Infection Control Today

DEC 2018

ICT delivers to infection preventionists & their colleagues in the operating room, sterile processing/central sterile, environmental services & materials management, timely & relevant news, trends & information impacting the profession & the industry

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Page 22 of 32

22 ICT December 2018 12-week period. A total of 35 patient, privacy curtains were hung in several different units of the hospital. The curtains were identical in appearance and touch and were swabbed twice weekly for four weeks and then once a week for eight weeks. The hand grip area on each curtain was sampled using saline-soaked swabs and plated onto blood agar. Colony counts were plotted by time and compared to occupancy levels for each unit. In total, 582 swabs were collected during the trial. Destructive testing was conducted at the end of the trial to determine counts per area and partial speciation of the isolates. As the researchers report, "Contamination was rapid. Twenty-eight curtains demonstrated contamination on the frst swab; all curtains were contaminated by week two. Contami- nation levels increased substantially at week fve, followed by steady increases each week thereafter. Based on destructive testing, the average Colony Forming Units per square inch (CFU/in2) for all curtains was 190. In Unit 1, where occupancy was 100 percent throughout the trial, the CFU/in2 was 395 compared to 91 to Unit 2 whose occupancy was 52 percent. Methicillin-resistant Staphylococcus aureus (MRSA) was found on 12 (34%) of the curtains (7 of 9 curtains in Unit 1). Vancomycin-resis- tant-enterococci (VRE) were identifed on 1/12 of Unit 4 curtains. No Carbapenem-resistant Enterobacteriaceae (CRE) were detected." Older studies have indicated similar fndings. Ohl, et al. (2012) obtained swab cultures twice weekly from the leading edge of 43 curtains in 30 rooms in two intensive care units and a medical ward. Curtains were marked to determine when they were changed. The researchers found 12 of 13 curtains (92 percent) placed during the study showed contamination within one week. Forty-one of 43 curtains (95 percent) demonstrated contamination on at least 1 occasion, including 21 percent with MRSA and 42 percent with VRE. Eight curtains yielded VRE at multiple time points: three with persistence of a single isolate type and fve with different types, suggesting frequent recontamination. As Ohl, et al. (2012) observe, "Several factors make the privacy curtains that separate patient care areas in most hospitals a potentially important site of environmental contamination. First, healthcare workers and patients frequently touch privacy curtains before, during, and after care encounters. This may promote transfer of bacteria to curtains. Indeed, prior studies have found that curtains are frequently contaminated with potentially pathogenic bacteria, including VRE and MRSA. Second, available evidence suggests that bacterial pathogens on privacy curtains may travel to patients by way of health care workers' hands. Healthcare workers are likely to touch curtains after performing hand hygiene but before patient care. Studies employing hand imprint cultures demonstrate that bacterial pathogens are readily transferred from vinyl curtains to healthcare workers' hands. These bacteria may then transfer to the patient during the subsequent care encounter. Third, privacy curtains are diffcult to disinfect and clean and are infrequently changed. In our institution, privacy curtains may hang for several weeks before changing. Because pathogens may survive on hospital surfaces for days or weeks, this makes curtains potentially important vehicles for transmission of pathogens from prior room occupants to new patients." The researchers add, "Our fndings indicate that contamination of curtains occurs rapidly after they are placed in the healthcare setting. This has implications for interventions to reduce contamination of privacy curtains. The most immediate implication of this and other studies showing substantial bacterial contamination of privacy curtains is that healthcare workers should complete hand hygiene after touching privacy curtains and before touching the patient. The fnding that transfer of organisms to curtains occurs rapidly suggests that even frequent changing or cleaning of curtains may not effectively reduce contamination. There is need for strategies to inhibit curtain contami- nation and potential transfer of bacteria from curtains to patients on a more continuous basis. We were unable to determine whether curtain contamination arose from an infected or colonized patient at the site of the sampling, from a patient in a nearby bed, or from the hands of healthcare workers providing care for patients known to be colonized or infected with these organisms. This information may inform interventions to lower the rate of curtain contamination. Finally, estimates of curtain contamination may depend on the surface area of the curtain swabbed for culture. However, the area swabbed in this study covered the high-touch surface of curtains that were likely to be touched during routine patient care." A Word About Soft-Surface Contamination and Hand Hygiene The hand carriage connection to privacy curtains was studied by Larocque, et al. (2016) who obtained imprints of healthcare workers' fngertips when participants were approached, after hand hygiene with alcohol handrub, and directly after handling curtains. Participants' hands were heavily contaminated at baseline, in some cases with potentially pathogenic species. Half of the participants (n = 30) acquired bacteria on their fngertips from handling curtains, illustrating that privacy curtains may be involved in the transmission of infection to emergency department patients. As the researchers note, "This study suggests that baseline hand hygiene in our ED is poor, with one-third of healthcare workers growing potentially pathogenic bacteria at baseline compared with only 7 percent (n = 2) post-hand hygiene. Half of our participants acquired new strains of bacteria by handling hospital curtains; however, none were pathogenic, conficting with previous studies. Ohl et al. showed that direct swabbing of curtains yielded an average of 13.2 bacterial colonies per 800 cm2. Trillis, et al. reported similar results, demonstrating that small numbers of nosocomial pathogens are transferred to gloved hands after touching contaminated curtains. The discrepancy between our results and the previous study4 may be because of differences in acquisition kinetics between gloved and non-gloved hands, a difference between ED and inpatient units, or that our recently changed curtains were not heavily contaminated. This small, observational cohort study has several limitations. HCWs achieved a median 0.79 log10 colony forming unit reduction after HH, which is a lesser reduction than anticipated based on previous reports. This study was conducted in an ED setting; therefore, fndings may not be generalizable to other clinical areas where curtains are cleaned or changed on different schedules or used with different frequency. Finally, curtains themselves were not swabbed; therefore, it remains unknown whether the curtains were not contaminated with pathogens or whether transmission to healthcare worker hands was not effcient." In the Trillis, et al. (2008) study, researchers found 42 percent of curtains surrounding patients' beds to provide privacy to be contaminated with VRE, 22 percent with MRSA and 4 percent with C. diffcile. Sexton, et al. (2018) sampled soft surfaces at three healthcare facilities for heterotrophic plate count (HPC) bacteria, Staphylococcus spp, Streptococcus pyogenes, and Escherichia coli followed by a tracer study with a virus surrogate seeded onto volunteer hands and commonly touched surfaces. The occurrence of microbial contaminants was determined along with microbial reductions using the soft surface sanitizer. Soft surfaces were swabbed pre- and post-intervention. The researchers found that the tracer viruses were spread to 20 percent to 64 percent of surfaces in long-term care facilities and 13 percent to 41 percent of surfaces in and physicians' offces. Only one pathogen, MRSA, was recovered. The waiting room chairs had the highest concentration of HPC bacteria before disinfection and the privacy curtains had the lowest. Reductions of up to 98.5 percent were achieved with the sanitizer in healthcare settings and up to 99.99 percent under controlled laboratory conditions.

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