A predominantly clonal multi-institutional outbreak of Clostridium difficile-associated diarrhea with high morbidity and mortality.

TLDR: A strain of C. difficile that was resistant to fluoroquinolones and had binary toxin and a partial deletion of the tcdC gene was responsible for this outbreak ofC.difficile-associated diarrhea.

Abstract: Background In March 2003, several hospitals in Quebec, Canada, noted a marked increase in the incidence of Clostridium difficile–associated diarrhea. Methods In 2004 we conducted a prospective study at 12 Quebec hospitals to determine the incidence of nosocomial C. difficile–associated diarrhea and its complications and a case–control study to identify risk factors for the disease. Isolates of C. difficile were typed by pulsed-field gel electrophoresis and analyzed for binary toxin genes and partial deletions in the toxin A and B repressor gene tcdC. Antimicrobial susceptibility was evaluated in a subgroup of isolates. Results A total of 1703 patients with 1719 episodes of nosocomial C. difficile–associated diarrhea were identified. The incidence was 22.5 per 1000 admissions. The 30-day attributable mortality rate was 6.9 percent. Case patients were more likely than matched controls to have received fluoroquinolones (odds ratio, 3.9; 95 percent confidence interval, 2.3 to 6.6) or cephalosporins (odds rati...