Asymptomatic C. difficile carriers key source of nosocomial transmission
Approximately 19% of health care-related Clostridium difficile cases at a Veterans Affairs hospital and affiliated long-term care facility, or LTCF, were linked to residents with LTCF-associated C. difficile infection or asymptomatic C. difficile carriage, according to recently published findings. Most came from asymptomatic carriers, underscoring their important role in transmission, researchers said.
The findings build on previous research conducted by Curtis J. Donskey, MD, professor of medicine at Case Western Reserve University and an infectious disease physician at the Louis Stokes Cleveland VA Medical Center, and colleagues, which showed that LTCF residents often harbor C. difficile.
“In previous studies, we demonstrated that asymptomatic carriage of toxigenic C. difficile is common in the LTCF affiliated with the Cleveland VA hospital,” Donskey and colleagues wrote in Infection Control and Hospital Epidemiology. “Carriers with high burden of C. difficile in stool were more likely to have skin and/or environmental shedding, suggesting that this subset of carriers might pose a relatively high risk for transmission.”
For the current study, Donskey and colleagues tested their hypothesis that LTCF residents with C. difficile infection (CDI) or asymptomatic carriage of toxigenic strains contribute substantially to transmission in the LTCF and hospital during acute-care admissions. They assessed transmission events over a 6-month period by tracking patient movement and analyzing C. difficile isolates.
During the study, Donskey and colleagues identified 29 LTCF residents as asymptomatic carriers. Among them, 37.9% were transferred to the hospital at least once.
Overall, 37 health care-associated CDI cases were reported, including 26 that were acquired in the hospital and 11 that were acquired in the LTCF. Seven CDI cases, or 18.9%, were linked to LTCF residents with LTCF-associated CDI or asymptomatic carriage, including three hospital-acquired cases (11.5%) and four LTCF-acquired cases (36.4%). Five of the seven transmission events (71.4%) were linked to four asymptomatic carriers compared with two transmission events that were linked to CDI cases.
All four asymptomatic carriers associated with transmission events had a relatively high burden of carriage, as well as groin, skin and/or environmental shedding, “suggesting that such carriers may present the greatest risk for transmission,” Donskey and colleagues wrote.
“These findings have broad implications for control of C. difficile because interfacility transfer of CDI patients occurs frequently among LTCFs and hospitals,” they concluded. “Greater emphasis on infection control measures and antimicrobial stewardship in LTCFs is needed, and these efforts should focus on LTCF residents during hospital admissions.” – by Stephanie Viguers
Disclosures: Donskey reports receiving research funding from Altapure, Clorox, EcoLab and GOJO, and serving on an advisory board for Synthetic Biologics. Please see the study for all other authors’ relevant financial disclosures.