Malaria Fact Sheet
What is malaria?
Malaria is a serious and sometimes fatal disease caused by the bite of a mosquito infected with one of four malaria blood parasites. Infected female mosquitoes are responsible for the spread of human disease. In the United States, most infections are a result of travel to foreign countries though local transmission has occurred, particularly in states such as Florida and Texas. In New York State, nearly all cases of malaria are associated with foreign travel however rare instances of local transmission of malaria have occurred in Long Island and New York City.
Who gets malaria?
Anyone can get malaria however, most cases occur in people living in or traveling to a country where malaria is common. Malaria is currently a problem in tropical or subtropical areas of Asia, Africa, and Central and South America.
How is malaria spread?
Malaria is spread by the bite of an infected female Anopheles mosquito. Malaria may also be spread by transfusion of blood from infected people or by the use of contaminated (dirty) needles or syringes.
People with untreated or inadequately treated malaria may spread infection to a mosquito that bites them. These infected mosquitoes can in turn spread the disease by biting and infecting healthy people. Spreading malaria directly from one person to another does not occur. Stored blood products can remain infectious for 16 days.
What are the symptoms of malaria and when do they appear?
Symptoms may include high fever, chills, sweats and headache, vomiting, and in some instances may progress to jaundice (yellowing of skin and eyes), anemia, blood clotting defects, shock, kidney or liver failure, central nervous system disorders, coma, and death. Cycles of chills, fever, and sweating occurring every one, two, or three days is a good indicator of malaria in a person recently returning from a tropical area.
The time between the infectious mosquito bite and the development of malaria symptoms typically ranges from 10 days to 4 weeks depending on the type of Plasmodia involved, although a person may feel ill as early as 7 days or as late as 1 year later. One species of Plasmodium, called P. vivax, may have a longer incubation period of several months to 4 years between mosquito bite and initial symptoms. When infection occurs by blood transfusion, the time from bite to symptoms depends on the number of parasites transferred but is usually less than 2 months. With certain malaria species, dormant forms (forms that stay in the body but are inactive) can cause illness months to years later.
How is malaria diagnosed?
Symptoms, travel history, and a physical exam can cause a health care provider to suspect malaria. Laboratory tests, which show if a malaria parasite is present or not, will confirm a diagnosis.
What is the treatment for malaria?
Treatment for malaria depends on the specific parasite of infection; geographic area where the infection came from; whether or not the infection is drug resistant; and health, pregnancy status, and drug allergy status of the person with the infection. Most drugs that are used to treat malaria work against the parasite in the blood. Some of these drugs include chloroquine, atovaquone-proguanil (Malarone®), artemether-lumefantrine (Coartem®), and mefloquine (Lariam®).
Does past infection with malaria make a person immune?
People with repeated attacks of malaria may develop a partially protective immunity. Such people can still be infected by malaria parasites but may not develop severe disease, and frequently lack any typical malaria symptoms.
What can be done to prevent the spread of malaria?
Since malaria is not native to the United States, exposure of American citizens occurs most often during foreign travel to areas where malaria is common. It is very important to contact health officials to determine the proper preventive drug therapy to take before traveling. The liberal and frequent use of mosquito repellents as well as using a bed net can be very effective in preventing mosquito bites. More information on repellents can be found at Environmental Protection Agency- insect-repellents. In addition, when using repellents:
- Be sure to follow label directions.
- Try to reduce the use of repellents by dressing in long sleeves and pants tucked into socks or boots.
- Children should only handle repellents with adult supervision. Adults should apply repellents to their own hands first and then gently spread it on the child's exposed skin. Avoid applying directly to children's hands. After returning indoors, wash your child's treated skin and clothing with soap and water or give the child a bath.
- Do not apply near eyes, nose or mouth and use sparingly around ears.
- After returning indoors, wash treated skin with soap and water.
