On Aug. 6, 2025, the Tacoma-Pierce County Health Department (TPCHD) reported an East Pierce County, Washington woman who has not traveled recently was diagnosed August 2 with malaria. She is receiving treatment and we continue to monitor her status.

The TPCHD are working with Washington State Department of Health (DOH) and U.S. Centers for Disease Control and Prevention (CDC) to investigate potential sources of infection. It’s possible she was recently infected with malaria in Washington. If confirmed, this would be the first known locally acquired case of malaria in Washington.

The most likely cause of a locally acquired case is a mosquito biting someone infected with a travel-associated case of malaria, then passing the infection on to this patient.