Prevalence and genetic diversity of enteric viruses in Sub-Saharan Africa: a systematic review and meta-analysis

Abstract

Rotavirus A (RVA), norovirus (NoV), human astrovirus (HAstV), and sapovirus (SaV) are the main viruses responsible for acute gastroenteritis worldwide. Among them, RVA is generally the most prevalent, predominantly in Sub-Saharan Africa. With the introduction of RVA vaccines, several epidemiological changes have been reported in cases of viral gastroenteritis, particularly in Sub-Saharan Africa. Therefore, it is essential to understand the current burden and diversity of these viruses in order to guide public health interventions and vaccination strategies in the region. Our objective was to examine changes in prevalence data and circulating genotypes of RVA, NoV, SaV, and HAstV associated with acute gastrointestinal infections in both adults and children in Sub-Saharan Africa, based on studies published between 2010 and 2023. A systematic search was conducted in PubMed and Google Scholar to identify relevant studies published between 2010 and 2023, focusing exclusively on Sub-Saharan Africa. No restrictions were applied in terms of language or age group. Study selection, data extraction, and methodological quality assessment were performed using standardized procedures. Heterogeneity between studies was assessed using Cochrane’s Q test and the I² statistic in a random-effects model. Combined prevalence estimates for RVA, NoV, SaV, and HAstV were calculated using Comprehensive Meta-Analysis software. A total of 55 studies from 19 countries in Sub-Saharan Africa were included. The combined prevalence was 31% for RVA, 14% for NoV, 12% for SaV, and 5% for HAstV. Overall, enteric viruses accounted for a combined prevalence of 22%. High heterogeneity (I² > 73%) was observed for most viruses. Genotyping data from 27 studies conducted in 13 countries showed high genetic diversity. RVA had 33 G/P combinations, the most common being G1P[8] and for NoV the GII.4 and GII.6 genotypes predominated. The high prevalence and genetic diversity of enteric viruses observed in this study underscore the continuing burden of viral gastroenteritis on public health in sub-Saharan Africa and confirm the need for ongoing surveillance to inform vaccination and control strategies.