Sero survey: 1,544 tested, 180 found with Covid-19 antibodies in Haryana

The data shared by the health department shows that at least 12% of the people covered by the survey had developed antibodies. The first round of serological survey started in late June across the five districts.

In Haryana, out of the 1,544 people covered under the ongoing serological survey to detect the prevalence of Covid-19 infection across five districts, at least 180 people have been found to have developed antibodies. The five districts covered by the survey include Gurugram, Faridabad, Sonepat, Ambala and Panchkula. At least one-third or 60 cases were reported from Sonepat — the highest among the five districts.

According to the official, the remaining 17 districts will be now be covered under the serological survey, where districts will have to conduct at least 400 antibody tests each month. (Vipin Kumar/HT Photo)

The data shared by the health department shows that at least 12% of the people covered by the survey had developed antibodies. The first round of serological survey started in late June across the five districts.

A serological survey is an epidemiological tool that helps in detecting unreported or past cases of Covid-19 and in understanding the prevalence of the disease in communities. In the survey, blood samples are randomly collected from various high-risk population groups — based on the categories identified by the Indian Council of Medical Research (ICMR) — to look for antibodies against Covid-19. Antibodies are generated in the body as an immune response to fight against the infection and provides protection against contracting the same infectious disease again.

The serological test is not prescribed to diagnose active Covid-19 infections as it takes one to three weeks for the body to develop antibodies after getting infected. Studies are ongoing to ascertain if people who recover from the infection can get infected again.

The serological survey showed that the maximum number of positives for Covid-19 antibodies were traced in Sonepat. Out of 350 blood samples collected, 60 were confirmed positive for SARS-CoV-2 virus. A maximum number of 454 antibody tests were done in Gurugram, out of which 56 were confirmed positive Covid-19 antibodies. Likewise, in Faridabad 209 tests were conducted with 28 people testing positive. In Ambala, 176 people were covered under the survey, out of which 27 were found to be positive. Panchkula reported the least number of positive cases. Out of 355 tests conducted, nine were found to be positive for Covid-19 antibodies.

“The serological survey is a surveillance mechanism to estimate how much of the population has been infected over time. People might have been asymptomatic, without showing any signs or symptoms, and did not get tested as a result. They develop immunity against the infection. Such people are covered under the serological antibody tests that help in figuring out the incidence of infection,” said a senior state health official of the Integrated Disease Surveillance Programme (IDSP). Under the survey, people who have a higher exposure to contract the coronavirus are covered. It includes population groups, such as shopkeepers, drivers, police personnel, health workers, pregnant women among others, as directed by the ICMR guidelines.

According to the official, the remaining 17 districts will be now be covered under the serological survey, where districts will have to conduct at least 400 antibody tests each month. “About 1,800 IgG Enzyme-Linked Immunosorbent Assay (Elisa) kits have been provided to all the districts, including the five districts earlier covered in the serological survey, to conduct 400-600 tests every month,” said the official.

“In Gurugram, the next round of serological survey with a larger sample size is likely to start from next month,” said Dr Virender Yadav, chief medical officer(CMO), adding that the plan is being prepared. It is likely that the district health department will take the assistance of a private healthcare company to conduct at least 1,800 antibody tests in the city to be conducted over the next four to five months.

Despite repeated attempts, Dr B K Rajora, chief medical officer, Sonepat, could not be reached for comment.