A crow in Island County had been found to be infected with West Nile virus, county health officials said Wednesday.

The crow was found in September and sent to the Washington Animal Disease Diagnostic Laboratory at Washington State University for testing.

“The crow was reported to us by a veterinarian in Oak Harbor,” said Katie Hicks, an environmental health specialist for Island County.

“The bird was euthanized, frozen and sent for testing; fortunately the doctor followed correct protocol,” she said.

Also this week, a Clark County man in his 50s was confirmed as Washington’s third person infected with West Nile virus. Blood tests at the state Public Health Laboratories in Shoreline were confirmed by the Centers for Disease Control and Prevention (CDC).

The man became ill in early September and did not travel out of the state during the time he was bitten by an infected mosquito. He developed mild symptoms — a rash and fever — and has since recovered. The disease is not spread person-to-person so the man was not a threat to public health.

So far there have been three humans, five horses and two birds reported with West Nile in Washington.

Hicks noted that mosquitoes are the disease’s prime carrier and offered some clear guidelines that people should follow:

• Avoid being in mosquito areas at dawn or dusk;

• Make sure door and window screens are in good condition;

• Use mosquito repellent;

• Take a look around the house and yard and get rid of any standing water by turning over old tires, wheelbarrows or dog dishes, birdbaths and water troughs to eliminate small puddles where mosquitoes breed.

Most people who are infected with West Nile virus don’t get sick or have symptoms, yet it can be a very serious disease for a small number of people, especially those older than 50.

Last month, the CDC confirmed two other human cases of West Nile infection in a man and woman in Pierce County — the first people reported to acquire the infection within the state.

Island County health officer Dr. Roger Case said that while cooler weather will help diminish the mosquito population, spring isn’t far away.

“While we have focused our interests on Avian influenza, which isn’t here, we need to remind ourselves that the vectors for West Nile Virus are here, and are an issue we can and should address,” Case said in a statement.

“I sincerely hope that we don’t have to wait for a death from West Nile Virus to prompt our community into forming a county-wide mosquito control district, which is the most effective measure to address mosquito borne illness,” he added.

West Nile virus is primarily a bird disease. Mosquitoes become infected by feeding on infected birds, and then pass the virus to uninfected birds, humans, horses or other hosts.

Crows, ravens, magpies and jays are especially susceptible to dying from the virus.

The Department of Health is monitoring for the presence of West Nile virus by tracking mosquito samples, horses and dead birds.

Hicks recommended South Whidbey residents call 321-5111 if they suspect someone has been infected. For more information, visit www.doh.wa.gov/WNV.