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Contaminated surfaces may be a source of transmission for the globally emerging pathogen, Candida auris. Because floors may be a source of C. auris contamination on hands, strategies for inactivating or removing C. auris from floors were investigated. A sporicidal disinfectant and UV-C were most effective in inactivating C. auris on floors.
We compared the effectiveness of 4 sampling methods to recover Staphylococcus aureus, Klebsiella pneumoniae and Clostridioides difficile from contaminated environmental surfaces: cotton swabs, RODAC culture plates, sponge sticks with manual agitation, and sponge sticks with a stomacher. Organism type was the most important factor in bacterial recovery.
In a randomized trial, adjunctive ultraviolet-C light treatment with a room decontamination device and sodium hypochlorite delivered via an electrostatic sprayer were similarly effective in significantly reducing residual healthcare-associated pathogen contamination on floors and high-touch surfaces after manual cleaning and disinfection. Less time until the room was ready to be occupied by another patient was required for electrostatic spraying.
The surface environment in rooms of coronavirus disease 2019 (COVID-19) patients may be persistently contaminated despite disinfection. A continuously active disinfectant demonstrated excellent sustained antiviral activity following a 48-hour period of wear and abrasion exposures with reinoculations. Reductions of >4-log10 were achieved within a 1-minute contact time for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and the human coronavirus, 229E.
Respiratory viruses can be transmitted by fomite contact, but no data currently exist on the transfer of enveloped viruses. The transfer efficiency of human coronavirus from various hard surfaces ranged from 0.46% to 49.0%. This information can be used to model the fomite transmission of enveloped viruses.
We evaluated the ability of an ultraviolet-C (UV-C) room decontamination device to kill Candida auris and C. albicans. With an organic challenge (fetal calf serum), the UV-C device demonstrated the following log10 reductions for C. auris of 4.57 and for C. albicans of 5.26 with direct line of sight, and log10 reductions for C. auris of 2.41 and for C. ablicans of 3.96 with indirect line of sight.
We evaluated the robustness of sterilization technologies when spores and bacteria were placed on “dirty” instruments and overlaid with blood. The results illustrate that steam sterilization is the most effective sterilization technology with the largest margin of safety, followed by ethylene oxide and hydrogen peroxide gas plasma.
Background:Clostridioides difficile is a major cause of antibiotic-associated colitis and the most common healthcare-associated pathogen in the United States. Interrupting the known transmission mechanisms of C. difficile in hospitals requires appropriate hand hygiene, disinfection of potentially contaminated surfaces, and patient equipment. However, only limited data are available on the effectiveness of germicides against various strains of C. difficile, with and without fetal calf serum, and at multiple exposure times. For this reason, we undertook the following evaluation to determine the effectiveness of germicides. Methods: The effectiveness of the sporicidal activity of the germicides against 5 strains of C. difficile was evaluated using a quantitative carrier test, a standard of ASTM International developed by Sattar et al. In this protocol, metal carriers (1 cm diameter 0.7 mm thick) were inoculated with 10 L spore suspension, containing ~103 or 106 C. difficile spores, and we then exposed them to 50 L germicide for 1, 5, 10, or 20 minutes. The following C. difficile strains were used in these studies: ATCC strains 9689; J9; BI-9; 630; and CF-4. To determine whether C. difficile spore susceptibility was similar to other spores, we also tested Bacillus atrophaeus spores, ATCC strain 19659. Fetal calf serum (FCS) was used to simulate organic matter. Results: In general, high-level disinfectants (eg, OPA, glutaraldehyde), chemical sterilants (eg, peracetic acid), and high concentrations of chlorine (>5,000 ppm) were generally sporicidal (>3 log10 reduction) in 5–10 minutes (and sometimes 1 minute). This level of sporicidal activity was demonstrated for the various strains of C. difficile spores and B. atrophaeus spores (Table 1). There did not appear to be any significant differences in inactivation of C. difficile spores (BI-9 strain) in the presence or absence of FCS (Table 2). Discussion: The sporicidal activity of disinfectants is critical because such formulations are routinely used to eliminate the risk associated with noncritical and semicritical instruments and environmental surfaces. Our data suggest that immersion in most (but not all) high-level disinfectants for 10 minutes is likely to be successful in eradicating C. difficile spores (>4 log10 reduction) from semicritical equipment (eg, endoscopes). Additionally, high concentrations of chlorine and some high-level disinfectants will kill C. difficile spores in 1 or 2 minutes.
