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Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention


Malaria is a disease passed through the blood. It is typically passed to humans through the bite of an infected mosquito but can also be passed from mother to unborn child or during a blood transfusion from an infected donor.


Malaria is caused by a specific type of parasite.

Most often, a mosquito picks up the parasite when it bites someone with malaria. The mosquito can pass the parasite to a new person when it bites them. The parasite then travels to and multiplies in the liver.

After several days, the new parasites leave the liver and pass into the bloodstream. The parasites infect the red blood cells and within 48 hours, the infected red blood cells burst. The parasites then go on to infect more red blood cells.

Malaria Cycle

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Risk Factors

Living in or traveling to hot, humid climates where Anopheles mosquitoes are common is the most common risk factor for malaria. Africa, Asia, and Latin America all have areas where malaria is common. Fatal cases have occurred in tourists visiting game parks and other rural areas in east Africa.

Your chance of getting malaria increases dramatically if basic prevention step listed below are not followed.


There are no symptoms in the early stage of infection.

Symptoms usually begin within 10 days to four weeks after being bitten by an infected mosquito. Symptoms may include:

  • Recurrent fevers—as high as 106° F (41.1° C)
  • Chills and sweats
  • Muscles aches
  • Headaches
  • Nausea and/or vomiting
  • Diarrhea
  • Anemia
  • Yellow coloring of the eyes and skin— jaundice
  • Dark or discolored urine

Seek medical care right if you suspect malaria or if you have traveled to an area of the world where malaria occurs. Without treatment, the cycle of red blood cell destruction and fever will continue. This can lead to death.

Some types of malaria may not produce symptoms for a year or more. The severity of symptoms and death rate are often associated with the specific type of malaria.


The doctor will ask about your symptoms, medical history, and travel history. A physical exam will be done. Malaria will be diagnosed with blood tests. The blood test will also help identify the specific type of parasite causing your infection.


Prescription drugs are used to treat malaria by killing the parasites. The choice of an antimalarial agent depends on:

  • Specific type of parasite
  • Severity and stage of infection
  • Area of the world you may have contracted malaria. Certain areas have types of malaria that are resistance to certain drugs.

Medications will also be given to reduce fever, which may shorten the infection time.


To reduce your chance of getting malaria when in a high-risk area:

  • Visit with a travel clinic or your doctor before your trip. Review what preventative medications you may need.
  • If required, take antimalarial medication before, during, and after travel. Follow your doctor's instructions.
  • Use DEET insect repellent when outside. A higher percentage of DEET will protect your for a longer period of time.
  • Use proper mosquito netting at night. Look for netting treated with insecticide.
  • Do not rely on electronic mosquito repellents. These devices do not prevent mosquito bites.
  • Use flying insect spray in non air-conditioned rooms while sleeping.
  • Wear clothing that covers as much skin as possible.
  • Avoid being outdoors from dusk to dawn. This is when mosquitoes are most active.
  • Stay in air-conditioned or screened rooms when possible.




  • Malaria: topic home. Center for Disease Control website. Available at: Updated June 12, 2014. Accessed June 19, 2014.
  • Malaria and travelers. Center for Disease Control website. Available at: Updated November 9, 2012. Accessed June 19, 2014.
  • Malaria. EBSCO DynaMed website. Available at: Updated June 17, 2014. Accessed June 19, 2014.
  • 8/31/2009 DynaMed Systematic Literature Surveillance. Enayati A, Hemingway J, et al. Electronic mosquito repellents for preventing mosquito bites and malaria infection. Cochrane Database Syst Rev. 2009;(2):CD005434.
  • 8/20/2013 DynaMed Systematic Literature Surveillance. Purssell E, While AE. Does the use of antipyretics in children who have acute infections prolong febrile illness? A systematic review and meta-analysis. J Pediatr. 2013 May 7.
  • 10/1/2013 DynaMed Systematic Literature Surveillance. Reimer LJ, Thomsen EK, et al. Insecticidal bed nets and filariasis transmission in Papua New Guinea. N Eng J Med. 2013 Aug 22; 369(8):745-753.

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