Malaria

Malaria is a disease spread by the bite of Anopheles mosquitoes. It is common in warm parts of the world, especially in places like sub-Saharan Africa, Asia, and Latin America. People who get malaria often feel very sick with fever, fatigue, vomiting, and headaches. In serious cases, it can make a person very ill or even cause death.

The disease is caused by tiny germs called parasites from the Plasmodium group. These parasites enter the body when a mosquito bites and then travel to the liver and blood. There are five kinds of these parasites, but three of them cause the most severe sickness.

Luckily, there are ways to prevent and treat malaria. Using mosquito nets and insect repellents helps stop mosquitoes from biting. There are also medicines that can prevent malaria and two vaccines approved by the World Health Organization. Even so, many people still get sick each year, especially in poor areas, because the disease is hard to control and some medicines don’t work as well anymore.

Etymology

The word malaria comes from old Italian words meaning "bad air." People long ago thought that diseases came from bad air around swamps. They called the sickness by other names like "ague" or "marsh fever" because it was common in wet, marshy places. The study of malaria is known as malariology.

Signs and symptoms

When someone gets malaria, they might feel very hot and cold, have a bad headache, feel sick to their stomach, or even throw up. In more serious cases, their skin might look yellow, and they could have trouble thinking clearly.

These feelings usually start about two weeks after a mosquito bite, but sometimes it can take longer. If the sickness gets very bad, it can hurt important parts of the body, like the brain or kidneys, and this can be very dangerous. It is important to get help right away if these severe signs show up.

Cause

Malaria happens when tiny germs called parasites from a group named Plasmodium get into a person’s body. These germs are carried by special mosquitoes called Anopheles.

When an infected mosquito bites a person, it puts these germs—called sporozoites—into the blood. The germs travel to the liver, where they grow and multiply. After a few days, they leave the liver and enter the blood, where they infect red blood cells. Inside these cells, the germs grow and split, making many new germs. This causes the symptoms of malaria, like fever and feeling very tired.

Some germs stay hidden in the liver and can cause the sickness to come back later. Only female Anopheles mosquitoes spread malaria because they need blood to survive. They usually bite at night. Malaria can also very rarely be passed through blood transfusions, but this is uncommon.

Pathophysiology

Further information: Plasmodium falciparum § Pathogenesis

Malaria starts when a mosquito bites a person and puts tiny organisms called sporozoites into their blood. These sporozoites travel to the liver and grow inside liver cells for about 8 to 30 days. After this time, they break out and enter the blood, infecting red blood cells. Inside these cells, they grow and multiply, then break out again every 2 or 3 days. This breaking out causes fever and other symptoms.

Some types of malaria can hide in the liver for months or even years before becoming active again. This can cause the disease to return after a long time.

The body tries to fight off malaria, but the organisms have ways to hide. In the liver, they hide inside cells that protect them. Once they move into red blood cells, they change their surface to avoid being detected by the body’s defenses. They also stick to other cells or walls in the body, which can cause problems like severe illness.

Some people have natural protections against malaria. For example, certain changes in their blood can make it harder for the malaria organisms to survive. These changes can cause side effects, but they also help prevent severe malaria.

Diagnosis

Main article: Diagnosis of malaria

Malaria can be tricky to recognize because its signs look like other illnesses. Doctors usually think about malaria if someone has a fever or a temperature above 37.5 °C and no clear reason for it. In places where malaria is common, doctors also watch for signs of low strength in children, like pale palms or low blood strength levels.

The best way to know for sure if someone has malaria is to test a blood sample. Looking at a special stain of blood under a microscope is the most trusted method. Quick tests that find pieces of the germ in a small blood drop are also used, especially where microscopes aren’t available. These quick tests are fast and easy to use, but they have some limits. In April 2026, new quick tests were approved to better find certain types of malaria that can hide from older tests.

Treatment

Malaria is treated with special medicines called antimalarial medications. Since 2001, doctors usually give two medicines together to make sure the sickness goes away completely and to stop the germs from getting used to the medicine. One of these medicines is usually a type called artemesinin, and the other is a different medicine that helps. The exact medicines used depend on what kind of germs caused the sickness, where the person lives, and their health history.

There are different kinds of medicines that can be used together. Some include artemether and artesunate, while others are like chloroquine or quinine. For simpler cases of malaria, people can take medicine by mouth for a few days. For more serious cases, special medicines given into a vein are needed, and the person needs to be watched very closely.

Sometimes, the germs can get used to medicines and become harder to treat. This is why it’s important to use the right medicines and follow the doctor’s instructions.

Prognosis

When people with uncomplicated malaria get the right treatment, they can usually get better completely. But severe malaria can get very bad very quickly and can even cause death in just a few hours or days. In the worst cases, even with special care, about 1 in 5 people may not survive.

Malaria can also harm many parts of the body, like the brain, kidneys, liver, and spleen. For children, malaria can cause a lack of healthy red blood cells and damage the brain directly. Those who survive brain damage from malaria may later face problems with thinking, behavior, and seizures.

