Orange County is experiencing an unusually aggressive start to the West Nile virus season, prompting concern from public health officials. The Orange County Mosquito and Vector Control District says it has detected the virus in 206 mosquito samples so far this year. That’s nearly nine times the number recorded by this point in 2025 and the highest level of activity ever documented through the end of July. Officials say the early surge suggests conditions have been favorable for mosquito populations carrying the virus. While the increase is alarming, no human cases have been reported in Orange County this year. Health officials are urging residents to eliminate standing water around their homes, use insect repellent, and wear long sleeves and pants when outdoors during peak mosquito activity. During Orange County’s worst West Nile virus outbreak in 2014, officials detected 505 infected mosquito samples by the end of summer, along with 280 human cases and nine deaths.
