CLOSTRIDIUM-DIFFICILE COLONIZATION IN RESIDENTS OF LONG-TERM-CARE FACILITIES - PREVALENCE AND RISK-FACTORS

Objective: To determine the period prevalence of Clostridium difficile disease and asymptomatic carriage in the residents of long-term care facilities (LTCF) and to characterize the risk factors for colonizatio n or associated disease.Design: Period prevalence survey. Setting: Two long-term care facilities in St. Paul, MN. Participants: Specimens we re collected from 225 LTCF residents. Measurements: The dependent vari able was the culture result for C. difficile, which was isolated and i dentified using selective culture media and a commercial anaerobe iden tification kit. Tissue culture assay was used to detect the ability of each C difficile isolate to produce toxin. Independent variables (inc luding gender, age, race, current medical diagnoses, severity of under lying disease, case mix, current clinical symptoms, current medication s, antibiotic use within 4 weeks prior to specimen procurement, and ot her pertinent history) were obtained from the current medical record o f each participant. Results: Of 225 stool cultures that were obtained, 16 (7.1%) were positive for C difficile. None of the residents with a positive culture was symptomatic. History of nosocomial infection and the use of antibiotics in general, cephalosporins, trimethoprim/sulfa methoxazole (TMP/SMX), and histamine-2 blockers were significantly ass ociated with positive C. difficile culture (P less-than-or-equal-to 0. 05) by univariate analyses. Trends towards significance (0.05 < P < 0. 10) were noted for narcotic use, previous hospitalization, LTCF, and n on-insulin-dependent diabetes mellitus. Logistic regression analysis r evealed significant, independent predictors of positive culture: antib iotic use in general (P = 0.028; relative risk = 3.31), histamine-2 an tagonist use (P = 0.038; relative risk = 3.27), cephalosporin use (P = 0.038; relative risk = 4.66), and TMP/SMX use (P = 0.007; relative ri sk = 8.45). Conclusions: The use of antibiotics, particularly cephalos porins and TMP/SMX, is a significant risk factor for asymptomatic carr iage of C difficile in long-term care facilities. The use of H-2 block ers was also a significant risk factor for carriage; however, this fin ding has not been reported previously and should be confirmed by indep endent studies. These medications should be used judiciously in the LT CF population. When diarrheal diseases are encountered in LTCF residen ts, a high index of suspicion for C difficile infection should be main tained and the appropriate diagnostic and therapeutic measures taken.