Ventura County health officials confirmed on Wednesday the first mosquitoes to test positive for West Nile virus in the county this year.
The Ventura County Environmental Health Division said the California Department of Public Health confirmed that mosquitoes collected in the city of Fillmore on June 17 tested positive for the virus. Officials said West Nile virus is established in Ventura County and that additional positive mosquito samples are expected.
The mosquito sample is the first collected in Ventura County in 2026 to test positive for West Nile virus.
Ventura County Public Health said no human cases of West Nile virus have been identified in the county so far this year.
Health officials urged residents to take precautions to reduce their risk of exposure by eliminating standing water on their properties, ensuring doors and windows have tight-fitting screens without holes, wearing long pants and long-sleeved shirts when outdoors, particularly at dawn and dusk, and using an Environmental Protection Agency-approved insect repellent containing picaridin, DEET, oil of lemon eucalyptus (or PMD), or IR3535.
Officials also noted that West Nile virus can affect horses and advised owners to contact their veterinarian for information about protecting their animals.
Residents can report mosquitoes or potential mosquito breeding sources in Ventura County by calling the mosquito complaint hotline at (805) 658-4310.
The agency provides mosquito-eating fish for use in unattended swimming pools and ornamental ponds to help control mosquito populations.