부산대학교 도서관

From September 11 through October 9, 2007, a c1uster of colonizations/infections associated with mu1tidrug-resistant Acinetobacter baumannii (MDRAB) was identified and investigated at a 12-bedded surgica1 intensive care unit (ICU) of a medica1 center. This event was identified by infection control personnel through routine surveillance and the ICU staffs were informed immediately. After the on-site observation, hand hygiene and contact precaution were reinforced and the colonized/infected patients were cohorted. The environment was disinfected with 5,000 ppm hypochlorite solution immediately and once a week for the next 3 weeks. Reviewing of the medical records revealed that MDRAB was discovered from the sputum, centra1 venous catheter, and blood samples of 6 patients. All patients received broad-spectrum antimicrobia1 therapy and intubation for ventilatory support before this event. To elucidate the mode of transmission and source of colonization/infection, microbial surveillance of the environment and hospital staffs were undertaken. Among 109 swab cu1tures collected from ICU environment and hands of 12 hea1thcare workers, MDRAB was identified from c1ean area (1 isolate), patient area (n=8), and hand cultures (n=l). Isolates of A. baumannii other than MDRAB were identified from patient area (n=3) and hand cultures (n=5) The genotypes of 14 surveillance isolates were identica1 to that of MDRAB isolates from patients. During the investigation, vancomycin-resistant Enterococcus faecium (VRE) were also isolated from the c1ean area (4 isolates), patient area (n=12), and hand cultures (n=2). An identical genotype was found of 12 VRE isolates. To revea1 the other cryptic MDRAB or VRE cases, active microbial surveillance of 7 other patients who resided at the ICU was conducted. None of the sputum specimens was found to have MDRAB, while VRE were discovered from 2 stool specimens. After infection control measures were reinforced and compliance was monitored, the cluster was under control. This study showed that contamination of the environment and the further spread through the hands of hospital staff contributed to the cross transmission of MDRAB among patients occurred. Furthermore, a concomitant VRE outbreak was not noted until the active microbial surveillance was conducted.