Detection of rubella cases through the measles laboratory surveillance network in South-East Nigeria: 2020-2024

Abstract

Introduction: rubella remains a public health concern in Nigeria, particularly in countries without routine rubella vaccination. This study assessed rubella virus circulation in South East Nigeria using measles surveillance data, in order to better understand the burden of rubella in the region and inform strategies for future vaccine introduction and disease control. Methods: a retrospective cross-sectional study was conducted using measles surveillance data collected between January 1, 2020 and December 31, 2024 across South Eastern Nigeria under the Integrated Disease Surveillance and Response (IDSR) framework. Descriptive statistics were used to present frequencies and percentages, while bivariate analysis assessed associations between variables, with significance set at p < 0.05. Results: out of 6,145 febrile rash cases, 742 (12.1%) were confirmed rubella IgM-positive. Children under one year significantly accounted for 40% of cases (p<0.001), and over 80% occurred in children under 10 years. Females represented 52.3% of cases, with 7% of IgM-positive females within the childbearing age range but there was no statistically significant difference observed in rubella incidence between genders (p > 0.05). Seasonal peaks were consistently observed in the first quarter of each year, and geographic clustering was observed in all the states within the Zone. Conclusion: rubella is endemic in South East Nigeria, with ongoing transmission among children and women of reproductive age. The absence of rubella vaccination contributes to early-age vulnerability and increased risk of congenital rubella syndrome. These findings support the urgent need to introduce rubella-containing vaccines into Nigeria´s national immunization schedule and strengthen surveillance systems.