Prevalence and genotype distribution of norovirus and rotavirus among children under five with diarrheal infection in lower-middle-income countries after Rotavirus vaccine introduction: A systematic review and meta-analysis

Rotavirus and norovirus are the leading viral causes of acute diarrheal disease worldwide. Both viruses encompass multiple genotypes and subgenotypes, and this genetic diversity presents a significant challenge to rotavirus vaccine effectiveness and development. High-quality evidence on the prevalence and circulating genotypes of these enteric viruses among children under five years of age remains limited, particularly following the introduction of rotavirus vaccination in low and middle-income countries (LMICs). Therefore, this systematic review and meta-analysis aimed to synthesizes available evidence on the prevalence and genotype distribution of norovirus and rotavirus in this population.

A systematic literature search was conducted across five major databases PubMed, Scopus, ScienceDirect, Embase, and Web of Science between February 20 and 28, 2026. Duplicate removal, title and abstract screening, full-text review and data extraction were performed independently by two investigators using the Rayyan web-based platform. STATA version 17 software was used for statistical analysis. A random-effects model was applied to estimate pooled prevalence and effect sizes. Heterogeneity was evaluated using Cochran's Q statistic, the I2 statistic, forest plots, and Galbraith plots. Publication bias was assessed using both graphical (funnel plots) and statistical methods.