Evaluation of Ultraviolet-C Light for Rapid Decontamination of Airport Security Bins in the Era of SARS-CoV-2

Background:

Contaminated surfaces are a potential source for spread of respiratory viruses including SARS-CoV-2. Ultraviolet-C (UV-C) light is effective against RNA and DNA viruses and could be useful for decontamination of high-touch fomites that are shared by multiple users.

Methods:

A modification of the American Society for Testing and Materials standard quantitative carrier disk test method (ASTM E-2197-11) was used to examine the effectiveness of UV-C light for rapid decontamination of plastic airport security bins inoculated at 3 sites with methicillin-resistant Staphylococcus aureus (MRSA) and bacteriophages MS2, PhiX174, and Phi6, an enveloped RNA virus used as a surrogate for coronaviruses. Reductions of 3 log₁₀ on inoculated plastic bins were considered effective for decontamination.

Results:

UV-C light administered as 10-, 20-, or 30-second cycles in proximity to a plastic bin reduced contamination on each of the test sites, including vertical and horizontal surfaces. The 30-second cycle met criteria for decontamination of all 3 test sites for all the test organisms except bacteriophage MS2 which was reduced by greater than 2 log₁₀ PFU at each site.

Conclusions:

UV-C light is an attractive technology for rapid decontamination of airport security bins. Further work is needed to evaluate the utility of UV-C light in real-world settings and to develop methods to provide automated movement of bins through a UV-C decontamination process.

Effectiveness of Ultraviolet-C Light and a High-Level Disinfection Cabinet for Decontamination of N95 Respirators

BACKGROUND

Shortages of personal protective equipment (PPE) including N95 respirators are an urgent concern in the setting of the global COVID-19 pandemic. Decontamination of PPE could be useful to maintain adequate supplies, but there is uncertainty regarding the efficacy of decontamination technologies.

METHODS

A modification of the American Society for Testing and Materials standard quantitative carrier disk test method (ASTM E-2197-11) was used to examine the effectiveness of 3 methods, including ultraviolet-C (UV-C) light, a high-level disinfection cabinet that generates aerosolized peracetic acid and hydrogen peroxide, and dry heat at 70°C for 30 minutes. We assessed the decontamination of 3 commercial N95 respirators inoculated with methicillin-resistant Staphylococcus aureus (MRSA) and bacteriophages MS2 and Phi6; the latter is an enveloped RNA virus used as a surrogate for coronaviruses. Three and 6 log10 reductions on respirators were considered effective for decontamination and disinfection, respectively.

RESULTS

UV-C administered as a 1-minute cycle in a UV-C box or a 30-minute cycle by a room decontamination device reduced contamination but did not meet criteria for decontamination of the viruses from all sites on the N95s. The high-level disinfection cabinet was effective for decontamination of the N95s and achieved disinfection with an extended 31-minute cycle. Dry heat at 70°C for 30 minutes was not effective for decontamination of the bacteriophages.

CONCLUSIONS

UV-C could be useful to reduce contamination on N95 respirators. However, the UV-C technologies studied did not meet pre-established criteria for decontamination under the test conditions used. The high-level disinfection cabinet was more effective and met criteria for disinfection with an extended cycle.

Emerging trends in mediastinitis: National Veterans Health Administration experience with methicillin-resistant Staphylococcus aureus prevention

OBJECTIVES

Perioperative bacterial decolonization and prophylactic antibiotic therapy at the Veterans Affairs Health Care System have changed over the past decade. Our objectives were to identify associated changes in the microbiology of mediastinitis and to perform a contemporary survival analysis in patients with mediastinitis after isolated coronary artery bypass grafting procedure.

METHODS

From January 2006 to December 2015, 45,323 consecutive patients underwent coronary artery bypass grafting at 83 medical centers. The Veterans Affairs Health Care System nationwide administrative database was queried to identify patients with postoperative mediastinitis and obtain patient-level data. Simple descriptive statistics and multivariable logistic regression were used to analyze microbiologic data and identify risk factors for infection. Poisson regression was used to determine yearly incidence estimates. Cox proportional hazard model identified predictors of long-term survival from date of operation.

