Srinagar, Oct 29: The survey by government medical college, Srinagar has indicated that people in this summer capital of the J&K are still far from achieving herd immunity against the Coronavirus infection.
The survey on Seroprevalence of SARS-CoV-2 infection in the district Srinagar, to estimate the seroprevalence of IgG antibodies against pathogen among the general population, has found that 40.6% people have been infected with the virus.
Conducted on 17and 18 October, a total of 2361 blood samples were analyzed for the presence of IgG antibodies against SARS-CoV-2, the coronavirus that causes Covid-19.
Among them, nine hundred fifty-nine (959) samples were positive for IgG against the virus, giving a seroprevalence of 40.6%
“Out of the 2,361 participants, 1,335 were male and 1,026 were female. The seroprevalence was significantly higher among females (459/1026=44.7%) as compared to males (500/1335=37.5%).”
The seroprevalence also increased significantly with age, it said. “Those with a history of ILI (Influenza Like infection-symptoms in the previous three months, and those with a history of contact with a known COVID-19 case had higher seroprevalence as compared to their counterparts with no such history.”
The survey found that among the 432 participants who reported a negative COVID-19 test (RAT/RT-PCR), 159 (36.8%) were seropositive.
“If we apply the estimates of this study to the current adult population of District Srinagar, which is approximately just over 15 Lac, then the number of IgG positives in the District at the time of the survey was expected to be over 6 Lac,” reads the survey report concluded by the Department of Community Medicine in collaboration with the Department of Biochemistry, GMC Srinagar and Chief Medical Officer Srinagar, Directorate of Health Services Kashmir.
The report underlined that IgG antibodies against SARS-CoV-2 usually develop two weeks after the infection.
“Thus, the presence of IgG antibodies is indicative of past SARS-CoV-2 infection. A recently infected person will not show presence of IgG antibodies.”
The report also underlined that IgG against SARS-CoV-2 should be perceived as diagnostic of COVID-19. “A person with IgG antibodies against SARS-CoV-2 is usually not infective to others. For diagnosis of current infection and possible potential of infecting other persons, RT-PCR is the diagnostic modality of choice. Recently Rapid Antigen Tests have also been used for diagnosis of current infection.”
The report said that given the current scenario of positive cases emerging from the district, it is expected that the seroprevalence may further increase in the near future as more and more individuals become infected and develop antibodies against the pathogen.
A dominant theme that drives the government bodies to conduct such survey is to check for levels of ‘herd immunity’, or if around 60-80% of the population have encountered the infection. Srinagar is still far from achieving it in wake of the survey.
