Statewide test positivity and sewage markers are ticking up in California; health officials say hospitalizations remain low but vulnerable people should stay current on vaccines.

Napa County alerted residents after a dead crow outside Napa tested positive for West Nile virus. Officials say there are no local human cases so far.

New research ties wildfire smoke to thousands of U.S. deaths and hundreds of thousands worldwide. Experts and public‑health agencies offer clear steps to reduce exposure.