Disease and Condition

Malaria
What is it?

Malaria is a serious, parasitic infection that is spread by the bite of certain mosquitoes. A parasite is an organism that survives by living inside a larger organism, called a host.
Who gets it?

Anyone living in or traveling to an area of the world where malaria is more commonly transmitted can get this disease. It is more common in tropical climates, such as Central and South America, Haiti and the Dominican Republic, Africa, the Indian subcontinent, Southeast Asia, the Middle East, and Oceania. Malaria is considered “endemic” to these regions, which means it is native to, or naturally occurring, in these areas. While small outbreaks sometimes occur within the United States, malaria is not a serious problem here.
What causes it?

Malaria is spread in three ways. The most common is by the bite of an infected female Anopheles mosquito. However, malaria can also be spread through a transfusion of infected blood or by sharing a needle with an infected person. There are four different species of parasites that cause malaria. They are the Plasmodium falciparum (which is the most fatal), P. vivax, P. malariae, and P. ovale. When an infected mosquito bites a person, the parasites enter the bloodstream and travel to the liver. They multiply in the liver, then travel back into the blood, where they continue to grow and multiply so quickly that they clog blood vessels and rupture blood cells. When the red blood cells burst, the parasites are released and then attack other red blood cells. Malaria is not contagious, which means one person cannot pass it directly to another. However, if a mosquito that is not infected bites an infected person, it picks up the malaria parasites. Animals can also get malaria, but animal malaria cannot spread to humans, and human malaria cannot spread to animals.
What are the symptoms?

It takes anywhere from eight days to several months for the parasites to multiply in the liver, then enter the bloodstream. The most dangerous parasite, falciparum, usually takes between 8 and 12 days. While the parasites are in the liver, the person does not feel sick. However, once they enter the bloodstream, symptoms begin. At first, the person may have flu-like symptoms, including low fever, chills, fever, headache, body aches, nausea, vomiting, and a general feeling of illness. The chills and fever are referred to as “malaria ague.” Symptoms usually follow a cycle of uncontrollable shivering, then high fever, then intense sweating, which brings down the fever. The patient is by this time exhausted and sleeps. Then, the cycle of chills, fever, and sweats begins again and continues to occur sometimes every other day, or every third day. This may go on for anywhere between a week and a month. There is a chronic form of malaria where symptoms reoccur as much as 50 years after the first infection. Untreated malaria can cause jaundice, which is a yellow coloring of the skin and eyes, and anemia. Falciparum malaria causes more severe symptoms because it destroys so many red blood cells so quickly that they block the blood vessels in major organs, such as the kidneys. Falciparum malaria can also affect brain function. When this occurs, symptoms include a high fever (at least 104 deg. F), severe headache, confusion, delirium, and drowsiness, and can result in coma and convulsions. Falciparum malaria also causes an enlarged spleen, as well as kidney and liver failure. Malaria during pregnancy can result in premature birth, miscarriage, or stillbirth. People who live in areas where malaria is common can get the disease repeatedly and never fully recover.
How is it diagnosed?

Your doctor will take a complete medical history so he or she can assess your risk factors for malaria. It is important to tell your doctor if you have been traveling in an area where malaria is endemic, even as long ago as one year. He or she will also perform a complete physical examination, looking specifically for symptoms such as chills, fever, and an enlarged spleen. If your doctor thinks you may have malaria, he or she will take a blood sample to be tested in a laboratory. The parasite that causes malaria can be seen on a blood smear under a microscope. The malaria parasite multiplies over time, so you may need to give more than one blood sample to make the diagnosis. Because falciparum malaria must be treated immediately or it can be fatal, you should insist upon a malaria blood test if you have flu-like symptoms and have recently traveled to a high risk area.
What is the treatment?

Malaria can be cured if treated while in its early stages. Treatment depends upon the type of malaria you have. Falciparum malaria is considered a medical emergency and the patient is admitted to the hospital for treatment with the antimalarial drugs chloroquine or quinine, often intravenously, combined with tetracyline, an antibiotic. In some countries where malaria is common, the parasite has become resistant to quinine, so different combinations and doses of medication may need to be given. The patient may also need kidney dialysis, blood transfusions, oxygen therapy, and intravenous (IV) fluids, depending upon the severity of symptoms. Other types of malaria are treated successfully with chloroquine, which is taken by mouth. The length of time anti-malaria drugs must be taken depends upon the type of malaria, the age of the patient, and how severe the symptoms are. Even with drug treatment, malaria symptoms can recur if the parasite remains in the liver. Patients who have recovered from the P. vivax or P. ovale strains of malaria can take a drug called primaquine to prevent reoccurences of the disease.
Self-care tips

There are ways to protect yourself if you are traveling to a country that is known to have a high population of malaria-carrying mosquitoes. You can avoid mosquito bites by using a mosquito repellent spray or lotion on your body and clothes and staying in well-screened areas, especially after dark. Your sleeping area should have repellant-treated mosquito netting over the bed. When outdoors, wear clothing that covers your entire body. Avoid leaving any containers of standing water outside where mosquitoes can breed. If you know you will be traveling in an area where malaria is common, see your doctor first. You can take antimalarial drugs before leaving the United States, then continue to take these drugs for approximately four weeks after returning home. You should still follow all the precautions listed above for avoiding mosquito bites. See a healthcare professional immediately if you have been in an area endemic to malaria and you have any flu-like illness with fever.

This information has been designed as a comprehensive and quick reference guide written by our health care reviewers. The health information written by our authors is intended to be a supplement to the care provided by your physician. It is not intended nor implied to be a substitute for professional medical advice.