TITLE: DISSEMINATION OF MULTIPLE RESISTANT ORGANISMS IN AN ICU IN JAPAN

AUTHORS: Satoru Oku, MD, Junko Kuri, MD, Keiji Goto, MD, Hiroshi Katayama, MD, Masahisa Hirakawa, MD
AFFILIATION: Okayama University, Okayama City, Japan.

INTRODUCTION: Methicillin-Resistant Staphylococcus aureus (MRSA) infection would influence morbidity and mortality in critical patients, and has been a serious social problem in Japan. We retrospectively investigated the MRSA- positive patients in the intensive care unit (ICU) in our teaching hospital.
MATERIALS AND METHODS: 992 patients who admitted to general ICU in our hospital were examined. To detect MRSA organisms, specimens from sputa, pharynx or possible infected sites were obtained from all the patients three times per week, and were sent to the Central Laboratory in our hospital. We took care of the MRSA-positive patients according to the WHO recommendation.
RESULTS: 119 patients (12.0%) were positive (including colonization) for MRSA. The percentage of MRSA-positive in emergency-admitted patients (26.3%) was significantly greater than that of planned-admitted patients (5.4%). The duration which took the cultures turned positive was generally very short (3.6 day), especially in the emergency-admitted patients (2.7 days) compared to the planned-admitted patients (5.7 days). Most of the MRSA-positive patients admitted to ICU with MRSA, or were detected as positive on admission. In the patients who were suspected to catch MRSA in ICU, it took from 10 days to 3 weeks that cultures turned positive. The mortality rate of the MRSA- positive patients (17.6%) was significantly higher than overall mortality (5.0%) in our ICU.
DISCUSSION: Although we managed the patients according to the WHO recommendation, the infection rate was high, and infection affected the mortality. Our data suggest that MRSA was brought into ICU from wards in our hospital or other hospitals in our community. Since we have to treat the serious cases in ICU, it is difficult to restrict admission due to MRSA infection or colonization. Teaching hospitals have the same role in the community. Therefore, the strategies in single department or single hospital to control the dissemination of multiple resistant organisms like MRSA would not be enough.