RESULTS

During the study period, 348 patients (0.78%) developed postoperative mediastinitis-with a stable rate of incidence (Cochrane-Armitage test, P = .69). Of patients with microbiologic data, 75.5% of infections (n = 188) were caused by gram-positive and 24.5% (n = 61) gram-negative organisms. The incidence of methicillin-resistant Staphylococcus aureus mediastinitis decreased during the study period (Cochrane-Armitage test, P = .013). Gram-negative mediastinitis occurred earlier than gram-positive mediastinitis (median, 15.0 vs 25.0 days; P < .0001). Patients with mediastinitis did not have increased 30-day mortality (2.0% vs 1.9%; P = .9), but had worse long-term survival compared with uninfected patients (P < .0001).

CONCLUSIONS

The incidence of methicillin-resistant S aureus mediastinitis has decreased over the past decade. Gram-negative bacteria are responsible for 1 in 4 cases of mediastinitis and infection is diagnosed earlier in the postoperative period than gram-positive mediastinitis. These findings highlight the need for efforts to prevent gram-negative and methicillin-susceptible S aureus mediastinitis.

Efficacy of a povidone iodine preparation in reducing nasal methicillin-resistant Staphylococcus aureus in colonized patients

In a randomized, nonblinded, placebo-controlled trial, a single application of a 10% povidone iodine preparation significantly reduced nasal methicillin-resistant Staphylococcus aureus at 1 and 6 hours after application, but suppression was not sustained at 12 or 24 hours. Twice-daily treatment for 5 days did not reduce nasal methicillin-resistant S aureus measured 12 hours postdosing in comparison to controls. These results suggest that single preoperative applications of povidone iodine will be effective for short-term suppression of S aureus during the perioperative period.

Are reduced concentrations of chlorine-based disinfectants effective against Candida auris?

Chlorine-based disinfectants are commonly used in rooms of patients with Candida auris, but there is uncertainty regarding optimal concentrations that provide efficacy while minimizing the potential for adverse effects. We found that 2 chlorine-based disinfectants were effective against C auris with 1 minute of contact time at concentrations of 4,000 parts per million or higher. Lower concentrations were effective only with increased contact times that may not be practical in real-world health care settings.

Rate of Clostridioides difficile Culture Positivity Among Hospitalized Patients

The rate of nosocomial C. difficile in Rhode Island is among the highest in the country. Colonization with C. difficile is uncommon but can lead to falsely identifying a patient as having C. difficile infection. Additionally, unrecognized C. difficile colonization may act as a reservoir in the hospital. During a 19-day period, rectal swabs obtained for routine VRE surveillance were cultured for C. difficile. Overall, 51 (7.9%) of 649 patients had C. difficile by culture. The majority (n=36, 71%) of patients from whom a rectal swab grew C. difficile did not have a sample sent to the clinical laboratory. Hence, at least 5.5% of the 649 patients were colonized. One patient was classified as having hospital-acquired C. difficile since the clinical specimen was sent to the clinical laboratory on hospital day 4. This patient was culture positive on admission and hence misclassified as having hospital- acquired C. difficile.

Efficacy of an ultraviolet-A lighting system for continuous decontamination of health care-associated pathogens on surfaces

We found that ultraviolet-A (UV-A) light exposure resulted in a modest reduction in recovery of methicillin-resistant Staphylococcus aureus (MRSA), Candida auris, bacteriophage MS2, and bacteriophage Phi X174, but not Clostridioides difficile spores, on steel disk carriers. Four hours of UV-A exposure from a ceiling light fixture resulted in a significant reduction in pathogenic microorganisms recovered from in-use medical equipment. These findings suggest that UV-A could be useful as a means to provide continuous low-level decontamination of surfaces in health care facilities.

Patients' capability, opportunity, motivation, and perception of inpatient hand hygiene

BACKGROUND

Studies that examine the perceptions and behaviors of patients regarding patient hand hygiene rarely examine the viewpoint of patients about their hand hygiene behavior relative to current resources provided in the hospital.