Disclosures: Drs. Rutala and Weber are consultants to PDI (Professional Disposable International)
Background: Most medical and surgical devices used in healthcare facilities are made of materials that are sterilized by heat (ie, heat stable), primarily steam sterilization. Low-temperature sterilization methods developed for heat and moisture sensitive devices include ethylene oxide gas (ETO), hydrogen peroxide gas plasma (HPGP), vaporized hydrogen peroxide (VHP), and hydrogen peroxide plus ozone. This study is the first to evaluate the microbicidal activity of the FDA-cleared VHP sterilizer and other methods (Table 1) in the presence of salt and serum (10% FCS). Methods: Brushed stainless steel discs (test carriers) were inoculated with test microbes (Table 1) and subjected to 4 sterilization methods: steam, ETO, VHP and HPGP. Results: Steam sterilization killed all 5 vegetative and 3 spore-forming test organisms in the presence of salt and serum (Table 1). Similarly, the ETO and the HPGP sterilizers inactivated the test organisms with a failure rate of 1.9% for each (ie, 6 of 310 for ETO and 5 of 270 for HPGP). Although steam had no failures compared to both ETO and HPGP, which demonstrated some failures for vegetative bacteria, there was no significant difference comparing the failure rate of steam to either ETO (P > .05) or HPGP (P > .05). However, the VHP system tested failed to inactivate all the test organisms in 76.3% of the tests (206 of 270; P < .00001) (Table 1). Conclusions: This investigation demonstrated that steam sterilization was the most effective method, followed by ETO and HPGP and, lastly, VHP.
Disclosures: Dr. Rutala was a consultant to ASP (Advanced Sterilization Products)
Background: Surgical instruments that enter sterile tissue should be sterile because microbial contamination could result in disease transmission. Despite careful surgical instrument reprocessing, surgeons and other healthcare personnel (HCP) describe cases in which surgical instruments have been contaminated with organic material (eg, blood). Although most of these cases are observed before the instrument reaches the patient, in some cases the contaminated instrument contaminates the sterile field, or rarely, the patient. In this study, we evaluated the robustness of sterilization technologies when spores and bacteria mixed with blood were placed on dirty (uncleaned) instruments. Methods: Dirty surgical instruments were inoculated with 1.5105 to 4.1107 spores or vegetative bacteria (MRSA, VRE or Mycobacterium terrae) in the presence or absence of blood. The spores used were most resistant to the sterilization process tested (eg, Geobacillus stearothermophilus for steam and HPGP and Bacillus atrophaeus for ETO). Once the inoculum dried, the instruments were placed in a peel pouch and sterilized by steam sterilization, ethylene oxide (ETO), or hydrogen peroxide gas plasma (HPGP). These experiments are not representative of practice or manufacturer’s recommendations because cleaning must always precede sterilization. Results: Steam sterilization killed all the G. stearothermophilus spores and M. terrae when inoculated onto dirty instruments in the presence or absence of blood (Table 1). ETO failed to inactivate all test spores (B. atrophaeus) when inoculated onto dirty instruments (60% failure) and dirty instruments with blood (90% failure). ETO did kill the vegetative bacteria (MRSA, VRE) under the same 2 test conditions (ie, dirty instruments with and without blood). The failure rates for HPGP for G. stearothermophilus spores and MRSA were 60% and 40%, respectively, when mixed with blood on a dirty instrument. Conclusions:This investigation demonstrated that steam sterilization is the most robust sterilization process and is effective even when instruments were not cleaned and the test organisms (G. stearothermophilus spores and MRSA) were mixed with blood. The low-temperature sterilization technologies tested (ie, ETO, HPGP) failed to inactivate the test spores but ETO did kill the test bacteria (ie, MRSA, VRE). These findings should assist HCP to assess the risk of infection to patients when potentially contaminated surgical instruments enter the sterile field or are unintentionally used on patients during surgery. Our data also demonstrate the importance of thorough cleaning prior to sterilization.
