Clostridium difficile cytotoxin B in adults with diarrhea: a comparison ofpatients treated or not treated with antibiotics prior to infection

Objective To study the detection rate of Clostridium difficile cytotoxin B in stool specimens from adults with diarrhea as related to previous antimic robial treatment. Methods Stool specimens from 802 adult patients with diarrhea and 203 healt hy controls were tested for C. difficile cytotoxin B using a cell cytotoxic ity assay. Antibiotic susceptibility testing of C. difficile was performed with the E test. Results Of 173 patients treated with antimicrobial medication within 5 week s of onset of diarrhea, 60 (35%) were positive for C. difficile cytotoxin B (group A) compared to only 41 (7%) of 629 untreated patients (group B) and two of the 203 (1%) healthy controls. Compared to patients in group A, pat ients in group B possessed characteristics not usually connected with C. di fficile disease. They were generally younger (median age 40 years vs. 73 ye ars), had been hospitalized less frequently (10% vs. 67%), had more often t ravelled abroad within the previous 2 weeks (46% vs. 1%), and more often ha d multiple enteropathogens (41% vs. 3%). Minimal inhibitory concentrations for vancomycin, metronidazole and fucidic acid to C. difficile isolates ran ged from 0.5 to 4 mg/L, from 0.125 to 256 mg/L and 0.25 to 4 mg/L, respecti vely. Conclusions The detection rate of C. difficile cytotoxin Bin patients with diarrhea, not associated with antibiotic treatment, is comparable to that i n healthy control subjects. It probably merely reflects a carrier state wit hout clinical significance.