Sickle Cell Disease: Essential Information for Africans 

By: Tii Ngwachi Munghieng, MD. Medically reviewed by A. Odutola; MBBS, PhD, FRCSEd.

 

Comparison of normal round red blood cells with crescent-shaped sickle cells, which block blood vessels in sickle cell disease. Click on image toenlarge

 

Highlights 

• Sickle Cell Disease (SCD) is a genetic blood disorder common in Africans.

• SCD is marked by the normally round red blood cells taking on an abnormal (half-moon) crescent or sickle shape, which reduces their ability to travel normally through blood vessels.

•  SCD evolved as a genetic adaptation to malaria, providing some protection against the disease, which is prevalent in Africa.

• The Sickle Cell Trait (SCT) is common in sub-Saharan Africa too, with 20-30% of populations in countries like Nigeria and Cameroon affected.

• Due to this protective role of SCT against malaria, the survival rate from severe malaria is high, resulting in a high probability of producing children with SCD.

• SCD contributes significantly to child mortality, with estimates indicating that 50-90% of affected children may die before age five due to lack of treatment.

• Many regions in Africa face challenges in accessing comprehensive healthcare, worsening the burden of SCD

 

Introduction 

At least 240,000 children in Africa are born annually with sickle cell disease (SCD). [1] SCD is a common genetic blood disorder marked by red blood cells that take on an abnormal crescent (half-moon) or sickle shape. This impairs their ability to travel normally through blood vessels. Among the various forms of SCD, sickle cell anemia (SCA) is the most severe form.

The Sickle Cell Trait (SCT) plays a central role in the inheritance of SCD. SCT occurs when a person inherits one normal hemoglobin gene (HbA) and one sickle hemoglobin gene (HbS), typically causing no symptoms. However, when two individuals with SCT have children, there is a 25% chance the child will inherit SCD. This genetic mechanism contributes significantly to the high prevalence of SCD in Africa.

 

Fig. 1: Percentage prevalence of sickle cell disease in Africa. Image credit: Twum et al. 2023. Click on image to enlarge.

 

In many African countries, especially those in Central and West Africa (see figure  1) like Cameroon, Ghana, and Nigeria, SCD prevalence ranges from 20% to 30%, and in some regions of Uganda, it can reach as high as 45%. [2] Tragically, most children with severe forms of the disease die before the age of five.

This article explains why SCD is so common in Africans, examining the role of genetics, the sickle cell trait (SCT), evolutionary advantages, and the link to malaria.

 

Burden of Sickle Cell Disease in Sub-Saharan Africa

 

Burden of sickle cell disease in Africa, Click on image to enlarge.

 

Africa bears the heaviest burden of Sickle Cell Disease (SCD) globally. Worldwide, more than 300 000 children are born with sickle cell disease every year, and over 75% occur in sub-Saharan Africa. [3] 50-80% of people with SCD die before the age of five in some regions due to lack of diagnosis and treatment. [3]

SCD has no gender selection. It affects males and females equally, as it is inherited in an autosomal recessive manner, meaning the condition is not linked to sex chromosomes. [4]

 

The Burden of Sickle Cell Trait in Malaria-Endemic Sub-Saharan Africa

Sickle Cell Trait (SCT), the carrier state (HbAS), affects 15-30% of the population in sub-Saharan Africa. [4] SCT offers some protection against severe malaria, which explains its high prevalence in regions where malaria is endemic.

The Downside of Sickle Cell Trait

Although the sickle cell trait (SCT) is protective against malaria, when two partners with SCT give birth to a child, there's theoretically a 1 in 4 (25%) chance of the child having SCD. This occurs when an individual inherits two sickle cell genes (HbS)—one from each parent. These abnormal genes produce defective hemoglobin (oxygen-carrying unit in blood) called hemoglobin S. Under low oxygen conditions, this hemoglobin causes red blood cells to deform into a sickle shape, making them rigid and sticky. [4]

 

Sickle cell inheritance diagram showing a 1 in 4 chance of sickle cell disease (SS) when both parents have the sickle cell trait (AS). Click on image to enlarge.

