Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Font Size

Norovirus Causes Most Hospital Infection Outbreaks

3 Bacteria and 1 Virus Cause Almost 60% of Hospital-Associated Outbreaks, Survey Shows
By Cari Nierenberg
WebMD Health News
Reviewed by Laura J. Martin, MD

Feb. 2, 2012 -- Norovirus is the leading cause of infection outbreaks in hospitals throughout the country, a new study reveals.

The virus, which causes a "stomach flu" known as gastroenteritis, was the culprit in some 18% of all outbreaks in U.S. hospitals during a two-year period. It also was responsible for 65% of unit closures in health care facilities.

Norovirus has also been associated with outbreaks on cruise ships.

Symptoms of norovirus infection include nausea, vomiting, diarrhea, and stomach cramps. In a hospital setting, this rapidly spreading infection can be transmitted from person to person by having direct contact with someone who has the virus, by touching contaminated objects or surfaces, or from eating contaminated food or water.

The virus is found in the vomit or stool of infected people.

For this study, researchers sent out more than 5,000 online surveys to professionals involved in controlling and preventing hospital infections. They were asked to describe the type and number of infectious outbreaks at their facilities between 2008 and 2009. They were also asked if these outbreaks were investigated within the hospital or with help from a state health department.

Of the 822 U.S. institutions responding to the survey, 289 of them, or 35%, had investigated at least one infectious outbreak during the two-year period.

"It is clear that outbreaks of health care associated infections occur with some frequency in hospitals as well as non-acute settings," the researchers write.

Investigating Hospital Outbreaks

The study, which was published in the American Journal of Infection Control, found that four types of organisms were responsible for nearly 60% of the outbreaks reported.

Norovirus was the leading cause of outbreaks. It caused a little more than 18% of infectious outbreaks investigated by the hospitals participating in the survey. Not far behind was Staphylococcus aureus, a bacterium commonly found on the skin or in the nose, which caused 17% of outbreaks.

The third leading cause of hospital outbreaks was Acinetobacterspp, a bacterial infection commonly seen in very ill patients in intensive care units. It caused almost 14% of infectious outbreaks in the health care settings. Fourth was Clostridium difficile, a bacterial infection often linked to the use of certain antibiotics. It caused slightly more than 10% of outbreaks.

Today on WebMD

man holding his stomach
Get the facts on common problems.
blueberries in a palm
Best and worst foods.
woman shopping
Learn what foods to avoid.
fresh and dried plums
Will it help constipation?
diverticuliltis illustration
couple eating at cafe
sick child
Woman blowing bubble gum

Send yourself a link to download the app.

Loading ...

Please wait...

This feature is temporarily unavailable. Please try again later.


Now check your email account on your mobile phone to download your new app.

Woman with crohns in pain
Woman with stomach pain
diet for diverticulitis
what causes diarrhea