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

Educational interventions to improve compliance with disinfection practices of noncritical portable medical equipment: A systematic review

OBJECTIVE

To describe educational interventions that have been implemented in healthcare settings to increase the compliance of healthcare personnel (HCP) with cleaning and disinfection of noncritical portable medical equipment (PME) requiring low-level disinfection (LLD).

DESIGN

Systematic review.

METHODS

Studies evaluating interventions for improving LLD practices in settings with HCP, including healthcare students and trainees, were eligible for inclusion.

RESULTS

In total, 1,493 abstracts were identified and 1,416 were excluded, resulting in 77 studies that underwent full text review. Among these, 68 were further excluded due to study design, setting, or intervention. Finally, 9 full-text studies were extracted; 1 study was excluded during the critical appraisal process, leaving 8 studies. Various forms of interventions were implemented in the studies, including luminescence, surveillance of contamination with feedback, visual signage, enhanced training, and improved accessibility of LLD supplies. Of the 8 included studies, 4 studies reported successes in improving LLD practices among HCP.

CONCLUSIONS

The available literature was limited, indicating the need for additional research on pedagogical methods to improve LLD practices. Use of visual indicators of contamination and multifaceted interventions improved LLD practice by HCP.

Beyond duodenoscope-transmitted infections: Analysis of surface bioburden and UV-C mitigation within a tertiary care endoscopy unit

BACKGROUND

An inpatient endoscopy unit is a care hub for patients from throughout the hospital and can be the site of health care-associated infections (HAIs). Shared surfaces and other nonmedical devices (keyboards) have been increasingly recognized as sites of pathogen transmission. Beyond standard cleaning of high-touch target areas, we queried whether the addition of automated devices delivering low-intensity doses of ultraviolet (UV)-C radiation could further reduce bioburden in an academic endoscopy unit.

METHODS

Bioburden on previously identified high-touch/communal surfaces was measured before and after the installation of automated, low-intensity UV-light emitting devices (UV Angel) that passively monitor and disinfect targeted surfaces with Ultraviolet-C light (UV-C) light.

RESULTS

High-touch sites (keyboards) had a baseline bacterial contamination of >80%, whereas individual procedure rooms and common areas had a >57% contamination rate. Following the implementation of automated UV-C light decontamination, bioburden was reduced on average by >91% at high-touch surfaces and within procedure rooms.

DISCUSSION/CONCLUSIONS

Nonsterile hubs of patient care could serve as sites of "silent" HAI transmission. We have identified high-touch surfaces within an endoscopy unit that have a high bioburden of bacterial contamination and demonstrated that the installation of passive, automated UV-C light disinfection devices can reduce bioburden significantly, possibly mitigating HAI transmission between patients.

A Review of the Evidence on the Role of Floors and Shoes in the Dissemination of Pathogens in a Healthcare Setting

Background: It is generally accepted that shoes and floors are contaminated with pathogens including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridium difficile, yet correlation to clinical infection is not well established. Because floors and shoes are low-touch surfaces, these are considered non-critical surfaces for cleaning and disinfection. The purpose of this review is to assess peer-reviewed literature inclusive of floors and shoe soles as contributors to the dissemination of infectious pathogens within healthcare settings. Methods: Using the Preferred Reporting Items for Systematic Reviews (PRISMA) methodology, PubMed and Medline were searched for articles assessing the presence of pathogens on or the transmission of pathogens between or from floors or shoe soles/shoe covers. Inclusion criteria are the human population within healthcare or controlled experimental settings after 1999 and available in English. Results: Four hundred eighteen articles were screened, and 18 articles documented recovery of bacterial and viral pathogens from both floors and shoes. Seventy-two percent (13/18) of these were published after 2015, showing increased consideration of the transfer of pathogens to high-touch surfaces from shoe soles or floors during patient care. Conclusions: There is evidence that floors and shoes in healthcare settings are contaminated with several different species of health-care-associated pathogens including MRSA, VRE, and Clostridium difficile.

