Study: Even Cleaning Procedures Can't Kill C. Diff in Hospitals

Clostridium difficile persisted on a variety of surfaces, such as hospital surfaces and surgical gowns, even after appropriate decontamination procedures, researchers found.

After recommended treatment with disinfectant, C. difficile spores were found on hospital surgical gowns, as well as on stainless steel and vinyl flooring, reported Lovleen Tina Joshi, PhD, of the University of Plymouth in England, and colleagues, writing in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

"The spores of the bacteria were able to grow after decontamination. This shows that spores are becoming resistant and we need to reconsider how we decontaminate and employ hygiene measures in hospitals," Joshi said in a statement.

When asked if these results were surprising, Vanessa Stevens, PhD, of the University of Utah in Salt Lake City, who was not involved with the research, told MedPage Today, "yes and no."

"We've known for a long time that C. difficile spores persist in healthcare environments for weeks or months, presumably despite ongoing cleaning activities, [but] studies to test the effect of sporicidal agents on C. difficile incidence have been somewhat conflicting, with benefits mostly being demonstrated in outbreak rather than non-outbreak settings," she said in an email. "We also know that variation in cleaning practices can result in suboptimal spore killing."

Indeed, Joshi and colleagues noted in a statement that part of their motivation for doing this research was a case within an American hospital, where gowns were suspected in C. difficile transmission, and later found to be contaminated with C. difficile.

Stevens added that the Infectious Diseases Society of America (IDSA) clinical practice guidelines for C. difficile recommend "an [Environmental Protection Agency]-registered sporicidal agent" for cleaning.

"But this designation might give a false sense of security that spores are actually being killed," she noted, referring to the findings of the study.

Joshi and colleagues found that C. difficile spores were able to both "transfer and adhere to polypropylene spun gowns after being spiked in a liquid medium." Joshi noted that as the number of spores did not increase during contact time (10 seconds, 30 seconds, 1 minute, 5 minutes, 10 minutes), the transfer of spores likely occurred within the first 10 seconds. This was designed to assess the potential for transmission to patients, by mimicking transfer of infectious bodily fluid in the clinical setting, the team said.

The findings have implications for infection control procedures, Stevens noted, adding that following best practices for environmental cleaning with sporicidal agents may not kill C. difficile spores, and recommending "multi-faceted" prevention efforts.

"Single use items should be treated as contaminated and disposed of properly, [and] mechanical removal of spores from hard surfaces via wiping may help to reduce bioburden," she told MedPage Today. "Environmental cleaning efforts should also be supplemented by assiduous attention to hand hygiene, early isolation, and antimicrobial stewardship activities."

Joshi and colleagues added that their results suggested that C. difficile spores, after appropriate exposure to a disinfectant "at the recommended contact time and concentration, can continue to remain viable, adhere, and transmit via hospital gowns."

"This highlights the importance of ensuring that single-use surgical isolation gowns are used appropriately in infection prevention and control, i.e., that gowns are adorned upon entering and disposed of when exiting a single room to prevent onward spore transmission and incidence of [C. difficile infection]," they wrote.

Joshi said the work should help inform future guidelines on infection control and biocides, and can be applied to hospitals anywhere in the world.

"It may be prudent to reconsider how much biocide we use currently, and to ensure infection control is standardized," she said.

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