Role of infection control measures in limiting morbidity associated with multi-resistant organisms in critically ill patients

A retrospective comparative study was performed to determine the impact of infection control measures (ICMs) on colonization and infections due to met hicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae (pro ducing transferable extended-spectrum p-lactamase, KPESBL), and multiresist ant Enterobacter aerogenes (MREA) in intensive care unit patients. Infectio n Control Measures included surveillance cultures, isolation procedures and mupirocin for MRSA nasal carriage. The numbers of patients infected and/or colonized by MRSA, KPESBL or MREA were compared during two consecutive one -year periods (Period 1 before ICMs, and Period 2 after ICMs). The antibiot ic consumption during the two periods was analysed. In Period 1 and Period 2, respectively, the rate of patients infected or colonized by at least one of the three organisms was 15% and 6.8% (P = 0.001); by MRSA 7.7% and 2.6% (P = 0.004); by KPESBL 1.7% and 0% (P = 0.25); and by MREA 5.6% and 4.3% ( P = 0.47). During Period 2, there was a clear-cut decrease in the percentag e of patients infected by MREA (P = 0.018), a non-significant decrease in t hose infected by KPESBL (P = 0.06), and no decrease in patients infected by MRESA (P = 0.22). When calculated per 1000 patient-days, for Period 1 and Period 2, respectively, the rate of patients infected or colonized by at le ast one of the three organisms was 11.9 and 8.8; for MRSA it was 4 and 2.2; for KPESBL it was 1 and 0; and for MREA it was 4 and 4. Antibiotic cost wa s pound 98.7 in Period 1 and pound 62.7 in Period 2. ICMs contributed to th e control of infections and colonizations due to MRSA and KPESBL but not th ose due to MREA. (C) 2000 The Hospital Infection Society.