Thousands of scientists around the world are working on problems raised by the COVID-19 pandemic. Here is a summary of some recent research from peer-reviewed academic journals and scientific agencies:
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More evidence is pointing toward bats and pangolins (a scaly Asian anteater) as the source of the novel coronavirus. The journal Science is reporting that an analysis of 43 genome sequences from three strains of related coronaviruses from bats and pangolins shows the virus may have arisen through genetic shuffling between the two species, with the component that lets it bind to healthy cells coming from viruses native to pangolins. The authors conclude that reducing direct human contact with wild animals is critical to preventing such pandemics in the future. Putting different species together in a market setting could increase the potential for cross-species spillover infections.
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A non-peer-reviewed study from the University of Toronto says deaths from COVID-19 would have been nearly five times higher in Ontario had physical distancing measures not been implemented. The same study says that relaxing public health measures such as physical distancing without increasing testing, isolation and contract tracing will lead to a resurgence of the illness in the province. It says returning to normal or near-normal levels of contact will quickly cause more cases than the medical system can handle. It concludes the most important factor in the incidence of the disease is the number of contacts without physical distancing.
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The journal Science says the first cases of the major breakout of COVID-19 that occurred in New York City originated from Europe and other places in North America. It found limited evidence of any instances of the virus coming in from China. The authors sequenced 90 virus genomes from 21 New York neighbourhoods. They concluded it arrived in the city through multiple foreign and domestic routes and was quickly sustained through community transmission. The authors conclude that travel restrictions don't do much good once the virus has arrived and that widespread early testing is crucial.
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The Journal of the American Medical Association is reporting that hundreds of Chinese doctors experienced a sharp drop in mood, a rise in depression and anxiety and a doubling of their fear of workplace violence from the COVID-19 pandemic — even though they worked far from the pandemic's epicentre in Wuhan. The study surveyed 385 first-year medical residents in Shanghai and compared the data with results from previous years. Where this year's class saw sharp changes across most measures of mental health and workplace violence, last year's class had stable scores.
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More evidence is emerging that the sense of taste is closely linked to COVID-19, the journal Gastroenterology reports. It has published research showing nearly half of those who contract COVID-19 experience changes in their ability to detect flavours. The authors suggest the change was missed in earlier reports because of the severity of other symptoms. But of the 817 patients studied, 49.8 per cent said their sense of taste changed. Researchers suspect the figure could be higher because patients' charts may not have noted every symptom. The authors say changes to the sense are common enough that it could be a way to identify carriers who show no other symptoms.
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The Journal of the American Medical Association says some patients who appear to have recovered from COVID-19 may still be infectious. It has published a study that found 11 out of 69 patients still showed the presence of the virus 9 to 17 days after being discharged from hospital. The authors warn that the study was conducted at one facility with a small sample size and its findings may not show up elsewhere. Still, they say it's a good reason for hospitals to pay attention to and follow up with discharged patients.
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This report by The Canadian Press was first published June 1, 2020
Bob Weber, The Canadian Press