West Nile virus (WNV) …can cause severe neurological disease in humans, for which there is no treatment or vaccine. From 2009 to 2018, California has reported more human disease cases than any other state in the United States…High-burden ZIP codes were identified in nine counties within southern California and California's Central Valley. These ZIP codes accounted for 44% of WNV cases reported
- Vector-Borne and Zoonotic Diseases Characterizing Areas with Increased Burden of West Nile Virus Disease in California, 2009–2018 June 2, 2021.