West Nile Virus Detected in Mosquitoes in U.S. Cities

Mosquitoes in San Diego's Rolando neighborhood and Evanston, Illinois, have tested positive for the West Nile virus, with San Diego reporting its first positive mosquito detection since 2023 and Illinois confirming its first human case this year. Four dead birds in San Diego also tested positive, prompting public health advisories to eliminate standing water and use protective measures against bites. Health officials in affected areas emphasize the importance of using insect repellent and reducing exposure, especially for vulnerable populations. In response to increased risk, mosquito control spraying is scheduled in communities such as Belleville, New Jersey, and Reading, Massachusetts, using EPA-approved pesticides. Residents in these regions are advised to minimize exposure during spraying and heed local health guidance. No human West Nile virus cases have been reported in San Diego so far this year.