Disclosures: Dr. Rutala was a consultant to ASP (Advanced Sterilization Products)
Background:Candida auris is an emerging fungal pathogen that is often resistant to major classes of antifungal drugs. It is considered a serious global health threat because it has caused severe infections with frequent mortality in over a dozen countries. C. auris can survive on healthcare environmental surfaces for at least 7 days, and it causes outbreaks in healthcare facilities. C. auris has an environmental route of transmission. Thus, infection prevention strategies, such as surface disinfection and room decontamination technologies (eg, ultraviolet [UV-C] light), will be essential to controlling transmission. Unfortunately, data are limited regarding the activity of UV-C to inactivate this pathogen. In this study, a UV-C device was evaluated for its antimicrobial activity against C. auris and C. albicans. Methods: We tested the antifungal activity of a single UV-C device using the vegetative bacteria cycle, which delivers a reflected dose of 12,000 µW/cm2. This testing was performed using Formica sheets (7.6 × 7.6 cm; 3 × 3 inches). The carriers were inoculated with C. auris or C. albicans and placed horizontal on the surface or vertical (ie, perpendicular) to the vertical UV-C lamp and at a distance from 1. 2 m (~4 ft) to 2.4 m (~8 ft). Results: Direct UV-C, with or without FCS (log10 reduction 4.57 and 4.45, respectively), exhibited a higher log10 reduction than indirect UV-C for C. auris (log10 reduction 2.41 and 1.96, respectively), which was statistically significant (Fig. 1 and Table 1). For C. albicans, although direct UV-C had a higher log10 reduction (log10 reduction with and without FCS, 5.26 and 5.07, respectively) compared to indirect exposure (log10 reduction with and without FCS, 3.96 and 3.56, respectively), this difference was not statistically significant. The vertical UV had statistically higher log10 reductions than horizontal UV against C. auris and C. albicans with FCS and without FCS. For example, for C. auris with FCS the log10 reduction for vertical surfaces was 4.92 (95% CI 3.79, 6.04) and for horizontal surfaces the log10 reduction was 2.87 (95% CI, 2.36–3.38). Conclusions:C. auris can be inactivated on environmental surfaces by UV-C as long as factors that affect inactivation are optimized (eg, exposure time). These data and other published UV-C data should be used in developing cycle parameters that prevent contaminated surfaces from being a source of acquisition by staff or patients of this globally emerging pathogen.
Background: Well-designed infection prevention programs include basic elements aimed at reducing the risk of transmission of infectious agents in healthcare settings. Although most acute-care facilities have robust infection prevention programs, data are sporadic and often lacking in other healthcare settings. Infection control assessment tools were developed by the CDC to assist health departments in assessing infection prevention preparedness across a wide spectrum of health care including acute care, long-term care, outpatient care, and hemodialysis. Methods: The North Carolina Division of Public Health collaborated with the North Carolina Statewide Program for Infection Control and Epidemiology (SPICE) to conduct a targeted number of on-site assessments for each healthcare setting. Three experienced infection preventionists recruited facilities, conducted on-site assessments, provided detailed assessment findings, and developed educational resources. Results: The goal of 250 assessments was exceeded, with 277 on-site assessments completed across 75% of North Carolina counties (Table 1). Compliance with key observations varied by domain and type of care setting (Table 2). Conclusions: Comprehensive on-site assessments of infection prevention programs are an effective way to identify gaps or breaches in infection prevention practices. Gaps identified in acute care primarily related to competency validation: however, gaps presenting a threat to patient safety (ie, reuse of single dose vials, noncompliance with sterilization and/or high-level disinfection processes) were identified in other care settings. Infection control assessment and response findings underscore the need for ongoing assessment, education, and collaboration among all healthcare settings.
