Sickle Cell: A strange malaria advantage, but not immunity

For Rehema Ogutu, malaria is strangely not the enemy she has spent most of her life fearing.

Diagnosed with sickle cell disease (SCD) when she was only six months old, the 44-year-old has endured years of hospital admissions, blood transfusions and painful crises. Yet, living in Kisumu, a region where malaria remains a major public health concern, she says the mosquito-borne disease has barely featured in her long medical journey.

Her story is one that many sickle cell warriors in Kisumu share.

While their condition exposes them to severe anaemia, infections, painful crises and other potentially life-threatening complications, several warriors say they rarely, if ever, test positive for malaria. Some say they have gone more than a decade without being diagnosed with the disease, even when they experience symptoms that feel like malaria.

It is a curious reality that has left some warriors wondering whether sickle cell disease, or the genetic changes associated with it, somehow gives them an advantage against malaria.

Rehema says she was introduced to the reality of sickle cell disease almost immediately after birth. "I was diagnosed with sickle cell at the age of six months. Since then, I have been living with it," she says.

It has not been an easy journey. For years, she was in and out of hospital, experiencing crises that would interrupt her normal life. But over the past four years, approaching five, she says her situation has changed dramatically.

"I have not been in crisis. Not even malaria. I don't know the secret, but I think God is working something," she says.

She attributes her improved health partly to remaining faithful to her medication, including hydroxyurea and folic acid.

The only major challenge she currently faces is leg ulcers, which have become a persistent problem but malaria, despite Kisumu's location in the Lake Victoria basin, is not among her current health concerns.

Rehema recalls being diagnosed with malaria only once, more than a decade ago. It happened at a private hospital where she was tested and admitted after being found to have a high malaria parasite load.

She was treated and recovered.

"Since then, I have never had malaria. I only experience the symptoms of having malaria sometimes. You may feel tired, nauseous, you don't want to do anything or eat, but when you are tested, you find that you don't have malaria," she says.

Her experience is not unique. Rehema says conversations with fellow sickle cell warriors have repeatedly revealed similar experiences.

At a recent conference, she says, warriors compared their experiences with malaria and many reported that they also rarely tested positive for the disease. "We don't know the secret behind it. Maybe a doctor can clarify it more deeply," she says.

For her, however, the absence of malaria feels like an unexpected advantage.She understands that malaria in someone already living with SCD could create another layer of danger.

"Having malaria is not something somebody would like to experience. If you have sickle cell and at the same time you have malaria, it means you can have crises more often and be transfused now and then," she says.

Rita Achieng, 29, also knows what it means to grow up with sickle cell disease. She learnt she had the condition when she was 10 years old, although her mother had known from the time she was six months old.

Rita was frequently taken to clinics, admitted to hospital and sometimes transfused as a child. "Life has been up and down," she says.

But like Rehema, malaria has hardly been part of her story. Rita says she has sought medical care mainly because of sickle cell crises or infections rather than malaria.

She was told by healthcare workers that people living with SCD may not get malaria as frequently as others, although she was never given a detailed explanation for why this might happen.

For her, the distinction is important."If you have sickle cell and malaria at the same time, you will be admitted again and again, the crises will be there and your haemoglobin will go down. So it is an advantage for us," she says.

That perception of an advantage, however, needs an important scientific qualification. People living with sickle cell disease are not protected against malaria in the same way that people with sickle cell trait are. The genetic relationship between the two conditions is far more complicated.

The sickle cell gene became common in parts of Africa where malaria was historically widespread because carrying one copy of the gene offered protection against severe malaria. But inheriting two abnormal copies causes sickle cell disease, a serious blood disorder.

This distinction is critical in understanding the experiences of warriors such as Rehema and Rita.

Dr Dickens Lubanga, a paediatrician at Bungoma County Referral Hospital, says the relationship between malaria and sickle cell disease is rooted in genetics and evolution.

The sickle cell gene became more common in malaria-endemic populations because people carrying the trait had a survival advantage against severe malaria.

"The sickle cell gene developed in areas which had a lot of malaria before. The reason why it developed in areas which had malaria was to offer some kind of adaptation to the community," Dr Lubanga explains.

In simple terms, people with sickle cell trait, who carry one sickle cell gene and one normal gene, have some protection against severe malaria. People with sickle cell disease, however, inherit two abnormal genes and face the serious complications associated with the disease.

The Centers for Disease Control and Prevention says people with sickle cell trait usually do not have the symptoms of sickle cell disease,  although they can pass the gene to their children. When both parents have the trait, there is a 25 per cent chance that a child will inherit sickle cell disease.

Dr Lubanga says nature effectively selected for the trait because malaria was killing large numbers of people.

"If you have the trait, you are protected against malaria. But if you have the disease, it increases your chances of having complicated malaria if you get malaria," he says.

That distinction means that while Rehema and other warriors may observe that they rarely test positive for malaria, their sickle cell disease should not be considered a form of immunity. Instead, their experience sits within a complicated interaction between genetics, malaria and the way abnormal red blood cells behave.

