A Prospective Longitudinal Study of Transmission of Multidrug Resistant Organisms (MDROs) between Environmental Sites and Hospitalized Patients – Interim Analysis of the TransFER Study
Background: Contaminated hospital surfaces may be sources for bacterial transmission. However, the nature and efficiency of bacterial transmission between patients and surfaces in hospital rooms remain unknown. We describe the dynamics and quantity of MDRO transmission between surfaces and patients admitted into newly-cleaned hospital rooms.
Methods: We performed a prospective cohort study enrolling patients admitted to newly-disinfected hospital rooms at a tertiary care medical center and a community hospital. Samples from patients and room surfaces were cultured and analyzed to describe the level of colonization of 4 MDROs (MRSA, VRE, MDR Acinetobacter and C. difficile [Cdiff]) at scheduled intervals during hospitalization in the same room (day of enrollment, day 3, day 7, weekly thereafter, and on discharge). Rodac plates were used to sample 8 specific surfaces in patient rooms using previously-published methods. Patient specimens were collected from anterior nares, pharynx, axillae, rectum, and if available, from wounds, indwelling devices and feces.
Results: Data from 40 enrolled patient-room pairs were examined in this interim analysis. At enrollment, 5 (13%) of patients were colonized and 26 (65%) rooms were contaminated with one of the four MDROs. VRE and bathroom floors were the most commonly implicated organism and surfaces, respectively. Four (80%) patients had persistent colonization with the same organism throughout the hospitalization. By Day 3, 22 (58%) rooms had MDRO contamination. Of these, 12 (55%) rooms were newly contaminated while 10 (45%) rooms had residual surface contamination with organisms identified on enrolment (day 1). There were 4 (10%) apparent transmission events: 2 were patient-to-environment transfer events (Cdiff and VRE) and 2 were environment-to-patient transfer events (Cdiff and MRSA) (Figure).
Conclusion: Patients and surfaces in disinfected and cleaned rooms were frequently colonized with MDROs. These organisms persist in patients and on surfaces. Transmission of MDRO between patient and room surfaces occurred in 10% of hospitalizations. Molecular identification and related studies are underway. Future research should study interventions to interrupt this bi-directional transmission cycle.
L. F. Chen,
M. Gergen, None
M. Better, None
B. Nicholson, None
S. S. Lewis, None
C. Woods, None
W. Rutala, Clorox: Consultant, Consulting fee
ASP: Consultant, Consulting fee
D. J. Weber, None
R. W. Moehring, None
D. J. Sexton, UpToDate: Editor, Royalties
National Football League: Consultant, Consulting fee and Educational grant
Cubist: Grant Investigator, Grant recipient
Johnson and Johnson: Consultant, Consulting fee
D. Anderson, None