Prevalence and relative risk of Rotavirus Gastroenteritis in children under five years in Nigeria: a systematic review and meta-analysis.

Rotavirus is responsible for most cases of gastroenteritis and mortality in children below 5 years of age, especially in developing countries, including Nigeria. Nonetheless, there is limited data on the nationwide estimate for the prevalence of rotavirus. This systematic review and meta-analysis sought to determine the pooled prevalence of rotavirus infections and its relative risk among children below 5 years of age in Nigeria. Eligible published studies between 1982 and 2021 were accessed from 'PubMed', 'Science Direct', 'Google Scholar' and 'African Journal Online', 'Web of Science', 'Springer', 'Wiley' were systematically reviewed. The pooled prevalence, relative risk and regional subgroup analyses were calculated using the random effects model at 95% confidence interval (CI). A total of 62 selected studies, including 15 studies case-control studies, were processed in this review from a pooled population of 18,849 children. The nationwide pooled prevalence of rotavirus among children below 5 years of age in Nigeria was 23% (CI 95%; 19-27). Regional subgroup analysis showed that the Southern region had a prevalence of 27% (CI 95%; 21-32) while the Northern region had a 20% (CI 95%; 16-25%) prevalence, although the difference was not significant ( = 0.527). Rotavirus was implicated in most cases of acute gastroenteritis with a relative risk of 5.7 (95% CI: 2.9-11.2). The high prevalence and relative risk of rotavirus infections among children in Nigeria shows that rotavirus is an important cause of acute gastroenteritis in Nigeria. Thus, there is a need for further surveillance, especially at community levels together with the introduction of rotavirus vaccines into the national immunization program.