Who Is at Risk for Clostridium difficile-Associated Diarrhea? Identification of Risk Factors for the Development of Clostridium difficile-Associated Diarrhea Following Treatment of Polymicrobial Surgical Infections

Objective: To determine if there are identifiable risk factors for the development of Clostridium difficileassociated diarrhea in surgical patients after treatment of polymicrobial infections. Design: Record review of an 11-year dataset of consecutive infections treated in surgical patients in a single hospital. Data were prospectively collected on adult surgery and trauma surgery patients. Participants: 4178 intra-abdominal, surgical site, or skin or skin-structure infection patients. Methods: Data were collected on patients previously treated for any infection who required readmission with a new infection including C. difficile-associated diarrhea. Collected data included chart reviews, patient examination findings, results of physician interviews, and reviews of pharmacy, laboratory, and microbiologic data. Patient data included age, gender, race, patient location at the time of Clostridium diarrhea diagnosis, pre-infection medical comorbidities, and the use or nonuse of transfusions. C. difficile infection was diagnosed by culture or toxin assay. All infections treated initially or at any time with metronidazole, penicillins, ureidopenicillins, cephalosporins, carbapenems, aminoglycosides, fluoroquinolones, and clindamycin were identified and categorized by the occurrence of subsequent C. difficile-associated diarrhea. Results: 98 (2.3%) of the 4178 infection patients developed C. difficile-associated diarrhea. Of the 98 affected patients, 65 had been treated for intra-abdominal infections, 22 for surgical site infections, and 11 for skin or skin-structure infections. Patients who developed C. difficile-diarrhea were more likely to be of advanced age, have pre-existing pulmonary disease, have had a transfusion, and have acquired the infection while hospitalized. C. difficile patients were likely to have been on ventilator support or dialysis or to have received a transfusion. At diagnosis, the white blood cell count was 13,700. Ten of the 98 patients died, for a crude mortality rate of 12.7%. The median length of antibiotic treatment before developing C. difficile diarrhea was 8.5 days, and 43.9% of the patients received >1 antibiotic. Fifty percent of the patients were still receiving antibiotics when they developed the C. difficile infection. Patients treated with carbapenem developed C. difficile infection at a 3.5% rate. Patients treated with other antibiotics had a 2.1% rate of C. difficile infection. Conclusions: Older patients with severe illness are most likely to develop C. difficile infections while being treated with antibiotics. No specific antibiotic class was found to be associated with an increased incidence of C. difficile infection. Reviewer's Comments: A really interesting paper! Patients with odontogenic infections that are polymicrobial in nature often receive multiple antibiotics for a prolonged period and may develop C. difficile-associated diarrhea. (Reviewer-Sterling R. Schow, DMD).