MOSES LAKE, Wash. — Mosquitoes collected near Crab Creek north of Moses Lake have tested positive for West Nile virus, Grant County Mosquito Control District No. 1 announced this week.
The mosquitoes were trapped Aug. 24 during routine testing, and results were confirmed Sept. 3 by the Oregon Veterinary Diagnostic Laboratory. Officials say it is possible mosquitoes carrying the virus could be present in other areas of the county.
“Although most people will not get seriously ill from West Nile virus, we do not want anyone to get sick because of a mosquito bite,” said Amber McCoy, investigation and response manager for the Grant County Health District.
Grant County is the third county in Washington to report positive mosquito samples this year, following Benton and Yakima counties. No human or animal cases have been reported in Washington in 2025, though Idaho confirmed a West Nile-related death in August. The last reported human case in Grant County was in 2015.
West Nile virus is the leading cause of mosquito-borne disease in the U.S. Most people infected do not become seriously ill, but about 1 in 150 develop severe illness affecting the central nervous system. There is no specific treatment, though hospital care may be required in severe cases.
Health officials urge residents to prevent mosquito bites by using EPA-approved repellents, wearing long sleeves and pants, repairing window screens, and eliminating standing water around homes. Birds and horses are also at risk; veterinarians recommend equine vaccination.
Grant County Mosquito Control District No. 1 began annual mosquito control efforts in March and will continue through October. So far, the district has set 1,494 traps and tested more than 869 mosquito samples.
More information is available at gcmcd1.org and granthealth.org.