Prevention

There are several ways to help stop malaria. These include getting a vaccine, taking special medicines, stopping mosquitoes from biting, and keeping mosquitoes away.

Vaccines

It has been hard to make a good malaria vaccine because the germs that cause malaria change a lot. Two vaccines have been approved to help protect children from malaria. The first one, called RTS,S or Mosquirix, started being used in some African countries in 2019. By 2023, over three million children had gotten this vaccine, and it helped lower the number of malaria cases. The second vaccine, R21/Matrix-M, was approved in 2023 and has been shown to work very well in stopping malaria in children.

Mosquito control

Main article: Mosquito control

Stopping mosquitoes from biting people is very important. This can be done in several ways, such as using special clothing, treating water around homes so mosquitoes can’t breed, and using nets that are treated with safe chemicals to kill mosquitoes. These methods have helped lower malaria cases a lot.

Personal protection

Insect repellent and loose clothing that covers most of the body are good ways to keep mosquitoes away. Clothing can also be treated with a safe chemical to help stop mosquitoes from biting.

Environmental control

Since many mosquitoes breed in standing water, emptying water from containers around the home can help stop mosquitoes from growing. Using special treatments in water that can’t be drained is another way to kill mosquito babies.

Indoors

Using nets that are treated with safe chemicals and spraying the inside walls of homes with special treatments can help stop mosquitoes from spreading malaria. These methods have been very useful in lowering malaria cases.

Insecticide-treated nets

Mosquito nets help keep mosquitoes away from people. Nets treated with safe chemicals are even better because they can kill mosquitoes before the mosquitoes can bite. These nets work best when used at night and have helped prevent many cases of malaria.

Indoor residual spraying

Spraying the inside walls of homes with safe chemicals can kill mosquitoes that rest there after biting. This helps stop mosquitoes from spreading malaria to others.

Structures

Putting screens on windows and doors can stop mosquitoes from coming inside homes. This is a good way to keep mosquitoes out without changing daily habits.

Limitations in vector control

As more chemicals are used to stop mosquitoes, some mosquitoes can become resistant to them. This means the chemicals don’t work as well anymore. Mosquitoes can also change their behavior, like biting at different times or resting outside, which makes it harder to stop them.

Preventive medication

Special medicines can help prevent malaria for people traveling to places where malaria is common. These medicines need to be taken before, during, and after the trip. They are not usually used for people who live in areas with malaria because of cost and possible side effects.

Others

Teaching people about malaria and how to stop it can help lower cases. This includes covering standing water where mosquitoes breed and recognizing malaria early. These steps are especially helpful in crowded areas where malaria can spread easily.

Epidemiology

According to the World Health Organization's 2025 World Malaria Report, there were about 282 million new cases of malaria around the world in 2024, with 610,000 deaths. Children under five years old were most affected, making up 75% of malaria deaths in Africa that year.

Malaria is spread by mosquitoes called Anopheles, and it is common in tropical and subtropical areas where these mosquitoes thrive. This includes parts of the Americas, Asia, and Africa. The disease was once found in Europe and North America but is no longer common there. However, since 2015, the WHO European Region has been free of malaria, though travel-related cases still happen. The United States stopped malaria as a major health issue in 1951, but some cases are found each year in travelers returning from areas where malaria is common. Africa still has the most cases and deaths, with 95% of the global burden.

People most at risk from severe malaria include young children, pregnant women, and those with weakened immune systems, such as people affected by HIV/AIDS. Travelers to areas where malaria is common are also at risk because they lack immunity.

Climate change

Climate change may affect malaria spread, but the exact impact and areas affected are not certain. Changes in temperature and rainfall in Africa since 1900 might influence mosquito numbers and breeding.

Changes in geographic distribution

Climate change has caused malaria to spread to higher altitudes and areas that were previously free of the disease. Warmer temperatures allow mosquitoes to live in places that were once too cold, such as highland areas in Africa, South America, and parts of Asia.

Increased transmission season

Warmer temperatures and changes in rainfall have led to longer malaria seasons in tropical regions. In some parts of Africa, the season has lengthened by several months. In regions like West Africa and parts of India, rising temperatures and longer rainy seasons have increased malaria cases.

Effects of extreme weather events

Extreme weather events like heavy rain, flooding, and droughts can create good breeding places for mosquitoes. Flooding creates standing water, while droughts can lead people to store water in open containers, both of which help mosquitoes thrive. This has been seen in parts of sub-Saharan Africa and South Asia.

Resistance and adaptation of vectors

Warmer temperatures speed up the growth of malaria parasites in mosquitoes and have been linked to mosquitoes becoming more resistant to insecticides, making it harder to control malaria. A global survey found that Anopheles mosquitoes in Africa, Asia, and South America have developed resistance to common insecticides like pyrethroids.

History

Main articles: History of malaria and Mosquito-malaria theory

The parasite that causes one type of malaria has existed for between 50,000 to 100,000 years, but it only became more common about 10,000 years ago, around the same time that farming and villages began. Ancient writers, like the Roman Columella, noticed fevers that came and went, which might have been malaria. In places like southern Italy, Sardinia, the Pontine Marshes, and near the Tiber River in Rome, there was lots of standing water where mosquitoes could breed.