METHODS

Voluntary interviews that employed a 16-item survey tool were used among patients (N = 107) in outpatient clinics at post-admission visits. The survey was created using the Behavior Change Wheel, Capability, Opportunity, Motivation Behavior model. Patients were asked whether they brought hand sanitizer to the hospital, used hospital resources to clean their hands, and their perspective on patient hand hygiene importance compared with hospital staff, as well as their satisfaction or lack of satisfaction with hand hygiene independence.

RESULTS

Most of the participants (65, 60.7%) reported that prior to being admitted to the hospital, they were able to maintain cleaning their hands with little or no difficulty. During their admission, only 21 (19.6%) of the participants reported needing little or no assistance. More than one-half of the participants, 34 (31.8%) and 23 (21.5%), respectively, reported, mostly or completely agreeing that the hand hygiene of the health care staff was more important than their own. Close to one-half of the participants (50, 46.7%) reported not being satisfied at all with their ability to maintain their hand hygiene in the hospital, whereas only 10 (9.3%) were very satisfied with their ability to maintain hand hygiene.

CONCLUSIONS

Findings from this study will enhance our understanding of how to incorporate inpatient hand hygiene into existing infection control programs in inpatient settings.

Efficacy of a novel ultraviolet light-emitting diode device for decontamination of shared pens in a health care setting

Shared pens and styluses are a potential source for transmission of health care-associated pathogens and respiratory viruses in health care facilities. A novel ultraviolet light-emitting diode device was effective in reducing bacteria and viruses inoculated on pens and in reducing methicillin-resistant Staphylococcus aureus transferred to pens by colonized patients. The device could be useful in reducing the risk of transmission of pathogens by shared writing utensils.

Urinary Metabolites of Green Tea as Potential Markers of Colonization Resistance to Pathogenic Gut Bacteria in Mice

Background

The gut microbiome (GMB) generates numerous chemicals that are absorbed systemically and excreted in urine. Antibiotics can disrupt the GMB ecosystem and weaken its resistance to colonization by enteric pathogens such as Clostridium difficile. If the changes in GMB composition and metabolism are sufficiently large, they can be reflected in the urinary metabo-lome. Characterizing these changes could provide a potentially valuable biomarker of the status of the GMB. While preliminary studies suggest such a possibility, the high level of data variance presents a challenge to translational applications. Since many GMB-generated chemicals are derived from the biotransformation of plant-derived dietary polyphenols, administering an oral precursor challenge should amplify GMB-dependent changes in urinary metabolites.

Methods

A course of antibiotics (clindamycin, piperacillin/tazobactam, or aztreonam) was administered SC daily (days 1 and 2) to mice receiving polyphenol-rich green tea in drinking water. Urine was collected at baseline as well as days 3, 7, and 11. Levels of pyrogallol and pyrocatechol, two phenolic molecules unequivocally GMB-dependent in humans but that had not been similarly examined in mice, were quantified.

Results

In confirmation of our hypothesis, differential changes in murine urinary pyrogallol levels identified the treatments (clindamycin, piperacillin/tazobactam) previously associated with a weakening of colonization resistance to Clostridium difficile. The changes in pyrocatechol levels did not withstand corrections for multiple comparisons.

Conclusions

In the mouse, urinary pyrogallol and, in all likelihood, pyrocatechol levels, are GMB-dependent and, in combination with precursor challenge, deserve further consideration as potential metabolomic biomarkers for the health and dysbiotic vulnerability of the GMB.

Perceptions of Patients, Health Care Workers, and Environmental Services Staff Regarding Ultraviolet Light Room Decontamination Devices

BACKGROUND

Mobile ultraviolet C (UV-C) room decontamination devices are widely used in health care facilities; however, there is limited information on the perceptions of patients, health care workers (HCWs), and environmental services staff (EVS-staff) regarding their use for environmental decontamination.

METHODS

An anonymous questionnaire was administered to participants in 4 medical/surgical units of a tertiary care hospital where UV-C devices were deployed for a 6-month period. Survey questions assessed perceptions regarding the importance of environmental disinfection, effectiveness of UV-C decontamination, willingness to delay hospital admission in order to use UV-C, and safety of UV-C devices.

