MONDAY, April 7, 2025 (HealthDay News) -- A notorious hospital-associated infection has been spreading through hospitals much more readily than people suspected, a new study says.
The bacterium Clostridium difficile – commonly called C. diff – spreads within intensive care units more than three times as much as previously thought, researchers reported in JAMA Network Open.
C. diff can spread covertly from surface to surface for weeks in an ICU before finally infecting a patient, and often passes between patients who aren’t in the hospital at the same time, researchers said.
“There's a lot going on under the hood that we're just not seeing,” senior researcher Dr. Michael Rubin, an epidemiologist and infectious diseases specialist at the University of Utah, said in a news release. “And if we ignore that, then we’re potentially putting patients at unnecessary risk.”
C. diff typically infects people whose gut bacteria has been wiped out by powerful antibiotics, according to the U.S. Centers for Disease Control and Prevention (CDC). The opportunistic bacterium moves in and displaces healthy bacteria, causing diarrhea, abdominal pain and fever.
The bacterium is exceptionally hardy, researchers noted. It can survive for a long time outside the body, in the form of spores carrying a protective coating that can withstand antibacterial agents like alcohol-based cleansers.
C. diff infection is lethal in about 6% of cases in the United States, researchers said in background notes.
The disease is highly contagious, but up to now it’s been unclear how it spreads through health care facilities, researchers said. Previous research indicated that direct patient-to-patient transmission was rare.
To track infections in hospitals, researchers gathered C. diff samples from nearly 200 patients across two ICUs and collected thousands of samples from hospital room surfaces and health care professionals’ hands.
The team then used genetic analysis to precisely track bacterial movement of C. diff strains around a hospital.
Researchers found C. diff exposure among 10% of ICU patients, either on the person’s body or in their room.
In most of those cases, the C. diff was genetically identical to that found on another patient’s body or room, suggesting that the bacteria spread between patients rather than coming from outside the hospital.
“We find about the same amount of patient-to-patient transmission as previous studies,” lead investigator Lindsay Keegan, a research associate professor in epidemiology at University of Utah Health, said in a news release.
“But what we find that’s novel is that there is a lot more movement of C. diff between surfaces, from surface-to-patient, and from patient-to-surface than previously found,” Keegan added.
When hands and surfaces were taken into account, C. diff spread was 3.6 times greater than if researchers only considered direct transmission between patients, results show.
Further, for more than half of potential C. diff transmissions, the two patients involved weren’t even in the hospital at the same time, researchers said. In some cases, their hospital stays were separated by weeks.
This shows bacteria from one person can be inadvertently transferred to surfaces in another room, where they will lie in wait for another patient, researchers said.
“What I'm hoping we get from this paper is that health care providers put a greater emphasis on infection prevention measures and adhere to them as much as they possibly can,” Rubin said.
Using personal protective equipment such as gloves and gowns is crucial, along with rigorous handwashing, Rubin said.
“Those are the measures that can help interrupt this type of invisible transmission.”
More information
The U.S. Centers for Disease Control and Prevention has more about C. difficile.
SOURCE: University of Utah, news release, April 4, 2025