What is malaria?

Malaria is a serious, sometimes fatal infection caused by parasites that you can get from a mosquito bite.

What is the cause?

Parasites called Plasmodium cause malaria. Different types of plasmodium cause different symptoms. The parasites are carried from one person to another by mosquitoes. Mosquitoes get infected when they bite an infected person. The infected mosquito can then pass the parasites to you when it bites you.

After an infected mosquito bites you, the parasites travel through your bloodstream to your liver, where they grow and make another form of the parasites. The new form of the parasites leaves the liver and enters the bloodstream where they infect 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 the cells 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. When the parasites have infected your blood cells, you start to have symptoms.

The infection does not spread directly from person to person. However, malaria can be spread by contact with infected blood, for example, through blood transfusion, organ transplant, or the sharing of needles or syringes contaminated with blood. Malaria may also be spread from a mother to her unborn baby.

Mosquitoes that carry malaria are found mostly in tropical and subtropical areas, such as:

  • Some parts of Africa
  • Central America
  • Caribbean countries
  • India
  • Some parts of the Middle East
  • Some parts of South America
  • Southeast Asia

What are the symptoms?

Symptoms may include:

  • Low red blood cell count
  • Blood in the bowel movements
  • Headache
  • High fever (up to 105°F, or 40.6°C) with shaking chills and heavy sweating
  • Yellowish skin and eyes (jaundice)
  • Muscle aches
  • Nausea and vomiting
  • Convulsions or coma

The infection may cause a fever every 12 to 48 hours because 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 infection you have.

How is it diagnosed?

Your healthcare provider will ask about your symptoms and recent travels and examine you. You will have blood tests to look for the parasites.

How is it treated?

Malaria is an emergency that must be treated in the hospital. It can be cured with prescription medicine. The type of medicine and length of treatment depends on the type of malaria you have, your age, and how sick you are.

With proper treatment, symptoms of malaria usually go away quickly and are cured within 2 weeks. Without the right treatment, malaria symptoms can return and it can cause death.

After repeated exposure to malaria, you may become partly immune. This means you may not get as sick the next time you are bitten by an infected mosquito.

How can I help take care of myself?

Follow your healthcare provider’s instructions. Ask your provider:

  • How and when you will hear your test results
  • How long it will take to recover
  • If there are activities you should avoid and when you can return to your normal activities
  • How to take care of yourself at home
  • What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

How can I help prevent malaria?

There is no vaccine that prevents malaria, but there are medicines that can help prevent infection. If you are traveling to a malaria risk area:

  • Visit your healthcare provider 4 to 6 weeks before your trip for a prescription for an antimalarial medicine. There are several choices, depending, for example, on where you will be traveling and whether you are pregnant or breast-feeding. Take the medicine exactly on schedule without missing any doses. This may include before and during your travels and after you are back home, depending on which medicine you take.
  • Take these precautions to avoid mosquito bites:
    • Schedule travel to tropical areas during seasons when mosquitoes are less active.
    • Stay in places that are clean, insect free, and have air conditioning or well-screened windows.
    • Avoid wearing perfume or other scented products because they can attract mosquitoes.
    • Stay indoors at dawn and in the early evening, when mosquitoes are most likely to be around.
    • Use an insect repellent whenever you are outdoors. Don’t use more repellent than recommended in the package directions. Don’t put repellent on open wounds or rashes. Don’t put it on your eyes or mouth. When using sprays for the skin, don’t spray the repellent directly on your face. Spray the repellent on your hands first and then put it on your face. Then wash the spray off your hands.
      • Adults should use repellent products with no more than 35% DEET. Children older than 2 months can use repellents with no more than 30% DEET. DEET should be applied just once a day. Wash it off your body when you go back indoors.
      • Picaridin may irritate the skin less than DEET and appears to be just as effective.
      • Spray clothes with repellents because insects may crawl from clothing to the skin or bite through thin clothing. Products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other insects and can keep working after laundering. Permethrin should be reapplied to clothing according to the instructions on the product label. Some commercial products are available pretreated with permethrin. Permethrin does not work as a repellent when it is put on the skin.
      • In some studies, oil of lemon eucalyptus, a plant-based repellent, provided as much protection as repellents with low concentrations of DEET, but it hasn’t been as well tested as DEET. Oil of lemon eucalyptus should not be used on children under age 3.
    • Use a spray that kills flying insects in the room where you sleep. Sleep under a mosquito net if you are sleeping in an area with open and unscreened windows or doors.
    • Wear long pants and long-sleeved shirts, especially from dusk to dawn. This is the time when you are most likely to get bitten.
    • Mosquitoes lay eggs in water. To reduce mosquito breeding, drain standing water from flowerpots, buckets, barrels, cans, and other items that collect water. Avoid swimming in places where mosquitoes breed, like small ponds or lagoons.

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Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2014-06-02
Last reviewed: 2014-06-02
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
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