Africa carries most of the world's sickle cell disease and almost none of its cures

Three papers published within five weeks of each other describe the same problem from different ends. One estimates how many African children have sickle cell disease. One examines why most of them are never diagnosed. The third explains why the therapies that can cure the disease are, in practical terms, unavailable to almost all of them.

The count

Until now, the burden of sickle cell disease across much of Africa has been estimated from patchy data. A systematic review and modelling analysis published in The Lancet Child & Adolescent Health searched MEDLINE, Embase, Global Health (CABI) and African Journals Online for studies published between 1 January 2000 and 10 September 2025 reporting prevalence in children and adolescents under 15 in sub-Saharan Africa [s1]. Forty studies contributed 71 prevalence datapoints from 22 countries across all four subregions [s1].

Pooled 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 under five, and 1·78% (0·21–12·09) in children and adolescents under 15 [s1]. Broken down by haemoglobin phenotype, HbSS prevalence was 0·70% (0·15–3·44) in infants and 0·69% (0·17–2·80) in under-fives, while HbSC was 0·29% (0·06–1·46) and 0·28% (0·05–1·50) respectively [s1].

Applied to UN 2023 population denominators, those rates translate to an estimated 1,165,800 (95% CI 260,600–5,662,100) infants, 2,752,200 (632,700–12,253,200) children under five, and 8,854,800 (1,068,900–60,148,700) children and adolescents under 15 living with sickle cell disease in sub-Saharan Africa in 2023 [s1].

Those confidence intervals are enormous, and the authors do not hide it: study quality was moderate overall and heterogeneity was substantial [s1]. The under-15 estimate spans a factor of more than fifty between its lower and upper bounds. What the analysis establishes is not a precise number but a floor and a geography. Regional prevalence among under-fives was highest in central Africa at 2·07% (95% CI 0·30–12·76), followed by west, southern and east Africa, with the absolute burden concentrated in Nigeria, Ethiopia and the Democratic Republic of the Congo [s1].

Why the count is uncertain in the first place

The precision problem and the treatment problem share a root cause: most affected children are never diagnosed. A separate paper describing a portable diagnostic platform notes that WHO estimates 75% of diagnosed cases worldwide are in sub-Saharan Africa, that under-five mortality among affected children reaches as high as 90%, and that an estimated 80% of affected children remain undiagnosed [s3].

That paper reports results from a large-scale clinical study in Nigeria using a portable device pairing microchip electrophoresis for haemoglobin variants with wireless networks, designed for settings where laboratory infrastructure is thin [s3]. The stated aim is to shorten the path from test to clinic referral to follow-up, and to generate case reports that can feed national surveillance [s3]. It is a diagnostics paper, not an outcomes trial — it does not report whether earlier diagnosis changed survival in this cohort.

The cure gap

A review in BMJ Global Health takes up what happens after diagnosis. Haematopoietic stem cell transplantation is curative, but the review reports that only seven African countries — Algeria, South Africa, Tanzania, Morocco, Nigeria, Egypt and Tunisia — have established transplant programmes, that those centres are concentrated in urban areas, and that the procedure costs $100,000 to $200,000 per patient [s2]. Patients who travel abroad for transplant frequently return to health systems unequipped to manage complications or provide long-term follow-up [s2].

Gene editing was supposed to relax the binding constraint. Because approaches such as CRISPR-Cas9 and exagamglogene autotemcel modify a patient's own haematopoietic stem cells outside the body, they remove the need for a matched donor and the risk of graft-versus-host disease [s2]. The review notes that regulatory approvals in the United States and Europe affirm safety and efficacy, with durable increases in fetal haemoglobin and reduced vaso-occlusive episodes [s2].

Price is where it stops. The review cites US list prices of $3.1 million for Lyfgenia and $2.2 million for Casgevy, and notes these reflect only the direct cost of the gene therapy, before hospital stays and supportive care [s2]. The procedure requires apheresis to collect mobilised autologous CD34+ cells, ex vivo modification, myeloablative conditioning, and then weeks of severe cytopenias requiring regular transfusion support and prolonged stays in specialised transplant facilities [s2]. In health systems where most patients pay out of pocket and insurance coverage is limited, the review argues, that package is not merely expensive but structurally inaccessible [s2].

The barriers the review identifies beyond cost are the ones that take longest to fix. Most African countries lack guidelines addressing gene therapy and its research, and existing frameworks in some countries may not accommodate long-term follow-up requirements, management of off-target effects, or quality assurance of imported or locally manufactured products [s2]. Cold chain requirements and weak supply chains constrain distribution; manufacturing requires high-quality raw materials whose cross-border sourcing may be poorly regulated; and the workforce to manufacture and formulate cell and gene therapies would have to be trained largely from scratch [s2].

What is actually being built

The review points to work already under way rather than treating the gap as static. Tanzania, a member of the SickleInAfrica consortium, is developing sickle cell registries, newborn screening programmes, improved hydroxyurea access and clinical care initiatives [s2]. In 2021 the Sickle Cell Programme at Muhimbili University of Health and Allied Sciences launched a Sickle Cell Disease Advanced Therapy Programme intended to build researcher, clinician and advocate capacity for advanced therapies [s2].

It also holds up a comparison outside Africa. India's National Sickle Cell Elimination Mission, launched in 2023 and running to 2047, aims to screen 70 million people and expand access to treatment; gene therapy is not yet available there, but institutions are developing cost-reduced gene-editing tools and local production of CRISPR components and viral vectors [s2].

What to watch

The prevalence analysis ends with a policy conclusion rather than a scientific one: that the burden, especially in west and central Africa, underscores the need to scale up newborn and early childhood screening, prophylaxis, vaccination and comprehensive care within existing child health platforms, alongside stronger surveillance to close the evidence gaps [s1].

That ordering is worth noting. The cheapest interventions in sickle cell care — screening, penicillin prophylaxis, vaccination, hydroxyurea — are the ones the burden data point toward, and they are unglamorous next to a one-time genetic cure. The two papers together suggest the realistic near-term question is not when gene therapy reaches Lagos or Kinshasa, but whether the children who would eventually be its candidates are being identified at all.

Sources

• Prevalence estimates of sickle cell disease among children and adolescents in sub-Saharan Africa: a systematic review and modelling analysis, The Lancet Child & Adolescent Health, 20 April 2026
• Beyond hematopoietic stem cell transplantation: positioning Africa for scalable uptake of innovative sickle cell therapies, BMJ Global Health, 25 May 2026
• Enhancing access to sickle cell disease diagnosis in Africa using the Gazelle portable digital microchip electrophoresis platform, Blood Cells, Molecules and Diseases, 24 April 2026