A larger second flu peak has hit Sonoma and Napa counties as H3N2 and rising wastewater signals push test positivity and hospital visits higher. Health officials urge vaccination and early treatment.

Santa Clara County confirmed a measles case in an adult who recently traveled abroad; officials say the vaccinated patient is isolating and urged residents to check MMR status.

Aedes aegypti — a bottle‑cap‑breeding, day‑biting mosquito that can spread dengue and Zika — has been detected in parts of the Bay Area; officials urge residents to clear standing water.

Napa County is monitoring Rohlffs Manor after two residents were diagnosed with Legionnaires’ disease. Initial environmental samples at the complex tested negative as officials continue to investigate.