Malaria is a disease passed through the blood. It is caused by a parasite. The parasite is typically passed to humans through the bite of an infected mosquito.
Malaria is caused by one of the following four types of parasites:
- Plasmodium falciparum
- Plasmodium vivax
- Plasmodium ovale
- Plasmodium malariae
An Anopheles mosquito becomes infected when it bites someone with malaria. Another bite will pass the malaria to a new person.
Malaria can also be passed from a mother to her unborn child. It can also be passed through a blood transfusion from an infected donor.
Plasmodium falciparum is by far the most dangerous of the forms of malaria. In most areas it is also the most common form.
Risk factors that increase your chance of malaria include:
- Living in or traveling to hot, humid climates where Anopheles mosquitoes are prevalent
- Failing to use DEET-containing insect repellents when outdoors
- Failing to use mosquito netting (especially netting treated with permethrin) while sleeping
- Failing to use medications to prevent malaria infection
Geography: Africa, Asia, and Latin America:
- Malaria occur regularly among tourists who fail to follow recommended precautions
- The majority of fatal cases of malaria seem to be acquired by tourists visiting game parks and other rural areas in east Africa
Once inside the bloodstream, parasites travel to the liver. There they and multiply (hepatic phase). During this phase, the infected person has no symptoms.
After several days, the parasites' offspring are released into the bloodstream. There they infect red blood cells. Within 48 hours, the infected red blood cells burst. The parasites infect more red blood cells. This process leads to:
- Recurrent fevers (as high as 106 degrees F)
- Diffuse muscles aches
- Nausea and/or vomiting
- ]]>Jaundice]]> (yellow coloring of the skin or eyes)
Symptoms usually begin within 10 days to four weeks after being bitten by an infected mosquito. P. malariae may not produce symptoms for a year or more. P. falciparum infections tend to cause more severe symptoms. They are associated with higher death rates.
The doctor will ask about your symptoms, medical history. The doctor will also ask about your travel history. A physical exam will be done. You will have:
- Blood tests—to analyze your blood for parasites
Prescription drugs are used to treat malaria. They kill the parasites. Choice of antimalarial agent depends on:
- The type of parasite
- Severity and stage of infection
The following medications are used alone or in combination:
- Chloroquine]]> —in many parts of the world, P. falciparum is resistant to this drug
- ]]>Mefloquine]]> (Lariam)*
- ]]>Doxycycline]]> *
- ]]>Clindamycin]]> *
- ]]>Malarone]]> *
- ]]>Quinidine]]> *
- ]]>Quinine]]> *
- Combination of pyrimethamine and sulfadoxine ( ]]>Fansidar]]> )*
- ]]>Primaquine]]> (for hepatic (first) phase of P. vivax and P. ovale )
*Commonly used to treat resistant strains of P. falciparum .
To reduce your chance of getting malaria when in an area where malaria is prevalent:
- Take antimalaria medication prior to, during, and after travel. Follow your doctor's instructions. Take medication exactly as prescribed.
- Use DEET insect repellent when outside. It should be at least 30%-35%.
- Use proper mosquito netting at night.
- 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 prevalent.
- Seek medical care immediately for any illness with high fever.
Centers for Disease Control
World Health Organization
Public Health Agency of Canada
Center for Disease Control website. Available at: http://www.cdc.gov . Accessed 1/30/2009.
Principles and Practice of Infectious Diseases. 6th ed. Churchill Livingstone Inc; 2005.
Navy Medical Department Pocket Guide to Malaria Prevention and Control . Bureau of Medicine and Surgery; 1998.
Last reviewed January 2009 by ]]>David L. Horn, MD, FACP]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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