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How widespread is asymptomatic COVID-19 infection?
A customer and worker at an ALDI in Duesseldorf, Germany, April 29, 2020.
Reuters
No one knows for sure, and for the moment lots of the evidence is anecdotal.
For a small example, consider the nursing home in Washington where many residents became infected. Twenty-three tested positive. Ten of them were already sick. Have more eventually developed symptoms. But three people who tested positive never came down with the illness.
When doctors tested 397 people staying at a homeless shelter in Boston, 36% came up positive for COVID-19 – and none of them had complained of any symptoms.
In the case of Japanese citizens evacuated from Wuhan, China, and tested for COVID-19, fully 30% of those infected were aymptomatic.
An Italian pre-print study that has not yet been peer-reviewed found that 43% of people who tested positive for COVID-19 showed no symptoms. Of concern: The researchers found no difference in how potentially contagious those with and without symptoms were, based on how much of the virus the test found in individuals’ samples.
The antibody serosurveys getting underway in different parts of the country add further evidence that a good number – possibly anywhere from around 10% to 40% – of those infected might not experience symptoms.
Asymptomatic SARS-CoV-2 infection appears to be common – and will continue to complicate efforts to get the pandemic under control.
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William Petri, Professor of Medicine, University of Virginia
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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