The literature search was carried out through PubMed^® (https://pubmed.ncbi.nlm.nih.gov/), Google Scholar (https://scholar.google.com/), and ScienceDirect (https://www.sciencedirect.com/), employing a combination of Boolean operators (and, or) and predetermined keywords. Our search terms were ‘hemoglobinopathies and Africa or blood disorders and Africa’, ‘sickle cell disease and Africa’, and ‘thalassemia disease and Africa’. To ensure the relevance of our findings, we restricted the search to publications between January 1981 and December 2022. The titles of the articles were selected based on the following eligibility criteria: (1) the study location must be within Africa, and (2) the study must have reported the detection of sickle cell or thalassaemia disease or both. For an article to be considered, it must have reported the number of newborns screened, the number of haemoglobinopathies detected, and the testing method employed to identify the specific haemoglobinopathy. Studies without a direct focus on haemoglobinopathies in Africa and studies that did not provide information on the method used for screening were excluded (Figure 1). Research articles and systematic reviews with metadata that suited the inclusion criteria were retrieved. In addition, we conducted supplementary validation by thoroughly reviewing the references cited in the eligible articles.

Data were extracted into a Microsoft Office Excel 2016 (Microsoft Corporation, Redmond, Washington, United States) spreadsheet. For each eligible study, data extracted included study location or geographical zone, publication year, screening period, newborns screened, haemoglobinopathies tested, and the testing method used. The percentage prevalence of sickle cell and thalassaemia diseases reported for each study was calculated by dividing the number of haemoglobinopathies detected by the total number of newborns screened for haemoglobinopathies, multiplied by 100. Packages found in R-studio (Posit, Public-Benefit Corporation, Vienna, Austria), such as ggplot2 and tidyverse, were used to generate the geographical zones with colour codes, using the calculated prevalence.

According to the World Health Organization, in 2010, defective haemoglobin genes affected around 5% of the world’s population; more than 300 000 infants are born with clinically severe haemoglobin abnormalities yearly. Research shows these figures will increase from 305 800 in 2010 to 404 200 in 2050.¹¹ Although about 80% of affected children are born in underdeveloped countries, 83% are born with SCD, with the remainder having thalassaemia syndromes.¹⁶ About 50% to 80% of children with SCD and more than 50 000 children with major thalassaemia die in low- and middle-income countries.¹¹ Fortunately, NBS with comprehensive care for SCD has been found to reduce early child mortality.¹⁷ As of 2023, no African country had succeeded in making SCD a universal national health intervention.^18,19,20 However, pilot screening programmes have been conducted by the member countries of the Consortium on Newborn Screening in Africa, such as Kenya, Ghana, Liberia, Nigeria, Tanzania, Zambia and Uganda, and by other non-consortium members, such as Benin, Burkina Faso, Democratic Republic of Congo, Gabon and Mali.

The data analysis from NBS programmes in Africa shows that SCD is prevalent among populations in Central and West Africa (Figure 2a). More SCD prevalence exists in individuals residing in the Democratic Republic of Congo. Conversely, β-thalassemia is prevalent among people in the northern parts of Africa (Figure 2b), with Algeria and Morocco having the highest prevalence.²¹ In Algeria and Morocco, ~75% are Caucasians of Arabic origin, while the Congolese are multi-ethnic, with a significant percentage of black people. It is well documented that Arab countries, such as Morocco, have consanguinity of up to 30% and contribute significantly to the increased prevalence of inherited metabolic errors.²² Conversely, while SCD affects approximately 1 in 365 live births among Africans, the sickle cell trait is found in about 1 in 13 Africans.²³ Apart from Tunisia, where the prevalence of SCD is 9 in 10 000, the incidence of SCD is high in the western and central parts of Africa.

