Norovirus, also known as the stomach bug, is spreading across the U.S. Here's what to know about the contagious virus and how best to prevent an infection.

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.

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

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.

Health care providers are not required by law to report norovirus cases to the state health department, so the data reflect estimates from schools, long-term care facilities and day cares.

The brief but miserable symptoms have no treatment except hydration and rest. Doctors have several tips on how to stop the spread.

CHICOPEE, Mass. (WWLP) – A new strain of Norovirus is impacting children and adults, and it’s spreading in our state. Respiratory illnesses continue to surge, that’s because it’s colder and more people are indoors allowing germs to spread, but it can be prevented.

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.

An outbreak of the norovirus has been reported at the Pasadena Evacuation Center, officials confirmed. The Pasadena Public Health Department said that three cases of the norovirus were confirmed at the Pasadena Convention Center shelter on Friday morning.

New CDC data indicates a rise in cases of norovirus, often colloquially referred to as "stomach flu." Test positivity has spiked.