Study tackles targeted surveillance for C. difficile

TESTING patients with just three risk factors upon hospital admission has potential to identify nearly three out of four asymptomatic carriers of Clostridium difficile, according to a new study published in the May issue of the American Journal of Infection Control, the official publication of the Association for Professionals in Infection Control and Epidemiology (APIC).

Researchers from Mayo Clinic in Rochester, MN, analyzed stool samples from 320 patients showing no symptoms of C. difficile at hospital admission using a real-time polymerase chain reaction (PCR) assay. Samples from 31 of 320 patients tested positive for C. difficile, resulting in a colonization rate of 9.7 per cent. The authors wanted to estimate the reservoir of colonized patients as a source of potential transmission because despite rigorous infection control measures, C. difficile infection was increasing at their institution.

In this study, independent predictors of C. difficile colonization were found to be recent hospitalization, chronic dialysis and corticosteroid use. According to the authors, one or more of the three independent risk factors were present in 155 (48%) of study participants, and screening only those with one or more of these factors would have identified 23 C. difficile carriers (74%).

“In our population, by targeting those with identified risk factors, we would need to screen approximately half of those patients with anticipated stays longer than 24 hours, to identify three-fourths of those colonized with C. difficile,” said the authors. “This is in the range of previously published screening efficiency rates for MRSA.”

However, the authors also state that these results should be interpreted keeping in mind that only 22% of all eligible patients provided stool for C. difficileNIke Dunk SB Low