Strategies to Curb C difficile and Norovirus Outbreaks

Rachel Lutz

New approaches are needed to control outbreaks and clusters of C. difficile and norovirus.

New approaches are needed to control outbreaks and clusters of Clostridium difficile (C. difficile) and norovirus, according to a recent article.

Ann Fisher, MD (pictured), and Louise-Marie Dembry, MD, MS, MBA, from the Yale University School of Medicine, pointed out that at hospital settings, which contain already-vulnerable populations, gastrointestinal outbreaks can be especially dangerous and cause increased morbidity and mortality. They acknowledged that implementing effective preventative measures against norovirus and C. difficile can be challenging, and decided to review new literature that has the potential to change traditional prevention strategies to better control such outbreaks.

The first important point, the authors wrote, is to define the outbreak — an increased occurrence above baseline rates. For norovirus, the person-to-person spread is about 1.86 days in a hospital setting, and most of the outbreaks in long-term care facilities are not foodborne. In C. difficile cases, asymptomatic carriers are at risk for infection as well as transmitting the infection to others, with that risk increasing with the number of exposures. Verifying the diagnosis is also imperative, the researchers explained, because the size of an outbreak can be significantly diminished if a positive test result is determined quickly.

Both vomiting (norovirus) and diarrhea (C. difficile) can create airborne droplets, leading to further contamination, the investigators said. By determining a transition route—whether airborne, from contaminated surfaces, foodborne illness, or otherwise—healthcare centers would be able to better control exposure and limit the amount of infections.

To prevent infections, healthcare centers should assess hand-hygiene practices and monitor compliance as soon as possible, even before test results are available, the researchers recommended. Centers may also utilize infection-prevention resource teams when dedicated infection-prevention staffs are not available. These types of teams can suggest areas that have prevention deficits and ways to redesign the spaces. Specifically, hands should be washed with soap and water for at least 20 seconds after patient care. The researchers said that method is the “gold standard” for removing norovirus viral particles and C. difficile spores. They stressed that alcohol-based hand rub is not effective against these infection sources.

Personal protective equipment practices were also assessed. The investigators noted that these items are typically single-use, must include clean gloves, and should include masks when there is a potential for aerosolization. Equally vital is to carefully remove such equipment, as to not contaminate oneself in the removal process.

“Cleaning prior to disinfection of potentially contaminated surfaces is required to decrease bioburden,” the study authors wrote. “During outbreaks, increased frequency of cleaning is recommended with attention to high-touches surfaces where there is likely a higher bioburden.”

The researchers explained that hydrogen peroxide-based solutions are not recommended (nor are wipes) but that instead, healthcare centers should utilize chlorine bleach solutions of at least 1000 ppm based on manufacturers’ instructions.

In their closing notes, the study authors added that the role of staff illness in C. difficile outbreak is not yet understood, but said that healthcare personnel can transmit spores to patients unknowingly. Ward closure, including reduced levels of ward-wide antimicrobial stewardship, may be 1 option used to control transmissions.

The article, titled “Norovirus and Clostridium difficile outbreaks: squelching the wildfire,” was published in the journal Current Opinion in Infectious Diseases.

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