New COVID-19 Test Identifies Asymptomatic Carriers
May 4, 2020
The Jerusalem Post — Ben-Gurion University researchers have developed an algorithm-based test that can speed COVID-19 testing eightfold and help identify asymptomatic carriers.
The testing system is based on the method of pooling, taking samples of several individuals at once. For 384 individuals, only 48 tests are required (one per every eight individuals), reducing the cost, time and quantity of testing kits required.
Each individual’s sample becomes part of six different pools. If the results come out negative, everyone in the pool could be declared healthy.
The method has already proven extremely successful in its first tests and clinical trials are now underway at Soroka University Medical Center.
Dr. Tomer Hertz from BGU’s Shraga Segal Department of Microbiology, Immunology and Genetics explains that special liquid dispensing robots are entrusted with generating the pools.
“In order to generate the pools you need to basically mix together different sets of samples, which is an error-prone job best done by robots. The mixing is done in a way that once you receive the results from the pool, you already know which individuals are infected.”
Preparing the pools originally required about five hours, but the time is reduced to one hour by using more advanced robots. After the pools are prepared, they are tested by diagnostics laboratories just like with normal samples.
Moreover, because the sample of each person is tested six times, it is more effective regarding the problem of false positives or false negatives, which are often generated by mistakes or contaminations of the samples, explains Prof. Angel Porgador, also from BGU’s Shraga Segal Department and the National Institute for Biotechnology in the Negev.
“The number of tests required, in this case one of every eight people, and therefore the reduction in cost, depends on the carrier rate that it is aimed for. If the carrier rate gets lower, we can aim for a 24-fold reduction in cost, if it gets higher again in case of a new wave of infection, it could become only two-fold,” Porgador explains.
Prof. Porgador is the coordinator of the BGU Coronavirus Response Effort, under whose auspices the project was started.
Experiments performed on the samples already tested by the Soroka University Medical Center laboratory gave the method a 100% success rate in detecting virus carriers.