Prevalence of SARS CoV-2 infection among Health Care Workers of a hybrid tertiary COVID 19 hospital in Kerala

ABSTRACT

Back ground and objectivesThis study was undertaken to estimate the prevalence of SARS-CoV-2 infection among Health care workers [HCWs] of a hybrid COVID treatment hospital in Kerala. MethodsThe study was conducted during 3rd week of January 2021. Among 3550 HCWs, 979 subjects were selected by stratified random sampling and grouped into high risk and low risk category based on job setting. Demographic details and clinical information regarding previous history of COVID 19 were collected at the time of SARS-CoV-2 IgG testing. ResultsFrom 979 subjects, the data with respect to 940 health care workers were analysed. SARS-CoV-2 IgG was detected in 19.1% of HCWs. Seroprevalence among high risk group was 20.3% and that in low risk group was 7.4% [p=0.005]. In high-risk group, seropositivity was noted in 30.54 % of nurses, 19% hospital attenders, 18.9% resident doctors and 6.4% consultant doctors. In those with past history of SARS-CoV-2 infection, seropositivity was 75.4%. In those who were COVID positive during July2020, 33.3% were still IgG reactive. Interpretation and conclusionThe study reported 19.1% SARS CoV-2 IgG reactivity among health care workers in our hospital. Seropositivity was significantly higher in high risk group compared to low risk group. Antibody decay kinetics in our study is comparable to that in published literature. Infection control challenges in hybrid hospitals account for higher seropositivity in this study compared to overall seroprevalence among HCWs in Kerala.