KENNEWICK (AP) — A woman in southeastern Washington has tested positive for West Nile virus — the first human case in the state this year.

The Tri-City Herald reports the Benton-Franklin Health District announced the case Tuesday.

Officials say the woman in her 70s lives in Benton County and likely became infected there.

The virus is usually transmitted through the bite of an infected mosquito.

Most people don't become ill, but about one in five develop a fever and other symptoms. In rare instances, it can be fatal.

Two people in the state died last year after West Nile diagnoses. Another 24 people in the state were diagnosed with West Nile virus in 2015.

So far this year, infected mosquitoes have been found in Benton, Franklin, Adams, Grant, Stevens and Yakima counties, and an unvaccinated horse in Yakima County tested positive, the health district said.