C. diff might not originate from external transmission but rather from within the infected patient themselves.
Hospital staff dedicate significant effort to safeguard patients from infections during their hospital stay. Through practices ranging from hand cleanliness to the use of isolation rooms and stringent cleaning procedures, they strive to prevent infections. Yet, even with these measures, hospital-onset infections still occur—the most common of which is caused by the bacterium Clostridioides difficile, or C. diff, the culprit of almost half a million infections in the U.S. each year.
Surprising findings from a new study in Nature Medicine suggest that the burden of C. diff infection may be less a matter of hospital transmission and more a result of characteristics associated with the patients themselves.
The study team, led by Evan Snitkin, Ph.D. and Vincent Young, M.D., Ph.D., both members of the Departments of Microbiology & Immunology and Internal Medicine/Infectious Diseases at the University of Michigan Medical School and Mary Hayden, M.D. of Rush University Medical Center, leveraged ongoing epidemiological studies focused on hospital-acquired infections that enabled them to analyze daily fecal samples from every patient within the intensive care unit at Rush University Medical Center over a nine-month period.
"By systematically culturing every patient, we thought we could understand how transmission was happening. The surprise was that, based on the genomics, there was very little transmission."
Essentially, there was very little evidence that the strains of C. diff from one patient to the next were the same, which would imply in-hospital acquisition. In fact, there were only six genomically supported transmissions over the study period. Instead, people who were already colonized were at greater risk of transitioning to infection.
"Something happened to these patients that we still don't understand to trigger the transition from C. diff hanging out in the gut to the organism causing diarrhea and the other complications resulting from infection," said Snitkin.
Hayden notes this doesn't mean hospital infection prevention measures are not needed. In fact, the measures in place in the Rush ICU at the time of the study – high rates of compliance with hand hygiene among healthcare personnel, routine environmental disinfection with an agent active against C diff, and single patient rooms – were likely responsible for the low transmission rate. The current study highlights, though that more steps are needed to identify patients who are colonized and try to prevent infection in them.
Where did the C. diff come from? "They are sort of all around us," said Young. "C. diff creates spores, which are quite resistant to environmental stresses including exposure to oxygen and dehydration…for example, they are impervious to alcohol-based hand sanitizer."
However, only about 5% of the population outside of a healthcare setting has C. diff in their gut—where it typically causes no issues.
"We need to figure out ways to prevent patients from developing an infection when we give them tube feedings, antibiotics, proton pump inhibitors—all things which predispose people to getting an actual infection with C. diff that causes damage to the intestines or worse," said Young.
The team next hopes to build on work investigating the use of A.I. models to predict patients at risk of C. diff infection to identify patients who are likely to be colonized and who could benefit from more focused intervention.
Said Snitkin, "A lot of resources are put into gaining further improvements in preventing the spread of infections, when there is increasing support to redirect some of these resources to optimize the use of antibiotics and identify other triggers that lead patients harboring C diff and other healthcare pathogens to develop serious infections."
Reference: "Longitudinal genomic surveillance of carriage and transmission of Clostridioides difficile in an intensive care unit" by Arianna Miles-Jay, Evan S. Snitkin, Michael Y. Lin, Teppei Shimasaki, Michael Schoeny, Christine Fukuda, Thelma Dangana, Nicholas Moore, Sarah E. Sansom, Rachel D. Yelin, Pamela Bell, Krishna Rao, Micah Keidan, Alexandra Standke, Christine Bassis, Mary K. Hayden and Vincent B. Young, 18 September 2023, Nature Medicine.
DOI: 10.1038/s41591-023-02549-4
The study was funded by the National Institutes of Health and the Centers for Disease Control and Prevention.
News
Can introducing peanuts early prevent allergies? Real-world data confirms it helps
New evidence from a large U.S. primary care network shows that early peanut introduction, endorsed in 2015 and 2017 guidelines, was followed by a marked decline in clinician-diagnosed peanut and overall food allergies among [...]
