Overview
- Local officials in Sacramento reported six West Nile virus–positive mosquito samples and three positive dead birds concentrated in Carmichael with additional activity in Tahoe Park, prompting stepped-up surveillance and ground treatments.
- Massachusetts health officials confirmed the state’s first West Nile virus–positive mosquito sample of 2026 from Clarksburg after laboratory testing and urged precautions for at-risk residents.
- No human or animal West Nile cases have been reported so far this year in Massachusetts and the Sacramento notices did not report human cases.
- Vector-control districts will expand mosquito trapping and lab testing and perform targeted ground adulticide treatments where infected mosquitoes are found, and officials are asking residents to remove standing water and use repellent.
- Health agencies warn that warmer summer weather will boost mosquito populations, that symptoms usually appear two to six days after a bite, and that people over 50 face higher risk of severe disease.