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

According to the CDC’s latest surveillancethere were 91 norovirus outbreaks reported in the country in the first week of December, which was higher than in previous weeks. The data only provides a limited snapshot of how prevalent norovirus is across the US today, but 2024 is an especially bad year for stomach flu.

Although norovirus is often associated with cruise ships, it’s a big source of stomachaches everywhere. The most contagious virus is leading cause of foodborne illness in the US, it usually sends people to their beds and toilets with diarrhea, vomiting, and other flu-like symptoms that last up to three days. While the cases are rarely life-threatening, about 100,000 Americans are hospitalized as a result of it each year.

Like many other diseases, norovirus took a bit of a hiatus in the early years of the covid-19 pandemic, thanks to increased social travel. As people’s lives and social norms have largely returned to normal, however, norovirus and other germs have made an unwanted return. But 2024 is an outlier even compared to average trends.

According to the CDCthere were 495 norovirus outbreaks reported in the US between August and December this year, which is higher than the 363 norovirus outbreaks reported during those same months in 2023. Norovirus cases can occur at any time, but the disease likely to peak between November and April in the US And the reported outbreaks so far this season are higher than the range observed in the same time period in previous seasons, since 2012.

These reports are only part of the picture. CDC’s surveillance system only includes outbreaks reported by health departments in 14 states (a full list can be found here HERE). And most norovirus cases go completely unreported, because people often just wait out their symptoms without seeking treatment. So outside of outbreaks that are clearly traced to a specific food source (such as recent outbreak involving some oysters), it can be difficult to tell when and where norovirus currently strikes.

Another important factor is our limited immunity to norovirus. There are several types of norovirus that cause illness going around at one time, and being recently infected with one strain may not protect you from others. Our resistance to a specific strain can also wear off over time, perhaps last for several months for some unlucky people.

People can take steps to reduce their risk of spreading and catching norovirus, however. If you currently have or have recently experienced vomiting and diarrhea, for example, you should avoid direct contact with people if possible and wash your hands frequently with soap and water. 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 if you feel better, because the virus can be shed in the stool for two weeks or longer.

Although it can be difficult to get rid of a party pooper without paying attention to these tips, you can reduce your risk of getting norovirus from food. You should always wash fruits and vegetables and cook your shellfish thoroughly. You should always clean your kitchen utensils, boards, and surfaces, especially after preparing shellfish. And you should wash your hands thoroughly after handling uncooked food, because norovirus or other food-borne germs can be transmitted through your hands that accidentally touch your mouth in late.

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