Malaria

What is malaria?

Malaria is a serious, sometimes fatal infection of red blood cells.

How does it occur?

Four types of parasites called Plasmodium cause malaria. The parasites are carried by mosquitoes. When a mosquito bites an infected person, parasites in the person's blood are picked up by the mosquito. After the parasites grow in the mosquito for a week or more, the parasites can enter your blood if the mosquito bites you. The parasites then enter your liver, where they grow and multiply.

After a time, the parasites leave the liver and enter red blood cells. This may take just a few days or as long as several months. The parasites make more parasites in the red cells until they become swollen and burst. This releases new parasites into the bloodstream. The new parasites then infect more red blood cells. While the parasites are in the liver, you may not feel sick, but when the parasites have infected your blood cells, you begin to have symptoms.

Malaria risk is high in over 90 countries with tropical climates, including the following areas:

• tropical parts of Africa
• Central America
• Dominican Republic
• Haiti
• India
• tropical parts of the Middle East
• Pacific island region
• tropical parts of South America
• Southeast Asia.

What are the symptoms?

Symptoms of malaria include:

• high fever (up to 105°F, or 40.6°C) with shaking chills
• heavy sweating when the fever suddenly drops
• fatigue
• headache
• muscle aches
• malaise (a general feeling of sickness)
• abdominal discomfort
• nausea and vomiting
• feeling faint when you stand or sit up quickly.

In addition, if you have the type of malaria caused by the plasmodium falciparum parasite, you may have other severe symptoms:

• extreme sleepiness, delirium, unconsciousness, convulsions, and coma
• shortness of breath caused by pulmonary edema (fluid inside the lungs that interferes with breathing)
• dark-colored urine caused by kidney failure
• anemia and bleeding problems.

How is it diagnosed?

If you become ill with a fever or flulike illness after traveling in a malaria risk area within the past year, see your healthcare provider right away. Tell your provider that you have been traveling in a malaria risk area. Your provider will review your medical history and examine you. You will have blood tests to look for the parasites.

How is it treated?

Malaria can be cured with prescription drugs. The type of drugs and length of treatment depend on which kind of malaria you have, your age, and how ill you are.

How long do the effects last?

With proper treatment, symptoms of malaria usually go away quickly, with a cure within 2 weeks. Without proper treatment, malaria can be fatal, or symptoms can keep coming back for many years.

After repeated exposure, you may become partly immune. This means you may not get as sick when you are infected. You cannot become completely immune to malaria.

How can I take care of myself?

The infection may cause a fever every 12 to 48 hours. Each new generation of parasites causes a fever when they leave the red blood cells they have infected. The different types of parasites grow at different rates, so the time between fevers depends on the type of malarial infection you have. Once you learn how often you have fevers, you can predict when you're going to feel sick again. Make sure that at these times you are not alone, you have medicine for fever, and you drink lots of fluids so that you do not become dehydrated. You may feel well between attacks.

What can be done to prevent malaria?

If you are traveling to a malaria risk area:

• Visit your healthcare provider 4 to 6 weeks before foreign travel for a prescription for an antimalarial drug. Take your antimalarial drug exactly on schedule without missing doses, including before and during your travels and for 4 weeks after you return home.
• Prevent mosquito bites:
  • Use an insect repellent on skin that is not covered by clothing whenever you are outdoors. Do not use more repellent than recommended in the package directions. Don't put repellent on open wounds or rashes. Do not apply it to your eyes or mouth. When using sprays, do not spray directly on your face--spray the repellent on your hands first and then put it on your face. Wash the spray off your hands. Be careful with children because repellents can make them ill.

    Repellent products containing either DEET or picaridin as active ingredients have been proven to provide longer-lasting protection than others. Oil of lemon eucalyptus, a plant-based repellent, hasn't been as well tested. But in some studies it provided as much protection as repellents with low concentrations of DEET. Oil of lemon eucalyptus should not be used on children under age 3. Adults should use products with no more than 35% DEET. Children should use repellents with no more than 10% DEET. DEET should be washed off your body when you go back indoors. Picaridin is a repellent just recently made available in the US. It can be less irritating to the skin than DEET.

    Spray clothes with repellents because mosquitoes may bite through thin clothing. Do not spray repellent on the skin under clothing. You may spray clothing with DEET or permethrin. Some products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear. Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated clothing repels and kills mosquitoes and continues to work after repeated laundering. Do not put permethrin on your skin.

  • Use a spray that kills flying insects in the room where you sleep.
  • Wear long pants and long-sleeved shirts, especially from dusk to dawn. This is the time when you are most likely to get bitten.
  • Sleep under a mosquito net if you are not living in screened or air-conditioned housing.