“Seroprevalence of COVID-19 among health care personnel at a tertiary care teaching hospital”

Abstract

Introduction: COVID-19 seroprevalence studies for Health Care Personnel (HCP) can provide relevant information on the proportion of people who have experienced a recent or past infection and provide information about populations that may be immune and potentially protected. Aim of the study was to determine the seroprevalence of COVID-19 and associated factors among HCP and to correlate COVID-19 antibody results with respect to time duration since laboratory confirmed positive COVID-19 test and vaccination.

Methodology: A prospective, cross-sectional study in HCP working at Shree Krishna Hospital and Pramukhswami Medical College, Karamsad was conducted at Microbiology section of Central Diagnostic Laboratory (CDL). Following approval from Institutional Ethics Committee, the study was conducted from March 2021- June 2022. The serological test to measure COVID-19 IgG antibody was done by Enzyme Linked Fluorescent Assay (ELFA, VIDAS, Biomerieux) in 118 eligible HCP. Antibody response was correlated with age, gender, occupation, work area, symptoms, test requests and test results. Correlation of COVID-19 antibody results with respect to time duration since laboratory confirmed positive COVID-19 test and after vaccination was done. All the data was entered and analysed in Microsoft Excel 2010.

Results: Seroprevalence of COVID-19 was found to be 97.45% (115/118) in HCP. Seroprevalence was 100 % in all the age groups except 18-30 and 41-50 years; 100% in all the professional categories except consultant doctors and resident doctors; 100% in HCP working in non-COVID-19 unit and 100% in participants not tested for COVID-19 test. 13 (37.14%) HCP were seropositive beyond 11 months duration after positive COVID-19 test. In 49 (44.54%) HCP, SARS-CoV-2 IgG antibody were found beyond 7 months duration after COVID-19 vaccine. SARS-CoV-2 IgG antibody were positive in eight (6.96%) non-vaccinated and 107 (93.04%) vaccinated participants.

Conclusions: COVID-19 infection and/or COVID-19 vaccination might have contributed to excellent seroprevalence in health care personnel (HCP) of our hospital. Persistence of SARS-CoV-2 IgG antibody for longer duration was observed in HCP with past infection as well as past vaccination. Natural COVID-19 infection might have contributed to seropositivity in a few nonvaccinated, asymptomatic & RTPCR/RAT negative/not done HCP.