Cases of norovirus, a wretched and highly contagious stomach bug, are surging in parts of the United States this winter, according to government data.
The most recent numbers from the U.S. Centers for Disease Control and Prevention show there were 91 outbreaks of norovirus reported during the week of Dec. 5, up from 69 outbreaks the last week of November.
Numbers from the past few years show a maximum of 65 outbreaks reported during that first week of December.
A norovirus infection is characterized by sudden vomiting and diarrhea. Outbreaks are often seen on cruise ships , in congregate living situations like nursing homes and jails, as well as schools and places where people are close together. Earlier this month, hundreds of cruise passengers fell ill with norovirus on three different ships, according to the CDC, which recorded outbreaks of the virus on 14 cruises overall this year. December has so far seen the highest number of cruise ship outbreaks in the span of a month compared with any other month in 2024.