Background: The contaminated healthcare environment, including operating rooms (ORs), can serve as an important role in transmission of healthcare-associated pathogens. Studies are very limited regarding the level of contamination of ORs during the surgery of a patient on contact precautions and the risk to the next surgery patient after standard room cleaning and disinfection. Objective: Here, we investigated the microbial burden on the OR environment when patients on contact precautions receive surgery, and we assessed the impact of cleaning and disinfection on the contamination of OR environmental sites. Methods: This investigation was conducted in the ORs of an academic facility during an 8-month period. It involved 10 patients on contact precautions for multidrug-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA; n = 7); carbapenem-resistant Enterobacteriaceae (CRE) plus MRSA (n = 2); and vancomycin-resistant Enterococcus (VRE) plus MRSA (n = 1), who underwent surgery. Environmental sampling was performed at the following time points: (1) immediately before the surgical patient’s arrival in the OR, (2) after surgery but before the OR cleaning and disinfection, and (3) after the OR cleaning and disinfection. In total, 1,520 environmental samples collected from 15 OR sites for 10 surgical patients at 3 time points were analyzed. Relatedness among environmental MRSA isolates was determined by pulsed-field gel electrophoresis. Results: Overall, the mean CFUs of aerobes per Rodac plate (CFU/25 cm2) were 10.1 before patient arrival, 14.7 before cleaning and disinfection, and 6.3 after cleaning and disinfection (P < .0001, after cleaning and disinfection vs before cleaning and disinfection). Moreover, 7 environmental sites (46.7%) after cleaning and disinfection, including bed, arm rest, pyxis counter, floor (near, door side), floor (far, by door), steel counter (small, near bed), and small computer desk, had significantly lower mean counts of aerobes than before patient arrival or before cleaning and disinfection (Fig. 1). The mean CFUs of MRSA per Rodac plate (CFU/25 cm2) were 0.04 before patient arrival, 0.66 before cleaning and disinfection, and 0.08 after cleaning and disinfection (P = .0006, after cleaning and disinfection vs before cleaning and disinfection). Of environmental sites where MRSA was identified, 87.2% were on floors (41 of 47) and 19.1% were after cleaning and disinfection (9 of 47, 8 from floors and 1 from pyxis touchscreen). The A2/B2 MRSA strain was identified on different environmental sites (eg, floor, computer desk, counter) in various rooms (eg, OR2, OR10, and OR16), even after cleaning and disinfection (Fig. 2). Conclusions: Our study has demonstrated that the OR environment was contaminated with aerobic bacteria and MRSA after surgery and that MRSA persisted in the environment even after cleaning and disinfection. Enhanced environmental cleaning in the perioperative environment used for patients on isolation is necessary to prevent transmission of healthcare-associated pathogens in ORs.
Disclosures: Drs. Rutala and Weber are consultants to PDI (Professional Disposable International)
To compare the microbicidal activity of low-temperature sterilization technologies (vaporized hydrogen peroxide [VHP], ethylene oxide [ETO], and hydrogen peroxide gas plasma [HPGP]) to steam sterilization in the presence of salt and serum to simulate inadequate precleaning.
Test carriers were inoculated with Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, vancomycin-resistant Enterococcus, Mycobacterium terrae, Bacillus atrophaeus spores, Geobacillus stearothermophilus spores, or Clostridiodes difficile spores in the presence of salt and serum and then subjected to 4 sterilization technologies: steam, ETO, VHP and HPGP.
Steam, ETO, and HPGP sterilization techniques were capable of inactivating the test organisms on stainless steel carriers with a failure rate of 0% (0 of 220), 1.9% (6 of 310), and 1.9% (5 of 270), respectively. The failure rate for VHP was 76.3% (206 of 270).
Steam sterilization is the most effective and had the largest margin of safety, followed by ETO and HPGP, but VHP showed much less efficacy.
Clonal Mycobacterium mucogenicum isolates (determined by molecular typing) were recovered from 19 bronchoscopic specimens from 15 patients. None of these patients had evidence of mycobacterial infection. Laboratory culture materials and bronchoscopes were negative for Mycobacteria. This pseudo-outbreak was caused by contaminated ice used to provide bronchoscopic lavage. Control was achieved by transitioning to sterile ice.
A novel disinfectant studied using an EPA protocol demonstrated sustained antimicrobial activity (ie, 3–5 log10 reduction) in 5 minutes after 24 hours for Staphylococcus aureus, vancomycin-resistant Enterococcus, Candida auris, carbapenem-resistant Escherichia coli and antibiotic-susceptible E. coli, and Enterobacter spp. Only ∼2 log10 reduction occurred with carbapenem-resistant Enterobacter spp and K. pneumoniae, and antibiotic-susceptible K. pneumoniae.