The U.S. is seeing a "quad-demic" as cases of COVID-19, flu, RSV and norovirus spread at the same time. Experts said this is what you need to know.

First came the fires. Then, there was ash and contaminated water. Now, some survivors of the Southern California wildfires are dealing with outbreaks of norovirus and other stomach ailments at a shelter set up to help evacuees.

Norovirus infections jumped a stomach-turning 159% last month compared to the same span last year in NYC, where flu cases are also up nearly 25% so far in 2025, city Department of Health data reveal. There were 1,264 norovirus cases last month in Gotham, compared to 488 in December 2023.

Norovirus outbreak strikes evacuees at Pasadena shelter, with three confirmed cases and preventive measures underway.

Rates of norovirus in that CDC system have reached levels at or above last season's peak in all regions of the country. Norovirus test positivity rates look to be the worst in the Midwest, in a grouping of states spanning Kansas through Michigan.

The Pasadena Public Health Department said they will support the American Red Cross and onsite medical teams following a Norovirus outbreak at the city's evacuation center.

You can also get norovirus by touching objects or surfaces that are contaminated and then putting your hands in your mouth without washing them first. Hand-washing with soap and water is key, as hand sanitizer will not do the trick in the case of norovirus, experts say.

Three people have tested positive for norovirus amid a cluster of 28, the Pasadena Public Health Department said on Friday.

As many people know all too well, norovirus is a wicked illness. It causes gastroenteritis, a fancy name for violent

The cases mark the fourth norovirus outbreak on Holland America ships since early December, following others on its Eurodam, Rotterdam and Zuiderdam vessels. Other companies, including Cunard Line and Princess Cruises also saw outbreaks in recent weeks.

No. Hand sanitizer is simply not as effective against norovirus as it at killing other pathogens due to the virus's firm shell, Dr. William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center, told TODAY.com recently.

Although individual norovirus cases aren’t reportable in Oregon, outbreaks of norovirus are, and our “norovirus data year” starts in August and runs through the following July. This season, through the end of December Oregon recorded 29 norovirus outbreaks. (An outbreak is defined as two or more cases stemming from the same confirmed exposure).