West Nile virus found in mosquitoes in Pierce County

TACOMA, Wash. – Health officials found West Nile virus as they were sampling mosquitoes near the Port of Tacoma earlier this month.

The samples came from the Gog-le-hi-te Wetlands near the Puyallup River, just north of Highway 509, on Aug. 14.

“People should assume West Nile Virus infection is possible in Pierce County and take steps to prevent breeding mosquitoes and avoid mosquito bites,” said Nigel Turner, director of the Communicable Disease division. “Most importantly, know when to get care if you have been bitten.”

It’s the first time West Nile virus has been found in mosquitoes west of the Cascades in Washington. It was found in birds in Pierce County in 2002, 2008 and 2009, and two people tested positive for the virus in the county in 2006.

It was the only sample site in Pierce County this year, but the Department of Health said it will set up and monitor five more sites across the county.

“Even though it shows up sporadically, we believe increased testing would likely reveal more cases of West Nile virus,” Turner said.

The good news? Mosquito season usually ends in the middle of September.

Nearly every state sees West Nile virus in either birds, mosquitoes or people at some point.

Here’s more from the Department of Health:

Who’s most at risk for West Nile Virus?

It only takes one bite to acquire the virus from an infected mosquito, and West Nile virus can pose a health threat to anyone exposed. But less than 1 percent of people infected with the virus will develop severe illness. Some are at higher risk of severe disease, including people 60 years old or older, those with compromised immune systems or underlying medical conditions.

What are the symptoms?

Symptoms of West Nile virus include headache, fever, muscle and joint aches, swollen lymph nodes and a rash. Symptoms usually develop 2 to 14 days after an infected mosquito bites you. Those with more severe symptoms—such as severe headache, stiff neck or confusion—should seek medical attention.

Health officials have not seen any cases of West Nile virus in Pierce County among people, birds or horses. West Nile activity typically shows up early to mid-August. People should take steps to control mosquito populations and prevent exposure to bites.

Drain, dress and repel.

You can take simple steps to avoid mosquito bites and reduce mosquito breeding sites around your home.

Drain and routinely empty anything that holds water, like gutters, pet bowls, tires, bird baths at least twice a week. Keep water moving in ornamental ponds by recirculating water or by installing a fountain.

Dress in long-sleeved shirts and long pants, especially at dawn and dusk when mosquitoes are most active.

If outdoors, use mosquito repellent where mosquitoes are active.

Use properly fitted door and window screens and stay indoors around dawn and dusk.

No vaccine is available for humans, but there is one for horses. About 1 in 3 horses that become ill with the virus will die. One horse in the state had a confirmed case of WNV in 2018, in Grant County. Talk to your equine veterinarian if you have questions about the West Nile virus vaccine. Get more information at the WSDA website.

If you find a dead bird, be aware some birds may die from West Nile virus. Don’t handle dead birds with your bare hands. Find information about dead birds, West Nile virus prevention and mosquito repellents at www.tpchd.org/westnile.