Clostridium difficile-associated diarrhea: epidemiological data from Western Australia associated with a modified antibiotic policy.

The incidence of Clostridium difficile-associated diarrhea (CDAD) has increased dramatically in hospitals worldwide during the past 2 decades. In Western Australia, this increase was most obvious during the 1980s, when there was also an increase in the use of third-generation cephalosporin antibiotics. A study of the epidemiology of CDAD and the use of third-generation cephalosporins during 1993-2000 was undertaken. From 1993 through 1998, the incidence of CDAD remained relatively stable (2-3 cases per 1000 discharges annually). Then, a significant decrease in the incidence occurred, from 2.09 cases per 1000 discharges (95% confidence interval [CI], 1.71-2.47) in 1998 to 0.87 cases per 1000 discharges (95% CI, 0.63-1.11) in 1999 (P<.0001); this decrease persisted into 2000. A decrease in third-generation cephalosporin use occurred during the period of the study because of changes in the prescribing policy. These findings suggest that a reduction in the use of third-generation cephalosporins can reduce the occurrence of CDAD.