Norovirus cases have more than doubled in Massachusetts compared to last season, data shows
BOSTON - Massachusetts is seeing an increase in reported norovirus cases this season, according to Department of Public Health data. The number of cases recorded in November and December by the state is more than double what it was the year before over the same time period.
This past November, there were 134 laboratory-confirmed cases of the highly contagious stomach bug, followed by 279 in December. In 2023, there were only 52 reported cases in November and 112 in December.
There's been a steady increase in reported norovirus cases in recent years. Massachusetts reported 678 total norovirus cases in 2022, 1,252 in 2023 and 2,080 in 2024. Case numbers are typically highest in February and March.
DPH monitoring norovirus increase in Massachusetts
DPH's Bureau of Infectious Disease and Laboratory Sciences has been monitoring the rise in norovirus cases. It's possible that some of the reported instances of norovirus are a result of false positive tests, DPH said.
Other parts of the country are also seeing a surge in norovirus activity. The Minnesota Department of Public Health reported about twice as many cases as usual in December.
What is norovirus?
The Centers for Disease Control says norovirus "is a very contagious virus that causes vomiting and diarrhea." While some people may refer to it as a stomach flu, it is not actually caused by the influenza virus.
Symptoms occur about 12 to 48 hours after exposure to the virus. Most people feel better after one to three days, but they can still be contagious for up to two weeks after that. Doctors say that you should not need to seek medical attention unless you become too dehydrated.
"Unfortunately there isn't really any treatment for norovirus," said Dr. Daniel Kuritzkes, who is chief of Infectious Diseases at Brigham and Women's Hospital. "If you're simply unable to keep down fluids, you're beginning to feel lightheaded when you stand up, and you're becoming dehydrated, then you need to seek medical attention so that you can get fluid replacement."
How do you prevent norovirus?
DPH advises anyone feeling sick to stay home and wash their hands well with soap and water. Hand sanitizer alone won't kill norovirus germs, the agency says.
Anyone who comes down with norovirus should not prepare or handle food for others for at least three days after their symptoms end, DPH says.
