Stanislaus County Public Health officials have confirmed that four Stanislaus County residents have been infected with West Nile Virus (WNV). These are the first human cases of WNV recorded in the county in 2023. WNV is primarily transmitted to humans through the bite of infected mosquitoes. Public Health and the local mosquito abatement districts announced the first pools of mosquitoes positive for WNV in June of 2023. One case of equine WNV was also recently identified.

All four human WNV cases are adults who developed neurological illness, known as neuroinvasive WNV.

Most people infected with West Nile do not have noticeable symptoms and likely will not know that they have been infected. Some people may develop mild symptoms, including fever, headache, and fatigue. Rarely, WNV can cause serious neurologic illness, such as encephalitis or meningitis, which can lead to long‐term disability or death. Certain populations, such as older adults, people with diabetes, and people with weakened immune systems, are more likely to develop serious illness when infected with WNV.

Dr. Thea Papasozomenos, Stanislaus County Public Health officer, stressed the importance of community awareness and engagement.

“Because there is no vaccine and no specific treatment for West Nile Virus, it is important for people to take steps to protect themselves and their families from mosquito bites,” Papasozomenos said. “We also urge residents to help control the mosquito population by dumping and draining any standing water around their homes, and reporting neglected swimming pools, as these can serve as mosquito breeding sites.”

Public Health emphasizes taking the following proactive measures to prevent mosquito bites and helping to keep mosquito numbers in check to reduce the risk of further disease transmission in the community:

Drain all sources of standing water around homes and properties to prevent mosquito breeding. Regularly empty flowerpots, bird baths, gutters, and other containers that collect water.

Dress in long sleeves, long pants, socks, and shoes outdoors to minimize exposure to mosquito bites, especially during dawn and dusk when mosquitoes are most active.

Defend with an Environmental Protection Agency (EPA)‐registered insect repellent that contains ingredients like DEET, picaridin, or oil of lemon eucalyptus to protect exposed skin from mosquito bites.

Dusk and Dawn: Minimize outdoor activities during peak mosquito activity times, typically during dawn and dusk.

Residents who come across dead birds, particularly crows, jays, ravens, or birds of prey, are encouraged to report them to California West Nile Virus dead bird call center at (877) WNV‐BIRD (968‐2473) or westnile.ca.gov/report. Birds serve as the natural hosts of WNV.

Residents are also asked to report neglected swimming pools to their local mosquito abatement district.

For up‐to‐date information and resources related to West Nile Virus and the ongoing efforts to prevent its spread, visit westnile.ca.gov/faq.