To ease global virus test bottleneck, Israeli scientists suggest pooling samples
Technion and Rambam Hospital set to publish research showing testing the samples of 32 or 64 patients at a time can quickly rule out entire groups
Nathan Jeffay is The Times of Israel's health and science correspondent
Rambam Medical Center and the Technion in Haifa say they have come up with a faster and more efficient way to test people for the coronavirus, by pooling samples.
According to the hospital, by testing the samples of up to 32 or even 64 people at a time, it can quickly establish if any have the virus. Only in cases where the virus is found in the group of samples will the individuals in the pool need to take their own tests to determine who is carrying COVID-19.
The scientists say this could ease the bottleneck at coronavirus testing labs worldwide, and potentially take millions of people out of unnecessary quarantine.
The idea occurred late last week to Dina Berenbaum, a graduate of the Technion Israel Institute of Technology, who contacted her former professor, from where it was quickly developed.
“This could have a big impact on reducing the burden in labs,” Technion microbiologist Idan Yelin told The Times of Israel Wednesday, explaining that one of the major problems facing healthcare professionals worldwide is the overload at testing facilities.
Yelin and his colleagues are set to publish their research online shortly, inviting hospitals to try their method. “Normally to take a project like this up to publishing would take many months,” Yelin noted.
Berenbaum, who works as a junior data scientist, finished her biotechnology engineering degree four years ago.
It occurred to her that instead of testing samples one by one, it would make sense for labs to pool the swabs from patients. If nobody in the pool tests positive, lab staff can quickly move on, and only if there are positives test swabs one-by-one.
Yelin, who tested the idea alongside Berenbaum, said there was a concern that coronavirus wouldn’t show up if samples were pooled and the virus of carriers was “diluted” with the samples of others.
Yelin said: “We went to Rambam Health Care Campus, to the virology lab. We took the samples of ribonucleic acid (RNA) that are taken by swab from the patient, and we started looking for the sequence of coronavirus.”
He reported that even when 64 samples were mixed together, just one of them from a coronavirus carrier, the test flagged up the positive result.
Yelin noted that the accelerated process could allow people who are in isolation as a precaution, out of fear that they have been exposed to the virus, to be tested easily without health services being overwhelmed, as their swab material could be added to a testing pool.
Pool testing could also enable fast screening at airports, some of which are struggling to conduct person-by-person coronavirus tests, and also give peace of mind at institutions like old age homes, he suggested. There, regular pool testing could be conducted to reassure residents that everyone is free of COVID-19 — and quickly identify people who have coronavirus.
He said: “If you’re going to a place that seems ‘clean,’ but really want to make sure no one is infected and want to test everyone to be sure, this test is the way to go.”
Pooling has been used since World War II and was suggested in the 1990s as a way of testing for HIV.
“There are some logical difficulties in deploying the method, but we hope it can up the number of tests and find even silent carriers, those with no symptoms. This possibility can lower the chance of infection and flatten the curve,” said Technion biology Professor Roy Kishony.
Moran Szwarcwort Cohen, director of the virology laboratory at Rambam Health Care Campus, said the research “will enable more efficient and faster testing if a large number of samples are surveyed.”
“I was very pleased to succeed, but thanks to the very sensitive method used, I was not surprised.”