Prevalence of sickle cell disease and sickle cell trait among children and adolescents in Nigeria: A systematic review and meta-analysis

Background Sickle cell disease (SCD) is one of the most common genetic disorders in the world, with Nigeria believed to have the highest burden. Despite the high burden in the country, the true prevalence of SCD and its main driver- the sickle cell trait (SCT)- is unknown, which is important for planning and resource allocation. Hence, we conducted a systematic review and meta-analysis of the prevalence of SCD, SCT, and the associated sociodemographic factors in Nigerian children and adolescents. Methods The search strategy of this study included MeSH terms, keywords, and entry words from the following databases (AJOL, Google Scholar, PubMed, EMBASE, Cochrane Library, Scopus, and Web of Science collections). The inclusion criteria were studies on children and adolescents in Nigeria that reported the prevalence of SCD and/or SCT and were available in English. The quality of the studies was assessed using the National Institutes of Health Quality Assessment Tool. We used a cumulative meta-analysis to estimate the pooled prevalence, regional prevalence, and associated sociodemographic factors. Publication bias was assessed using funnel plots and Egger's test. Results Of the 40,081 articles obtained from the literature search, we included 30 studies comprising 141,793 participants in the final analysis after a stepwise screening. The pooled prevalence of SCD, sickle cell anemia (SCA), and SCT were 3.6%, 2.9%, and 21.8%, respectively. The northwestern geopolitical zone had the highest pooled prevalence of SCD (5.6%) and SCT (26.8%). The southeast region had the lowest pooled prevalence of SCD (1.4%), while the southwestern region had the lowest pooled prevalence of SCT (19.3%). There was no relationship between SCA and sex or socioeconomic status. Conclusion The pooled prevalence of SCD, SCA, and SCT among children and adolescents was high, with the highest burden in the northwestern geopolitical zone in Nigeria. In addition, there was no relationship between the prevalence of SCA, sex, or socioeconomic class. Systematic review registration: PROSPERO ID: CRD42024556354