risk of symptomatic case, 87.9% lower, RR 0.12, p = 0.006, treatment 128, control 1,342, adjusted per study, odds ratio converted to relative risk, control prevalence approximated with overall prevalence, multivariable, primary outcome.
Abstract: Vol 119, No 5, May 2021
Journal of the Indian Medical Association
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.
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
MBBS, MD (Medicine), DM (Endocrinology), Postdoctoral Senior
Resident and Corresponding Author
MBBS, MD (Medicine), Postdoctoral Trainee
MBBS, DNB (Pediatrics), Postdoctoral Trainee
MBBS, MD (Medicine), DM (Endocrinology), Professor
MBBS, MD (Medicine), DM (Endocrinology), FRCP, FACE,
Speciality Certificate in Endocrinology, FICP, Professor
MBBS, DNB (Pathology), Consultant Pathologist, Scientific
Clinical Research Laboratory, Kolkata 700013
MBBS, DTM&H, MD (Medicine), DM (Endocrinology), MRCP,
Professor and Head
Received on : 08/03/2021
Accepted on : 23/03/2021
Editor's Comment :
Please send us corrections, updates, or comments. Vaccines and
treatments are complementary. All practical, effective, and safe means should
be used based on risk/benefit analysis. No treatment, vaccine, or intervention
is 100% available and effective for all current and future variants. We do not
provide medical advice. Before taking any medication, consult a qualified
physician who can provide personalized advice and details of risks and
benefits based on your medical history and situation. FLCCC and WCH
provide treatment protocols.