There’s one potential party guest that you definitely want to steer clear of this New Year’s Eve: norovirus. Recent data from the Centers for Disease Control and Prevention shows that outbreaks of norovirus are being reported across the U.S.
According to the CDC’s latest surveillance, there were 91 norovirus outbreaks reported nationally during the first week of December, which is up substantially from previous weeks. The data only provides a limited snapshot of how widespread norovirus truly is throughout the U.S. right now, but 2024 was an especially bad year for getting sick with the stomach bug.
Though norovirus is often associated with cruise ships, it’s a prolific source of gastrointestinal misery everywhere. The highly contagious virus is the leading cause of foodborne illness in the U.S., typically sending people to their beds and toilets with diarrhea, vomiting, and other flu-like symptoms that last for up to three days. While cases are rarely life-threatening, about 100,000 Americans are hospitalized as a result of it annually.
Like many other diseases, norovirus took a bit of a break during the early years of the covid-19 pandemic, thanks to increased social distancing. As people’s lives and social habits have largely returned to usual, however, norovirus and other germs have made an unwelcome comeback. But 2024 has been an outlier even compared to typical trends.
According to the CDC, there were 495 norovirus outbreaks reported in the U.S. between August and December this year, which is higher than the 363 norovirus outbreaks reported during those same months in 2023. Cases of norovirus can occur any time, but the disease tends to peak between November and April in the U.S. And reported outbreaks so far this season are higher than the range observed during the same time period in past recent seasons, dating back to 2012.
These reports are just part of the picture. The CDC’s surveillance system only includes outbreaks reported by health departments in 14 states (a full list can be viewed here). And most cases of norovirus go unreported in general, since people usually just wait out their symptoms without seeking medical attention. So outside of outbreaks clearly traced to a specific food source (such as a recent outbreak involving certain oysters), it can be difficult to tell when and where norovirus is currently striking.
Another important factor is our limited immunity to norovirus. There are several types of disease-causing norovirus circulating at any one time, and being recently infected by one strain might not protect you from the others. Our immunity to a specific strain also tends to wane over time as well, perhaps lasting as little as a few months for some unlucky people.
People can take steps to minimize their risk of spreading and catching norovirus, however. If you’re currently having or recently experienced vomiting and diarrhea, for instance, you should avoid direct contact with people if possible and consistently wash your hands with soap and water. You should not use hand sanitizer instead, since the virus’s physical structure makes it resistant to alcohol. And you should avoid preparing food for others for a while even after you feel better, since the virus can be shed in poop for two weeks or longer.
While it might be hard to ward off a party pooper ignoring these tips, you can reduce your risk of catching norovirus from food. You should always wash fruits and vegetables and cook your shellfish thoroughly. You should regularly clean your kitchen utensils, cutting boards, and surfaces, especially after preparing shellfish. And you should thoroughly wash your hands after handling uncooked food, since norovirus or other foodborne germs could be transmitted by your hands inadvertently touching your mouth later.
There are scientists and pharmaceutical companies working on norovirus vaccines, with some about to reach late-stage clinical trials. So with any luck, the nightmare of norovirus will someday be a distant memory.