Short-Course Anti-Microbial Therapy Does Not Increase Treatment Failure Rate in Patients with Intra-Abdominal Infection Involving Fungal Organisms.

Background: Fungi frequently are isolated in intra-abdominal infections (IAI). The Study to Optimize Peritoneal Infection Therapy (STOP-IT) recently suggested short-course treatment for patients with IAI. It remains unclear whether the presence of fungi in IAI affects the optimal duration of anti-microbial therapy. We hypothesized that a shorter treatment course in IAI with fungal organisms would be associated with a higher rate of treatment failure. Methods: Patients enrolled in the STOP-IT trial were stratified according to the presence or absence of a fungal isolate. They were analyzed as a subgroup based on original randomization to either the control group or an experimental group that received a four-day course of anti-microbial therapy and by comparison with those without a fungal component to their infection. Descriptive comparisons were performed using a (2), Fisher exact, or Kruskal-Wallis test as appropriate. The primary outcome was a composite of recurrent IAI, surgical site infection, and death. Results: A total of 411 patients in the study (79%) had available culture data, of which 58 (14%) had positive fungal cultures. The most common organisms were Candida albicans and C. glabrata. The treatment failure rate was equivalent in the experimental and control arms (29.6% vs. 22.6%; p=0.54). Patients with fungal isolates were more likely to have malignant disease (25.9% vs. 9.6%; p=0.0004) and coronary artery disease (22% vs. 12%; p=0.04), but were otherwise similar to those without fungal isolates. Patients with fungal isolates had more hospital days (median 10 vs. 7; p<0.0001) and more days to resumption of enteral intake (median 5 vs. 3; p=0.0006), but there was no difference in the composite outcome. Conclusions: Patients with IAI involving fungal organisms randomized to a shorter course of anti-microbial therapy had no difference in the rate of treatment failure. These results suggest that the presence of fungi in IAI may not indicate independently the need for a longer course of anti-microbial therapy.