 

The sickled cells:

• Clump together in blood vessels, blocking blood flow and causing pain (vaso-occlusive crises)

• Break down prematurely, leading to chronic anemia. [5]

• Damage organs, as oxygen requirements are compromised, resulting in long-term complications such as stroke, kidney disease, and organ failure. [3]

 

The Impact of Sickle Cell Disease in Africa

Due to the protective role of SCT against malaria, the survival rate from severe malaria is high, leaving a high probability of producing children with SCD. But SCD negatively impacts Africans in the following ways;

• High Mortality Rates: In sub-Saharan Africa, up to 80% of children with SCD die before the age of five, largely due to a lack of early diagnosis and proper management. [3]

• Chronic Health Challenges: Survivors face recurrent health issues, including severe and recurrent pain, infections, delayed growth, and multi-organ damage; all of which reduce their quality of life.

• Reduced Life Expectancy: Life expectancy for individuals with SCD in Africa is significantly lower than in the general population, often not exceeding 40 years in regions with inadequate healthcare. [6]

• Economic Burden: Families face immense financial stress due to frequent hospitalizations and treatment costs. The condition also affects national productivity as many patients cannot contribute fully to society. [2]

All of these cause a decline in the value of goods and services produced (GDP) in Africa in any given period.

 

How to Recognize Sickle Cell Disease

SCD can be recognized or diagnosed through many signs and symptoms.

Common Symptoms and Signs of Sickle Cell Disease

Sickle Cell Disease usually becomes apparent after 6 months of age, as fetal hemoglobin (HbF), which protects against symptoms, decreases. [5]

Common symptoms and signs include:

Infographics on common symptoms of sickle cell disease. Credit.

• Anemia: The rapid and continuous breakdown of sickled red blood cells (chronic haemolysis), leads to fatigue, pallor (pale appearance), and jaundice (yellow discolouration of tissues like the conjunctiva, skin, nails, etc) . Also, repetitive transfusion due to anemia in a child can indicate SCD.

• Pain Crises: Episodes of severe pain (vaso-occlusive crises) caused by blocked blood flow due to clumped sickled cells. These crises can affect the chest, back, abdomen, and joints.

• Poor Growth and Delayed Puberty: Chronic anemia and recurrent illnesses hinder physical development in children.

• Swelling of Hands and Feet also called (Dactylitis): This is an early symptom in children caused by blocked blood flow in small blood vessels.

• Frequent Infections: SCD damages the spleen, making individuals more susceptible to bacterial infections like pneumonia, meningitis, and sepsis (bacteria or toxins in the blood).

• Jaundice and Gallstones: Caused by excessive breakdown of red blood cells.

• Organ Damage: Long-term complications such as kidney disease, stroke, and heart problems.

 

How is Sickle Cell Disease Diagnosed?

SCD can be diagnosed when someone presents to a healthcare professional with  complaints like bone and joint pains, pale appearance, fatigue, etc.

The healthcare professional will take a detailed medical history, perform a physical examination and depending on the circumstances, may order some of the following tests to confirm a clinical diagnosis:

1. Blood-Based Laboratory Tests for Sickle Cell Disease

a) Sickle Cell Screening Test (Sickling Test)

• A basic test that checks whether red blood cells sickle (change shape) under low oxygen conditions. The test is common in many African settings due to its simplicity and affordability.

b) Hemoglobin Electrophoresis

• A more advanced test used to identify different types of hemoglobin in the blood.
• It confirms the presence of Hemoglobin S (HbS), the abnormal form of hemoglobin responsible for SCD.
• Hemoglobin electrophoresis is the gold standard but may not be widely available in rural areas due to costs and infrastructure challenges.

c) High-Performance Liquid Chromatography (HPLC)

• A precise and reliable method to detect abnormal hemoglobin variants, including HbS.
• While accurate, HPLC requires advanced laboratory equipment, which may be scarce in resource-limited settings.

d) Solubility Test

• A rapid test to check for the presence of HbS in the blood.
• It cannot distinguish between sickle cell disease and trait.

Other methods of SCD diagnosis like Newborn screening and genetic testing are gradually gaining ground in Africa.

2. Genetic tests (during pregnancy)

• Chorionic villus sampling: A prenatal test that studies a small piece of the placenta to check a baby's genetic makeup. 

• Amniocentesis: Another prenatal test that studies a small sample of amniotic fluid to check a baby's genetic makeup 

3. Other tests

• Imaging studies: Such as an ultrasound, CT scan, or MRI scan, to check for complications of SCD 
• Liver and kidney function tests: To check for kidney and liver damage 
• Cultures: To check for infections in the blood, urine, or other sites 
• Echocardiography: To evaluate the heart's function 

 

How is Sickle Cell Disease Treated?

