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As new strains strike, brace for norovirus outbreaks that can sicken staff, patients
Canadians offer valuable insights into fighting an outbreak
Cruise ships have become notorious for norovirus outbreaks that ruin passengers' exotic vacations. But as two new strains sweep the country, norovirus wields the greatest punch against long-term care facilities and hospitals, where outbreaks afflict patients and employees and lead to absenteeism and staff shortages.
More than 1,300 norovirus outbreaks occurred nationwide in the fall of 2006. While half of them were in long-term care facilities, a significant number occurred in hospitals, the Centers for Disease Control and Prevention in Atlanta reported. For example, in New York state, 26 (8%) of 333 outbreaks of acute gastroenteritis occurred in hospitals. In North Carolina, health authorities confirmed that norovirus was the cause of death of a 90-year-old nursing home patient last year. That is the first time the virus has been directly identified as a cause of death in the United States.1
Norovirus outbreaks are likely to increase this fall and winter, as well, as part of a seasonal trend, says Jacqueline Tate, PhD, an officer with CDC's Epidemiologic Intelligence Service. With new strains, the transmissibility will be even greater than usual, she says. "There can be high attack rates associated with norovirus because it has such a low infectious dose," she says.
In 2008, norovirus surveillance will increase as it becomes reportable through the National Outbreak Reporting System. Norovirus has an incubation period of just 12-48 hours and is characterized by vomiting, diarrhea, abdominal cramping and nausea. To limit transmission, CDC recommends strict adherence to infection control and environmental decontamination.
Preventing the spread of norovirus infection
The Centers for Disease Control and Prevention provides the following guidance to health care facilities seeking to control a norovirus outbreak:
(Editor's note: A CDC fact sheet on norovirus in health care facilities is available at www.cdc.gov/ncidod/dhqp/id_norovirusFS.html.)
Although norovirus is not usually life-threatening, hospital outbreaks are disruptive and even debilitating. Royal University Hospital in the Saskatoon Health Region in Canada weathered a norovirus outbreak last winter, which sickened 34 patients, 88 employees, and 16 physicians. The health region now shares its "lessons learned" from the 2006 outbreak with other hospitals.
Saskatoon Health Region has used the experience to improve its overall response plan for infectious diseases, but it also is bracing for the possibility of another norovirus outbreak. "Plan ahead because outbreaks can strike at any time," advises Donna Wiens, RN, BN, CIC, regional manager for infection prevention and control.
Hospital sets up Incident Command System
As it usually does, the norovirus outbreak in Saskatoon began in the community. Most likely the first patient came to the emergency room with severe gastroenterological symptoms and was admitted.
"We had reports from a unit saying, 'We're seeing vomiting and diarrhea in [several] patients. Please come and investigate,'" recalls Wiens.
Soon it became clear that there had been other, unrecognized cases. Some employees already had gotten ill. "Often, once you investigate, [you realize] the situation is bigger than you realize," she says. "Reports started coming from other units saying, 'We have this problem, too.' We had at least four units that had confirmed cases of norovirus during that same outbreak period."
Within a couple of days, the health region decided to convene an Incident Command System, which brought together a team that included managers, infection control, employee health, and public health. The team met each day — or sometimes twice a day — to review the cases and strategies to stop transmission.
The outbreaks cannot be controlled without taking stringent measures to prevent transmission, says Wiens. Norovirus "may be self-limiting in an individual. You get sick and you get better. But it's very transmissible. We know that people can get sick more than once. The immunity is very short. Outbreaks are not quickly self-limiting.
"I've seen outbreaks poorly controlled that went on for six weeks or more. They just keep recirculating in a population," she says.
While the health region focused on infection control, the command team provided feedback and communication to the staff as well as the public through regular press releases, pamphlets, and daily updates to employees. "You have to work closely with staff to get their buy-in and get the best result possible," says Jean Morrison, RN, MN, MHSA, chief nursing officer and vice president, performance excellence.
Combating the outbreak
To control the outbreak, the health region implemented a number of measures at Royal University Hospital:
After the outbreak subsided, Saskatoon Health Region reviewed its policies and decided to make some changes. To reduce the risk of hand contamination, employees were required to remove artificial nails. Their fingernails must be clipped short and polish-free.
The hospital also is encouraging employees to change out of their uniforms at the end of a shift and not wear them home. New lockers are being installed to give employees a place to store their street clothes.
Meanwhile, the hospital also learned that individual units need the flexibility to make decisions that suit their needs. To enable that, the hospital is creating unit-specific response plans that allow staff to have input when an infectious disease emerges or some other disaster occurs. "We will be putting together a template to make decisions and act at the unit level," says Morrison.
1. Centers for Disease Control and Prevention. Norovirus activity — United States, 2006-2007. MMWR 2007; 56:842-846.