With India running out of COVID-19 Test Kits (RTPCR) and Rapid Antibody Test kits yet to be imported, the central government in New Delhi has started advising states to start “pool testing”. Uttar Pradesh on Monday became the first State to announce “pool testing”.
Union terriroty Andman and Nicobar Islands started pool testing (with five samples together) about 10 days ago. The group test reduces the number of test kits utilised, compared to the testing of individual samples. It expedites the testing process along with optimization of resources. The method is often used during large outbreaks and invisible community transmission, experts say.
This cost-effective testing is expected to be followed by other states soon. Maharashtra has also applied for the same, sources said. Explaining the process, Dr Amita Jain, State nodal officer for COVID-19 testing and Head of the Microbiology Department, King George Medical University, tells FPJ, "In pool testing, swab samples of multiple people are pooled together and tested. If the result of a pool is negative, we can conclude that this segment of population doesn’t covid19 infection.
However, if the result is positive, then all people in the sample would have to go for individual test.”The group testing of samples will be done using a single RTPCR (Reverse transcription polymerase chain reaction).The government is yet to finalise number of samples to be taken in one pool. Besides, it is unclear which population or locality will be taken for the new method of diagnosis.
Dr Jain added, “The size of the pool is yet to be decided. Ideally, it should be five samples per pool. The group testing can’t be done in the hotspot or contamination zone where chances of most of these tests coming positive are high. And we have to repeat the test for all individuals separately which will be time and resource consuming. A buffer zone outside the hotspot can be used for the pool test.”
She, however, insisted that there were plenty of testing kits. "But to identify all vulnerable people, we need to scale up the tests. But taking large number of samples may not serve the purpose.” Researchers from Israel have shown that samples of 64 people can be effectively tested.
UP is currently testing close to 2,300 samples every day in 10 designated labs in the government set-up. The plan is to take it up to 4,000 tests a day by next week, says Dr Jain.