RESULTS

Questionnaires were completed by 102 patients, 130 HCWs, and 47 EVS-staff. All of the HCWs and EVS-staff and 99% of the patients agreed that environmental disinfection is important to reduce the risk of exposure from contaminated surfaces. Ninety-eight percent of the EVS-staff, 89% of the HCWs, and 96% of the patients felt that the use of UV-C as an adjunct to routine cleaning increased confidence that rooms are clean. Ninety-four percent of the EVS-staff, 85% of the HCWs, and 90% of the patients expressed a willingness to delay being admitted to a room in order to have UV-C decontamination completed. Seventy-nine percent of the EVS-staff, 76% of the HCWs, and 86% of the patients had no concerns about the safety of UV-C devices.

CONCLUSIONS

Patients, HCWs, and EVS-staff agreed that environmental disinfection is important and that UV-C devices are efficacious and safe. Educational tools are needed to allay safety concerns expressed by a minority of HCWs and EVS-staff.

Environmental Contamination with Candida Species in Multiple Hospitals Including a Tertiary Care Hospital with a Candida auris Outbreak

Background

Environmental sources have been implicated as a potential source for exogenous acquisition of Candida species, particularly the emerging multidrug-resistant Candida auris. However, limited information is available on environmental reservoirs of Candida species in healthcare facilities.

Methods

During a 6-month period, cultures for Candida species were collected from high-touch surfaces in patient rooms and from portable equipment in 6 US acute care hospitals in 4 states. Additional cultures were collected from sink drains and floors in one of the hospitals and from high-touch surfaces, portable equipment, and sink drains in a hospital experiencing an outbreak due to C. auris. Candida species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectometry.

Results

Candida species were recovered from patient rooms in 4 of the 6 hospitals. Seven of 147 patient room cultures (4.8%) and 1 of 57 (1.8%) portable equipment cultures were positive, with the most common species being C. parapsilosis. For the hospital where additional sites were sampled, Candida species were recovered from 8 of 22 (36.4%) hospital room floors and 4 of 17 (23.5%) sink drains. In the facility with a C. auris outbreak, Candida species were frequently recovered from sink drains (20.7%) and high-touch surfaces (15.4%), but recovery of C. auris was uncommon (3.8% of high-touch surfaces, 3.4% of sink drains, and 0% of portable equipment) and only present in rooms that currently or recently housed a patient with C. auris.

Conclusion

Candida species often contaminate surfaces in hospitals and may be particularly common on floors and in sink drains. However, C. auris contamination was uncommon in a facility experiencing an outbreak, suggesting that current cleaning and disinfection practices can be effective in minimizing environmental contamination.

Impact of Reduced Fluoroquinolone Use on Clostridioides difficile Infections Resulting From the Fluoroquinolone-Resistant Ribotype 027 Strain in a Veterans Affairs Medical Center

Background

Fluoroquinolone restriction has been proposed as a control measure for Clostridioides difficile infection (CDI) outbreaks associated with fluoroquinolone-resistant ribotype 027 strains. However, relatively few reports of fluoroquinolone restriction interventions have evaluated the impact on C. difficile strain types and fluoroquinolone resistance.

Methods

In a hospital and affiliated long-term care facility (LTCF), antimicrobial stewardship and environmental cleaning interventions were implemented between 2009 and 2018, and C. difficile isolates during this period (~20 per year) were ribotyped and tested for fluoroquinolone resistance by moxifloxacin minimum inhibitory concentrations (MICs). Pearson's correlation coefficient was used to assess the association between use of fluoroquinolones and the percentage of CDI cases due to the 027 strain over time.

