West Nile Virus Activity - 2023
We conduct adult-mosquito-control treatments (AMTs) only when we detect a positive West Nile virus (WNV) mosquito. We use these treatments to reduce the risk of human infection. Treatments must be performed as quickly as possible to protect public health and safety, and prevent illness and even death.
Below is a list of AMTs that took place in 2023. Press releases, pesticides used, and links to treatment maps are listed for each of the treatments. If you are interested in subscribing to our adult-mosquito-control treatment notifications, or have questions about WNV and mosquito control, please see the additional information section at the bottom of this page.
WNV "season" usually begins around spring and lasts until early fall. Continue to check back for updates on 2024 treatments.
| Treatment Date | Treatment Location | Treatment Zip Codes | Treatment Map Link | Press Release Link | Pesticide Used | Pesticide Label | Pesticide Safety Data Sheet |
| 10/13/23 | San José and Milpitas | 95035, 95112, 95131, and 95134 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 9/18/23 | San José | 95110, 95112, and 95125 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 9/14/23 | Palo Alto and Mountain View | 94301, 94303, 94304, 94306, and 94040 | Interactive Map | Press Release | Merus 3.0 | Label | Safety Data Sheet |
| 9/11/23 | San José and Milpitas | 95035 and 95132 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 9/7/23 | San José and Unincorporated Santa Clara County | 95124 and 95118 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 9/5/23 | San José and Unincorporated Santa Clara County | 95121, 95135, and 95148 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 8/31/23 | San José | 95125 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 8/29/23 | San José | 95112, 85116, and 95122 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 8/22/23 | San José and Unincorporated Santa Clara County | 95124 and 95118 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 8/17/23 | Sunnyvale | 94086 and 94087 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 8/16/23 | San José | 95132 | Interactive Map | Press Release | Merus 3.0 | Label | Safety Data Sheet |
| 8/3/23 | Sunnyvale and Santa Clara | 94085, 94086, 94087, and 95051 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 8/2/23 | Milpitas and San José | 95035 and 95134 | Interactive Map | Press Release | Zenivex | Label | Safety Data Sheet |
| 7/27/23 | Stanford and Palo Alto | 94301, 94304, 94305, and 94306 | Interactive Map | Press Release | Merus 3.0 | Label | Safety Data Sheet |