Malaria

What is malaria?

Malaria is a serious and sometimes deadly disease. You can get malaria if an infected mosquito bites you. This type of mosquito carries a parasite called Plasmodium. Four different types of Plasmodium (P. falciparum, P. vivax, P. ovale, and P. malariae) affect humans.

Who gets malaria?

Anyone who visits an area where malaria transmission occurs can get the illness. Most cases in the U.S. occur in people who have traveled from tropical or subtropical areas of the world. The World Health Organization has estimated that there were 263 million cases of malaria in 2023. Maps of countries where malaria is common can be found in the CDC Yellow Book: Health Information for International Travel resource. Visit the CDC Yellow Book at https://wwwnc.cdc.gov/travel/page/yellowbook-home.

Some people are at higher risk of getting malaria and developing severe disease. These groups include pregnant women, infants, children under five years of age, people with HIV/AIDS, and travelers coming from areas where malaria is present.

How is malaria spread?

The parasite that causes malaria is usually spread by the bite of an infected female Anopheles mosquito. In addition, an infected mother can transmit the parasite to her infant before or during delivery. In rare cases, the malaria parasite is spread by blood transfusion, organ transplant or sharing needles or syringes with malaria-infected blood.

What are the symptoms of malaria?

Symptoms vary depending on the type of Plasmodium that causes the infection. They might include fever and flu-like illness, chills, headache, muscle aches and tiredness. In some cases, the illness can progress to severe anemia, jaundice (yellow coloring of the skin and eyes), kidney and respiratory failure, seizures, mental confusion, coma and even death. Some types of malaria are less severe. However, if untreated, the symptoms can continue for weeks or months with episodes of fever and chills. With some types of malaria, relapses of the disease might occur years after treatment that was thought to have been successful.

How soon after exposure do symptoms appear?

The symptoms usually appear 7–30 days after the bite of the mosquito, depending on the type of malaria involved. Some strains may not show symptoms for 10 months or more.

How is malaria diagnosed?

Health professionals may suspect malaria based on the patient's travel history, symptoms, and medical exam results. To confirm the diagnosis, laboratory tests must be done on samples of blood. The most common test involves identifying the malaria parasites by examining a specially prepared and stained drop of the patient's blood under a microscope.

What is the treatment for malaria?

Doctors can prescribe drugs to treat malaria. Start treatment right away, even if the disease is mild. This helps to prevent complications and possible death. A person who does not receive the right treatment can carry the infection for many years. The duration depends on the Plasmodium type involved. Treatment usually depends on the type of malaria, where the disease was acquired, and patient factors like age and pregnancy status.

Do people who have been in contact with someone with malaria infection need to be tested and treated?

Contacts of individuals with malaria infection should be tested if they had the same mosquito exposure as the patient and have become symptomatic.

How can malaria be prevented?

To reduce your risk of malaria, use mosquito repellents and wear protective clothing while traveling or living in areas where malaria is present. Travelers to areas where malaria is found might also be advised to take anti-malaria medications to prevent the disease.

How can I get more information about malaria?

• If you have concerns about malaria, contact your healthcare provider.
• Call your local health department. You can find your local health department at vdh.virginia.gov/health-department-locator/
• Visit the CDC Malaria page at cdc.gov/malaria/ for more information.
• Visit https://www.epa.gov/insect-repellents for information about mosquito repellents.