Malaria is an illness caused by a parasite, usually an infected mosquito. A parasite is an organism that lives in another host (such as a human) and gets nourishment at the host's expense.


Malaria is spread from person to person by anopheline mosquitos. Areas where malaria occurs are tropical regions of:

  • Sub-Saharan Africa.

  • Asia.

  • Oceania (Australia and near-by Pacific Islands).

  • Latin America.


Malaria may cause very mild symptoms, severe disease and even death.

Following the bite of an infected mosquito, a period of time goes by (incubation period) before the first symptoms appear. The incubation period is typically 8 to 25 days. Patients with uncomplicated malaria typically have a fever of unknown cause. Other common symptoms include:

  • Headache.

  • Weakness.

  • Night sweats.

  • Muscle and joint pains.

Fever may come and go, recurring every 2 to 3 days. As a general rule, all travelers that get a fever and who have visited a place where malaria is common, should be considered to have malaria until or unless the diagnosis is disproved.

Severe disease typically occurs in a person with no prior malaria illness and an infection with only one of the four different malaria species (plasmodium falciparum). Symptoms may include:

  • Drowsiness.

  • Seizures.

  • Shortness of breath.

  • Severe weakness.

  • Loss of appetite.

  • Vomiting.

  • Very high fever.

Physical findings of severe malaria may include:

  • Elevated temperature.

  • Paleness of the skin (may be a sign of anemia).

  • Large spleen or liver.

  • Yellowish color of the skin and usually white part of the eyes (jaundice).

  • Severe drowsiness.

  • Convulsions.

  • Very low blood pressure.


Sometimes the symptoms of malaria go away by themselves or can come back after malaria is treated with medicine. This is called a relapse. It occurs because the malaria may lie inactive or sleeping (dormant) in the liver.


Your caregiver will be able to diagnose malaria by finding parasites on a blood smear examined under a microscope. Other lab work may also be done.


Travelers should take precautions so they do not get malaria when they visit a malaria risk area. Prevention of malaria can aim at:

  • Preventing infection by avoiding bites by parasite-carrying mosquitoes.

  • This includes protection measures such as insecticide treated bed nets (ITN's). When used correctly, ITNs prevent mosquito bites and decrease the spread of malaria.

  • Preventing disease by using anti-malarial drugs. The drugs do not prevent initial infection through a mosquito bite, but they prevent the development of malaria parasites in the blood, which are the forms that cause disease. All travelers to areas of the world where malaria occurs should discuss taking anti-malarial drugs with their caregiver before leaving to their destination.

  • Mosquito control.


Medications are available for the treatment of malaria.