Norovirus took the top spot for infection outbreaks in U.S. hospitals from 2008 to 2009 and was responsible for most department closures as well, a study finds.
Researchers looked at 822 survey results from hospitals around the country that reported on outbreak investigations, what triggered them and how they were controlled.
In the two years of the study there were 386 outbreak investigations that 289 hospitals reported. Outbreak investigations were most often located in medical or surgical intensive care units, and almost a third took place in locations such as rehab units, emergency departments, skilled nursing facilities and long-term acute care hospitals. In 344 of the 386 investigations, identifying an unusual organism was the most frequent trigger.
Four organisms caused the majority of outbreaks (almost 60%): norovirus, which causes severe gastroenteritis (18.2%), Staphylococcus aureus, or staph, a bacterium that can cause food poisoning, pneumonia and skin infections (17.5%), Acinetobacter spp, a bacterium common in hospitals (13.7%), and Clostridium difficile or C. difficile, a bacterium that can cause colon inflammation and diarrhea (10.3%).
In 22.6% of investigations the outbreak caused the closure of a unit or department, which affected an average 16.7 beds for an average 8.3 days. Norovirus was linked with the most closures in all settings except for neonatal intensive care units. Among the control plans most often used were taking more or better precautions and improving cleaning.
About 52% of the investigations were reported to an outside agency and 28.4% included help in the investigation from an outside source. The study notes that in most states reporting an outbreak to the health department is mandatory.
“An infection prevention and control program and its staff should be prepared for all aspects of an outbreak investigation,” the authors wrote, “through written policies and procedures as well as communication with internal and external partners.”
The study is published in the February issue of the American Journal of Infection Control.