A multi-site cross-sectional study on the burden of SARS-CoV-2 in healthcare workers in Madagascar.

The prevalence of infections and risk factors that go along with them give insights into the burden of disease and effectiveness of infection prevention and control strategies. In this study we investigated the burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and associated epidemiological factors in three regions of Madagascar among healthcare workers. Between May and June 2021, we conducted a multi-site cross-sectional study among healthcare workers in eight University Hospital Centers, during the local second wave and before the coronavirus disease 2019 vaccination campaign in three regional capitals of Madagascar. We collected demographic information and relevant SARS-CoV-2 exposure history and tested for both immunoglobulin G antibodies to SARS-CoV-2 spike protein, using enzyme-linked immunosorbent assay and active SARS-CoV-2 infection using real-time reverse transcription-polymerase chain reaction. A total of 1006 healthcare workers enrolled in the study out of which 53.8% tested positive for either acute infection or SARS-CoV-2 antibodies. Approximately 50% of the participants reported receiving inadequate training on SARS-CoV-2 and associated infection prevention and control measures, inadequate supply of Personal Protective Equipment (PPE) and discomfort when using available PPE. Prevalence of acute infection was 3.4% without statistically significant variation in the different regions or health facilities as well as the different profession groups and units of work. Average seroprevalence of SARS-CoV-2 IgG antibodies was 52.0%, varying between 47.8% and 53.3% across the different regions. No significant difference was observed for region, gender, profession, and different risk groups. Predictive multivariable model showed significant association between seropositivity and healthcare facility and age (p<0.05). Our results revealed high infection rate of SARS-CoV-2 in HCWs in all three selected regions of Madagascar. The high disease burden identified in the study population might characterize the extent of high undocumented infection rates in HCWs in other regions of Madagascar.