Malaria was brought to the Americas by Europeans and enslaved West Africans in the 1500s. In 1880, a French doctor named Charles Louis Alphonse Laveran saw the malaria parasite inside red blood cells and proved that it causes the disease. Later, other scientists showed that mosquitoes spread malaria.

In 1897, a Scottish doctor named Sir Ronald Ross proved that mosquitoes carry malaria from one person to another. His important work helped save many lives.

The bark of the cinchona tree, which grows in the Andes, was used for centuries to treat fever, including malaria. In the 1800s, scientists learned to extract a medicine called quinine from the bark. Later, other medicines were developed, but some kinds of malaria became resistant to them.

In the 1940s, a new medicine from a plant called Artemisia annua was discovered and is now used to treat severe malaria.

Eradication efforts

Main article: Eradication of malaria

There have been two major global efforts to stop malaria. The first was led by the World Health Organization from 1955 to 1969. The second began in the 21st century through the United Nations' Millennium and Sustainable Development Goals. By 2025, malaria had been eliminated or greatly reduced in many parts of the world, such as most of Europe, North America, Australia, North Africa, the Caribbean, parts of South America, and Asia. However, it remains common in much of central Africa.

The first effort used a chemical called DDT to control mosquitoes and quick treatment to stop the disease from spreading. It successfully removed malaria from many places, but stopped working well when mosquitoes became resistant to DDT and medicines lost their power. The program stopped in 1969, and focus shifted to other ways to fight malaria, like using bednets with insecticides.

In 2000, malaria control became an important goal of the United Nations. From 2005 to 2014, much more money and tools like bednets and quick tests helped reduce cases and deaths. By 2015, many countries were close to stopping malaria, but progress slowed after that due to challenges like climate change, conflicts, and mosquitoes becoming resistant to medicines. The World Health Organization updated its strategy in 2021 to keep working toward a world with little to no malaria by 2050.

Society and culture

Economic consequences

Malaria is not just a disease linked to poverty; it can actually cause poverty and slow down economic growth. Countries with malaria often have much lower average incomes compared to those without it. For example, in 1995, countries with malaria had an average income about five times lower than those without.

Poverty also makes people more likely to get malaria because they can't afford prevention or treatment. The economic impact of malaria in Africa is very high, costing about US$12 billion each year. This includes healthcare costs, lost workdays, and problems with education and tourism. Severe malaria, especially in children, can cause lasting health issues that affect learning and productivity.

Counterfeit and substandard drugs

Some countries in Asia have found fake or poor-quality medicines for malaria. These fake drugs can be very dangerous because they don’t work properly. The World Health Organization has set up a system to quickly share information about these fake medicines so that authorities can act. Fighting fake drugs is important to keep people safe.

War

Malaria has affected many wars throughout history. During World War II, malaria was a big problem for soldiers, especially for U.S. troops in the South Pacific. Many soldiers got sick, and it affected military operations. Countries like Germany also faced losses from malaria and spent resources to prevent it. The U.S. started a program to control malaria around military bases, which later helped form the Centers for Disease Control and Prevention.

Research directions

Scientists are working together globally to find better ways to stop malaria. In 2007, they made a plan called malERA to guide future research. By 2015, they updated this plan to include six important areas: basic science, fighting drug resistance, understanding how malaria spreads, tools to stop it, combining different methods, and health policy research.

Researchers have been trying to create a malaria vaccine since the 1960s. As of February 2026, two vaccines are being used after successful tests. There are three main types of vaccine being studied. Some aim to stop the infection before it reaches the liver, others target the infection in the blood, and some try to stop the spread of the disease to mosquitoes.

Scientists are also looking for new medicines because malaria can become resistant to existing drugs. They study how to make current drugs work better and explore new targets in the parasite, like its proteasome, proteases, and kinases.

Research on mosquitoes focuses on understanding which species spread malaria and finding ways to control them, including possible genetic changes.

Because malaria is linked to poverty, researchers also study social and economic factors that make it harder to stop the disease. They look at improving access to diagnosis and treatment, especially in areas that lack resources, and understanding community views to encourage the use of preventive tools like bed nets.

New technologies, such as climate data and artificial intelligence, are being used to predict malaria outbreaks. These tools help health workers act before outbreaks happen.

Recent advances in genetics offer new ways to control malaria. Scientists are studying how to change mosquitoes using gene editing tools like CRISPR-Cas9 to either make them resist malaria parasites or prevent them from having offspring. These ideas are still new and need careful thought, but they could be very helpful alongside current methods.

Other animals

Malaria is not just a problem for humans; it can also affect animals. While the main types of malaria that infect people do not spread from animals, some types can infect both humans and monkeys. Scientists study these animal infections to better understand human malaria.

Many animals, including birds, reptiles, and mammals, can get malaria. For example, some types mainly affect birds and can harm bird populations in places like Hawaii and the Galapagos Islands. Climate changes may also affect how widespread these infections become.

References and notes