VENTURA — On September 5, 2025 the Ventura County Environmental Health Division (Division) received confirmation from the California Department of Public Health that a bird collected during the fourth week of August (8/25) from the Simi Valley area tested positive for West Nile Virus (WNV). WNV is established in Ventura County and additional WNV positives are expected. This is the first detection of WNV activity this year in Ventura County.
On September 13, 2022, the Ventura County Environmental Health Division (Division) received confirmation from the California Department of Public Health that a bird collected during the fourth week of August from the City of Simi Valley area tested positive for West Nile Virus (WNV). This is the first bird collected in 2022 to test positive for WNV in Ventura County. There are no confirmed human cases at this time.
WNV is considered endemic, so we can expect the virus to stay in our environment.
