Are Community-Based Hospitals Safe from Carbapenem-Resistant Enterobacteriaceae in Korea?

Carbepenems are used with increasing frequency to treat multidrug-resistant isolates, especially strains producing extended-spectrum β-lactamases [1, 2]. Resistance to carbapenems has been uncommon among Enterobacteriaceae. However, the emergence of β-lactamases with direct carbapenem-hydrolyzing activity has contributed to an increased prevalence of carbapenem-resistant Enterobacteriaceae (CRE) [3]. CRE are particularly problematic given the high mortality associated with infections caused by CRE, and the potential for widespread transmission of carbapenem resistance via mobile genetic elements [3, 4]. We should recall 2 outbreaks in New York City [5]. At hospital A, 2 patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) were identified. During the next 6 months, a total of 30 additional patients were identified as having CRKP. Thirty of 32 isolates were considered to be acquired nosocomially, with median length of hospital stay before a positive culture result of 18.5 days. At hospital B, an initial case of CRKP was recognized, followed by 2 more cases within 2 months. In the ensuing 3 months, another 24 cases were identified. All isolates were considered to be acquired nosocomially. We assume that horizontal transmission of carbapenem-resistant organisms occurred at these 2 hospitals. The emergence of carbapenem-resistant Gram-negative bacteria has been increasingly reported, especially Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacter spp. in Korea [6]. Among Gram-negative bacteria, the proportion of CRE has been very low, compared with that of P. aeruginosa and A. baumannii [1, 6]. However, the trend is increasing [6]. Lee et al. [7] investigated the prevalence and risk factors of CRE in a single community-based hospital in Korea. Until now, most research on carbapenem-resistant Gram-negative bacteria including CRE was performed in tertiary acute care hospitals in Korea. However, Lee et al. conducted their study at a mid-sized community-based hospital, including not only the intensive care unit but also the general wards. Many patients had been transferred from long-term care facilities (LTCFs). In this study, a total of 41 (1.6%) CRE isolates were identified, including 13 of Enterobacter aerogenes, 8 of K. pneumoniae, 5 of Enterobacter cloacae, and 15 others. They reported that risk factors for CRE included vascular catheters,