Overview
- Los Angeles County reported its first human West Nile case of 2026 on Monday, an Antelope Valley resident hospitalized with encephalitis after developing symptoms in late June.
- Wisconsin confirmed its first 2026 detections when mosquitoes in Milwaukee County and a wild bird in Bayfield County tested positive, though no human cases have been reported in the state.
- Texas health officials have confirmed additional neuroinvasive cases, including a hospitalized man in his 80s and a woman in her 60s in El Paso, and multiple cases in Houston and Harris County.
- Local vector-control agencies are increasing mosquito trapping, pooled testing and targeted treatments such as fogging and larvicide applications in neighborhoods where infected mosquitoes or birds were found.
- Health agencies urge residents to reduce standing water, use EPA-approved repellents, repair screens and limit outdoor activity at dawn and dusk because most infections are mild but older or immunocompromised people can develop severe neurologic disease.