Prevalence estimates of sickle cell disease among children and adolescents in sub-Saharan Africa: a systematic review and modelling analysis

BACKGROUND: There is a scarcity of data reporting on the burden of sickle cell disease across many African settings, particularly among children, who have the highest risk of preventable morbidity and mortality in the absence of early diagnosis and care. We aimed to estimate the prevalence of sickle cell disease and the absolute number of paediatric cases in sub-Saharan Africa to inform policy and service responses.

METHODS: For this systematic review and modelling analysis, we searched MEDLINE, Embase, Global Health (CABI), and African Journals Online (AJOL) for studies published from Jan 1, 2000, to Sept 10, 2025, that reported the prevalence of sickle cell disease among children and adolescents younger than 15 years in sub-Saharan Africa. We pooled crude prevalence using random-effects meta-analysis. We then fitted a mixed-effects meta-regression for age band (infants [aged 0 to <12 months], children aged <5 years, children and adolescents aged <15 years), sickle cell disease phenotype (total sickle cell diseases, haemoglobin SS [HbSS], haemoglobin SC [HbSC], and other compound heterozygous variants), Socio-demographic Index (SDI), World Bank income group, and geographical coordinates (latitude, longitude, interaction), plus a country random intercept. Absolute cases for 2023 were derived with the UN World Population Prospects.

FINDINGS: 40 studies contributed 71 prevalence datapoints from 22 countries across all four subregions of sub-Saharan Africa. Estimated prevalence for all sickle cell diseases was 1·54% (95% CI 0·34-7·49) in infants, 1·51% (0·35-6·72) in children younger than 5 years, and 1·78% (0·21-12·09) in children and adolescents younger than 15 years. By haemoglobin phenotype, the prevalence of HbSS was 0·70% (0·15-3·44) in infants, 0·69% (0·17-2·80) in children younger than 5 years, and 0·80% (0·09-5·11) in children and adolescents younger than 15 years, while that of HbSC was 0·29% (0·06-1·46), 0·28% (0·05-1·50), and 0·33% (0·04-2·43) across the same age groups, respectively. Using UN 2023 population denominators, we estimated 1 165 800 (95% CI 260 600-5 662 100) cases in infants, 2 752 200 (632 700-12 253 200) cases in children younger than 5 years, and 8 854 800 (1 068 900-60 148 700) cases in children and adolescents younger than 15 years living with sickle cell disease in sub-Saharan Africa in 2023. Regional prevalence (children aged <5 years, all sickle cell diseases) was highest in central Africa (2·07% [95% CI 0·30-12·76]), followed by west, southern, and east Africa. The burden was concentrated in populous countries, particularly Nigeria, Ethiopia, and the Democratic Republic of the Congo. Study quality was moderate overall and heterogeneity was substantial.

INTERPRETATION: Despite data gaps in many countries, the burden of sickle cell disease, especially in west and central Africa, underscores the urgent need to scale up newborn and early childhood screening, prophylaxis, vaccination, and comprehensive care within child health platforms, alongside strengthened surveillance to close evidence gaps and guide sustainable policy reforms.

FUNDING: None.