Epidemiological Survey of the Extended-spectrum β-lactamase-producing Bacteria in Hospitals and Nursing Homes in Morioka Secondary Medical Area Zone of Iwate Prefecture

Abstract

The spread of ESBL-producing bacteria (ESBLs) in local communities is a crucially important issue related to infection control. We investigated the relevance of isolation of ESBLs and the risk factors influencing the isolation rates of these organisms at medical facilities (4 rural hospitals, A-D; 4 nursing homes, a-d) located in the Morioka medical area. The isolation rates of ESBLs at 4 hospitals were estimated from the patient medical records from April 2013 to March 2014. Also, ESBLs were isolated from stool samples from residents in 4 nursing homes during almost the same period, and were analyzed to ascertain their genotypes. Furthermore, we compared the isolation rates of ESBLs among four hospitals to determine the influence of use of third-generation cephalosporins and alcohol-based hand rubs, and also among four nursing homes to identify the clinical backgrounds of the nursing home residents influencing the isolation rates. The isolation rates of ESBLs in hospitals and nursing homes were 13.3% (3.6-25.0%) and 9.3% (3.4-21.0%), respectively. Hospital B, which had the highest isolation rate of ESBLs, showed the highest rate of use of third-generation cephalosporins. On the other hand, Hospital A, with a lower isolation rate of ESBLs, showed the highest frequency of use of alcohol rubs. The rate of use of enteral nutrition was significantly higher in the nursing homes with higher isolation rate of ESBLs than those with lower isolation rates (odds ratio 2.71, p < 0.05). Nursing home c, with a significantly higher isolation rate of ESBLs, showed higher usage of adult diapers as well as higher rates of residents with recent hospitalization and high-level care. All ESBLs (13 Escherichia coli) isolated from nursing home c showed the same genotype: CTX-M-3. Although numerous ESBLs were isolated from the hospitals and nursing homes investigated in this study, the isolation rates of ESBLs and the clinical backgrounds of the patients differed greatly among the medical facilities in the same area. Furthermore, as patients and residents were transferred reciprocally among the hospitals and nursing homes, it was suggested that infection control for ESBLs at any individual facility alone was not sufficient and also that cooperative education and information sharing on ESBLs among facilities in the same area might be important.