A decades-old lab procedure could help the United States claw its way out of yet another crippling coronavirus testing shortage, but the nation is only beginning to ramp it up now.
The method, called “pooled testing,” allows labs to test combinations of multiple swab samples in batches. If the virus turns out to be present in a batch, then each of its samples gets retested to determine which are positive. But if a batch is negative, then all of its samples are considered virus-free and don’t need to be tested individually, saving both time and scarce supplies.
In the US, which has more than 4 million confirmed cases and many more unconfirmed, public and private laboratories are swamped. Turnaround times of as long as 19 days for test results are making it all but impossible to contain the virus.
Proponents say that pooled testing, which has already been deployed in China, Israel, and Germany, could be one of many innovations that would enable the US to scale up testing. And it might be particularly useful in settings where large numbers of people require routine tests, such as nursing homes and colleges welcoming back students in person in the fall.
But to the frustration of some public health experts, the FDA only just issued its first emergency authorization that allows a company to do this, months into the pandemic. In mid-July, Quest Diagnostics got cleared to test pools of suspected coronavirus samples. Days later, LabCorp was authorized to pool samples from people without symptoms. Meanwhile, a handful of other labs have been allowed to do pooling while they apply for authorization.
“Pooling just becomes a way to stretch capacity,” Carl Bergstrom, an epidemiologist at the University of Washington, told BuzzFeed News. “Why hasn’t there been more of a push to implement pooled testing at a commercial scale?”
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