Results of a Population-Based Survey to Estimate the Seroprevalence of SARS-CoV-2 Specific IgG Antibodies in Kashmir, India, Seven Months after the Appearance of the First COVID-19 Case

Background: Seroprevalence surveys are useful in estimating past infections and provide an appraisal of the cumulative number of infections in a population. We designed a population-based survey in Kashmir to estimate the seroprevalence of SARS-CoV-2 specific IgG antibodies in the general population aged 18 years and above. Methods: The survey was conducted among 110 villages and urban wards across ten districts in Kashmir from 17 Oct 2020 to 04 Nov 2020. Serum samples were tested for the presence of SARS-CoV-2 specific IgG antibodies using the Abbott SARS-CoV-2 IgG assay. Seroprevalence estimates were adjusted for the sampling design and assay characteristics. Findings: Out of 6397 eligible individuals enumerated, 6315 (98.7%) agreed to participate. The final analysis was done on 6230 participants. Seroprevalence adjusted for the sampling design and assay characteristics was 36.7% (95% CI 34.3%-39.4%). Seroprevalence was higher among the older population. Only one-half of symptomatic individuals reported having been tested. One out of every ten seropositive individuals reported a history of COVID-19 like symptoms. We estimated an infection fatality rate of 342 deaths per million infections. Interpretation: During the first seven months of the COVID-19 epidemic in Kashmir valley, approximately 37% of individuals were infected. There is still a significant pool of susceptible people in Kashmir. The number of infections will continue to rise unless infection prevention measures are practiced by the population. Funding: National Health Mission Jammu & Kashmir Declaration of Interests: We declare no competing interests, financial or otherwise. Ethics Approval Statement: The study was approved by the Institutional Ethics Committee of Government Medical College Srinagar.