Overview
- UKHSA reports a recent increase within expected seasonal levels, with the highest rates in children and people over 65.
- California public health data cite wastewater readings labeled high in the U.S. Midwest and Northeast, with Sacramento and San Francisco elevated by Dec. 20.
- Norovirus spreads primarily via the fecal–oral route from contaminated hands, surfaces or food, requires a very low infectious dose and can persist on hard surfaces for days to weeks.
- Symptoms typically begin 12–48 hours after exposure and last 1–3 days, and people may remain contagious for days or longer after recovery.
- Guidance stresses soap-and-water handwashing over alcohol sanitizers, bleach-based disinfection for surfaces, hot cycles for dishes and laundry, and staying off work or school and away from hospitals or care homes until 48 hours after symptoms stop.