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 methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae (producing transferable extended-spectrum beta-lactamase, KPESBL), and multi-resistant Enterobacter aerogenes (MREA) in intensive care unit patients. Infection 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 antibiotic 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 percentage of patients infected by MRSA (P=0.018), a non-significant decrease in those infected by KPESBL (P=0.06), and no decrease in patients infected by MREA (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 least 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 was pound98.7 in Period 1 and pound62.7 in Period 2. ICMs contributed to the control of infections and colonizations due to MRSA and KPESBL but not those due to MREA. Copyright 2000 The Hospital Infection Society.