Abstract
Objective: The Covid-19 pandemic has highlighted the need to strengthen diagnosis and genomic surveillance capacities. The Central African Republic was able to manage 5 waves during health monitoring and integrated genomic surveillance as a surveillance tool in 2021.
The aim of this study is to report surveillance data from the National Laboratory of Clinical
Biology and Public Health and describe the landscape of circulation of SARS-CoV-2 variants.
Materials and methods: This is a retrospective, descriptive observational study over a period of 3 years (ranging from April 2020 to November 2023) carried out on a population of consenting volunteers, from throughout the CAR, tested by RT -PCR on nasopharyngeal samples with sufficient information in the LNBCSP databases. Sequencing is largely carried out at the INRB in KINSHASA and from May 2023 at the LNBCSP.
Results and discussion: Out of 97,864 RT-PCR tests carried out, 9,764 came back positive, which corresponds to a prevalence of 9.98%. The average age of the patients was 39.97 years ± 13.76 and the sex ratio M/F was 2.12. The positivity of RT-PCR tests was significantly associated with age (p=0.001), sex (p=0.013) and clinical manifestations. Ten variants circulated during the 5 waves recorded. The landscape of circulating variants was dominated by the Omicron (B.1.1.529), Delta (B.1.617.2) variants and especially by B.1.620 and B.640 which marked the second wave in CAR.
Conclusion: This retrospective series provides key information for understanding the history of the Covid-19 pandemic in the CAR. Risk factors are identified and the variant circulation landscape described. Strengthening national genomic surveillance capacities would help the country adopt a better response against this pandemic.