40% of Srinagar residents have Covid-19 antibodies, sero-survey shows

Over 40 per cent people living in Srinagar district have developed Covid-19 antibodies, claims a latest seroprevalence survey conducted by a government hospital here, the results of which were questioned by the district administration citing small sample size of the study.

The results of the study conducted by the Government Medical College Srinagar (GMC) show a quantum jump from 3.8 per cent sero-prevalence recorded in a similar study conducted in the city in June, and suggests that a large fraction of the population in the summer capital of Jammu and Kashmir may have been infected by the novel coronavirus.

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

"We have conducted a sero-survey in Srinagar district which has revealed that over 40 per cent of the 2,400 persons tested negative but had developed antibodies," said Dr Muhammad Salim Khan, head of community medicine at GMC Srinagar.

Khan noted that the samples were taken randomly from 20 clusters in Srinagar district which also showed a higher prevalence of antibodies in the female population than males.

However, officials said the results should be interpreted with caution due to its small sample size.

"The sample survey was only 2,400 in a population of around 15 lakh. In order to get an accurate picture, the sample size should have been more,” an official said.

Giving details, the official said that earlier Srinagar had witnessed 18 per cent of positivity rate for Covid-19 when the testing capacity was around 60,000.

"However, when testing capacity was increased to 4 Lakh, the rate of positive patients in Srinagar was only 18,000," the official said.

The official noted that the survey results could be misconstrued, and can lead to complacency among the people.

"The trend is encouraging but there is no way we can say that Covid-19 will be defeated at a certain level of population by developing the antibodies. The scientific community is also wary of using the term herd immunity in the absence of a vaccine," he added.

Herd immunity occurs when a large number of people, usually 70 to 90 per cent, become immune to a contagious disease after being infected by it.

But there are many grey areas clouding the issue as far as the novel coronavirus is concerned with no consensus on when herd immunity sets in.

Srinagar has been the worst affected district by Covid-19 in Jammu and Kashmir with nearly 19,000 persons infected so far and 348 deaths due to the pandemic.

The district has 1,651 active cases as compared to 5,300 in the remaining 19 districts of the union territory.

Khan said a wider sero-survey is underway across the remaining nine districts of Kashmir valley where 400 samples have been collected from each district.

"The results are expected to come within two weeks from now," he added.

Jammu and Kashmir has witnessed nearly 85,000 Covid-19 infections and 1,455 deaths so far due to the pandemic.