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Causes - Malaria

Malaria is caused by the plasmodium parasite. The parasite spreads to humans through the bites of infected mosquitoes.

Types of plasmodium parasite

There are many different types of plasmodium parasite. Only 5 types cause malaria in humans.

Plasmodium falciparum

Mainly found in Africa. It's the most common type of malaria parasite and is responsible for most malaria deaths.

Plasmodium vivax

Mainly found in Asia and South America. This parasite causes milder symptoms than Plasmodium falciparum. But it can stay in the liver for up to 3 years, which can result in relapses.

Plasmodium ovale

Uncommon and usually found in West Africa. It can remain in your liver for several years without producing symptoms.

Plasmodium malariae

This is rare and usually only found in Africa.

Plasmodium knowlesi

This is rare and found in parts of southeast Asia.

How malaria spreads

The plasmodium parasite is spread by female anopheles mosquitoes. They most commonly bite between dusk and dawn.

Malaria cannot be directly spread from person to person. If a mosquito bites a person already infected with malaria, the mosquito can also become infected. It can then spread the parasite on to other people.

Once you're bitten, the parasite enters the bloodstream and travels to the liver. The infection develops in the liver. It then re-enters the bloodstream and invades the red blood cells.

The parasites grow and multiply in the red blood cells. The infected blood cells burst at regular intervals, releasing more parasites into the blood. Infected blood cells usually burst every 48-72 hours. Each time they burst, you'll have a bout of fever, chills and sweating.

Malaria can also spread through blood transfusions and sharing needles. This is rare.

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 23 March 2021
Next review due: 23 March 2024

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.