First and Preliminary Data about Sars-CoV-2 Serology among Asymptomatic Workers in Central African Republic

Context and Objectives: The pandemic induced by Sars-CoV-2 has disrupted the organization of work while its extent is not known in CAR. The objective of this study was to estimate the Sars-CoV-2 seroprevalence in the workplace in the Central African Republic. Methods: This is a cross-sectional study that took place at the Department of Occupational Medicine in Bangui. Asymptomatic workers who request to the Occupational Physician a medical certificate and consented were included in the study. A standard sheet was used to collect socio-demographic, professional and biological data. The serology of Sars-CoV-2 was based on 2 rapid immunochromatographic tests for detection of IgM and IgG separately: Covid-19 IgM / IgG Rapid Test (Cypress Diagnostics, Belgium) and Standard Q Covid-19 IgM / IgG Duo (SD Biosensor, Korea). Results: The seroprevalence of Sars-CoV-2 was 18.6% (CI [14.7-22.6]) including 1% positivity of IgM only, 1.0% of positivity of both IgM and IgG and 16.6% of positivity IgG only. Women (p = 0.001), young workers (<40 years; p = 0.01) and residents of Bangui (p = 0.05) were predominantly Sars-CoV-2 serological positive. Paradoxically, compliance with barrier measures was associated with a high Sars-CoV-2 seroprevalence (0.005). The group of health care workers, teachers and traders was more Sars-CoV-2 serological positive (0.0003) than other professions. Conclusion: The seroprevalence of Sars-CoV-2 remains low in CAR despite the progressive generalization of vaccination. The group of occupations with more Sars-CoV-2 seropositive people needs close monitoring and priority vaccination. Understanding the acceptability of vaccination, the kinetics of antibodies following vaccination and continue immunological surveillance in CAR require further studies.