood samples. In their recent survey of 1,100 health care workers, 0.45% tested positive for an active infection, and 2.2% tested positive for antibodies. In a previous round of testing in June, almost 4% of 2,237 people tested in the general population had a positive test for antibodies. The results show that the area is far from herd immunity and that health care workers may have lower rates than the general population due to personal protective equipment and social distancing. Additionally, for those that tested positive for antibodies in both the first and second round of COVID-19 testing, about 79% still had a high level of antibodies.

August 21, 2020

SARS-CoV-2 mutation in early 2020 was associated with less severe COVID-19

A variant of SARS-CoV-2 with a deletion in the ORF8 gene was found in patients in Singapore and other countries in early 2020. Researchers compared the medical records and patient samples for 131 individuals who were screened for the variant from January to March 2020. None of the 29 patients with this mutation in SARS-CoV-2 had hypoxia requiring oxygen compared to 26 out of 92 patients with the wild-type virus. The patients with the variant did have some serious symptoms such as pneumonia, but they had lower cytokine levels and other factors associated with severe COVID-19. This variant of SARS-CoV-2 has not been detected since March, possibly due to public health measures or the infectiousness of the variant. This study could provide valuable information for understanding the immune response to SARS-CoV-2 or for vaccine development.

August 20, 2020

Study of COVID-19 in pediatric patients shows high viral loads with mild symptoms

Researchers in Massachusetts enrolled 192 children (aged 0 to 22 years old) with possible or confirmed SARS-CoV-2 infection in a study. The children were tested for viral load, ACE2 expression, and SARS-CoV-2 related serology. While 49 children were diagnosed with acute SARS-CoV-2 infection, an additional 18 were diagnosed with MIS-C (multisystem inflammatory syndrome in children). Even though SARS-CoV-2 positive children usually had mild symptoms, nasopharyngeal viral load was particularly high in the first 2 days of symptoms and significantly higher than hospitalized adults with severe COVID-19. There was no age correlation in the children for viral loads, but younger kids had lower ACE2 expression. Those with MIS-C did not have high viral load but had higher antibodies against SARS-CoV-2. The study suggests that children can play a large part in the spread of COVID-19 even with mild symptoms.

August 19, 2020

COVID-19 outbreak on fishing boat in Washington suggests potential protection against reinfection for some individuals

Researchers in Seattle, Washington tested 120 out of 122 people on a fishing vessel for COVID-19 and antibodies against SARS-CoV-2 in May before the ship’s departure. Six individuals had positive antibody tests at the predeparture stage, and three of the six had neutralizing antibodies in an assay. After a few weeks, the ship’s crew was tested after an outbreak revealing 104 people with a positive viral or antibody test (an 85% positive rate). Three of the individuals with antibodies at the predeparture stage were not positive after the outbreak; the researchers reported in a pre-print paper that these three individuals had high neutralizing titers at predeparture that may have protected them. The news shows early promise that neutralizing antibodies from recovery of COVID-19 may offer protection from reinfection. The extent and duration of protection is not yet known.

August 18, 2020

Study of convalescent plasma for treating patients with severe COVID-19

An ongoing study from Houston area hospitals is investigating the use of plasma from recovered COVID-19 donors to treat patients with severe COVID-19 symptoms. The researchers published results showing significantly reduced mortality within 28 days for patients that were treated with plasma versus those treated with standard care. Specifically, the researchers found significant effects treating with convalescent plasma within 72 hours of hospitalization and with plasma that has a high anti-spike protein receptor binding domain titer. The study is ongoing but already shows promising results to reduce the mortality of COVID-19 and better understand the immune response to SARS-CoV-2.

August 17, 2020

US FDA approves Yale’s SalivaDirect COVID-19 diagnostic test

The SalivaDirect COVID-19 test, developed by Yale researchers, has been issued an emergency use authorization by the United States Food and Drug Administration. The testing method uses saliva for simple sample collection and has flexible components to avoid delays that can be caused by reagent shortages. The protocol does not require a nucleic acid extraction step to simplify testing and reduce components. Simple, inexpensive, and accurate tests will be important to keep up with COVID-19 test demands and ultimately report precise case results in various populations.

August 14, 2020

Results from a SARS-CoV-2 antibody study across England

A large study by Imperial College London tested approximately 100,000 people in England for COVID-19 antibodies using at-home finger-prick tests. The overall positive rate was 6% with a higher rate of 13% in London. Test rates were higher in care home workers or healthcare workers, and rates were higher for Black, Asian, and other ethnicity groups. The researchers found antibodies in 96% of people who had a previously confirmed PCR test for COVID-19. The test rates show that England has not reached herd immunity. The large-scale study will be repeated in the fall to see how prevalence changes.

