The Centers for Disease Control and Prevention headquarters in Atlanta on April 23, 2020. (Tami Chappell/AFP via Getty Images
Cases of a stomach virus have been on the rise across the United States in recent months, according to new data released by the Centers for Disease Control and Prevention (CDC).
Around 14 percent of tests for norovirus came back positive for the most recent week that ended Nov. 15, the CDC said in a report updated on Nov. 21. That’s about double from roughly three months ago in mid-August.
A norovirus case is usually characterized by the sudden onset of vomiting and diarrhea, and outbreaks occur in areas where people are close together. Cruise ships, nursing homes, prisons and jails, and schools often see outbreaks.
Norovirus is the leading cause of food-borne illness in the United States, responsible for 58 percent of such infections acquired in the country each year, according to the CDC.
On average, there are around 900 deaths, mainly in adults aged 65 and older, 109,000 hospitalizations, 465,000 emergency room visits, and 19 million to 21 million illnesses in the United States each year, it said.
Along with with vomiting and diarrhea, other frequently reported symptoms include nausea, stomach pains, ache, headache, and fever, officials say.
Generally, a person with norovirus will experience symptoms around 12 to 48 hours after they are exposed to the virus, say officials. Most people recover within one and three days.
Young children, older people, and those with weakened immune systems are most at risk, with dehydration from vomiting and diarrhea the top concern.
There is no medication to treat norovirus. Rehydration is recommended by drinking water and other liquids, with the exception of coffee, tea, and alcohol.
Anyone suffering from dehydration should seek medical help, authorities say. Symptoms of dehydration include a decrease in urination, dry mouth and throat, and feeling dizzy when standing. Dehydrated children may be unusually sleepy or fussy and cry with few or no tears.
A CDC graph updated on Nov. 21, 2025, shows the prevalence of norovirus in the United States. (CDC via The Epoch Times)
Health authorities say one way to prevent acquiring norovirus is to wash your hands with warm water and soap for around 20 seconds, especially after using the bathroom, before eating or preparing food, and before giving yourself or others medicine. Just hand sanitizer does not work well against norovirus, according to the CDC.
Scrubbing surfaces with household disinfectants can also help, officials say.
Norovirus is also known to be transmitted by raw or partially cooked shellfish, such as clams, oysters, scallops, and mussels, state health officials say. Outbreaks are often linked to oysters because they are frequently eaten raw.
Norovirus saw a surge in early December 2024 when dozens of outbreaks were reported around the United States. In 2025, the CDC has so far reported 15 norovirus outbreaks on cruise lines
The CDC said that outbreaks of the virus sickened dozens of people on two cruise ships in two separate cases in October, including one operated by Oceania Cruises and the other by Royal Caribbean. In the Royal Caribbean outbreak, 98 people were sickened, while 75 were sickened in the Oceania outbreak, CDC figures showed.
