Lack of association of outcomes with treatment duration and microbiologic susceptibility data in Clostridium difficile infections in a non-NAP1/BI/027 setting.

BACKGROUND

Concerns regarding the poor response of severe Clostridium difficile infection (CDI) treated with metronidazole have arisen over the last 5 y.

METHODS

We conducted a prospective, non-interventional study of CDI cases at our institution to evaluate the role of drug resistance, co-morbidities, and the emergence of hypervirulent strains on patient outcomes. A total of 118 adult inpatients with diarrhea and a positive stool for C. difficile toxin immunoassay had positive stool cultures and were included in the study. All 118 isolates had vancomycin and metronidazole susceptibility testing via the E-test method; rep-PCR was performed on 47 isolates. Of the 118 study patients, 107 were treated with either metronidazole or vancomycin.

RESULTS

Initial therapy was metronidazole in 98.1% (n = 105) and vancomycin in 1.9% (n = 2) patients. Evaluable clinical response within 5 days of treatment was noted in 52.5% (52/99) of cases. The mean duration of treatment was 11.7 ± 7.2 days. The 30-day all-cause mortality rate was 24.6% (29/118). Recurrence occurred in 23.6% (21/89). A recent stay in the intensive care unit was associated with increased 30-day mortality (odds ratio 3.58, p = 0.012). There were no isolates resistant to metronidazole or vancomycin. Only 1 isolate was possibly related to the NAP1/BI/027 reference strain. No strain-related differences in deaths or recurrence were noted.

CONCLUSIONS

Deaths related to CDI in our study appear to be related to multiple factors and did not appear to be independently related to antibiotic susceptibility, strain type, or treatment duration.