August 13, 2020

Early phase 1/2 results of Pfizer COVID-19 vaccine

The results from a phase 1/2 trial of Pfizer’s COVID-19 vaccine have been published in Nature. The 45 participants were randomly assigned to either placebo groups or one of three concentrations of the vaccine, BNT162b1. The vaccine was given as two doses except for the highest concentration. The researchers found SARS-CoV-2 antibodies that increased with dose level or after the second dose. The neutralizing titers were higher than those found in recovered COVID-19 patients. Vaccine efficacy will be determined in phase 3 trials.

August 12, 2020

SARS-CoV-2 antibody testing of health care workers in two London maternity units

Two hundred anesthetists, midwives, and obstetricians without previously confirmed COVID-19 or current symptoms of COVID-19 were tested for SARS-CoV-2 antibodies. The study in London reported 14.5% of healthcare workers were positive. Of those who tested positive, 35.5% reported being asymptomatic throughout the pandemic, and 59% never self-isolated based on symptoms. A recent symptom of anosmia was the strongest predictor of a positive antibody test for COVID-19. Studies such as this provide useful information about previously undetected cases and possible community spread of COVID-19.

August 11, 2020

SARS-CoV-2 antibody testing in New York City area health care personnel

Northwell Health, a large healthcare system in the New York City area, offered antibody testing against SARS-CoV-2 to healthcare personnel. Over 40,000 employees were tested (out of over 70,000 invited), and results were recently summarized in JAMA. Overall, 13.7% of people tested were positive for antibodies. For employees with a previous positive PCR test, 93.5% tested positive for antibodies. For employees with a negative PCR test, 89.7% tested negative for SARS-CoV-2 antibodies. The results were tabulated by demographics such as age, race/ethnicity, county of residence and job function. There was some variation in seropositive rates depending on factors such as job function and residence.

August 10, 2020

Increasing COVID-19 cases in children in the United States

The American Academy of Pediatrics and the Children’s Hospital Association recently reported child COVID-19 case numbers through July 30, 2020 for 49 states and regions such as New York City. Children have had a much lower hospitalization and death rate from COVID-19 compared to older age groups. There were over 330,000 confirmed child COVID-19 cases, which represented 8.8% of all confirmed cases. The overall rate in terms of population was 447 child cases per 100,000 children; this rate in children is far from herd immunity threshold estimates. The rate of child cases per population varied by region. States with the highest cases per child population were AZ, SC, TN, LA, MS, AR, FL, and NV.

August 6, 2020

FDA approves 2 semi-quantitative antibody tests for SARS-CoV-2

The U.S. Food and Drug Administration approved two SARS-CoV-2 antibody tests that provide an estimate measure of antibodies in the person’s blood. Serology tests have been used to test if someone has previously had SARS-CoV-2 and formed antibodies against the virus. More quantitative tests could be useful in understanding COVID-19 immunity.

August 5, 2020

Study explores cross-reactive T cells from exposure to non-SARS-CoV-2 coronaviruses

Researchers recently investigated cross-reactivity against SARS-CoV-2 from past exposure to four common cold coronaviruses using samples collected prior to 2019. The study evaluated the target sites of memory T cells that had reactivity against SARS-CoV-2. Of the 142 SARS-CoV-2 epitopes found, 66 were from the spike protein and 76 were from non-spike protein regions of SARS-CoV-2. The findings could have useful implications for vaccine research or further cross-reactivity research to better understand COVID-19 immunity and herd immunity.

August 4, 2020

Serological testing for COVID-19 shows local variation across Italy and 2.5% positive tests overall

Almost 65,000 people across Italy were tested for COVID-19 antibodies from late May to mid-July. The study reported a 2.5% positive test rate, which is about 6 times higher than confirmed cases but still far from herd immunity. There were geographical differences such as 7.5% positive in Lombardy in northern Italy but only 0.3% in Sicily in south Italy. Additionally, about 27% of positive cases were asymptomatic.

August 3, 2020

Childhood vaccinations in NYC during the COVID-19 pandemic

The NYC Department of Health and Mental Hygiene has monitored child vaccinations through the COVID-19 pandemic. This report shows the possible impact of COVID-19 on herd immunity to other diseases that do have vaccines. Their immunization registry includes 2.7 million records for children. In March and April, the number of immunizations administered was much lower than previous records for the same weeks in 2019. The concern for decreased immunity to diseases such as measles led to city programs encouraging people to continue their children’s scheduled vaccinations. Fortunately, New York City had increased vaccinations in May and June.

July 31, 2020

Study of immune response profiles to distinguish COVID-19 patients that may recover

Researchers analyzed the immune response of hospitalized COVID-19 patients to determine if certain immune profiles were associated with certain patient outcomes (recovery versus death). A set of five antibody features were able to separate the groups well. Survivors were also more likely to have a spike specific antibody response rather than a nucleocapsid response. The study could be valuable for guiding patient care or vaccine research for SARS-CoV-2.

July 30, 2020

Cross-reactive T cells to SARS-CoV-2 and other coronaviruses

A recent study reported T cell activity against SARS-CoV-2 in blood from 83% of patients with COVID-19 and 35% of unexposed healthy donors. They specifically investigated CD4+ T cells and reactivity against the SARS-CoV-2 spike glycoprotein. In addition, the SARS-CoV-2 reactive T cells from healthy donors showed similar activity to other coronaviruses (229E, OC43). This study suggests cross-reactivity from exposure to other coronaviruses could affect transmission and susceptibility of SARS-CoV-2.

July 29, 2020

Modeling study to estimate infection fatality rates in different countries

A study published in PLOS Medicine modeled transmission and mortality of SARS-CoV-2 in Hubei Province, China with an age-stratified SEIR model. The model was then applied to six regions in Europe to estimate the infection fatality rate (IFR). A more accurate IFR is important in estimating the impact of COVID-19, especially if herd immunity is reached through infection (versus vaccination). The researchers estimated overall IFR per region, such as 0.5% in Switzerland, and by age, such as 34% for people 80+ years old in Spain.

July 27, 2020

Temporal changes in IgM and IgG antibodies in hospitalized COVID-19 patients

Researchers recently reported the dynamic changes of serum antibodies in COVID-19 patients that were hospitalized in early 2020 in Wuhan, China. In this study, IgM and IgG antibodies were measured in 97 patients over a period of several weeks (typically 4 to 10 weeks after symptom onset). IgM and IgG antibodies declined significantly in many patients. The rapid decline in IgG levels in several patients raises concerns about the robustness and longevity of immunity.

July 24, 2020

Initial testing results for SARS-CoV-2 of blood donor samples in Canada

Canadian Blood Services is conducting a study to test 37,800 blood donations made in May and June of 2020 across nine provinces for SARS-CoV-2. Their initial results for 10,000 samples showed less than 1% of samples were positive for SARS-CoV-2 antibodies. This suggests Canada is far from reaching herd immunity.

July 15, 2020

T cell immunity against SARS-CoV-2 in patients with history of COVID-19, SARS, or neither virus

A study in Singapore reported SARS-CoV-2 specific T-cells in patients previously infected with COVID-19, SARS, or no history of either. The researchers studied T cell response to structural and non-structural regions of SARS-CoV-2. All COVID-19 (n=36) and SARS (n=23) subjects had a T cell response against one or both SARS-CoV-2 regions tested. In unexposed subjects (n=37), 51% had the specific T-cell response. Unexposed subjects either provided samples before July 2019 or tested negative for SARS-CoV-2 antibodies. The results could have important implications on cross-reactive protection from different coronavirus exposure.

July 14, 2020

COVID-19 vaccine mRNA-1273 induced immune responses in all participants in preliminary study

The mRNA vaccine developed by researchers at the National Institute of Allergy and Infectious Diseases and at Moderna showed promising results in a phase 1 study of 45 adults. Participants received two vaccinations 28 days apart. Researchers detected anti-SARS-CoV-2 immune responses in all participants, with higher responses in those that received the higher doses. Side effects in more than half of participants included fatigue, chills, headache and pain. Adverse effects graded as severe were more common after the second vaccination and more common in the group with the highest dose.

July 14, 2020

Insight into possible SARS-CoV-2 immunity from previously studied coronaviruses

Sariol and Perlman from the University of Iowa recently reviewed studies of the immune response to several coronaviruses that emerged prior to SARS-CoV-2. Understanding the innate and adaptive immune responses to coronaviruses such as SARS, MERS, or common cold coronaviruses could benefit the study of COVID-19 immunopathology and vaccine development. While a future vaccine to SARS-CoV-2 could help the world reach herd immunity, the authors caution that antibody responses to other coronaviruses can decrease over time.

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