While there is no universal cure for SCD, several treatments options can help patients live healthier lives. These include:

• Medications for symptoms
• Blood transfusion
• Lifestyle and supportive care
• Psychological support
• Bone marrow transplant

Below are simple explanations of how SCD is treated.

1. Medications to Manage Symptoms and Prevent Complications

a) Pain Relief

Pain crises are a common complication of SCD. Treatment includes:

• Over-the-counter pain relievers like acetaminophen or ibuprofen for mild pain.
• Prescription opioid for severe pain under close medical supervision.

b) Hydroxyurea

• A medication that reduces the frequency of pain crises and the need for blood transfusions.
• It works by increasing the production of fetal hemoglobin, which prevents red blood cells from sickling.

c) Antibiotics

• Penicillin is often given to children with SCD from birth until age 5 to prevent serious infections.

d) Folic Acid Supplements

• Helps the body produce new red blood cells and prevents anemia.

e) Crizanlizumab

• A newer treatment that reduces pain crises by preventing blood cells from clumping together.

2. Blood Transfusions

• Regular blood transfusions help treat severe anemia, prevent strokes, and manage complications.
• However, frequent transfusions can lead to iron overload, requiring medications like deferasirox to remove excess iron.

3. Lifestyle and Supportive Care

Patients with SCD can manage their condition by adopting healthy habits and working closely with healthcare providers. Self care options include:

a) Staying Hydrated

Drinking plenty of water prevents dehydration, which can trigger pain crises.

b) Eating Healthy Diet

Eating a balanced diet with adequate vitamins and minerals, including folic acid, supports red blood cell production.

c) Prevent Infections

Vaccinations, including the pneumococcal and meningococcal vaccines, protect against severe infections.

Prompt treatment with antibiotics is crucial when infections occur.

d) Regular Check-ups

Routine medical visits help monitor the disease, prevent complications, and ensure treatments are effective.

4. Psychosocial & Social Support

Living with SCD can be emotionally and socially challenging. Psychological and social support include:

• Counseling and Support Group: Connecting with others living with SCD can reduce feelings of isolation.

• Mental Health Care: Access to psychologists or counselors helps manage depression, anxiety, or stress related to the disease.

• Social Services Support: Transportation to and fro healthcare facilities and food vouchers are examples of social services support that public health managers and social services department provide to SCD patients in more advanced countries. These services are hardly available in SSA countries.

5. Bone Marrow Transplant (Stem Cell Transplant) 

This treatment is risky and not widely available in many parts of the world, especially in Africa. It is most successful in children with severe SCD who have a closely matched sibling donor.

 

Complications of Sickle Cell disease

Sickle cell disease can cause a host of complications due to organ damage, infections and blood clots. The complications can be grouped into acute or sudden, chronic or late and those associated with pregnancy as detailed in Table 1.

Table 1: Showing some common complications of sickle cell disease. Click on image to enlarge.

 

The processes underlying the various complications can be traced to the poor oxygen carrying ability of sickled red blood cells, their easy destruction, and their ability to stick to blood vessels and block them.

 

How is Sickle cell Disease Prevented?

While the sickle cell disease cannot be cured in most cases, it can be prevented by addressing its genetic transmission. Some preventive measures are outlined below;

1. Genetic Screening and Counseling

Screening and counseling are vital for preventing SCD in Africa, where premarital and prenatal genetic testing is often unavailable.

a) Premarital Screening

• Testing for the sickle cell trait before marriage is crucial for couples at risk of passing on SCD.
• In most African countries, premarital genetic screening programs have been introduced in some communities to identify carriers.

b) Genetic Counseling

• Couples who are both carriers of the sickle cell gene (AS genotype) can receive counseling on their reproductive options.
• Counseling helps individuals make informed decisions about family planning.

2. Community Awareness and Education

Many African communities have limited awareness about SCD and its genetic nature. Addressing this gap is crucial:

• Education Campaigns: Governments, health organizations, and community leaders should organize campaigns to teach people about SCD inheritance and prevention.

• Dispelling Myths: Cultural misconceptions about SCD (e.g., attributing it to curses or witchcraft) should be replaced with scientific explanations.

