Covid-19: Delhi govt’s 5-day sero-survey to begin today

1,195 fresh cases take Delhi tally to 1,35,598

The second round of ‘sero survey’ in the national capital will start from Saturday. The survey will be conducted between August 1 and August 5.

A sero-survey involves testing of blood serum of individuals to check for the prevalence of antibodies against an infection.

The government standard operating procedure (SOP) for field units for collection of blood samples says that the systematic random sampling methodology will be used for collection of samples with mandatory exclusion of individuals or households selected during the last sero survey conducted in June-July.

As many as 1,195 new cases and 27 deaths were reported in the last 24 hours. Of the total 1,35,598 cases in the city, 10,705 are active while 1,20,930 patients have recovered. The virusrelated fatalities have gone up to 3,963.

According to the SOP released by Delhi government’s directorate general of health services (DGHS), samples will be collected in a vaccumised tube or vacutainer with clot activator gel supplied by DGHS store.

“Teams in the field will collect the samples and will transport it the same day to the designated lab/s for processing. Sample collection must be completed latest by 2.00 pm so that samples reach the designated labs latest by 4.00 pm.

“All districts will ensure collection of a uniform number of samples each day so that the processing at labs is streamlined. No district will collect more than 10 per cent of sample targets per day,” it said.

The SOP also said that sample collection may be undertaken in the community (through visits by team/s) or at a designated spot or health facility appropriate for the public and the team.

“In both cases, a sample of only the identified person (as per the age group) from the identified household will be collected. Selection bias must be avoided,” it added.

Delhi’s first sero-prevalence study has found that 23.48 per cent of the people have been affected by Covid-19 in the city, which has several pockets of dense population.

The study was conducted from June 27 to July 10 by the National Centre for Disease Control (NCDC) in collaboration with the Delhi government. It also indicated that a large number of infected persons remain asymptomatic.

◗ A SERO-SURVEY involves testing of blood serum of individuals to check for the prevalence of antibodies against an infection