Pooled Testing Finds COVID-19 Infections Faster, More Efficiently

A faster, more efficient testing procedure for COVID-19, pooled testing, may help find people who are unknowingly spreading the virus. Finding asymptomatic carriers of the novel coronavirus isn’t easy due to the lack of tests in some places and the questionable accuracy of certain tests. But an Israeli research group just published an article about their pooled testing approach and it’s promising.

Pooled testing involves mixing several samples, representing several people, and then using only one test on them all. The research team took 384 samples and divided them into 48 groups. Each pool was tested. If a pool was negative, the separate samples did not need to be tested and the people were clear. If a pool tested positive, at least one of the samples was positive, so the researchers then did tests on the samples that made up that group to find which one or ones were infected.  They called their method P-BEST (Pooling-Based Efficient SARS-CoV-2 Testing ). “We found that P-BEST was able to correctly identify all positive carriers within these 4 sets of 384 samples using only 48 tests per set, providing an 8-fold increase in testing efficiency,” they wrote.

Pooled testing isn’t new. Divide people into pools, test each pool, and when a pool comes up positive, test all the people that went into that pool. The method does save some time and tests, but P-BEST starts with more pools, according to the researchers. In response, the method will be used in 12 labs in Israel by October, when it's believed the second wave will occur, along with the annual flu seaso.

Noam Shental, PhD, a computer scientist and lead author on the paper, said in an interview with the New York Times that the idea for the testing came from his mother. Years ago, she had listened to a talk he gave about an algorithm he had designed. She asked if that old algorithm could be used now, for COVID. Further proof that no matter how complicated the issue, mothers are frequently right.