Nanoparticle blueprints reveal path to smarter medicines
Lipid nanoparticles (LNPs) are the delivery vehicles of modern medicine, carrying cancer drugs, gene therapies and vaccines into cells. Until recently, many scientists assumed that all LNPs followed more or less the same blueprint, [...]
How nanomedicine and AI are teaming up to tackle neurodegenerative diseases
When I first realized the scale of the challenge posed by neurodegenerative diseases, such as Alzheimer's, Parkinson's disease and amyotrophic lateral sclerosis (ALS), I felt simultaneously humbled and motivated. These disorders are not caused [...]
Self-Organizing Light Could Transform Computing and Communications
USC engineers have demonstrated a new kind of optical device that lets light organize its own route using the principles of thermodynamics. Instead of relying on switches or digital control, the light finds its own [...]
Groundbreaking New Way of Measuring Blood Pressure Could Save Thousands of Lives
A new method that improves the accuracy of interpreting blood pressure measurements taken at the ankle could be vital for individuals who are unable to have their blood pressure measured on the arm. A newly developed [...]
Scientist tackles key roadblock for AI in drug discovery
The drug development pipeline is a costly and lengthy process. Identifying high-quality "hit" compounds—those with high potency, selectivity, and favorable metabolic properties—at the earliest stages is important for reducing cost and accelerating the path [...]
Nanoplastics with environmental coatings can sneak past the skin’s defenses
Plastic is ubiquitous in the modern world, and it's notorious for taking a long time to completely break down in the environment - if it ever does. But even without breaking down completely, plastic [...]
Chernobyl scientists discover black fungus feeding on deadly radiation
It looks pretty sinister, but it might actually be incredibly helpful When reactor number four in Chernobyl exploded, it triggered the worst nuclear disaster in history, one which the surrounding area still has not [...]
Long COVID Is Taking A Silent Toll On Mental Health, Here’s What Experts Say
Months after recovering from COVID-19, many people continue to feel unwell. They speak of exhaustion that doesn’t fade, difficulty breathing, or an unsettling mental haze. What’s becoming increasingly clear is that recovery from the [...]
Study Delivers Cancer Drugs Directly to the Tumor Nucleus
A new peptide-based nanotube treatment sneaks chemo into drug-resistant cancer cells, providing a unique workaround to one of oncology’s toughest hurdles. CiQUS researchers have developed a novel molecular strategy that allows a chemotherapy drug to [...]
Scientists Begin $14.2 Million Project To Decode the Body’s “Hidden Sixth Sense”
An NIH-supported initiative seeks to unravel how the nervous system tracks and regulates the body’s internal organs. How does your brain recognize when it’s time to take a breath, when your blood pressure has [...]
Scientists Discover a New Form of Ice That Shouldn’t Exist
Researchers at the European XFEL and DESY are investigating unusual forms of ice that can exist at room temperature when subjected to extreme pressure. Ice comes in many forms, even when made of nothing but water [...]
Nobel-winning, tiny ‘sponge crystals’ with an astonishing amount of inner space
The 2025 Nobel Prize in chemistry was awarded to Richard Robson, Susumu Kitagawa and Omar Yaghi on Oct. 8, 2025, for the development of metal-organic frameworks, or MOFs, which are tunable crystal structures with extremely [...]
Harnessing Green-Synthesized Nanoparticles for Water Purification
A new review reveals how plant- and microbe-derived nanoparticles can power next-gen water disinfection, delivering cleaner, safer water without the environmental cost of traditional treatments. A recent review published in Nanomaterials highlights the potential of green-synthesized nanomaterials (GSNMs) in [...]
Brainstem damage found to be behind long-lasting effects of severe Covid-19
Damage to the brainstem - the brain's 'control center' - is behind long-lasting physical and psychiatric effects of severe Covid-19 infection, a study suggests. Using ultra-high-resolution scanners that can see the living brain in [...]
CT scan changes over one year predict outcomes in fibrotic lung disease
Researchers at National Jewish Health have shown that subtle increases in lung scarring, detected by an artificial intelligence-based tool on CT scans taken one year apart, are associated with disease progression and survival in [...]
