To avoid getting infected, the Mayo Clinic says to wash your hands with soap and water for at least 20 seconds, especially after going to the bathroom or preparing food; wash fruits and vegetables; and disinfect contaminated surfaces.
Norovirus cases appear to be trending up, according to recent data. The National Respiratory and Enteric Virus Surveillance System reported that almost 14% of tests came back positive during the week of Nov. 15.
In the week of Oct. 11, 11% of tests taken ended up being positive, while nearly 7% were positive during the week of July 5.
Epic Research's communicable disease tracker shows Wyoming saw a particularly high number of cases between Oct. 19 and Nov. 1, with 33.2 cases per 100,000. Other states hit hard at this time were Oklahoma (27.3 cases per 100,000); Nebraska (30.6 per 100,000); Texas (26.5 cases per 100,000); and Alabama (24.7 cases per 100,000).
Norovirus cases also increased around this time last year as well: in the week of Nov. 16, 2024, 10% of tests came back positive. They hit a high of 24.82% in the week of Dec. 28,2024.
From Aug. 1 through Nov. 13 of this year, there were 153 norovirus outbreaks reported by state health departments that report to NoroSTAT, which works with the Centers for Disease Control and Prevention. Last year, there were 235 norovirus outbreaks in that same time period.
Norovirus, the CDC said, is a "very contagious virus that causes vomiting and diarrhea." It causes acute gastroenteritis, which is an inflammation of the stomach or intestines.
According to the Mayo Clinic, it commonly spreads via contaminated food, water or surfaces.
Many infections come from closed and crowded environments, such as hospitals, nursing homes, child care centers, schools and cruise ships.
Symptoms of norovirus can include nausea, vomiting, stomach pain or cramps, watery or loose diarrhea, a low grade fever and muscle pain. Diarrhea, stomach pain and vomiting, the Mayo Clinic said, usually start about 12 to 48 hours after exposure.
To prevent norovirus infections, the Mayo Clinic says to wash your hands with soap and water for at least 20 seconds, especially after going to the bathroom or preparing food; wash fruits and vegetables; and disinfect contaminated surfaces.
And if you actually end up getting it? Most people end up getting better within one to three days, the CDC said. There isn't a specific medicine to treat it, and antibiotic drugs won't help as they fight bacteria, not viruses, the health agency notes.