Malaria is a serious illness caused by parasites. This disease is a leading cause of illness worldwide, with up to 500 million cases reported each year.

Anyone who travels to a country where malaria is present is at risk for getting the infection. Malaria is common in tropical or subtropical areas of Asia, Africa, and Central and South America. The risk of malaria may be different between countries and between areas of a country.

Malaria is spread by the bite of an infected female Anopheles mosquito. These mosquitoes usually bite during the evening. In some cases, malaria has been transmitted through blood transfusions or shared needles or syringes. Direct person-to-person transmission does not occur, though is it possible for a pregnant person to transmit the infection to their fetus.


Malaria can be life-threatening. When symptoms start, they may be similar to the flu. See a doctor immediately if you become ill after returning from an area where malaria occurs.

Symptoms include:

  • Fever
  • Chills
  • Sweats
  • Headache

In some cases, symptoms may progress to:

  • Jaundice (yellowing of the skin and eyes)
  • Bleeding
  • Shock
  • Kidney or liver failure
  • Delirium
  • Coma

The time between the mosquito bite and the start of symptoms can range from seven to 30 days. Some people who live for a long time in an area with malaria do not show symptoms for years.


Talk to your doctor if you are traveling to an area where malaria is common. You will likely need to start taking a medicine to prevent malaria before you travel. You will need to continue taking the medicine for several weeks after returning.

To prevent exposure:

  • Wear protective clothing, such as long pants and sleeves.
  • Use insect repellents (preferably with DEET) when outdoors, especially in the evenings.
  • Use bed nets covered with insecticide.

Diagnosis and Treatment

Your doctor can diagnosis malaria with a blood smear or other tests that identify parasites in the bloodstream.

Treatment will depend on your location when the infection occurred and the type of parasite. If you are infected, your doctor may prescribe medication.

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