Pierce County investigates possible locally acquired malaria case
Aug 6, 2025, 1:45 PM
Sophia Mwinyi views Anopheles gambiae mosquitoes in the environmental chamber room insectary in the Joseph Black Building at the University of Glasgow on May 02, 2025 in Glasgow, Scotland. (Photo: Jeff J Mitchell, Getty Images)
(Photo: Jeff J Mitchell, Getty Images)
The Tacoma-Pierce County Health Department (TPCHD) is investigating what could be the first-known case of malaria acquired in Washington.
Health officials said an East Pierce County woman, who has not recently traveled, was diagnosed with the mosquito-borne illness on August 2. She is currently receiving treatment and being monitored.
that the public risk remains 鈥渧ery low.鈥�
The Washington State Department of Health and the Centers for Disease Control and Prevention are working with TPCHD to determine how she may have contracted the disease. Officials said the most likely scenario is that a mosquito bit someone infected with malaria due to travel, then transmitted the parasite to the local patient.
鈥淢alaria is a rare disease overall in the United States, and the vast majority of cases in the United States occur following exposures in countries with ongoing transmission,鈥� Dr. James Miller, the county鈥檚 health officer, said.
As part of the investigation, officials are conducting mosquito trapping and testing. Fortunately, mosquito populations in Pierce County are currently decreasing, according to TPCHD.
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Symptoms of malaria
Malaria symptoms typically include fever, chills, fatigue, body aches, and headaches. It can also cause nausea and vomiting. The disease is not spread person-to-person and is treatable with prescription medication if caught early
Nationwide, the U.S. sees about 2,000 to 2,500 travel-related cases annually, with Washington reporting 20 to 70 each year.
In 2023, the U.S. saw its first locally acquired mosquito-transmitted malaria case in two decades.
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