Antibody Responses to SARS-Cov-2 among Health Care Workers of a Tertiary Hospital in North-Eastern, Tanzania

BackgroundHealth Care Workers (HCWs) have been playing crucial role in treating patient with COVID-19. They have a higher occupational risk of contracting the disease than the general population, and a greater chance of them transmitting the disease to vulnerable patients under their care. Given their scarcity and low COVID-19 vaccine acceptance in Africa, it is essential that HCWs are seroprotected and their exposure to COVID-19 minimized. This study was therefore designed to determine IgG antibody response to SARS-CoV-2 among HCWs in North Eastern, Tanzania. MethodologyThis was a cross-sectional study carried out among 273 HCWs at Kilimanjaro Christian Medical Centre (KCMC), a tertiary, zonal referral hospital in Tanzanias North Eastern region. Stratified sampling was used to select study participants. Data were obtained from each consenting participant using a validated questionnaire. Blood samples were collected for SARS-CoV-2 IgG antibodies quantification by using an indirect ELISA test. RedCap software was used to enter and manage data. Statistical analysis was done by using STATA statistical software version 15 and GraphPad Prism v 9.0. A p-value of < 0.05 was considered the cut-off for statistical significance. ResultsAmong 273 HCWS only 37.9 % reported to have received COVID-19 vaccine. Except for one person, all of the participants had SARS-CoV-2 IgG antibody concentrations that were positive, with 64.5% of them having strong seropositivity. Female gender, allied health professionals, active smoking, COVID-19 patient interactions, COVID-19 vaccination receptivity, and adherence to recommended hand hygiene were found to be significant predictors of variation of median SARS-CoV-2 antibody concentration. The usage of personal protective equipment, history of previously testing PCR positive for COVID-19, the number of COVID-19 patient exposure and age were found to cause no significant variation in median antibody concentration among participants. ConclusionsThis study reports a high seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Kilimanjaro Christian Medical Centre. This suggests that HCWs have significant exposure to SARS-CoV-2 despite the low rate of vaccination acceptance even among HCWs. We recommend a strengthened Infectious Prevention and Control (IPC) in hospitals through provision of technical leadership and coordination according to WHO guidelines. We also recommend continued conduction of seroprevalence studies to estimate the magnitude and trends of SARS-CoV-2 infections in different populations in Tanzania. A better understanding of the past, current, and future transmission patterns of infectious pathogens is critical for preparedness and response planning, and to inform the optimal implementation of existing and novel interventions under the current and changing climate.