COVID-19: Guidelines issued for group sampling based on RT-PCR of migrants and returnees from abroad

NEW DELHI: The government decided to use a one-time, pooled sampling for screening among migrant workers and returnees abroad who are on the premises.

The same testing technique would also be used for monitoring in green zone districts that have reported no cases so far or in the past 21 days, he said in issuing 'Guidelines for pooled sampling based on RT-PCR for migrants/returnees. from abroad/green areas' on Thursday.

The decision has been made to use a one-time RT-PCR based pooled sampling for surveillance purposes for migrant workers in institutional quarantine facilities, international passengers in institutional quarantine facilities/hotels destined for quarantine, and for surveillance purposes in areas green (districts with no case)/no cases reported in the last 21 days), the guidelines indicated.

According to the guidelines to be followed for the grouping of samples, a cohort of 25 people will be identified, and trained laboratory personnel wearing appropriate protective equipment, such as apron, hand glove, will collect a nasal/throat swab according to the protocol. settled down. mask/glasses and mask N-95.

Proper labeling (name/age/gender/sample identification) should be done on the sample container, he said.

The guidelines established that 25 of those samples from said cohort would be packed in triple-layer packaging and transported to the identified laboratory under a cold chain according to the guidelines.

The external container mentioned for the test will also carry the sender's details (name/address/phone number). The samples will be divided into aliquots and, subsequently, the pooled samples of 25 samples will be analyzed in the laboratory using the RT-PCR method.

The report will be transmitted to the quarantine/facility in question within 24 hours.

If any of the pooled samples test positive, the individual samples will be analyzed from the aliquots preserved in the laboratory, he said.

A pooled test algorithm involves PCR detection of a group of samples comprising multiple samples from individual patients, followed by individual tests only if one group tests positive.

According to the ICMR notice issued on April 13, all individual samples in a negative group should be considered negative.

Pooling of samples for real-time RT-PCR screening for Covid-19 is only recommended in areas with low prevalence of Covid-19 (initially using low positivity proxy of less than 2 pc from existing data.

The number of deaths from Covid-19 increased to 2,549 and the number of cases increased to 78,003 on Thursday, registering an increase of 134 deaths and 3,722 cases in the last 24 hours until Thursday at 8 a.m., according to the Ministry of Union Health.