Prevalence of Antimicrobial-resistant Organisms in Residential Aged Care Facilities

Objective: To assess the frequency of, and risk factors for, colonisation with vancomycin-resistant enterococci (VRE), Clostridium difficile and extended-spectrum β-lactamase (ESBL)-producing organisms in residential aged care facilities (RACFs).

Design, Setting And Participants: We conducted a point prevalence survey in October-November 2010 in three RACFs associated with our health service. A single faecal sample was collected from each participating resident and screened for the presence of VRE, C. difficile and ESBL-producing organisms. Presence of risk factors for antibiotic-resistant organisms was identified using a questionnaire.

Main Outcome Measures: Prevalence of colonisation with VRE, C. difficile and ESBL-producing organisms; molecular typing of ESBL-producing organisms; prevalence of risk factors including presence of a urinary catheter, recent inpatient stay in an acute care setting and recent antibiotic consumption.

Results: Of 164 residents in the three facilities, 119 (73%) were screened. Mean age of screened residents was 79.2 years, and 61% were women; 74% had resided in the RACF for > 12 months, 21% had been given antibiotics within the past month and 12% had been in an acute care centre within the past 3 months. Overall rates of VRE (2%) and C. difficile (1%) colonisation were low, but ESBL-producing Escherichia coli was detected in 14 residents (12%) overall, with half of these residing in one wing of an RACF (27% of wing residents tested). Ten of the 14 ESBL-producing isolates had identical molecular typing patterns and belonged to genotye CTX-M-9. Eight of 13 residents had persistent colonisation on repeat testing 3 months later.

Conclusion: We found a high prevalence of multiresistant ESBL-producing E. coli in RACF residents. A clonal relatedness of isolates suggests possible transmission within the facility. RACFs should have programs emphasising processes that will limit spread of these organisms, namely good hand hygiene compliance, enhanced environmental cleaning and dedicated antimicrobial stewardship programs.