Introduction: Rotavirus is the leading cause of infectious diarrhoea and deaths in under five children globally. Method: The study was conducted to determine the proportion, severity and trend of rotavirus-associated diarrhoea in under five children. It was a hospital-based cross-sectional descriptive study using quantitative and laboratory testing methods of data collection, Semi-structured questionnaire was used to elicit information from respondents (mothers), whereas stool samples were collected from 203 under five diarrhoeic children who presented at the University of Uyo Teaching Hospital (UUTH) and St. Luke’s Hospital (SLH), Uyo for rotavirus assay. Ethical approval was obtained from the Ethical committees of the University of Uyo Teaching Hospital and that of the Akwa Ibom State Ministry of Health respectively. Data was analysed using SPSS version 20. Results: The proportion of rotavirus associated diarrhoea among under five children in this study was 46.8% and the overall Proportionate Morbidity Ratio (PMR) of rotavirus associated diarrhoea was 4.4% for the duration of study. Rotavirus isolation rate was slightly higher among male children 49(51.6%) and in children aged 12 months and less 35(36.8%). The rate of practice of hand washing with soap before food preparation was 77(50%) and the rate of exclusive breastfeeding was 48 (44.4%). However, there was no statistically significant association between rotavirus associated diarrhoea among under five children and hand washing (p = 0.120), age (p = 0.066), gender (p = 0.218) and exclusive breastfeeding status (p = 0.433). Rotavirus associated diarrhoea cases peaked during the “dry season” January to April and dropped during the “wet season” May to October. Conclusion and Recommendation: Seasonality of rotavirus diarrhoea is a good measure for monitoring rotavirus diarrhoea. Our data suggest that there is clear seasonality of rotavirusassociated diarrhoea in the part of Nigeria. Rotavirus vaccine should be included in the routine Expanded Programme on Immunization in the country.
