Molecular Prevalence of Human Astrovirus Among Children Under Five Years of Age With Gastroenteritis in Ilorin Metropolis, North-Central Nigeria: A Cross-Sectional Study.

BACKGROUND AND AIMS: Human astrovirus (HAstV) is a recognized cause of viral gastroenteritis, however, data from north-central Nigeria remain limited. This study aimed to determine the prevalence of classic HAstV RNA and explore associated factors among children under 5 years presenting with gastroenteritis in Ilorin, Nigeria.

METHODS

This hospital-based cross-sectional study was conducted from May 2025 to September 2025 among 200 children aged 13-59 months attending selected hospitals in Ilorin who presented consecutively. Stool samples were collected and analyzed using real-time reverse transcription polymerase chain reaction for classic HAstV RNA. Data were analyzed using R software. Participant characteristics were summarized descriptively, prevalence estimates were calculated with exact 95% confidence intervals, and associations with astrovirus detection were evaluated using Fisher's exact test, the Wilcoxon rank-sum test, and Firth penalized logistic regression.

RESULTS

Classic HAstV RNA was detected in 4 of 200 children under 5 years with acute gastroenteritis, giving an overall prevalence of 2.0% (4/200; 95% CI: 0.55%-5.04%). Prevalence was highest among children aged 49-60 months (2.94%), males (2.50%), rural residents (2.33%), users of borehole/well water (2.86%), and children attending daycare (4.0%). All astrovirus-positive children presented with vomiting, moderate dehydration, resided in rural communities, had animal contact, used borehole/well water, and received oral rehydration solution. No other characteristics were significantly associated with HAstV. Feeding method was the only factor significantly associated with detection (p = 0.03), with the highest prevalence among exclusively breastfed children (33.3%; 2/6). However, wide confidence intervals around both the raw prevalence and the adjusted odds ratio (aOR = 0.01; 95% CI: 0.00-0.29) indicate this finding is exploratory rather than confirmed, warranting confirmation in larger studies.

CONCLUSION

Astrovirus in this population is relatively low; however, it remains epidemiologically important, particularly as prevalence may vary with season. Continued surveillance and further molecular characterization are warranted.