Trend of expansion of SARS-CoV-2 infection and COVID-19 burden in Gabon (Central Africa) in mid-2021, based on a serological survey

OBJECTIVE: To estimate the seroprevalence of anti-SARS-CoV-2 antibodies in the general population in Gabon, Central Africa. METHODS: From May to July 2021, a cross-sectional study involving participants recruited in the general population in three districts in Gabon was conducted. Eligible participants who provided written informed consent were tested for anti-SARS-CoV-2 antibodies using a simple rapid diagnostic assay. RESULTS: Overall, 1609 participants were recruited, 1361 (84.6%) from urban sites and 248 (15.4%) from a rural area. The estimated overall seroprevalence was 13.1% (95% CI 11.4–14.8%). The risk of seropositivity increased with age, and the prevalence in the different age groups ranged from 12.9% (8.0–19.4%) in those aged 15–24 years to 23.3% (14.2–34.6%) in those ≥ 65 years old. A higher prevalence was found in the rural population (17.3%; 12.8–22.6%) compared with urban regions (12.3%; 10.6–14.1%). Being a woman was also associated with higher risk of infection (p < 0.001). CONCLUSIONS: This seroprevalence survey revealed a moderate seroprevalence in Gabon, illustrating a relatively low rate of circulation of the virus in the country and correlating with low numbers of confirmed cases and deaths reported to date.