What is malaria?
Malaria is a mosquito-borne disease caused by a parasite called Plasmodium. Four different types of Plasmodium affect humans. In recent years most cases in the U.S. have been in persons who acquired the disease in the tropics and sub-tropics. Worldwide, over 200 million cases are reported each year.
Who gets malaria?
Anyone can get malaria while visiting or living in an area where the disease is common. Cases in the U.S. occur in people arriving from tropical or subtropical areas of the world.
How is malaria spread?
Malaria is spread by the bite of an infected female Anopheles mosquito. A very small portion of infections are spread by transfusion of infected blood or via needlesticks.
What are the symptoms of malaria?
Symptoms vary depending on the specific type of Plasmodium involved, but include high fever, chills, sweats, and headache. In some cases, the illness can progress to lethargy, renal or respiratory failure, coma and death. If not treated, the symptoms can continue for weeks or months with episodes of fever and chills. With some types of malaria, relapses of the disease may occur for years after treatment. Malaria has been misdiagnosed as the flu.
How soon after exposure do symptoms appear?
The symptoms usually appear from 12 to 30 days after the bite of the mosquito, depending on the type of Plasmodium involved. Some strains may not cause symptoms for 10 months or even longer.
How long can an infected person carry this parasite?
Direct person-to-person spread does not occur but the untreated or inadequately treated person can carry the infection for one to three years depending on the type.
How is it diagnosed?
Examination of blood films under a microscope is the way to diagnose malaria. An experienced reader is needed to correctly identify the parasites on these films.
What is the treatment for malaria?
The treatment used will depend on the type of malaria and where the disease was acquired. Some types of malaria are becoming drug resistant in certain areas, so the treatment changes accordingly. A doctor specializing in infectious diseases may need to be consulted for current treatment recommendations. Treatment should begin as soon as possible, even if the disease is mild, in order to prevent complications and death.
How can malaria be prevented?
When traveling to areas of the world where malaria is common, specific preventive medicine is prescribed depending on which countries will be visited. Mosquito repellents, bed nets, screens and protective clothing should be used in some countries to protect against mosquito bites. Health departments may help travelers determine what precautions are needed.