West Nile virus threat emerges in Stanislaus County. Sample tests positive
Mosquito samples within the Turlock Mosquito Abatement District tested positive for the West Nile virus, indicating the potentially deadly disease could afflict residents in Stanislaus County.
The Turlock and East Side mosquito control districts said in a joint news release Thursday the samples were collected June 17 and sent for testing. The Turlock district covers portions of the county south of the Tuolumne River. East Side is responsible for mosquito abatement in Modesto and other communities north of the Tuolumne.
The districts urged residents to avoid mosquito bites, which can spread the virus, and also report sources of standing water where the insects multiply.
The news release said the sustained warm-up in the coming week will create conditions for a rapid increase in mosquitoes. “In response to this situation, both districts are enhancing their mosquito surveillance and control efforts,” the news release said. “This includes applying larvicides to known mosquito breeding sites, spraying when necessary and testing mosquito pools for viruses such as West Nile.”
West Nile causes an illness marked by fever and body aches in 20% of those bitten by an infected mosquito. It can last for weeks before people recover. A much more rare neurological reaction may result in high fever, headache, extreme fatigue, paralysis, coma, hospitalization or death. It happens in less than 1% of people infected.
Every year, the virus is a public health threat in the Central Valley through the summer and early fall.
Adults 55 and older are at higher risk for severe symptoms. The districts recommend a West Nile summertime plan to keep individuals and family members from getting infected from mosquito bites. The plan should include:
- Using insect repellent when outdoors.
- Wearing long sleeves and pants near dawn and dusk, which are peak times for mosquitoes.
- Making sure screens are tight-fitting over windows and doors at home.
- Reporting neglected swimming pools to mosquito abatement agencies.
- Vaccination of horses against West Nile virus. Ask your veterinarian.
Residents should empty buckets, birdbaths and flowerpots to prevent mosquitoes from breeding around their homes.
People who notice an unusual number of mosquitoes may contact their mosquito control district. Call East Side at 209-522-4098; Turlock at 209-634-1234.
This story was originally published June 26, 2025 at 6:57 PM.
