Norovirus cases are on the rise now

There’s one potential party guest you’ll definitely want to steer clear of this New Year’s Eve: norovirus. Recent data from the Centers for Disease Control and Prevention shows that norovirus outbreaks have been reported in the United States.

According to the CDC last surveillancethere were 91 norovirus outbreaks reported nationally during the first week of December, which is up substantially from previous weeks. The data provides only a limited snapshot of how widespread norovirus is actually across the United States right now, but 2024 has been an especially bad year to get sick with the stomach bug.

Although norovirus is often associated with cruise ships, it is a prolific source of gastrointestinal misery everywhere. The highly contagious virus is the leading cause of foodborne illness in the United States, they typically send 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 because of it this year.

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 normal, however, norovirus and other germs have an unwanted comeback. But 2024 was an outlier even compared to typical trends.

Welcome to WHOThere were 495 noroviruses in the United States between August and December of this year, which is higher than the 363 noroviruses that were reported during the same months in 2023. Norovirus cases can occur at any time, but the disease tends to peak between November and. April in the United States And the fires reported so far this season are higher than the interval observed during the same period in recent past seasons, dating back to 2012.

These reports are only part of the picture. The CDC’s surveillance system includes only outbreaks reported by health departments in 14 states (a full list can be viewed here). And most cases of norovirus go unreported as people usually just wait out their symptoms without seeking medical help. So apart from outbreaks clearly traced to a specific food source (such as a recent epidemic involving certain oysters), it can be difficult to know when and where norovirus is currently hitting.

Another important factor is our limited immunity to norovirus. There are several disease-causing types of norovirus circulating at any time, and being recently infected with one strain might not protect you from others. Our immunity to a specific strain also tends to wane over time, perhaps it will only last a few months for some unlucky ones.

People can take steps to minimize their risk of spreading and catching norovirus, however. If you have or have recently had vomiting and diarrhea, for example, you should avoid direct contact with people, if possible, and always wash your hands with soap and water. You should not use hand sanitizer instead, as 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, since the virus can be spread in poop for two weeks or more.

While it might be difficult to avoid a poor party that ignores these tips, you can reduce the risk of catching norovirus from food. You should always wash your fruits and vegetables and cook your shellfish thoroughly. You should clean your cookware, cutting boards and surfaces regularly, especially after preparing shellfish. And you should wash your hands thoroughly after handling raw food, as norovirus or other food-borne germs could be transmitted from your hands by inadvertently touching your mouth afterward.

There are scientists and pharmaceutical companies working on norovirus vaccines, with some to come late stage clinical trials. So with luck, the dream of norovirus will one day be a distant memory.