Isolation Critical to Preventing Transmission of C. diff Infection

A team of researchers from Leeds Teaching Hospitals National Health Service Trust and the University of Leeds in the United Kingdom is reporting in the latest issue of Clinical Infectious Diseases on the importance of isolation as quickly as possible following the onset of diarrhea to limit the transmission of Clostridium difficile infection (CDI).

Best, et al. acknowledges that the high transmissibility and widespread environmental contamination by Clostridium difficile suggests the possibility of airborne dissemination of spores. The researchers measured airborne and environmental C. difficile adjacent to patients with symptomatic CDI.

The researchers say they conducted air sampling adjacent to 63 CDI patients for 180 total hours and for 101 hours in control settings. Environmental samples were obtained from surfaces adjacent to the patient and from communal areas of the ward. C. difficile isolates were characterized by ribotyping and multi-locus variablenumber tandemrepeat analysis to determine relatedness.

Of the first 50 patients examined (each for one hour), just 12 percent had positive air samples, most frequently those with active symptoms of CDI (10 percent versus 2 percent for those with no symptoms). The researchers intensively sampled the air around 10 patients with CDI symptoms, each for 10 hours over two days, as well as a total of 346 surface sites. C. difficile was isolated from the air in the majority of these cases (7 of 10 patients tested) and from the surfaces around nine of the patients; 60 percent of patients had both air and surface environments that were positive for C. difficile. Molecular characterization confirmed an epidemiological link between airborne dispersal, environmental contamination, and CDI cases.

The researchers concluded that aerosolization of C. difficile occurs commonly but sporadically in patients with symptomatic CDI, thus perhaps explaining the widespread dissemination of epidemic strains. Best, et al. say that their study results emphasize the importance of singleroom isolation as soon as possible after the onset of diarrhea to limit the dissemination of C. difficile.

Reference: Best EL, Fawley WN, Parnell P and Wilcox MH. The Potential for Airborne Dispersal of Clostridium difficile from Symptomatic Patients. Clinical Infectious Diseases 2010;50:1450-1457.