C. Difficile Infections and Patient-to-Patient Transmission in Hospitals
In a surprising twist, a recent study suggests that the blame for hospital-acquired Clostridioides difficile (C. diff) infections may not lie with patients but instead with the lurking bacteria. Despite stringent infection control protocols, C. diff infections remain prevalent in hospitals, and this research sheds light on the underlying factors.
The study, conducted at a Chicago hospital with over 1,100 patients, revealed that slightly more than 9% of patients were "colonized" with C. diff. However, an extensive analysis of nearly 4,000 fecal specimens found minimal evidence of identical C. diff strains between patients, indicating limited in-hospital transmission.
Remarkably, only six potential patient-to-patient transmissions were identified. The real culprits were individuals silently harboring the bacterium, as they were 24 times more likely to transition to symptomatic infection compared to non-carriers.
Lead researcher Evan Snitkin, an associate professor at the University of Michigan Medical School, commented on the findings. "Our study suggests that the ICU's infection prevention measures, including strict hand hygiene compliance, thorough environmental disinfection against C. diff, and single patient rooms, effectively prevented its transmission. To make further strides in C. diff infection prevention, we must focus on understanding the triggers that prompt asymptomatic carriers to develop infections."
Contrary to prior assumptions, these findings challenge the notion that C. diff infections predominantly result from patient-to-patient transmission in hospitals. It underscores the importance of infection control measures while emphasizing the need for early identification and prevention strategies for asymptomatic carriers.
Hannah Newman, senior director of infection prevention at Lenox Hill Hospital, added her perspective. "Identifying symptomatic cases is straightforward, but colonization, where patients carry C. diff without symptoms, poses a challenge. Antibiotic use is suspected to trigger active infections, but other risk factors should be recognized."
Snitkin emphasized that antibiotics aren't the sole instigators of C. diff infections. "While antibiotics disrupting the microbiota are one trigger, it's a more complex issue. Not all carriers who receive antibiotics develop infections," he explained.
Additionally, older patients and those with a history of hospitalization are at the highest risk of C. diff carriage. Donna Armellino, senior vice president of infection prevention at Northwell Health, elaborated, "Many patients are already colonized, often due to prior surgeries or antibiotic use. Typically, only about 5% of the general population carries C. diff asymptomatically."
Armellino also questioned whether giving antibiotics to prevent C. diff infections before symptoms emerge should be explored further.
Lastly, the study's low patient-to-patient transmission rate might be attributed to the ICU's private rooms, contrasting with shared facilities in many hospitals.
Published in the journal Nature Medicine on September 18, 2023, these findings prompt a reevaluation of our approach to C. diff infection prevention in hospitals.
Sources:
Evan Snitkin, PhD, University of Michigan Medical School
Hannah Newman, MPH, Lenox Hill Hospital
Donna Armellino, RN, Northwell Health
Nature Medicine, September 18, 2023