Sickle cell disease occurs because of a mutation affecting the haemoglobin gene. The abnormal haemoglobin causes red blood cells to become rigid and sickle-shaped rather than remaining round and flexible. Normally, red blood cells move easily through blood vessels. Sickled cells, however, can become stiff, sticky and prone to clumping, blocking the flow of blood.

Dr Lubanga says the genetic mutation occurs on chromosome six and affects the haemoglobin produced by the body.

The resulting cells can polymerise and assume the characteristic sickle shape. That abnormal shape is at the centre of many of the complications experienced by warriors. When the cells block blood vessels, they reduce the flow of oxygen to tissues and organs, resulting in severe pain.

A blockage in blood vessels supplying the brain can result in a stroke. A blockage affecting the kidneys can contribute to kidney damage and eventually kidney failure. Blockages elsewhere can cause severe abdominal or limb pain, while complications involving the lungs can become life-threatening.

WHO describes SCD as a serious inherited blood disorder caused by a mutation in the HBB gene, resulting in abnormal sickle-shaped red blood cells that can block blood flow and cause severe complications.

The abnormal cells also die much earlier than normal red blood cells, contributing to chronic anaemia. This is why a sickle cell warrior can require regular medical monitoring, medication and, in some cases, blood transfusions.

Kenya records an estimated 14,000 babies born with SCD every year, with the highest burden concentrated around the Lake Victoria basin, western Kenya and the coastal region. Kenya's national infant-screening guidelines note that the burden of SCD follows malaria-endemic patterns and that without intervention, as many as nine in 10 children born with SCD in Sub-Saharan Africa may die before their fifth birthday.

Kisumu is among the most affected counties. Data from the Kisumu County Department of Health indicates that about 1,500 children are born with SCD annually, translating to approximately three to four out of every 100 newborns.

Globally, WHO estimates that about 7.74 million people were living with SCD in 2021, with nearly 80 per cent of cases occurring in Sub-Saharan Africa. In the same year, SCD was associated with an estimated 376,000 deaths globally when deaths attributable to complications are considered.

For Kisumu, the numbers become particularly significant because the county also sits within a malaria-endemic environment. Malaria remains one of Africa's biggest public health threats.

Kisumu's location around Lake Victoria makes malaria transmission a persistent concern. For a person with SCD, a malaria infection can be particularly dangerous because it can compound anaemia and trigger or worsen complications.

This is why the experiences of warriors who rarely test positive for malaria are intriguing.

Rehema says she has sometimes taken malaria tests when she feels feverish, weak or nauseated, only to be told that she does not have the infection.

She has occasionally bought antimalarial medicine herself after experiencing symptoms, even when tests were negative.

But medically, symptoms alone cannot establish malaria. Testing remains important because fever, weakness, fatigue and nausea can have many causes, including sickle cell-related complications and other infections.

Yvonne Adhiambo, a mother of two from Obunga, Kisumu, knows this first-hand. Her firstborn child does not have SCD, but her second child was diagnosed with the condition at the age of three.

She had seen the condition affect other children in her village and therefore understood how difficult the journey could become.

Her son has experienced periods of relative stability, including a stretch of almost one year without falling sick. But the crises eventually returned.

Yvonne says the illness affects virtually every part of her life, particularly because she lives in a low-income settlement.

Her son, like the warriors interviewed for this story, rarely gets diagnosed with malaria. Sometimes he develops fever and weakness and appears to have the symptoms of malaria. But after being taken to hospital, the tests come back negative.

"We were told by medics that some children with this condition have resistance to malaria, and that is an advantage to our children," she says.

But the advantage, she insists, cannot erase the pain of sickle cell disease. "The fact is, we are suffering when the pain comes in," she says.

Her family's struggles have also been compounded by the breakdown of support after the child's father left when he learnt of the diagnosis. Yvonne says the experience has taught her that families caring for children with SCD need stronger social support.

Her message to other mothers is to remain confident in their children and not allow the disease to define their future.

For Sharon Awuor, chief executive officer of Peperusha Binti, the stories of families such as Yvonne's demonstrate why awareness and practical support must go hand in hand.

Her organisation has spent about five years creating awareness and advocating on sickle cell disease in Kisumu.

The group also runs Coffee for Champions, a fundraising initiative through which supporters meet, discuss sickle cell disease and raise money to help children from vulnerable families. For the first four years, funds raised were used to purchase medication for children who could not afford treatment.

This year, the organisation changed its approach after recognising that buying medication repeatedly was not necessarily a long-term solution.

Through the 2026 fundraiser, the organisation paid health insurance contributions for seven children for one year, allowing them to access medication and healthcare services.

Over the five years, Awuor says, 47 families have benefited from the programme.

She says September's  Sickle Cell Awareness Month provides an opportunity to move the conversation beyond the disease itself and focus on prevention, testing, treatment and support.

For her, genotype testing should become an important part of discussions before marriage, especially in high-burden regions.

"Before you marry someone, kindly let us test for our genotype so that we reduce the number of children being born with sickle cell disease in our community, in Kisumu County and in our country at large," she says.