Los Angeles County public health officials report the county’s first human case of West Nile virus in 2026. The patient is described in local reporting as very ill, and health officials confirm that West Nile virus is transmitted through the bite of an infected mosquito. The announcement comes amid a broader increase in West Nile activity across the United States, according to coverage referencing national trends. Officials state the infection is spread when mosquitoes carrying the virus bite people and emphasize that mosquito bites are the primary route of transmission. Public health messaging focuses on prevention measures aimed at reducing exposure to mosquitoes. While the reports identify the first 2026 case in Los Angeles County, details such as the patient’s age and specific clinical course are not provided in the excerpts available. No additional cases in the county are mentioned in the supplied summaries.