Malaria

Cause

A bite from a parasite-infected mosquito causes malaria. There are five species of Plasmodium (P.) parasites that infect people.

Infection with P. falciparum

  • P. falciparum is found mostly in the tropics and subtropics (near the equator).
  • Infection with P. falciparum can lead to life-threatening complications after the first few days.
  • P. falciparum is often resistant to a popular antimalarial medicine (chloroquine) and needs treatment with other medicines.

Infection with P. vivax, P. malariae, P. ovale, or P. knowlesi

  • P. vivax and P. malariae occur all over the tropical regions of the world. P. ovale is found in western Africa, and P. knowlesi is found in Southeast Asia.
  • Infection with P. vivax, P. malariae, or P. ovale is usually not life-threatening, and a person may recover in a month without treatment. But infection with P. knowlesi may be fatal.
  • P. vivax, P. malariae, P. ovale, and P. knowlesi are generally not as drug-resistant as P. falciparum.
  • P. vivax P. ovale, and P. knowlesi may stay in the liver, requiring further treatment with medicine to prevent relapses.

How the disease spreads

Malaria is spread Click here to see an illustration. when an infected Anopheles mosquito bites a person. This is the only type of mosquito that can spread malaria. The mosquito becomes infected by biting an infected person and drawing blood that contains the parasite. When that mosquito bites another person, that person becomes infected.

In the United States, people who develop malaria are nearly always found to have contracted it while traveling in parts of the world where malaria is common. For more information, see the topic Travel Health.


Go to previous section Go to previous sectionGo to top of page Go to top of pageGo to next section Go to next section

Author: Maria G. Essig, MS, ELS Last Updated: May 8, 2009
Medical Review: E. Gregory Thompson, MD - Internal Medicine
W. David Colby IV, MSc, MD, FRCPC - Infectious Disease

© 1995-2009 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability 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.

Click here to learn about Healthwise
Click here to learn about Healthwise
Topic Contents
 Topic Overview
Arrow PointerCause
 Symptoms
 What Happens
 What Increases Your Risk
 When To Call a Doctor
 Exams and Tests
 Treatment Overview
 Prevention
 Home Treatment
 Medications
 Surgery
 Other Treatment
 Other Places To Get Help
 References
 Credits