West Nile Virus Discovery in Ada County

First WNV Positive Test of 2025 Season - Boise (7/22/26)

The Ada County Mosquito Abatement District (ACMAD) has confirmed that West Nile virus (WNV) has been detected in local mosquito populations for the first time in the 2026 season. The mosquito samples that tested positive were collected in Boise near West Hillcrest Drive.

ACMAD crews will treat and monitor the area around the detection site and continue control efforts throughout Ada County to prevent human cases of WNV.

What You Can Do to Prevent the Spread of West Nile Virus:

• Dump & drain standing water weekly - birdbaths, toys, flowerpots, buckets, old tires, rain gutters, etc.
• Keep window and door screens in good condition
• Avoid overwatering your lawn and garden
• Limit time outdoors at dusk and dawn - peak mosquito activity times
• Wear long sleeves and pants (light-colored clothing is best)
• Use an EPA-approved insect repellent and follow label directions

Track WNV in Ada County:
Visit the Mosquito Tracker on our website
Follow the ACMAD Facebook page for weekly updates on new detections
Look for Nextdoor notices of new detections in your neighborhood

Have concerns or need to report an issue?

• Watch this video to learn about ACMAD operations
• Call: (208) 577-4646
• Email: [email protected]
• adacounty.id.gov/Mosquito-Abatement

Stay safe and mosquito-aware this mosquito season!