Malaria: What to know about the world’s deadliest parasite

What is malaria?

Malaria is caused by five species of single-cell parasites in the Plasmodium genus group, and it is spread by the bite of infected female Anopheles mosquitoes. The parasite multiplies within red blood cells, eventually bursting them and entering the bloodstream. 

Symptoms of malaria

Malaria can start off feeling like a flu. Malaria can cause fever, chills, sweating, headache, and muscle aches. In severe cases, liver failure, seizures, abnormal bleeding, coma, or respiratory distress can develop. Without proper treatment, severe malaria can cause death within a few hours.  The disease also destroys red blood cells, causing anemia, especially in children and pregnant women. 

In severe cases of malaria, the parasite attacks the brain as well as the liver, potentially causing seizures, coma, breathing problems, kidney failure, and severe anemia. An estimated 8 million people develop life-threatening complications from malaria each year.

Treating malaria

Artemisinin-based combination therapies (ACTs) are the recommended first- and second-line treatment for uncomplicated malaria. ACTs are highly potent, fast-acting (parasite clearance is fast and people recover quickly), very well tolerated, and complementary to other classes of treatment.

The cost of an antimalarial medication can be as low as 40 cents, but for many at-risk people, accessing health care and medicines is the true challenge.

How can malaria be prevented?

MSF programs incorporate various prevention approaches, depending on context—from the distribution of mosquito nets to spraying chemicals to kill larva to prevent the breeding of mosquitoes. In some affected regions, malaria is highly seasonal, with the number of infections increasing exponentially during the few months of the rainy season.  

6 facts you should know about malaria

1.    Malnutrition can worsen the effects of malaria

Malnutrition the inability to take in enough food, or to fully utilize the food you eat, and is one of the single greatest threats to global public health. It is particularly devastating for children, whose developing immune systems can be severely impaired by acute cases, making them more vulnerable to other diseases.

A dual diagnosis of malaria and malnutrition can be fatal if not treated promptly. In remote communities in Angola, for example, it can take hours or days to reach a medical facility. To help people prevent and treat this common dual diagnosis, in 2023 MSF teams in Angola trained local health workers to treat mild cases of malaria and other diseases. This training included learning how to identify children who need additional care, so they could be referred to more specialized health facilities. 

2.    Climate change is increasing the risk of malaria in several regions

Climate change has increased the length and intensity of rainy seasons in many parts of the world,  which in turn creates ideal conditions for the mosquitoes that carry malaria, which breed in standing water.

Madagascar’s cyclone season typically lasts from October to May, but in recent years due to climate change the country has been severely affected by extreme weather events that challenge access to health facilities and threaten the overall state of health and nutrition. According to the World Health Organization, the rates of malaria cases and deaths in Madagascar increased by 25 to 55 percent between 2015 and 2022.

In Ikongo district, which already experiences a humid tropical climate, the effects of climate change are particularly severe: Many villages are surrounded by marshes and rivers, and heavy rains cause the flooding of plantations and rice fields.

Climate shocks have also increased in intensity in South Sudan, where devastating recurring floods over the past four years have not only displaced people but have increased the risk of diseases, as stagnant water left after extreme flooding serves as a breeding ground for mosquitos. Most patients we see at the hospital South Sudan’s Old Fangak have malaria, especially during the rainy season.

3.    Pesticides can be used indoors and outdoors to lower malaria risk 

Indoor spraying helps people lower their malaria risk in their homes; treating indoor surfaces kills the mosquitoes that transmit malaria. 

In Niger, MSF is supporting an indoor spraying campaign in villages with the highest malaria rates, where homes are sprayed at the onset of the peak malaria season.

4.    Remote areas are at particular risk of malaria 

In many remote areas, health care is hours or days away and can be expensive to reach. When time is of the essence, mild cases can rapidly progress and require treatment. 

Indigenous communities in Brazil's Yanomami community in the Amazon live next to areas that have been affected by illegal mining, which has caused extensive environmental degradation including by leaving large holes in the ground that fill with rainwater, creating ideal conditions for mosquitoes to breed. To help communities tackle the spike in malaria, MSF uses an active case detection strategy, with teams traveling long distances each day, by boat or on foot, to reach remote villages and test people for the disease.

5.    Displacement and war also increase malaria risk

Conflict and displacement interrupt people’s access to many basic necessities, such as clean water and hygiene. In South Sudan, where more than 800,000 people have fled to from Sudan over the past year and a half of war, shelters that were meant for temporary use are being used long-term, worsening already-poor sanitary conditions and further limiting access to health care due to overcrowding. During the rainy season in October 2023, MSF medical facilities in the area recorded a 70-percent positivity rate of malaria.

6.    Antimicrobial resistance could threaten our ability to treat malaria in the future

Antimicrobial resistance (AMR) is when microbes evolve to survive the use of medicines, such as antibiotics, against them. This can make medical care less effective for people with AMR, and treatments that could potentially save their life  may not work anymore. 

In southeast Asia, MSF teams are actively researching the emergence of artemisinin-resistant malaria and piloting strategies to combat it. We’re also working to find and treat patients with artemisinin-resistant strains of malaria, and adapting strategies and tools to better meet the challenges of resistance and malaria elimination.

How is MSF helping fight malaria around the world?

Malaria is one of the most common diseases MSF treats, and in 2023 we treated more than 3.7 million cases of malaria around the world.  Our malaria strategy focuses on improving prevention measures, reaching and treating the most vulnerable people, and enhancing advance planning for malaria seasons in the most affected regions where we work. 

One of the biggest challenges in fighting malaria is making sure people living in remote areas can access care. Using mobile clinics, our teams travel to remote villages to test for and treat malaria, and transfer those already severely sick to hospitals. 

Community health workers are also an important part of our malaria strategy, helping to reinforce prevention practices and educating people about the importance of using mosquito nets and seeking treatment for children when they have a fever. 

Our work on malaria 

In 2024, MSF projects helped treat malaria several countries. In Madagascar and Democratic Republic of Congo, and South Sudan recent climate events including torrential rains and flooding have increased breeding grounds for the mosquitos that spread malaria. In Sudan and Chad, MSF is helping people affected by displacement and Sudan’s ongoing war, where the lack of access to health care makes preventable conditions more difficult to treat.