3. Reproductive Options for Carriers

For couples identified as carriers, there are several options to prevent having a child with SCD. These include:

a) In Vitro Fertilization (IVF) with Genetic Testing

Though expensive and not widely accessible in Africa, this method ensures that embryos without SCD are conceived.

b) Donor Gametes

Couples can choose to use sperm or eggs from donors who do not carry the sickle cell gene.

c) Adoption

Adoption offers an alternative for couples who want to avoid the risk of passing on SCD.

4. Newborn Screening and Early Intervention

While newborn screening does not prevent SCD, it ensures early diagnosis, which can reduce complications and improve quality of life with early quality care. Many African countries still lack widespread newborn screening programs. [7]

 

Challenges of Sickle Cell Disease Treatment in Africa 

SCD in Africa poses a lot of challenges both for patients, families, and healthcare systems. Some of these challenges are outlined as follows;

1. High Prevalence and Genetic Burden

Africa has the highest global burden of SCD, with 75% of the world’s cases occurring on the continent. Many children are born with the disease, but due to limited awareness and diagnosis, most remain untreated.

2. Limited Awareness and Education

Many people in African communities lack knowledge about SCD, its causes, and management. Stigma and misconceptions, such as associating SCD with curses or witchcraft, often prevent patients from seeking care.

3. Delayed Diagnosis

Newborn screening is rare in most African countries, leading to late diagnosis of SCD. Without early detection, children are more likely to suffer severe complications or die before the age of five.

4. Inadequate Healthcare Infrastructure

Healthcare systems in many African countries face challenges such as:

• Shortage of healthcare professionals trained in SCD care.
• Limited access to diagnostic tools, such as hemoglobin electrophoresis.
• Inconsistent availability of essential medications like hydroxyurea and pain relievers.

5. High Cost of Treatment

The cost of managing SCD is often unaffordable for families, especially in low-income settings. This includes the cost of medications, hospital visits, and blood transfusions, which are vital for managing the disease.

6. Frequent Complications

SCD causes many health problems such as pain crises, severe anemia, infections (due to a weakened immune system), stroke, etc. Due to the limited healthcare resources in Africa, these complications can result in disability or death.

7. Social and Emotional Challenges

Living with SCD often causes emotional and social difficulties. Patients often face stigma, discrimination, and isolation. Families also struggle with the emotional burden of caring for a child with a chronic disease.

8. Low Research and Policy Support

SCD research and policy development remain underfunded in Africa. This lack of attention limits progress in improving patient care, raising awareness, and supporting families.

 

Conclusion 

Sickle Cell Disease (SCD) continues to be a major health concern in Africa, affecting millions of individuals. While efforts to improve awareness, diagnosis, and treatment are ongoing, challenges such as limited healthcare infrastructure, high costs, and stigma persist. To improve outcomes, it is essential to focus on better access to early diagnosis, treatment, and support for individuals with SCD. By addressing these issues, Africa can significantly improve the lives of those affected and reduce the impact of SCD on the continent.

 

References 

1. Williams TN. Sickle Cell Disease in Sub-Saharan Africa. Hematol Oncol Clin North Am. 2016 Apr;30(2):343-58. doi: 10.1016/j.hoc.2015.11.005. Available from here.

2. World Health Organization Africa. Sickle Cell Disease in the African Region. [Internet]. 22 June 2010. [Cited January 15, 2025’ Available from here.

3. Makani, J., Cox, S. E., Soka, D., et al. Mortality in Sickle Cell Anemia in Africa: A prospective cohort study in Tanzania. PLOS One, 2011;6(2), e14699. Available from here.

4. Rees DC, Williams TN, Gladwin MT. Sickle-cell disease. Lancet. 2010;376(9757):2018–2031. doi: 10.1016/s0140-6736(10)61029. Abstract available from here.

5. Serjeant, GR. The natural history of sickle cell disease. Cold Spring Harbor Perspectives in Medicine, 2013;3(10), a011783. Available from here.
 

6. Weatherall DJ, Clegg JB. Inherited hemoglobin disorders: An increasing global health problem. Bulletin of the World Health Organization, 2001;79(8), 704–712. Abstract available from here.

7. Tshilolo L, Kafando E, Sawadogo M, Cotton F, Vertongen F, Ferster A, Gulbis B. Neonatal screening and clinical care programmes for sickle cell disorders in sub-Saharan Africa: Lessons from pilot studies, Public Health, 2008;122(9)933- doi: 10.1016/j.puhe.2007.12.005. Available from here.

 

Published: January 28, 2025

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