Radical shift in COVID-19 testing needed to reopen schools and businesses, researchers say
Even as the United States ramped up coronavirus testing from about 100,000 per week in mid-March to more than 5 million per week in late July, the country fell further behind in stemming the spread of the virus. Now, diagnostics experts, public health officials, and epidemiologists are calling for a radical shift in testing strategy: away from diagnosing people who have symptoms or were exposed and toward screening whole populations using faster, cheaper, sometimes less accurate tests. By making it possible to identify and isolate infected individuals more quickly, proponents say, the shift would slow the virus’ spread, key to safely reopening schools, factories, and offices.
“America faces an impending disaster,” says Rajiv Shah, president of the Rockefeller Foundation. Testing, he says, needs to focus on “massively increasing availability of fast, inexpensive screening tests to identify asymptomatic Americans who carry the virus. Today, we are conducting too few of these types of tests.” Rebecca Smith, an epidemiologist at the University of Illinois, Urbana-Champaign (UIUC), agrees. To stop outbreaks from overwhelming communities, she says, “we need fast, frequent testing,” which could mean faster versions of existing RNA tests or new kinds of tests aimed at detecting viral proteins. But researchers say the federal government will need to provide major financial backing for the push....
....testing people only when they show symptoms and giving them test results days to weeks later does little to slow viral spread, says Daniel Larremore, an applied mathematician at the University of Colorado, Boulder.
Larremore and his colleagues have modeled the benefits of more frequent tests, even ones that are less accurate than today’s. Fast tests repeated every 3 days, with isolation of people who test positive, prevents 88% of viral transmission compared with no tests; a more sensitive test used every 2 weeks reduced viral transmission by about 40%, they report in a 27 June preprint on medRxiv....
