A review of nosocomial norovirus outbreaks: infection control interventions found effective.

The purpose of this study was to review documented outbreaks of enteric illness associated with nosocomial norovirus infections and to identify modes of transmission, morbidity and mortality patterns, and recommendations for control. Searches of electronic databases, public health publications, and federal, state/provincial public health websites were completed for 1 January 2000 to 31 December 2010. Computer-aided searches of literature databases and systematic searches of government websites identified 54 relevant outbreak reports. Transmission routes included person-to-person (18.5%), foodborne (3.7%) and in the majority (77.8%) the route was unknown. Actions taken during the outbreak to control infection included restricting the movements of patients and staff (22.5%), enhanced environmental cleaning (13.6%) and hand hygiene (10.3%). Rapid identification of norovirus outbreaks in hospitals is vital for the immediate implementation of infection control measures and isolation of infected individuals in this mainly immunocompromised population. Studies that statistically evaluate infection control measures are needed.