Issue: March 2012
February 02, 2012
2 min read

Norovirus the leading cause of infection outbreaks across US hospitals

Rhinehart E. Am J Infect Control. 2012. doi: 10.1016/j.ajic.2011.10.003.

Issue: March 2012
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Norovirus was responsible for 18.2% of all infection outbreaks and 65% of ward closures across US hospitals during a 2-year period, according to a study published in the American Journal of Infection Control.

To determine how often outbreak investigations are initiated in US hospitals and the triggers for these investigations — as well as the types of organisms and control measures involved — a team of researchers sent a two-part electronic survey to members of the Association for Professionals in Infection Control and Epidemiology in US hospitals during January 2010.

The first part of the survey focused on hospital demographics and the infection prevention or control program, while the second part looked at specific outbreak investigations. In all, the reserachers received 822 responses accounting for 386 outbreak investigations in 289 hospitals during a 24-month period from 2008 to 2009.

Sixty percent of the outbreaks, according to the study abstract, were caused by four organisms: norovirus (18%), Staphylococcus aureus (17%), Acinetobactor spp (14%) and Clostridium difficile (10%).

Medical/surgical units were the most common site of outbreak investigations (25.7%) according to a press release, with surgical units representing 13.9% of investigations. Norovirus occurred most in behavioral health and rehabilitation/long-term acute care units, with the researchers noting in the study that the other organisms occurred most often in medical/surgical units.

According to the release, the average number of confirmed cases per outbreak was 10.1, with an average duration of 58.4 days. Unit closures were reported in 22.6% of cases, causing an average of 16.7 bed closures for 8.3 days.

“It is clear that outbreaks of health care-associated infections occur with some frequency in hospitals as well as nonacute settings,” the researchers wrote. “An infection prevention and control program and its staff should be prepared for all aspects of an outbreak investigation through written policies and procedures as well as communication with internal and external partners.”

Disclosures: The researchers report no relevant financial disclosures.


Keith S. Kaye
Keith S. Kaye, MD

Norovirus can cause acute vomiting and diarrhea and can impact both patients and staff. Norovirus can be transmitted easily between individuals and can be relatively resistant to alcohol-based waterless hand hygiene agents and to standard hospital-grade disinfectants. Ideally, soap and water should be used to wash hands, and bleach-based solutions should be used to clean environmental surfaces.

- Keith S. Kaye, MD

Infectious Disease News Editorial Board member

Disclosure: Dr. Kaye reports no relevant financial disclosures.

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