Use this feature to invite colleagues, clients, and associates to view this content item(s). Please supply your name and email address (for reply purposes) and the recipient's name and email address. To send the email, click the "Send" button. Fields marked with an asterisk are required. To return, click the "Cancel" button.
Malaria by Michelle Badash, MS Definition Malaria is a blood-borne disease caused by a parasite. The parasite is typically transmitted to humans via the bite of an infected mosquito. Causes Malaria is caused by one of the following four types of parasites: Plasmodium falciparum Plasmodium malariae Plasmodium ovale Plasmodium vivax When a female Anopheles mosquito bites someone infected with malaria, the mosquito becomes infected with the parasite. When the mosquito bites the next person, the parasites are released into that person's bloodstream. Once inside the human bloodstream, parasites travel to the liver and multiply (hepatic phase). During this phase the infected person has no symptoms. After several days the parasites' offspring are released into the bloodstream, where they infect red blood cells. Within 48 hours, the infected red blood cells burst and the parasites infect more red blood cells. This process leads to the chills, fever, and other symptoms that are typical of malaria. Without treatment, the cycle of red blood cell destruction and fever will continue and may lead to death. Plasmodium falciparum is by far the most dangerous of the forms of malaria and, unfortunately, in most areas it is also the most common. Malaria can also be transmitted from a mother to her unborn child or from a transfusion of blood from an infected donor. Risk Factors A risk factor is something that increases your chance of getting a disease or condition. Failing to use DEET-containing insect repellants when outdoors Failing to use medications to prevent malaria infection Failing to use mosquito netting (especially netting treated with permethrin) while sleeping Geography: Africa, Asia, and Latin America; While deaths from 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. Living in or traveling to hot, humid climates where Anopheles mosquitoes are prevalent Symptoms A person infected with malaria will experience some or all of the following symptoms: Anemia Chills Diarrhea Diffuse muscles aches Headaches Jaundice (yellow coloring of the skin or eyes) Nausea and/or vomiting Recurrent fevers (as high as 106 degrees F) Symptoms usually begin within 10 days to 4 weeks after being bitten by an infected mosquito. However, P. malariae may not produce symptoms for a year or more. P. falciparum infections tend to cause more severe symptoms and are associated with higher death rates. Diagnosis The doctor will ask about your symptoms, medical history and travel history. The doctor will also perform a physical exam. You will have a blood test to analyze your blood for parasites. Treatment Malaria is treated with prescription drugs to kill the parasites. Choice of anti-malarial agent depends on the type of parasite, and the severity and stage of infection. In many parts of the world, P. falciparum is resistant to chloroquine, the mainstay of malaria treatment. The following medications are used alone or in combination: Artemisinin* Chloroquine Clindamycin* Combination of pyrimethamine and sulfadoxine (Fansidar)* Doxycycline* Malarone* Mefloquine (Lariam)* Primaquine (for hepatic phase of P. vivax and P. ovale) Quinidine* Quinine* *Commonly used to treat chloroquine-resistant strains of P. falciparum. Prevention To reduce your chance of getting malaria when in an area where malaria is prevalent: Avoid being outdoors from dusk to dawn, when anopheline mosquitoes are especially prevalent. Even if taking all precautions appropriately (including anti-malaria medication) seek medical care immediately for any illness associated with high fever. Take anti-malaria medication prior to, during, and after travel. Follow your doctor's instructions and take medication exactly as prescribed. Use DEET insect repellent (at least 30-35%) when outside. Use flying insect spray in non air-conditioned rooms while sleeping. Use proper mosquito netting at night. Wear clothing that covers as much skin as possible. Last reviewed: March 2003 by Lawrence Frisch, MD, MPH.