Los Angeles County health officials are warning that norovirus cases are on the rise across the region, with new data showing a significant uptick in virus levels detected in wastewater, a key early indicator of community spread. According to the Los Angeles County Department of Public Health, norovirus concentrations increased by 154% in the city of Los Angeles and more than 250% countywide over a recent three‑week testing period.
Norovirus, often called the “stomach bug”, is a highly contagious virus that spreads easily from person to person, by eating or drinking contaminated food or water, or through contact with infected surfaces. Symptoms typically develop 12 to 48 hours after exposure and can include vomiting, diarrhea, nausea, stomach cramps, fever and body aches.
Public health experts say norovirus outbreaks are common in the cooler months from late fall through early spring, when people spend more time indoors and close contact increases the risk of transmission. Officials urge heightened vigilance, especially in settings like schools, daycares, and shared living facilities.
Because norovirus spreads so easily and can survive on surfaces for days, authorities emphasize that proper hygiene is key to prevention. Washing hands thoroughly with soap and water — rather than relying solely on hand sanitizer — is one of the most effective ways to stop the virus from spreading. Health professionals also recommend disinfecting contaminated surfaces and avoiding food preparation when sick.
While most healthy adults recover within a few days, severe dehydration can occur, especially in young children, older adults, and people with weakened immune systems, potentially requiring medical attention.
