CDC posts new norovirus outbreak guidelines

January 12th, 2015

The Centers for Disease Control and Prevention has posted new guidelines on prevention of norovirus infections, compiling the latest information on the bane of cruise ships and hospitals alike.

Created by the CDC Healthcare Infection Control Practices Advisory Committee (HICPAC), http://www.cdc.gov/hicpac/ the document is entitled “Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, 2011"

A series of outbreaks in the last few years seems to have lulled, but no doubt norovirus will be a problem in some hospital or nursing home all too soon.

"These things tend to come in waves and every season is not the same," says Michael Bell, MD, HICPAC, executive secretary and deputy director of the CDC Division of Healthcare Quality Promotion. "I have no doubt that with the amount of long-term care facilities, day care facilities and other communal living situations — not to mention the growth of the cruise ship industry — that we will continue to see plenty of norovirus outbreaks."

Though rarely including fatal infections, norovirus outbreaks are extremely disruptive and expensive to control. Long-term care settings are particularly vulnerable to outbreaks due to the low infectious dose of norovirus (fewer than 10 viral particles), its persistence in the environment, and the close quarters and interaction typical among residents.

Many of the outbreaks have been associated with breaches in infection control measures, which include frequent hand disinfection, contact precautions with known patients and use of bleach or another appropriate disinfectant for environmental cleaning. Outbreaks have also been preceded by symptomatic illness in food handlers, reminding that norovirus can be a foodborne pathogen as well as transmitted through direct fecal-oral contact and through the environment. Transmission also goes the other way too, as outbreaks may include health care workers — some infected severely enough to be hospitalized.

"In this document there is a lot of emphasis on containment and environmental hygiene and cleaning," Bell says. "This is one of those things that is persistent in the environment, so there are several recommendations beyond routine cleaning to bring an outbreak to a close. The other issue is to make sure that the outbreak is promptly reported to state health authorities because it may not be purely hospital based. It's often a reflection of something happening in the community."