Serological survey to assess spread of Covid outbreak will start June 27
Around 20,000 people representing a cross-section of Delhi’s population will be tested across the 11 districts within two weeks under the revamped action plan issued by the ministry of home affairs after a meeting chaired by Union home minister Amit Shah on Sunday.
The National Centre for Disease Control (NCDC) will carry out the serological survey to assess the Covid-19 spread in the national capital for the Delhi government, a senior official aware of the process said on Monday, as officials in the city administration and the Union health ministry worked out details of how the programme will be launched later this week.
The serological survey -- a random test of 20,000 people from across the city to assess if they have in the past been infected by the coronavirus -- was suggested by the Union government in an effort to intensify efforts to contain the outbreak in Delhi, which now has 62,655 cases, second only to Maharashtra’s 135,796, data collated by HT showed on Monday.
The survey is scheduled to begin from June 27. “HLL Lifecare Limited is procuring antibody test kits on behalf of Centre for testing in Delhi. And National Centre for Disease Control under the Union ministry of health and family welfare will conduct the sero surveillance for Delhi government,” the senior government official, who asked not to be named, said.
Around 20,000 people representing a cross-section of Delhi’s population will be tested across the 11 districts within two weeks under the revamped action plan issued by the ministry of home affairs after a meeting chaired by Union home minister Amit Shah on Sunday.
Antibody tests detect the presence of antibodies produced by the body to fight Covid-19 infection. It helps identify people who have recovered from Covid-19 without being tested because they were asymptomatic, had mild disease, or could not get tested for some reason.
Finding these hitherto undetected cases will help the state government estimate the true burden of Covid-19 in Delhi and plan an appropriate response.
According to district-level officials, the protocols for the survey are being worked upon. “We have yet to receive the guidelines for sero-surveillance in Delhi. The details will be worked out through out the week. Currently, our teams are focussing on antigen testing,” said a district official, asking not to be named.
Delhi started using rapid antigen tests – that can give results in 15 minutes – on Thursday. Over 7,000 people were tested on the very first day, followed by over 12,000 people the next day. This has led to an increase in the number of cases in the city, with 3,000 cases being recorded on Sunday.
The focus is likely to be on north-west, central, west, and north districts that have been reporting a high number of cases.
It was not immediately clear which antibody test kits will be used, since previous attempts had to be aborted due to problems of reliability. In April, the Delhi government started using antibody testing in hot spot areas to check the prevalence of the infection. Only 62 people were tested using the rapid kits in Nabi Karim, all of which were negative. The government, as per the directions of the Indian Council of Medical Research (ICMR), stopped using the antibody kits made by two Chinese company after they showed varying results across the country.
“We had placed an order for 50,000 tests in March but cancelled it after Indian Council of Medical Research (ICMR) stopped antibody tests after kits from the two companies from China were found to be defective. We haven’t placed an order for more kits yet,” said an official from Delhi’s health department.
US-based medical devices company Abbott on Monday said it will supply one million laboratory-based antibody testing kits to various states, including Delhi, by the end of June.
Earlier this month, ICMR revealed the result of its pilot sero-surveillance study of 26,000 people from across India. The overall percentage of general population that was found to have been infected in the past is 0.73%, with urban areas having shown higher Covid-19 prevalence of about 1.09%, the study had revealed. These tests were carried out by kits made by Ahmedabad-based Zydus Cadila.
The ICMR director general Dr Balram Bhargava said the low prevalence rate showed there was no community transmission of the infection in India.
With the source of the infection unknown in nearly half the Covid-19 cases in Delhi, the health minister Satyendar Jain had said on June 10 there was transmission of the infection in the community in Delhi, but to term it as ‘community transmission’ was up to the centre. This survey might help answer the question.
