COMPARISON OF TREATMENT WITH IMIPENEM VS CEFTAZIDIME AS A PREDISPOSING FACTOR FOR NOSOCOMIAL ACQUISITION OF STENOTROPHOMONAS-MALTOPHILIA - A HISTORICAL COHORT STUDY

Imipenem is considered to confer greater risk for the acquisition of S tenotrophomonas maltophilia than are other beta-lactam antibiotics. We conducted a historical cohort study to directly compare the risks of S. maltophilia acquisition in patients treated with imipenem vs. cefta zidime during a 2-year period; 843 hospitalizations of 759 patients tr eated with ceftazidime (465 hospitalizations), imipenem (294), or both agents (84) were included. Acquisition, as measured by clinical detec tion, occurred in 24 hospitalizations. Rates of acquisition did not si gnificantly differ between the imipenem and ceftazidime groups (3.7 vs . 7.1 cases per 10,000 patients days; P =.2). In contrast, patients tr eated with both agents had higher acquisition rates (19 cases per 10,0 00 patient days; P =.002). Thus, patients treated with imipenem are no t at significantly higher risk for S. maltophilia acquisition than tho se treated with ceftazidime. The excessive risk for patients treated w ith bath agents may be related in part to longer antibiotic therapy an d a longer hospital stay.