Published in PLOS One on 2025-11-25, this study is presented as an attributed evidence briefing. The excerpts below are the original researchers’ words, reproduced under their Creative Commons Attribution licence. Health Signal has selected the abstract and, where needed, opening background paragraphs; the complete methods, results, limitations and references remain in the linked paper.
Original authors: Bwambale Jonani, Emmanuel Charles Kasule, Bwire Roman Herman, Joel Fredrick Arturo, Mwesigwa Calvin Mugambwa, Ssebulime Stephen, John Bosco Mundaka, Richard Kwizera, Gerald Mboowa, Felix Bongomin
Source: PLOS One • DOI 10.1371/journal.pone.0337090
Read the complete primary study ↗ · Creative Commons Attribution licence
From the researchers
Abstract
Sickle Cell Anemia (SCA) is a significant genetic disorder in Africa; however, comprehensive data on its prevalence and geographic distribution remain limited. We aimed to estimate the pooled prevalence of SCA (HbSS) in African populations and examine regional, demographic, and temporal variations from 1994–2024.
We systematically searched PubMed, Scopus, Google Scholar, and BASE databases for studies reporting SCA prevalence in African populations. Screening and quality assessments were performed using JBI tools. A random-effects meta-analysis with logit transformation was performed, with subgroup analyses by region, age, sex, and study design. Meta-regression explored heterogeneity sources, including geographic region, age category, diagnostic method, study design, and publication year.
From 115 studies with 1,203,839 participants and 17,458 confirmed HbSS cases, the pooled prevalence was 1.43% (95% CI: 1.08%–1.88%), with substantial heterogeneity (I2 = 99.1%) and a prediction interval of 0.21%–8.91%. Central Africa showed the highest prevalence (1.99%), and Southern Africa showed the lowest (0.59%). Children exhibited a higher prevalence (1.65%) than adults (0.45%), while sex differences were non-significant (males 2.71%, females 1.74%; p = 0.694). The prevalence has remained stable over three decades despite a six-fold increase in research output, although wide prediction intervals indicated substantial between-study variability. Electrophoretic techniques predominated (86.4% of cases). Diagnostic method (χ² = 16.73, p = 0.033) and age category (χ² = 33.66, p < 0.0001) significantly moderated the prevalence. The multivariable meta-regression was marginally significant (χ² = 29.01, p = 0.066), but substantial residual heterogeneity persisted (I2 = 98.6%). Leave-one-out sensitivity analysis showed that no single study significantly impacted the pooled estimates.
SCA represents a substantial and geographically variable public health challenge across Africa. These findings highlight the need for region-specific interventions, expanded newborn screening programs, improved diagnostic accessibility with quality assurance for point-of-care technologies, and continued surveillance to address geographic gaps.
Introduction
Sickle cell anemia (SCA) is an autosomal recessive genetic disorder characterized by abnormal hemoglobin S in red blood cells, causing them to sickle when deoxygenated [1–3]. Severe forms include hemoglobin SS (sickle-cell anemia) from homozygous HbS inheritance and HbS/βo thalassemia from co-inheritance of HbS with a βo thalassemia mutation, where individuals produce no normal beta-globin [1,4,5]. Other variations involve co-inheritance of HbS with different β-globin gene mutations, such as hemoglobin C, hemoglobin D-Los Angeles/Punjab, or β+ thalassemia, which results in reduced beta-globin production [4,5].
Between 2000 and 2021, worldwide SCA diagnoses increased by 382 per 100,000 live births, rising from 453,000–515,000 [6]. The genotype distribution was as follows: 76.5% SS and Sβ° births, 19.6% SC births, and 3.9% Sβ + . Globally, SCA mortality has increased, with sub-Saharan Africa experiencing the highest rates [7]. In 2021, 29,400 individuals died from SCA in this region, a 30.1% increase from 2000, representing 2.2% of child mortality and the 11th leading cause of all-cause mortality [5,6].
Reading this evidence
Use the full paper to check the study design, participant selection, comparator and outcome definitions before drawing a practical conclusion. An association does not by itself show cause and effect. A reported performance measure needs its denominator and uncertainty. A finding from a particular facility, sample or time period should retain that scope when it is discussed elsewhere.
This briefing makes the source accessible within the wider technology & industry desk. It does not assess an individual patient or certify a product. When considering relevance to another health system, examine the original authors’ account of context and limitations, then seek local implementation evidence. The related reporting below provides other studies to read alongside this one; it is a topic connection, rather than a claim that their results are directly comparable.
© 2025 Bwambale Jonani, Emmanuel Charles Kasule, Bwire Roman Herman, Joel Fredrick Arturo, Mwesigwa Calvin Mugambwa, Ssebulime Stephen, John Bosco Mundaka, Richard Kwizera, Gerald Mboowa, Felix Bongomin. Excerpts reproduced under CC BY. Selection, formatting and contextual notes by Health Signal. The researchers are the authors of the source study, not members of Health Signal’s staff.
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