The Epidemiology and Determinants of Poliomyelitis in Nigeria: A Systematic Review

Abstract

Background and Objectives: Poliovirus, a highly infectious viral disease, has been a major public health concern in Nigeria. Despite the country’s successful eradication of wild poliovirus in 2020, outbreaks of circulating vaccine-derived poliovirus type 2 continue to pose significant challenges. This study aims to assess the epidemic situation of poliomyelitis in Nigeria, analyzing historical trends, current epidemiology, vaccination strategies, and barriers to eradication. Methods: A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were gathered from World Health Organization (WHO) database, Centers for Disease Control and Prevention (CDC) database and National Primary Health Care Development Agency (NPHCDA). An initial total of 75 studies were identified through database searches. After duplicate removal, screening, and full-text assessment, 15 studies met the inclusion criteria and were included in the final review. These studies focused on the epidemiology of poliomyelitis in Nigeria, patterns of disease distribution, vaccination interventions, and public health responses. Results: Nigeria was declared free of wild poliovirus in 2020 following decades of extensive immunization efforts. However, between 2021 and 2023, over 1,028 cases of circulating vaccine-derived poliovirus type 2 were reported, with the majority occurring in northern states such as Kebbi, Sokoto, and Zamfara. Contributing factors include low immunization coverage, insecurity, vaccine hesitancy, and limited access to healthcare. Several types of vaccines, including the oral poliovirus vaccine and the inactivated poliovirus vaccine, have been deployed nationally. The introduction of the novel oral poliovirus vaccine type 2 in 2021 marked a significant milestone, with over 27 million children vaccinated in 2023. Nevertheless, logistical, cultural, and security-related challenges continue to affect the success of eradication campaigns. Conclusion: While Nigeria has successfully eliminated wild poliovirus, the persistence of circulating vaccine-derived poliovirus type 2 remains a major public health concern. Strengthening routine and supplementary immunization programs, including expanded use of the novel oral poliovirus vaccine type 2, is essential. Raising public awareness about the safety and importance of vaccination, particularly in underserved and conflict-affected communities, will be critical to achieving complete eradication. Strategic, inclusive interventions are needed to address systemic barriers, ensure equitable healthcare access, and maintain Nigeria’s polio-free status.