The Health ministry has issued guidelines for RT-PCR based pooled testing to assess the prevalence of Covid-19 among migrant workers and all those in institutional quarantine including international passengers, as the total count of confirmed patients in the country crossed 78,000.
In the past one day, India registered 3,722 new cases and 134 deaths, taking the total toll to 2,549. While 26,235 patients have been cured, the government wants to ramp up pool testing, given the arrival of international passengers and the movement of migrant workers across the country.
The pool sampling will be used as a surveillance tool in green zones as well where no case has been reported in the last 21 days.
According to the guidelines a cohort of 25 people will be identified and trained laboratory personnel will collect their throat and nasal swab following the protocol laid by the Indian council of medical research (ICMR).
The government will collect 25 such samples and transport them in triple-layer packaging to identified laboratories in the cold-chain.
“These pooled samples from 25 specimens shall be tested in the laboratory by RT-PCR method. The report will be conveyed to the quarantine or concerned facility within 24 hours,” the guidelines said.
If any of the pooled samples tests positive, individual samples would then be tested.
Pool testing is a cost effective and time saving method of detecting the spread of Covid among the population. Health ministry had also recommended using the rapid antibody tests for surveillance purposes. The test kits being used for this purpose were found to be faulty and states were told not to use such kits.
However, the recently developed Elisa test by the Pune-based National Institute of Virology has been found to have higher levels of accuracy and will be used to test random samples from hotspot districts.
While RT-PCR test which is considered the gold-standard in Covid testing detects any current infection in a person, the rapid test kits show the presence of antibodies in one’s body which take time to develop after catching the disease.
Covid cases are almost 26,000 in Maharashtra with total deaths nearing 1,000. Tamil Nadu saw an increase of 508 cases in a day reaching 9,227 while Gujarat saw a similar increase as yesterday reaching 9,267 cases.
Gujarat has also seen a poor mortality rate with 566 deaths so far. The number of deaths in Tamil nadu was 64 as of Thursday.