Results

Between 2009 and 2018, prescribing of fluoroquinolones to inpatients decreased by 43%, coinciding with significant reductions in the healthcare-associated CDI rates in the hospital and LTCF and a decline in the percentage of C. difficile isolates that were ribotype 027 from 70% to 10%. Ninety-five percent of ribotype 027 and 6% of non-027 isolates were moxifloxacin resistant. Hospital fluoroquinolone use was strongly correlated with the incidence of hospital-associated CDI (r = 0.79, 95% confidence interval, 0.31-0.95), but LTCF fluoroquinolone use was not correlated with LTCF-associated CDI (r = 0.29, 95% confidence interval, -0.43-0.77). During the study period, there were statistically significant downward trends in the use of penicillins, intravenous vancomycin, carbapenems, and clindamycin.

Conclusion

Our results provide support for fluoroquinolone restriction as a control measure for CDI outbreaks due to fluoroquinolone-resistant 027 strains, but also highlight the need for randomized trials as factors such as reduction in other antibiotic classes and improved cleaning may also impact CDI rates.

Impact of syndrome-specific antimicrobial stewardship interventions on use of and resistance to fluoroquinolones: An interrupted time series analysis

BACKGROUND

Fluoroquinolones are often prescribed unnecessarily and are an important risk factor for infection with fluoroquinolone-resistant gram-negative bacilli and Clostridioides difficile.

METHODS

We conducted a quasi-experimental study to determine the impact of sequential syndrome-specific stewardship interventions on use of and resistance to fluoroquinolones in a tertiary care hospital. An initial 2-year intervention focused on reducing treatment of asymptomatic bacteriuria and ensuring concordance of urinary tract infection treatment with guidelines. A second 5-year intervention focused on limiting overuse of fluoroquinolones for health care-associated pneumonia in conjunction with a formal stewardship program. The primary outcomes were fluoroquinolone use and changes in use over time analyzed by segmented regression analysis.

RESULTS

The asymptomatic bacteriuria and urinary tract infection intervention resulted in a significant reduction in fluoroquinolone use, with a significant change from an increasing to a decreasing rate of use (change in slope of quarterly defined daily doses/1,000 patient days -15.3, P < .01). The health care-associated pneumonia intervention resulted in a continued significant reduction in fluoroquinolone use (rate ratio = 0.68, P < .01). During the interventions, fluoroquinolone susceptibility increased significantly in Pseudomonas aeruginosa, but not in Escherichia coli, Klebsiella spp., or C difficile.

CONCLUSIONS

Antimicrobial stewardship interventions focused on specific syndromes may be effective in reducing fluoroquinolone use. In our hospital, reduction in fluoroquinolone use resulted in increased fluoroquinolone susceptibility in P aeruginosa, but not other Enterobacteriaceae or C difficile.

Contamination of health care personnel during removal of contaminated gloves

In simulations of contaminated glove removal, 37% of health care personnel using their typical doffing technique contaminated their skin with a fluorescent solution. The frequency of contamination was significantly lower when the technique recommended by the Centers for Disease Control and Prevention was used versus not used (8 of 34, 24% vs 29 of 66, 44%). In simulations in which only the palm of the glove was contaminated, a modified doffing technique, to minimize the risk for contact with contaminated surfaces, reduced contamination of personnel.

Impact of routine use of a spray formulation of bleach on Clostridium difficile spore contamination in non-C difficile infection rooms

The frequency of recovery of Clostridium difficile spores from surfaces after postdischarge cleaning of non-C difficile infection rooms was significantly reduced from 24%-5% after a commercial spray formulation of bleach was substituted for a quaternary ammonium disinfectant. These results suggest that routine use of a sporicidal disinfectant in all postdischarge rooms could potentially be beneficial in reducing the risk for C difficile transmission from contaminated surfaces.

Beyond high-touch surfaces: Portable equipment and floors as potential sources of transmission of health care-associated pathogens

Efforts to improve environmental cleaning and disinfection typically focus primarily on high-touch surfaces in patient rooms. This review highlights evidence that portable equipment and other shared devices and floors may be underappreciated as sources of dissemination of health care-associated pathogens. Practical approaches to address these sites of contamination are emphasized.

Decontamination devices in health care facilities: Practical issues and emerging applications

"No-touch" decontamination devices are increasingly used as an adjunct to standard cleaning and disinfection in health care facilities. Although there is evidence that these devices are effective in reducing contamination, there are several areas of controversy regarding their use. This review addresses some of the questions frequently posed by infection prevention and environmental services personnel about decontamination devices.

