An increasing number of healthcare-associated infection outbreaks are due to norovirus, an easily spreadable organism whose symptoms include vomiting and fever, according to a study in the American Journal of Infection Control.

Using survey responses from more than 800 members of the Association for Professionals in Infection Control and Epidemiology, researchers collected data on 386 outbreak investigations that occurred in 289 hospitals over a two-year period. More than 18% of the outbreaks were caused by norovirus, the researchers said. Other common infection-causing pathogens included Staphylococcus aureus, which caused 17.5% of outbreaks, and C. difficile, which caused 10%, according to the study.

Norovirus was also associated with 65% of the ward closures reported by respondents.

“The frequency of outbreaks in critical-care units is not surprising,” the authors wrote in the study. “However, the report of outbreaks in nonacute settings, such as behavioral health units, (long-term acute-care hospitals) and (skilled nursing facilities) is notable with norovirus as the most common causative organism in these settings. Norovirus has received increasing attention as a HAI because of the increase in hospitals as well as nonacute settings.”