Molecular epidemiology and genotypic characterization of rotavirus among children under five years of age with acute diarrheal illness in Addis Ababa, Ethiopia: cross-sectional hospital-based study

Abstract Background Rotavirus is the leading cause of diarrheal illness in children, with the greatest burden occurring in Sub-Saharan Africa, South Asia, and Southeast Asia. Ethiopia introduced the Rotarix rotavirus vaccine in 2013. Objectives To determine the prevalence and circulating genotypes of Rotavirus alphagastroenteritidis (RVA) among children under five years with acute diarrheal illness in Addis Ababa, Ethiopia. Methods A cross-sectional study was conducted in selected health facilities in Addis Ababa, Ethiopia, from September 2023 to August 2025. A total of 400 stool samples were collected. The samples were tested for rotavirus and genotyped using the TaqMan Array Card. Results Rotavirus alphagastroenteritidis (RVA) was detected in 79 (19.8%) of 400 samples; 76 of them were genotyped based on VP7 and/or VP4. Fifteen G-P genotype combinations were identified, with G3P[8] 11.8% (9/76), G1P[4] 10.6% (8/76), G12P[6] 7.9% (6/76), and G2P[4] 7.9% (6/76) being predominant circulating genotypes. Three genotypes, G8P[4], G10P[8], and G4P[8], were detected for the first time in Ethiopia. Conclusion This study provides updated information regarding the circulating genotypes of rotavirus among children with diarrhea in Addis Ababa. A wide diversity of genotypes was identified, including unusual genotypes that have not been previously reported in Ethiopia. These findings underline the importance of continued strain surveillance to monitor the emergence of new strains.