A man in his 20s from Walla Walla County has been confirmed as the first Washington resident to become infected with West Nile virus in the state this year.
He was likely exposed near his home and he was hospitalized, according to a news release from the state Department of Health.
Two other people from Washington — a man from King County in his 70s and a woman from Grays Harbor in her 50s — were infected while out of the state, the health department said.
Reports of some additional infections are being investigated, the health department said.
The virus is most commonly spread to humans by mosquitoes. Mosquitoes in Benton, Franklin and Grant counties have tested positive this year, with the total of 34 positive samples already surpassing the 28 found during the past three years combined, the health department said.
Most people who become infected don’t get sick, though some may develop fever, headache or body aches and a small percentage become seriously ill, the health department said.
To avoid mosquito bites, people are urged to take steps including staying inside at dawn and dusk, using repellent and wearing pants and long sleeves outdoors when possible, making sure window and door screens are in good condition and getting rid of standing water.
The most active year for human West Nile virus infection in Washington was 2009, with 38 cases.
Last year, there were two reported cases and in 2012 there were four, the health department said.
For more information on West Nile, call 1-866-78-VIRUS or go to www.doh.wa.gov.