Although the lack of testing and the limited literature have contributed to the scarcity of data on haemoglobinopathy testing in Africa, some countries have been making massive efforts to pilot robust NBS programmes to identify a selected number of these conditions. Our literature search made it increasingly apparent that obtaining data for haemoglobinopathy testing and disease prevalence for more than 50% of African countries became difficult. From 2014 to 2019, Uganda screened more than 220 000 newborns in Africa (Table 1) and is one of the African countries involved in mass screening through pilot programmes. In addition, other countries such as Ghana and Angola participate in mass testing via pilot programmes (Table 1). Isoelectric focusing has been Africa’s most widely used diagnostic haemoglobinopathy technique due to its higher resolution, low cost, and effortless performance.²⁴

A study was conducted in the northern part of Algeria and α-thalassemia was prevalent.²⁵ In Morocco, a study was conducted in three of the northern provinces, and α-thalassemia was also prevalent.³⁸ For the Republic of Congo, a study was conducted in 12 departments in the entire national territory of Congo, and SCD was prevalent.²⁶ In Malawi, a study was conducted in the central region of Malawi, and α-thalassemia was prevalent.³⁷ In Sierra Leone, a study was conducted on selected participants from the rural and urban areas, and β-thalassaemia was prevalent.³⁹

Testing for haemoglobinopathies is essential for early diagnosis and appropriate treatment. However, several challenges and limitations are associated with haemoglobinopathy testing in Africa. Here, we discuss the critical challenges with haemoglobinopathy testing in Africa and strategies to mitigate these challenges.

In Africa, interventions to control haemoglobinopathies focus on using primary healthcare and health promotion strategies to ensure policy formulation and implementation, legislation and regulation, and improving primary and secondary prevention measures.

One of the main strategies is to partner with local health organisations.¹⁹ Partnerships with local health organisations involve working with hospitals, clinics, community health centres, and other organisations to develop educational materials and outreach programmes to raise awareness about haemoglobinopathies and their impact on health.

National programmes for haemoglobinopathies, especially SCD and thalassaemia disorders, must be established and strengthened to prevent and control non-communicable diseases and should work together with national programmes for maternal and child health.⁵⁷ Key focus areas include advocacy, prevention and counselling, early detection and management, data collection and monitoring, research, community education, and collaboration. An integrated, multi-sectoral, and multi-disciplinary team of healthcare and social workers, teachers, parents, and concerned non-governmental organisations could address these areas. This team would focus on practical aspects of care delivery and programme implementation and monitoring.

Additionally, establishing genetic counselling and testing measures is essential.⁵⁸ Through genetic counselling, carriers of haemoglobinopathies can learn the risks of passing the disease on to their children, and receive guidance on family planning and reproduction options; this can help prevent the transmission of haemoglobinopathies through informed decision-making by families. Widespread community participation and support are required to ensure individuals have access to these services and promote awareness and education about haemoglobinopathies.

Implementing community-based actions, such as surveillance and supervision, monitoring at all levels of operation, and periodic national review, will ensure that accurate and timely data is collected and used to guide decision-making.⁵⁷ Community-based surveillance and supervision can involve training community health workers to identify and report cases of haemoglobinopathies and providing education and support to affected individuals and families. Monitoring at all operation levels, from the local to the national level, can help ensure that data are collected consistently and accurately and that appropriate data-backed interventions are implemented. Periodic national reviews can identify haemoglobinopathy prevalence and incidence trends and surveillance system gaps. These data can then inform policy making and day-to-day programme management decision-making, such as allocating resources for prevention and treatment programmes, developing guidelines for screening and diagnosis, and providing training and support for healthcare providers.

Promoting pilot programmes is another strategy for expanding haemoglobinopathy detection in Africa. Newborn screening programme pilot initiatives for haemoglobinopathies are being implemented in Angola,²⁷ Nigeria,⁵⁹ Ghana,⁶⁰ the Democratic Republic of Congo,^26,61 and the Republic of Benin.³⁰ However, many African countries do not have universal national NBS programmes for SCD and other haemoglobinopathies.

Haemoglobinopathies, such as SCD and β-thalassemia, are genetic disorders caused by abnormal haemoglobin affecting red blood cells. In Africa, several challenges limit the testing for these disorders, including a lack of resources, limited access to testing facilities, migration, financial constraints, lack of awareness, and stigma. To improve access to quality healthcare services and raise awareness of African haemoglobinopathies, we propose using affordable diagnostic tools, mobile clinics, government subsidies, education campaigns, and establishing records or registries. The future may see these proposed strategies implemented to improve healthcare services for African haemoglobinopathies.