On Dec. 28, 2024, the U.S. Centers for Disease Control and Prevention reported that cases of a wretched 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.

Norovirus is the leading cause of foodborne illness in the United States, responsible for 58% of such infections acquired in the country each year, according to the CDC. There are about 2,500 norovirus outbreaks reported annually in the United States. The outbreaks can occur throughout the year but are most common from November to April.