Amid the mass movement of migrant workers within the country and the return of lakhs of Indians from across the globe, the Ministry of Health and Family Welfare (MOHFW) on Thursday issued guidelines for RT-PCR based pooled sampling and quarantine facilities.
"The following guideline is in pursuance of letter of Secretary, MoHFW dated May 12, 2020, on the subject. A decision has been taken to use one time RT-PCR based pooled sampling for surveillance purposes for migrant workers in institutional quarantine facilities, international passengers in institutional quarantine facilities/hotels ear-marked for quarantine and for surveillance purposes in green zone," the document read.
The Health Ministry in their guidelines revealed that a cohort of 25 people will be identified, following which throat/nasal swab will be collected from the group. This would be done by laid down protocol trained laboratory personnel under appropriate protective gear (apron, hand glove, face-shield/goggles, N-95 mask), as per ICMR protocol. Thereafter, proper labelling (name/age/gender/specimen ID) would be done on the specimen container.
The guidelines stated that 25 such samples of such cohort would be packed in triple layer packaging and will be transported to the identified laboratory under cold chain as per ICMR guidelines. The outer container mentioning "be tested for SARS-CoV-2" will also bear the details of sender (name/address/phone number).
These 'pooled samples' of 25 specimens will be tested in the laboratory by RT-PCR method, following which report will be conveyed to the quarantine/concerned facility within 24 hours. If any of the pooled samples test positive, individual samples would be tested from the aliquoted samples preserved in the laboratory.
While ICMR had earlier allowed pool testing in states, it clarified that pool sampling was to be used 'surveillance purposes' only. In an earlier press briefing, ICMR scientist Dr. Raman Gangakhedkar had stated that only places where the possibility of seropositivity is less than 2%, 5 samples can be collected and tested to ascertain the growth trend of the virus. He stated that ICMR had not recommended individual diagnosis using pool testing because it can increase the price of testing.