COVID-19 seroprevalence study in asymptomatic healthcare workers, at a tertiary healthcare centre, India

ABSTRACT

Introduction: The Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) infection has evolved into a pandemic disease. The present knowledge is mainly based on available numerator data of confirmed positive cases only. The asymptomatic and mildly symptomatic cases are not brought into picture for testing at all, which is a major contributor to the pandemicity and hence creating bias in the documentation and understanding of the disease. The magnitude of the exposure of Healthcare Workers (HCW) and their potential for asymptomatic transmission makes it critical to know the incidence of infection in the healthcare population. Aim: The aim of the study was to evaluate the seroprevalence of Immunoglobulin G (IgG) SARS-CoV-2 among the asymptomatic HCW. Materials and Methods: This was a cross-sectional study conducted during January 2021 and February 2021 in SRM Medical College Hospital and Research Centre (SRM MCH & RC), a tertiary care hospital in Potheri, Chengalpattu district, Tamil Nadu, India. The HCW were asked to complete the standardised questionnaire including the basic information, symptoms of COVID-19 illness and utility of Personal Protective Equipment (PPE) based on World Health Organization (WHO) risk assessment and management of exposure of HCW in the context of COVID-19. They were divided into two groups, the staff who had direct patient exposure as group 1 with 82 participants and staff without direct patient exposure as group 2 with 46 participants. The serodetection of IgG SARS-CoV-2 antibodies was done using the Chemiluminescence Immunoassay (CLIA). The obtained results were statistically analysed with Statistical Package for the Social Sciences (SPSS) 20.0. A chi-square test (χ2) was performed and a p-value less than 0.05 was considered statistically significant. Results: A total of 128 HCW were studied. In group 1, there were 64.1% (n=82) of HCWs and in group 2 there were 35.9% (n=46) of HCWs. There were total of 74 (57.8%) males and 54(42.2%) females. No gender-specific differences were observed. The mean age in group 1 was 28.93 years and group 2 was 32.2 years. The staffs older than 40 years were more commonly affected. Adherence to strict PPE protocol was observed in 92.6% (76/82) in group 1 and 82.6% (38/46) in group 2. The difference between the groups were statistically significant (p=0.025). In this study, though the seroprevalence of COVID-19 infection was 9.8% (n=8) in group 1 and 13% (n=6) in group 2, it was statistically not significant. Conclusion: SARS-CoV2 Serology study helps to identify the asymptomatic (unestimated) cases. The results of the seroprevalence suggest that the strict adherence to PPE protocol helps to prevent COVID-19.