PIERCE COUNTY, WA (MyBellinghamNow.com) – Health officials in Pierce County are investigating what could be the state’s first-ever case of locally acquired malaria.

The Tacoma-Pierce County Health Department announced on Wednesday that an East Pierce County woman was diagnosed with malaria last Saturday.

It says the woman has not traveled recently and says it’s possible that she was infected in Washington.

The department says the risk to the public is very low as it works with the state Department of Health and CDC to investigate the source of the infection.

The most likely cause is that a mosquito bit someone who had been infected with malaria overseas, then passed the infection on to the woman.

According to the CDC, malaria cases in the United States are usually linked to travel, mainly from sub-Saharan African countries.

Washington sees anywhere from 20 to 70 reports of malaria cases each year.