The Shasta Mosquito and Vector Control District (SMVCD) have confirmed the first findings of West Nile virus (WNV) in Shasta County in the 2026 mosquito season from two mosquito samples. The two batches of mosquitoes were collected during routine trapping from sites in southeast Anderson.
In response to these results, SMVCD staff will be taking immediate action. By increasing immature mosquito monitoring in the area, we aim to find mosquito habitats and stop their growth in the water. Additionally, to disrupt the virus transmission cycle, SMVCD will be conducting ultra-low volume (ULV) adult mosquito control in the areas where mosquito activity and potential transmission risk continues.
Residents may receive email or text notifications for upcoming adult mosquito treatments. To sign-up, go to Mosquito Control Notifications on our website.
“These positive indicators serve as a reminder that WNV is endemic in our area, and the warm summer weather creates ideal conditions for WNV to multiply in local mosquitoes and birds,” stated Darcy Little, District Manager.
SMVCD staff urge residents to take precautions to avoid mosquito bites by implementing the 4 Ds of protection:
• Drain any standing water that may produce mosquitoes, including old tires, buckets, gutters, flowerpots and saucers. Some species of mosquitoes can lay their eggs in very small sources of water, like a bottle cap.
• Defend yourself and your home by using an effective insect repellent and making sure screens on doors and windows are in good condition.
• Dusk or Dawn, avoid outside activities during peak mosquito feeding times.
• Dress in long sleeves and pants when mosquitoes are active.
For more information about SMVCD’s services, WNV, or new emerging mosquito-borne diseases, contact the Shasta Mosquito and Vector Control District at (530) 365-3768 or visit www.ShastaMosquito.org.
2026 Shasta County West Nile virus activity: 0 dead birds, 0 sentinel chickens, 2 mosquito samples, and 0 humans tested positive for West Nile virus. 2026 California West Nile virus activity: 205 dead bird, 2 sentinel chickens, 670 mosquito samples, and 2 humans tested positive for West Nile virus.
