What to know about norovirus as cases surge across U.S.

New data shows cases of norovirus are rising in the U.S. According to the CDC, state health departments reported 91 cases during the week of Dec. 5, which is almost three times greater than the average weekly high of cases reported between 2021 and 2024. CBS News medical contributor Dr. Celine Gounder explains what to know. CBS News 24/7 is the premier anchored streaming news service from CBS News and Stations that is available free to everyone with access to the internet and is the destination for breaking news, live events, original reporting and storytelling, and programs from CBS News and Stations' top anchors and correspondents working locally, nationally and around the globe. It is available on more than 30 platforms across mobile, desktop and connected TVs for free, as well as CBSNews.com and Paramount+ and live in 91 countries. Subscribe to the CBS News YouTube channel: https://youtube.com/cbsnews Watch CBS News 24/7: https://cbsnews.com/live/ Download the CBS News app: https://cbsnews.com/mobile/ Follow CBS News on Instagram: https://instagram.com/cbsnews/ Like CBS News on Facebook: https://facebook.com/cbsnews Follow CBS News on X: https://twitter.com/cbsnews Subscribe to our newsletters: https://cbsnews.com/newsletters/ Try Paramount+ free: https://paramountplus.com/?ftag=PPM-05-10aeh8h For video licensing inquiries, contact: licensing@veritone.com