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Bureau of Disease Control

Malaria

What is Malaria?

Malaria is a serious disease spread by the bite of an infected mosquito. Anyone, any age, can contract malaria. The disease occurs in over 100 countries and territories. More than 40% of the people in the world are at risk. Large areas of Central and South America, Haiti, the Dominican Republic, Africa, the Indian subcontinent, Southeast Asia, the Middle East, and Oceania are considered malaria-risk areas. The World Health Organization estimates that yearly 300-500 million cases of malaria occur and more than 1 million people die from the disease. About 1,200 cases of malaria are diagnosed in the United States each year. Most cases in the United States are in immigrants and travelers returning from malaria-risk areas, mostly from sub-Saharan Africa and the Indian subcontinent.

What are the symptoms?

Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) Infection with one type of malaria,, Plasmodium falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and death.

For most people, symptoms begin 10 days to 4 weeks after infection, although a person may feel ill as early as 8 days or up to 1 year later. Two kinds of malaria, P. vivax and P. ovale, can relapse; some parasites can rest in the liver for several months up to 4 years after a person is bitten by an infected mosquito.

How is Malaria treated?

Malaria can be cured with prescription drugs. The type of drugs and length of treatment depend on which kind of malaria is diagnosed, where the patient was infected, the age of the patient, and how severely ill the patient was at start of treatment.

How do people catch this disease?

Malaria is spread by mosquitoes. Humans get malaria from the bite of a malaria-infected mosquito. When a mosquito bites an infected person, it ingests microscopic malaria parasites found in the person’s blood. The malaria parasite must grow in the mosquito for a week or more before infection can be passed to another person. If, after a week, the mosquito then bites another person, the parasites go from the mosquito’s mouth into the person’s blood.

What can be done to stop the spread of this disease?

For travelers to areas with malaria, the risk of being bitten by mosquitoes indoors is reduced by using air conditioning or windows and doors that are screened. Proper application of mosquito repellents containing 30% DEET as the active ingredient on exposed skin and clothing decreases the risk of being bitten by mosquitoes. (Deet is not recommended for children under two months of age) Check with the Centers for Disease Control (CDC) to find out which areas are experiencing outbreaks when you make your travel plans.

If you are planning to travel to an area where malaria occurs, visit your health care provider 4-6 weeks before foreign travel for any necessary vaccinations and a prescription for an antimalarial drug. Take your antimalarial drug exactly on schedule without missing doses.