Norovirus cases are on the rise right now

There’s one potential party guest you definitely want to avoid this New Year’s Eve: norovirus. The latest data from the Centers for Disease Control and Prevention shows that norovirus outbreaks have been reported in the US

According to the CDC latest observationthere were 91 norovirus outbreaks reported nationally in the first week of December, a significant increase from previous weeks. The data provide only a limited snapshot of how widespread norovirus is in the U.S. right now, but 2024. it was a particularly bad year for getting a stomach bug.

Although norovirus is often associated with cruise ships, it is a prolific source of gastrointestinal distress everywhere. The virus is highly contagious 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 up to three days. Although cases are rarely life-threatening, about 100,000 Americans are hospitalized as a result annually.

Like many other diseases, norovirus took a bit of a hiatus 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 normal, however, norovirus and other germs have unwanted return. But 2024 is an outlier even compared to typical trends.

According to the CDCThere were 495 reported norovirus outbreaks in the U.S. between August and December of this year, which is more than the 363 norovirus outbreaks reported in the same months of 2023. Norovirus cases can occur at any time, but the disease peaks between November and April in the U.S. And reported outbreaks so far this season are higher than the range seen during the same time period in recent recent seasons dating back to 2012.

These reports are only part of the picture. CDC’s surveillance system includes only outbreaks reported by health departments in 14 states (the full list can be seen at here). And most cases of norovirus go largely undetected because people usually just wait out their symptoms without seeking medical attention. So outside of outbreaks clearly traced to a specific food source (like recent an 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 noroviruses circulating at any given time, and being recently infected with one strain may not protect you from the others. Our immunity to a specific strain also tends to wane over time, perhaps lasting only a few months for some unfortunate people.

People can takes steps to minimize the risk of spreading and catching norovirus, however. If you currently have or have recently had vomiting and diarrhea, for example, you should avoid direct contact with people if possible and wash your hands frequently with soap and water. Instead, you should not use hand sanitizer because the physical structure of the virus makes it resistant to alcohol. And you should avoid preparing food for others for a while, even after you feel better, because the virus can be shed in the stool for two weeks or more.

Although it can be difficult to protect yourself from a partygoer, by following these tips, you can reduce your risk of contracting norovirus from food. You should always wash fruits and vegetables and cook shellfish thoroughly. You should clean your kitchen utensils, cutting boards and surfaces regularly, especially after cooking shellfish. And you should wash your hands thoroughly after handling uncooked food, as norovirus or other food-borne germs can be passed on by accidentally touching your mouth later.

There are scientists and pharmaceutical companies working on norovirus vaccines, with some on the way late stage clinical trials. So with any luck, the norovirus nightmare will someday be a distant memory.