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Condition Basics

What is malaria?

Malaria is a disease that causes a fever, chills, and muscle pain. You can get it from a bite from an infected mosquito. Malaria is very rare in Canada and the United States. It's most often found in Africa, Southern Asia, Central America, and South America.

Symptoms tend to come and go in cycles. Malaria may also cause more serious problems. These include damage to the heart, lungs, kidneys, or brain. It can even be deadly. But you can do a lot to prevent this infection.

What causes it?

You get malaria when a mosquito infected with parasites bites you and transfers the parasite to you. You can't get malaria just by being near a person who has the disease.

What are the symptoms?

Most malaria infections cause fever and flu-like symptoms that may come and go in cycles. These may include:

  • Fever. This is the most common symptom.
  • Chills.
  • Headache.
  • Sweats.
  • Fatigue.
  • Nausea and vomiting.
  • Body aches.
  • Generally feeling sick.

People who get infected many times may have the disease but have few or no symptoms. Canadians who are at the highest risk of malaria are usually visiting friends and relatives, but previous exposure to malaria does not prevent them from getting it again. How bad malaria symptoms are can vary depending on your age, general health, and the kind of malaria parasite that you have.

In rare cases, malaria can affect the brain or spinal cord and cause seizures or loss of consciousness. The most serious types of malaria infection can be deadly.

The time from when you get infected until symptoms appear is usually 7 to 30 days. But with some infections, signs of illness may not appear for many months.

How is it diagnosed?

The doctor will ask you questions about your health and do a physical examination. If the doctor thinks you may have malaria, they will use a blood smear to check for the disease. During this test, a sample of blood is placed on a glass slide, prepared, and looked at under a microscope.

A blood smear test can help diagnose malaria. It can also help a doctor see what type of malaria parasite you have and how many parasites are in your blood. This can help with decisions about treatment.

If the first blood smear doesn't show malaria, your doctor may order more tests every 12 to 24 hours.

A blood test that can diagnose malaria quickly is also available. If this rapid test points to malaria, the results are usually confirmed with a blood smear. Other blood tests may also be done.

How is malaria treated?

Malaria is treated with medicines called antimalarials. The medicine you get will depend on the type of parasite you have, your age and health, and other things. If you develop severe malaria, you may need to be admitted to hospital. You may not have a full recovery from severe malaria, so it is important to be diagnosed and treated early if you have malaria.

If you're going to areas where there is no medical care, you can get medicine to bring with you in case you get malaria symptoms. This is a short-term measure until you can get medical care. Seek care as soon as you can (best is within 24 hours).

The most up-to-date information about the treatment of malaria is available from Health Canada and the World Health Organization (WHO).

What can you do to prevent malaria?

  • If you can, avoid going to areas where malaria is common. Talk to your doctor before you go.
  • Prevent mosquito bites when you go to areas where malaria is common.
    • After dark, stay indoors in a screened or air-conditioned room.
    • Wear protective clothing. Wear long pants and long-sleeved shirts.
    • Use an insect repellent with 20 to 30% DEET or 20% icaridin. Children ages 6 months to 12 years should use products with icaridin instead of DEET. Read and follow all instructions on the label.
    • The Committee to Advise on Tropical Medicine and Travel (CATMAT) recommends that children younger than age 6 months use 10% icaridin when travelling in areas where the risk of malaria infection is high.
    • Use bed nets (mosquito netting) sprayed with or soaked in permethrin or deltamethrin. These chemicals repel or kill mosquitoes.
    • Use flying-insect spray indoors around sleeping areas.
  • Take medicine to prevent malaria. Start taking it before you leave on your trip. Keep taking it while you travel. When you get home, keep taking the medicine for as long as your doctor tells you to.


Adaptation Date: 5/2/2022

Adapted By: Alberta Health Services

Adaptation Reviewed By: Alberta Health Services

Adapted with permission from copyrighted materials from Healthwise, Incorporated (Healthwise). This information does not replace the advice of a doctor. Healthwise disclaims any warranty and is not responsible or liable for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.