Multicenter Study for Frequency and Clinical Features of Community-Associated Methicillin-Resistant Staphylococcus aureus in Korea / 감염과화학요법

ABSTRACT

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) infection has emerged in patients who do not have the established risk factors. In Korea, little is known about the epidemiology and clinical features of community-associated MRSA (CA-MRSA). MATERIAL AND METHODS: Clinical microbiology laboratory databases of 7 hospitals were reviewed to identify the patients from whom MRSA was isolated during the period of January to July 2005. Only one isolate per patient was enrolled. In order to identify the risk factors of MRSA acquisition, the medical records and the Health Insurance Review Agency databases were reviewed. CA-MRSA was defined as MRSA isolated from patient without established risk factors. We analyzed patient demographics, underlying medical conditions, characteristics of infection, and antimicrobial susceptibility profiles. RESULTS: Of total 3,251 S. aureus isolates, 1900 (58.4%) were MRSAs. Of the MRSA isolates, 114 (6.0%) were CA-MRSA. Of 114 CA-MRSA isolates, 22 (19.3%) were colonizers, 22 (19.3%) were pathogens, and the clinical significance of remaining 70 (61.4%) could not be determined. Median age of the 22 patients with CA-MRSA disease was 47 years. Nine patients had skin and soft tissue infections, 9 ear infections, 3 bacteremia, 1 septic arthritis. Seven patients had underlying medical disease. None died of the CA-MRSA infections. Of the 73 isolates of CA-MRSA, 47 (64.4%) were resistant to more than 3 classes of antibiotics besides beta-lactams. CONCLUSION: Although MRSA is highly prevalent among hospital-associated S. aureus infection, CA-MRSA infections are not common.