Malaria

Malaria spreads through bites from infected Anopheles mosquitoes.
Risk is higher in warm, wet areas with standing water.
Risk factors for malaria include travel or living in endemic regions, night-time exposure, and not using repellent or bed nets.
Young children, pregnant people, newcomers without immunity, and those with weak immune systems face higher risk of severe illness.
Some inherited traits can shift risk, and some risks are modifiable (things you can change), others are non-modifiable (things you can’t).

Genetic risk factors

Genes can influence how your body responds to Malaria parasites, shaping who gets infected easily and who develops severe illness. Some risk factors are inherited through our genes. A few well-studied red blood cell traits lower the chance of life-threatening malaria, while others can raise complications if infection occurs. Understanding genetic risk factors for malaria can also help explain why early symptoms of malaria may look milder in some people and more intense in others.

• Sickle cell trait: Carrying one copy of the sickle cell gene lowers the risk of severe malaria. The parasite struggles to grow in these red blood cells. Two copies cause sickle cell disease, which does not offer protection.

• Hemoglobin C variant: This hemoglobin change can reduce the chance of severe malaria. People with one or two copies may have milder infections.

• Thalassemia traits: Inherited reductions in hemoglobin (alpha or beta thalassemia) can protect against severe malaria. Carriers often have mild anemia but tend to face fewer life‑threatening malaria complications.

• G6PD deficiency: Some inherited G6PD changes appear to lower the chance of life‑threatening malaria. The effect can differ between males and females because the gene sits on the X chromosome. This trait also affects how red cells handle stress.

• Duffy-negative type: Lacking the Duffy protein on red blood cells blocks entry of the vivax parasite. This gives strong protection from vivax malaria but not from other types.

• Blood group O: People with type O blood have a lower risk of severe malaria. Their red blood cells form fewer clumps when infected, which may reduce complications.

• Ovalocytosis trait: An inherited red cell shape change common in Southeast Asia makes parasite entry more difficult. This can lower the chance of severe malaria.

• HLA immune types: Differences in immune genes can change how well the body recognizes malaria. Certain HLA patterns are linked to lower parasite levels and fewer severe outcomes. Effects vary by ancestry and region.

• Dantu blood group: This rare red cell variant found in parts of East Africa stiffens the cell membrane. Higher stiffness makes it harder for the most dangerous malaria parasite to invade.

• Other red cell genes: Variants in genes that control red cell receptors or calcium balance can shift malaria risk. Some reduce clumping or make cells less welcoming to the parasite. These effects are modest on their own but matter at a population level.

Transmission

Malaria spreads through the bite of infected Anopheles mosquitoes, which pick up the parasite when they feed on people with malaria. If you’re wondering how malaria is transmitted, it is not passed by casual contact, coughing, or sharing a home; people don’t give it directly to each other. Less common routes include blood transfusion, organ transplant, shared needles, and transmission from a pregnant person to the baby before or during birth. How infectious malaria is depends on the presence of these mosquitoes—where they are common, an untreated infection can lead to more cases as mosquitoes feed and pass the parasite on. In regions without Anopheles mosquitoes, infections in travelers usually don’t spread further, aside from rare events when an infected mosquito is imported.

When to test your genes

Malaria is an acquired infection, so genetic testing isn’t routine for diagnosis, but it can help in select situations. Consider testing if you have severe reactions to antimalarials (to guide drug choice), known red‑blood‑cell traits in your family (like G6PD deficiency or sickle traits), or unexplained severe malaria. Ask your clinician or a genetics professional.

Looking ahead can feel daunting, but most people with malaria recover fully when treatment starts early. Many living with malaria notice fever, chills, and fatigue that ease within a few days of the right medicines. Severe malaria—especially from Plasmodium falciparum—can move fast and affect the brain, lungs, or kidneys, which is why getting care quickly matters. Children under 5, pregnant people, and adults with other health conditions have a higher risk of complications, and in areas with limited medical access, the risk of death is higher. In places with strong healthcare systems, deaths from malaria are now uncommon, but globally the disease still causes hundreds of thousands of deaths each year.

The outlook is not the same for everyone, but people treated within 24–48 hours of early symptoms of malaria usually do well. Some may have lingering tiredness or anemia for a few weeks; for others, symptoms resolve quickly with no long-term effects. Certain types, like Plasmodium vivax or ovale, can “hide” in the liver and trigger relapses months later unless a specific follow-up medicine clears those resting forms. In medical terms, the long-term outlook is often shaped by both genetics and lifestyle—genetic traits like sickle cell trait can lower the risk of severe disease, and prevention steps such as bed nets, repellents, and prompt testing reduce future episodes.

Knowing what to expect can ease some of the worry. With effective treatment, most people return to normal activities soon after the fever breaks. Mortality is highest when diagnosis is delayed, when severe malaria develops, or when care is hard to reach; rapid testing and modern therapies have significantly improved survival. Talk with your doctor about what your personal outlook might look like, including relapse prevention if you had P. vivax or ovale, and what warning signs should prompt urgent care if symptoms return.

Malaria is treated quickly to clear the parasite, ease fever and chills, and prevent complications, with the exact medicines depending on the species (most often Plasmodium falciparum), where the infection was acquired, and local drug resistance. First-line treatment in many regions uses artemisinin-based combination therapy (ACT), which pairs an artemisinin drug with a partner medicine to kill parasites fast and reduce the chance of resistance; alternatives such as atovaquone–proguanil, quinine plus another drug, or mefloquine may be used based on availability, pregnancy, age, and resistance patterns. People with severe malaria usually need hospital care with intravenous artesunate (or quinine where artesunate is not available), fluids, careful monitoring for low blood sugar or anemia, and treatment for complications like breathing problems. If the infection is from Plasmodium vivax or P. ovale, doctors also prescribe a medicine such as primaquine or tafenoquine after the initial treatment to clear “dormant” liver forms and prevent relapse, with testing for an enzyme called G6PD to ensure safety. Ask your doctor about the best starting point for you, especially if you’re pregnant, traveling, or have other health conditions.

You don’t inherit malaria itself—the infection comes from mosquito bites. When people talk about genetic risk factors for malaria, they’re referring to inherited traits that change how your red blood cells and immune system handle the parasite. Genetics is only one piece of the puzzle, but certain gene changes can lower the chance of severe illness or influence which malaria species can infect you. For example, sickle cell trait and some thalassemia traits can blunt severe Plasmodium falciparum disease. An enzyme difference called G6PD deficiency may modestly change risk and also means drugs such as primaquine or tafenoquine require a safety test first. People who lack a red blood cell marker known as Duffy are naturally resistant to Plasmodium vivax. Parasite genetics matter too, because resistant strains can reduce how well certain medicines work in different regions.

For people living where malaria is common, other illnesses can change how severe it becomes and how it’s managed. HIV and malaria can worsen each other: HIV weakens immune defenses and raises the risk of severe malaria and treatment failure, while a malaria episode may briefly increase HIV levels in the blood and deepen anemia. In children, malaria can open the door to serious bacterial bloodstream infections, especially from Salmonella, which may complicate fever and make hospital care more likely. Intestinal worm infections and poor nutrition can add to malaria-related anemia and make early symptoms of malaria harder to spot. People with sickle cell disease face particular risks because malaria can trigger painful crises and dangerous drops in hemoglobin. Talk with your doctor about how your conditions may influence each other.

How genes can cause diseases

Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.

Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.