Overview
- CDC data show roughly 14% of norovirus tests were positive in mid-November, about double the level reported three months earlier.
- Wastewater and local reports point to increases in several states, with notable signals in Louisiana, Indiana and Michigan and Indiana clinicians noting higher-than-usual activity for this point in the season.
- Norovirus typically peaks between November and April, and last winter saw an unusually high December 2024 peak with test positivity near 25%, offering a benchmark for comparison.
- The virus spreads via contaminated food, surfaces and close contact, alcohol hand sanitizers work poorly against it, and officials stress soap-and-water handwashing, bleach-based surface disinfection and avoiding food preparation when ill.
- There is no specific antiviral treatment, so care focuses on hydration and monitoring young children, older adults and immunocompromised people, with guidance to stay home for 48 hours after symptoms resolve.