Multidrug-Resistant Gram-Negative Bloodstream Infections among Residents of Long-Term Care Facilities

Abstract

OBJECTIVE: Prevalence of multidrug-resistant (MDR) gram-negative (GN) bacteria is increasing globally and is complicated by patient movement between acute and long-term care facilities (LTCFs). In Asia, the contribution of LTCFs as a source of MDR GN infections is poorly described. We aimed to define the association between residence in LTCFs and MDR GN bloodstream infections (BSIs). DESIGN: Secondary analysis of data from an observational cohort. SETTING: Two tertiary referral hospitals in Singapore, including the 1,400-bed Tan Tock Seng Hospital and the 1,600-bed Singapore General Hospital. PARTICIPANTS: Adult patients with healthcare-onset (HCO) or hospital-onset (HO) GN BSI. METHODS: Patients were identified from hospital databases using standard definitions. Risk factors for both MDR GN HCO and HO BSI were analyzed using a multivariable logistic regression model. RESULTS: A total of 675 episodes of GN BSI occurred over a 31-month period. Residence in a LTCF was an independent risk factor for developing MDR GN BSI (odds ratio [OR], 5.1 [95% confidence interval (CI), 2.2-11.9]; P < .01) when antibiotics were not used within the preceding 30 days. This risk persisted beyond the first 48 hours of hospitalization (OR, 3.4 [95% CI, 1.3-9.0]; P = .01). Previous culture growing an MDR organism (OR, 1.8 [95% CI, 1.3-2.7]; P < .01), previous antibiotic use (OR, 1.8 [95% CI, 1.2-2.6]; P < .01), and intensive care unit stay (OR, 2.2 [95% CI, 1.2-3.9]; P = .01), increased the risk of MDR GN BSI. CONCLUSIONS: Residence in a LTCF is an independent risk factor for MDR GN BSI. Attempts to contain MDR GN bacteria in large Asian cities, where the proportion of the population that is elderly is projected to increase, should include infection prevention strategies that engage LTCFs.