About Malaria
Malaria is a disease caused by a parasite that is spread by certain species of mosquitoes. People are most commonly infected with malaria in tropical and subtropical regions of the world, particularly countries in sub-Saharan Africa, South America, and Southeast Asia.
The parasite that causes malaria lives in the gut of Anopheles mosquitoes and spreads when people or certain wildlife are bitten by infectious mosquitoes. Infected people can also spread the parasite back to mosquitoes if they are bitten.
Anopheles mosquitoes can be found in most regions worldwide, including in Washington state. However, not all Anopheles mosquitoes carry the plasmodium parasite, and it has not been detected in mosquitoes in Washington.
Who's At Risk
The only Washingtonians considered at risk for malaria are those who are traveling to regions where malaria is widespread, or those who have recently moved from regions with malaria. Past infections of malaria do not prevent you from future infection.
Most people get malaria when bitten by an infective mosquito carrying the malaria parasite. In rare occasions, malaria can also spread through blood transfusions or organ transplants. Malaria cannot spread from person to person.
Malaria in Washington
Although there are mosquitoes that can transmit malaria in Washington, local transmission of malaria is very rare. There has only been one recent occurrence of presumed mosquito-borne transmission of malaria in Washington.
Each year, people return to Washington state with malaria. If preventative steps are not taken, these individuals can spread the disease to mosquitoes in Washington. Active mosquito bite prevention while traveling is essential to reduce the risk of malaria being introduced locally. In addition, mosquito bite prevention upon return to Washington from an area with malaria can prevent local spread.
Symptoms
Most people begin to feel ill within a week after being bitten by an infected mosquito. Symptoms may include:
- Fever
- Chills
- Headache, muscle ache, and tiredness
- Nausea, vomiting, and diarrhea
Malaria can develop to become more severe. Symptoms of severe malaria include:
- Anemia and/or jaundice (yellow coloring of skin and eyes)
- Kidney failure
- Seizures
- Confusion
- Coma
If you have any of these symptoms, see your healthcare provider immediately, especially if you have recently traveled to an area where malaria is widespread.
Prevention and Treatment
There are medications that people can take to both prevent and treat malaria. If you are traveling out of the country, check CDC's Traveler Health Destinations to see if you are visiting an area where malaria spreads. Meet with your healthcare provider 4-6 weeks before your trip to discuss prevention options.
Prevention
- Prescriptions called ‘antimalarials’ are available to people to take prior to traveling abroad.
- Options are available based on your medical history, the destination country, urgency of the trip, and how often you would prefer to take medication.
Treatment
- Malaria is a treatable disease.
- Treatment plans will depend on the species of parasite and your medical history.
- Starting treatment immediately is the best way to treat malaria and prevent serious and life-threatening issues.
Prevent Malaria During Travel
Before you depart, take steps to prevent malaria infection:
- Check CDC's Traveler Health Destinations to see if malaria is a risk at your destination and stay up to date on CDC's Travel Health Notices.
- Schedule a pre-departure appointment with your healthcare provider or a travel clinic. Your healthcare provider will be able to give you guidance on how to keep yourself safe while abroad and may be able to prescribe preventative medication.
- Many Washingtonians who become ill with malaria did not fully complete their prescribed preventative medication. If prescribed medication, adhere to the guidance given to you by your healthcare provider.
While you are traveling, avoid mosquito bites:
- When outdoors, wear clothing that covers your skin and use an EPA-registered insect repellant on skin that is exposed. Use permethrin (a type of insecticide that is effective against mosquitoes) on clothing.
- Keep doors and windows closed or use intact screens to cover open windows and doors.
- Purchase and learn how to use a bed net if you plan to sleep outdoors or in areas that are not fully enclosed. Look for nets that are treated with permethrin.
- Keep air conditioning units on if available.
- Stay indoors at dusk and dawn, if possible. These times are when mosquitoes are most active.
Even if you don’t feel sick, it is important to continue to practice mosquito bite prevention efforts for at least 2-3 weeks after you return from your trip to avoid spreading the parasite to mosquitoes in Washington.
More Resources
For the Public
For Health Care and Local Health Partners
Notifiable Condition: Report Malaria
Yellow Fever Vaccine and Malaria Prevention Information, by Country, CDC Yellow Book