California is experiencing an unprecedented spike in West Nile virus cases, reaching levels not seen in five years. The outbreak has been fueled by unusually warm winter temperatures and an intense March heat wave, creating optimal breeding conditions for mosquitoes across the state. Health officials are urging residents to take preventive measures as the virus continues spreading, with confirmed fatalities among the state's population. The combination of climate anomalies and environmental factors has intensified public health concerns heading into peak mosquito season.

Summary auto-generated by AI from the original publisher's content. Editorial standards.