Norovirus was responsible for 18.2% of all infection outbreaks and 65%
of ward closures in U.S. hospitals during a 2-year period, according to a study
recently published in American Journal of Infection Control.
Four organisms — norovirus, Staphylococcus aureus,
Acinetobactor spp and Costridium difficile — were found to
be the most common culprits, according to the survey abstract.
“If we focus on the four most common organisms we found causing
outbreaks, two things come to mind,” survey author Emily Rhinehart, RN,
MPH, told Orthopedics Today. “One is standard precautions in
hospitals should reduce the risk of any or all of them. The second this is
there is a [Centers for Disease Control and Prevention] guideline — of
which I was one of the principal authors — on management of multidrug
resistant organisms that should prevent transmission.”
To determine how often outbreak investigations are initiated in U.S.
hospitals, the triggers for these investigations and the types of organisms and
control measures involved, the Rhinehart and colleagues sent a two-part
electronic survey to members of the Association for Professionals in Infection
Control and Epidemiology (APIC) in U.S. hospitals in January 2010. The first
part of the survey focused on hospital demographics and infection prevention or
control programs, while the second part looked at specific outbreak
In all, the investigators received 822 responses accounting for 386
outbreak investigations in 289 hospitals during a 24-month period. According to
the study abstract, nearly 60% of the outbreaks were caused by four organisms:
norovirus (18%), Staphylococcus aureus (17%), Acinetobactor spp
(14%) and C. difficile (10%).
Medical/surgical units were the most common site of outbreak
investigations, representing 25.7% of investigations with surgical units
representing 13.9%, according to a news release from the APIC. Norovirus
occurred most in behavioral health and rehabilitation/long-term acute care
units, with the authors noting in the study that the other organisms occurred
most often in medical/surgical units.
Noroviruses are a group of related RNA viruses that cause acute
gastroenteritis in humans, the investigators told Orthopedics
Today. The most common symptoms are diarrhea, vomiting and stomach pain.
Noroviruses spread from person to person, through contaminated food or water,
and by touching contaminated surfaces. Norovirus is recognized as the leading
cause of foodborne-disease outbreaks in the United States and have been
frequently reported as the cause of outbreaks on cruise ships.
“The thing about norovirus being the most common cause … was
not a shock or surprise,” Rhinehart said. “This was the first study
to actually quantify how frequently norovirus is causing outbreaks in
hospitals. It was common knowledge it was in hospitals and outbreaks were
occurring, but nobody knew how frequent it was.”
While basic practices can reduce infections and outbreaks in many cases,
Rhinehart said there are specific things orthopedic surgeons must keep in mind
to help reduce the occurrence of C. difficile.
“The issue with C. difficile, especially for the orthopedic
surgeon, is the appropriate use of antibiotics,” Rhinehart said.
“Orthopedic surgeons routinely order antibiotics as prophylaxis against
[surgical site infection], so they should stay within the guidelines for
administration … meaning you initiate the antibiotics within an hour of
the skin incision and discontinue it 24 hours postoperatively. The overuse of
antibiotics is what encourages the occurrence of C. difficile.”
According to the news release, the average number of confirmed cases for
all outbreaks 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
Rhinehart said she would like to see the survey repeated every 5 years,
saying “10 years ago, we would not have found norovirus as the most
frequent [culprit].” – by Robert Press
For more information:
- Rhinehart E, Walker S, Murphy D, et al. Frequency of outbreak
investigations in U.S. hospitals: Results of a national survey of infection
preventionists. Am J Infect Control. 2012. doi: