What is malaria?
Malaria is a disease of the blood that is transmitted to people by infected mosquitoes. Malaria is very common throughout the world. In the United States, the main risk is to persons traveling to tropical and subtropical countries where malaria is a problem.
What is the infectious agent that causes malaria?
Malaria iscaused by any one of four species of one-celled parasites, called Plasmodium. The parasite is spread to people by the female Anopheles mosquito, which feeds on human blood..
Where is malaria found?
Malaria transmission occurs in large areas of Central and South America, sub-Saharan Africa, the Indian subcontinent, Southeast Asia, the Middle East, and Oceania. The risk to travelers variesdepending on local weather conditions, the number of mosquitoes in the area, and the traveler's itinerary and time and type of travel.
How is malaria spread?
A person gets malaria from the bite of an infected female mosquito. The mosquito bite injects young forms of the malaria parasite into the person's blood. The parasites travel through the person's bloodstream to the liver, where they growto their next stage of development. In 6 to 9 days, the parasites leave the liver and enter the bloodstream again. They invade the red blood cells, finish growing, and begin to multiply quickly. The number of parasites increases until the red blood cells burst, releasing thousands of parasites into the person's bloodstream. The parasites attack other red blood cells, and the cycle of infectioncontinues, causing the common signs and symptoms of malaria.
When a non-infected mosquito bites an infected person, the mosquito sucks up parasites from the person's blood.
What are the signs and symptoms of malaria?
People with malaria typically have cycles of chills, fever, and sweating that recur every 1, 2, or 3 days. The attack of the malaria parasites on the person's red blood cells makesthe person's temperature rise and the person feel hot. The subsequent bursting of red blood cells makes the person feel cold and have hard, shaking chills. Nausea, vomiting, and diarrhea often go along with the fever. The destruction of red blood cells can also cause jaundice (yellowing of the skin or whites of the eyes) and anemia.
How soon after exposure do symptoms appear?
The time between amosquito bite and the start of illness is usually 7 to 21 days, but some types of malaria parasites take much longer to cause symptoms. When infection occurs by blood transfusion, the time to the start of symptoms depends on the number of parasites in the transfusion.
How is malaria diagnosed?
Malaria is diagnosed by a blood test to check for parasites.
Who is at risk for malaria?Anyone who lives in or travels to a country where there are malaria-infected people and mosquitoes is at risk.
What complications can result from malaria?
Malaria caused by Plasmodium falciparum can cause kidney or liver failure, coma, and death.
What is the treatment for malaria?
The treatment for malaria depends on where a person is infected with the disease. Different areas of the world havemalaria types that are resistant to certain medicines. The correct drugs for each type of malaria must be prescribed by a doctor.
Infection with Plasmodium falciparum is a medical emergency. About 2% of persons infected with falciparum malaria die, usually because of delayed treatment.
How common is malaria?
Worldwide, an estimated 200 million to 300 million malaria infections occur eachyear, with 2 million to 3 million deaths. Most deaths are from infection with Plasmodium falciparum.
About 1,200 cases of malaria are diagnosed in the United States each year.
Is malaria an emerging infectious disease?
Yes. Many countries have been experiencing a resurgence in cases caused by Plasmodium falciparum, the most deadly of the four human malaria parasites. Urban migration, poverty,...