Abstract: Vol 119, No 5, May 2021 21 Journal of the Indian Medical Association Original Article Prevalence of COVID-19 Infection and Identification of Risk Factors among Asymptomatic Healthcare Workers : A Serosurvey Involving Multiple Hospitals in West Bengal Sunetra Mondal1, Arijit Singha2, Debaditya Das3, Subhasis Neogi2, Piyas Gargari2, Moxit Shah2, Durairaj Arjunan2, Pradip Mukhopadhyay4, Sujoy Ghosh5, Jyothi Chowdhury6, Subhankar Chowdhury7 Background : The declining trend of COVID-19 infection in India has made healthcare personnel (HCP) and general public lenient about personal-protective-measures. Serosurveys to estimate the prevalence of SARS-CoV2 IgG antibodies, particularly in high-risk-zones like hospitals can give the real scenario and risk-factors can help prioritise the target population for urgent, effective vacccination. Methods : 1470 consecutive HCP from 4 tertiary-care-hospitals in Kolkata filled a questionnaire and were tested for serum SARS-CoV2-IgG by Enzyme-linked Immunosorbent Assay (ELISA). The prevalence of SARS-CoV2-IgG among asymptomatic HCPs was studied and the work environment, clinical comorbidities, personal habits and protective measures and pharmacologic prophylaxes were compared between those with and without SARS-CoV2IgG. Parameters of asymptomatic seroconverters were also compared to those with personal history of COVID-19Infection. Logistic regression was done to identify independent risk-factors. Results : Prevalence of asymptomatic seroconversion was 15.8%. Asymptomatic seroconverters (n=208) were mostly working in mixed hospitals (having both COVID-19 and non-COVID-19 wards, 57.7%), were non-doctors by profession (nurses-25.1%, others–51.4%). Among asymptomatic HCP, indepedendent positive risk factors for SARSCoV2 IgG-positivity were Diabetes Mellitus (DM) and multiple comorbidities (pboth<0.001) and prophylactic use of Hydroxychloroquine and Famotidine (pboth< 0.03). However, for symptomatic COVID-19 infection, working in COVID19 dedicated hospitals, and personal h/o COPD were positive risk-factors and Ivermectin prophylaxis a negative riskfactor (pall< 0.03). Conclusion:In our study conducted in the immediate pre-immunisation period, rate of asymptomatic seroconversion among HCPs is too low to presume herd immunity. Those working in mixed hospitals and DM, multiple comorbidities are at particularly high risk. [J Indian Med Assoc 2021; 119(5): 21-7] Key words : COVID-19, SARS-CoV2 IgG, ELISA, Seroprevalence, Healthcare personnel. M ore than a hundred million people worldwide have been infected with severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) over the past fourteen months. With the vaccination campaign targeting healthcare workers and the sudden decline in the daily number of cases in the country, the Department of Endocrinology and Metabolism, IPGME&R, Kolkata 700020 1 MBBS, MD (Medicine), DM (Endocrinology), Postdoctoral Senior Resident and Corresponding Author 2 MBBS, MD (Medicine), Postdoctoral Trainee 3 MBBS, DNB (Pediatrics), Postdoctoral Trainee 4 MBBS, MD (Medicine), DM (Endocrinology), Professor 5 MBBS, MD (Medicine), DM (Endocrinology), FRCP, FACE, Speciality Certificate in Endocrinology, FICP, Professor 6 MBBS, DNB (Pathology), Consultant Pathologist, Scientific Clinical Research Laboratory, Kolkata 700013 7 MBBS, DTM&H, MD (Medicine), DM (Endocrinology), MRCP, Professor and Head Received on : 08/03/2021 Accepted on : 23/03/2021 Editor's Comment : „ Among 1470..