The phenolic interactome and gut microbiota: opportunities and challenges in developing applications for schizophrenia and autism

Schizophrenia and autism spectrum disorder have long been associated with elevated levels of various small phenolic molecules (SPMs). In turn, the gut microbiota (GMB) has been implicated in the kinetics of many of these analytes. Unfortunately, research into the possible relevance of GMB-mediated SPMs to neuropsychiatry continues to be limited by heterogeneous study design, numerous sources of variance and technical challenges. Some SPMs have multiple structural isomers and most have conjugates. Without specialized approaches, SPMs can be incorrectly assigned or inaccurately quantified. In addition, SPM levels can be affected by dietary polyphenol or protein consumption and by various medications and diseases. Nonetheless, heterotypical excretion of various SPMs in association with schizophrenia or autism continues to be reported in independent samples. Recent studies in human cerebrospinal fluid demonstrate the presence of many SPMs A large number of these are bioactive in experimental models. Whether such mechanisms are relevant to the human brain in health or disease is not known. Systematic metabolomic and microbiome studies of well-characterized populations, an appreciation of multiple confounds, and implementation of standardized approaches across platforms and sites are needed to delineate the potential utility of the phenolic interactome in neuropsychiatry.

Spores on wheels: Wheelchairs are a potential vector for dissemination ofpathogens in healthcare facilities

In a hospital and affiliated long-term care facility, we found that shared wheelchairs were frequently contaminatedwith healthcare-associated pathogens, including Clostridium difficile spores. A network graph of 851 wheelchair transports over 3days demonstrated frequent movement between inpatient wards andoutpatient clinics, radiology, and physical therapy. These results highlight the potential for shared wheelchairs to serve as a vector for pathogen transmission.

Identification and Quantification by Targeted Metabolomics of Antibiotic-Responsive Urinary Small Phenolic Molecules Derived from the Intestinal Microbiota in Mice

Background: Urinary levels of small molecules generated by the gut microbiota (GMB) constitute potential biomarkers for the state of the GMB. Such metabolites include numerous small phenolic molecules linked to anaerobic bacteria, particularly Clostridium species. Due to multiple technical challenges, however, the relationship between these chemicals and the GMB remains poorly characterized. Improved, high-performance liquid chromatography-mass spectrometry (LC-MS)-based metabolomic analysis can now reliably separate and quantify low levels of multiple small phenolic molecules and their structural isomers.Methods: CF-1 (female mice) were treated over 2 consecutive days with either i) vehicle, ii) one of 2 different antibiotic regimens (clindamycin or piperacillin/tazobactam) known to inhibit intestinal anaerobes and promote colonization by Clostridium difficile and other pathogens or iii) an antibiotic (aztreonam) that suppresses facultative Gram-negative bacteria but not enterococci or anaerobes and does not promote pathogen colonization Urine collected 24 hours after the last treatment was analyzed by LC-MS.Results: We identified over 25 compounds, many of which had not been previously reported in mouse urine. Eleven small phenolic molecules showed significant antibiotic-related changes. Urinary levels of the hydroxyphenylpropionic acids were suppressed by clindamycin and piperacillin/tazobactam treatment, but were elevated in aztreonam-treated mice. In addition, aztreonam treatment was associated with elevated levels of the dihydroxyhydrocinnamic acids.Conclusions: Profiles of differential changes in urinary small phenolic molecules may provide an index of anaerobic bacterial species in the GMB and could prove useful in monitoring susceptibility to overgrowth of pathogens such as C. difficile.

Are Many Patients Diagnosed With Healthcare-associated Clostridioides difficile Infections Colonized With the Infecting Strain on Admission?

In a cohort of 480 patients admitted to an acute care hospital, 68 (14%) had positive perirectal cultures for toxigenic Clostridioides difficile on admission. Of the 11 patients (2%) diagnosed with healthcare-associated C. difficile infections, 3 (27%) had genetically related admission and infection isolates, based on whole-genome sequencing.