Prevalence of Rotavirus Genotypes Among Children Under Five in Central Asia: A Systematic Review and Meta-Analysis of...

Background/Objectives: Rotavirus remains a major cause of acute gastroenteritis among children under five years of age, particularly in regions with heterogeneous vaccine implementation. In Central Asia, differences in the timing and coverage of rotavirus vaccination may influence circulating genotype patterns, yet regional evidence remains fragmented. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA 2020 guidelines and registered in PROSPERO (CRD420251274198). Electronic databases (PubMed, Web of Science, ScienceDirect, and Google Scholar) were searched without date restrictions. Studies reporting laboratory-confirmed rotavirus infection and genotype distribution among children under five years in Central Asia were included. Random-effects meta-analysis of proportions was performed to estimate the pooled genotype proportions among rotavirus-positive children, with subgroup analyses comparing the before and after vaccine introduction periods. Results: Six studies (ten before vaccine introduction strata and four after vaccine introduction strata; N = 1713 rotavirus-positive children) were included. A significant decline in the G1P[8] genotype was observed following vaccine introduction, with pooled prevalence decreasing from 0.468 (95% CI: 0.363-0.577) to 0.068 (95% CI: 0.034-0.133) (p < 0.001). In contrast, G2P[4] increased from 0.134 to 0.485 (p < 0.001), while G9P[4] and G9P[8] also increased significantly. G3P[8] and mixed genotypes declined, whereas G4P[8], G12P[8], and untypable strains showed no statistically significant subgroup differences. Substantial heterogeneity was observed (I² > 90%), and evidence certainty was very low for all genotype outcomes. Conclusions: The available evidence suggests that rotavirus genotype distribution among children under five in Central Asia may have changed after vaccine introduction, with lower pooled proportions of G1P[8] and higher proportions of selected heterotypic genotypes in after vaccine introduction strata. Strengthened molecular surveillance using standardized genotyping protocols is needed to determine whether these patterns represent sustained genotype replacement or temporal fluctuation. These estimates are based on a small, heterogeneous evidence base with very low certainty and should be considered hypothesis-generating rather than confirmatory of a causal vaccine effect.