SARS-CoV-2 sero-surveillance among healthcare workers at a tertiary care reference centre in Central India: A cross-sectional study

Introduction: Health care workers (HCW), as the primary caregivers in the management of COVID-19 cases, are at a higher risk of acquiring infection. As such, they are associated with challenges to themselves including adverse health outcomes and emotional burdens. Additional challenges include compromised continuity of patient care, potential spread to patients and household contacts and increased mortality . Assessment of seroprevalence of SARS-CoV-2 IgG antibodies among HCWs can provide important data on pathogen exposure, infectivity and vaccine efficacy. This study aims to estimate the seroprevalence among different cadres of HCW and explore associations with demography, category of exposure to COVID-19 and vaccination status.
Methods: This cross-sectional study was conducted over a five-month period from January to May 2021 during the second wave of the COVID-19 pandemic. HCWs from various professional categories were recruited and tested for SARS-CoV-2 IgG antibodies. Data capturing demographic details, comorbidities, job role, work environment, history of exposure to COVID-19 patients, prior COVID-19 diagnosis, and vaccination status were collected and analysed.
Results: Out of 461 HCWs, anti-SARS-CoV-2 IgG antibodies were detected in 260 (56.4%; 95%CI: 51.8%-60.9%) individuals. Factors associated with significant higher seropositivity included age <35 years (p = 0.038), professional category (p = 0.0001), vaccinated status (p < 0.0001), previous RTPCR positive for COVID-19 (p = 0.017), posting in COVID unit (p=0.014), and close contact with COVID -19 cases (p=0.015). Upon logistic regression analysis, vaccination was the sole significant factor (OR: 5.52; 95% CI: 2.98 – 10.23; p < 0.0001) associated with greater antibody positivity.
Conclusion: We report higher seroprevalence in HCWs immediately following the rollout of vaccination in India. Role of antigenaemia in individuals with low seroprevalence in faculties and resident doctors is a matter of further research.