Connecting pathogen transmission and healthcare worker cognition: a cognitive task analysis of infection prevention and control practices during simulated patient care

BACKGROUND

Relatively little is known about the cognitive processes of healthcare workers that mediate between performance-shaping factors (eg, workload, time pressure) and adherence to infection prevention and control (IPC) practices. We taxonomised the cognitive work involved in IPC practices and assessed its role in how pathogens spread.

METHODS

Forty-two registered nurses performed patient care tasks in a standardised high-fidelity simulation. Afterwards, participants watched a video of their simulation and described what they were thinking, which we analysed to obtain frequencies of macrocognitive functions (MCFs) in the context of different IPC practices. Performance in the simulation was the frequency at which participants spread harmless surrogates for pathogens (bacteriophages). Using a tertiary split, participants were categorised into a performance group: high, medium or low. To identify associations between the three variables-performance groups, MCFs and IPC practices-we used multiblock discriminant correspondence analysis (MUDICA).

RESULTS

MUDICA extracted two factors discriminating between performance groups. Factor 1 captured differences between high and medium performers. High performers monitored the situation for contamination events and mitigated risks by applying formal and informal rules or managing their uncertainty, particularly for sterile technique and cleaning. Medium performers engaged more in future-oriented cognition, anticipating contamination events and planning their workflow, across many IPC practices. Factor 2 distinguished the low performers from the medium and high performers who mitigated risks with informal rules and sacrificed IPC practices when managing tradeoffs, all in the context of minimising cross-contamination from physical touch.

CONCLUSIONS

To reduce pathogen transmission, new approaches to training IPC (eg, cognitive skills training) and system design are needed. Interventions should help nurses apply their knowledge of IPC fluidly during patient care, prioritising and monitoring situations for risks and deciding how to mitigate risks. Planning IPC into one's workflow is beneficial but may not account for the unpredictability of patient care.

Empowering patients to prevent healthcare-associated infections

In recent years there has been increasing interest in the empowerment of patients to serve as partners in efforts to prevent healthcare-associated infections. However, patients often have limited awareness of the risk for acquisition and dissemination of healthcare-associated pathogens and have received limited information on how they might participate in infection prevention efforts. This review highlights some of the areas where patient empowerment initiatives in infection control and antimicrobial stewardship may be useful and reviews available evidence that such initiatives can be beneficial. Although patients are the primary focus of these initiatives, inclusion of family members should be considered in many situations because they often play a major role in healthcare decision-making.

Update on potential interventions to reduce the risk for transmission of health care-associated pathogens from floors and sinks

Health care facility floors and sink drains and other wastewater drainage sites are universally contaminated with potential pathogens and there are plausible mechanisms by which organisms can be disseminated from these sites. However, floors and sink drains are not addressed as potential sources of pathogen transmission in most health care facilities. One factor that has hindered progress in addressing floors and sinks has been the lack of practical and effective measures to reduce the risk for dissemination of organisms from these sites. This article provides an update on some of the potential interventions being used to reduce the risk for transmission of health care-associated pathogens from floors and sinks. Practical approaches to address these sites of contamination are emphasized.

Effectiveness of ultraviolet-C light treatment of shoes in reducing the transfer of pathogens into patient rooms by shoes of healthcare personnel

Contaminated shoes are a potential vector for dissemination of healthcare-associated pathogens. We demonstrated that healthcare personnel walking into patient rooms frequently transferred pathogens from their shoes to the floor. An 8-second treatment of shoes with a UV-C decontamination device significantly reduced the frequency of transfer of vegetative bacterial pathogens.

The microbiome of an outpatient rehabilitation clinic and predictors of contamination: A pilot study

BACKGROUND

Understanding sources of microbial contamination in outpatient rehabilitation (REHAB) clinics is important to patients and healthcare providers.

PURPOSE

The purpose of this study was to characterize the microbiome of an outpatient REHAB clinic and examine relationships between clinic factors and contamination.

METHODS

Forty commonly contacted surfaces in an outpatient REHAB clinic were observed for frequency of contact and swiped using environmental sample collection kits. Surfaces were categorized based on frequency of contact and cleaning and surface type. Total bacterial and fungal load was assessed using primer sets specific for the 16S rRNA and ITS genes, respectively. Bacterial samples were sequenced using the Illumina system and analyzed using Illumina-utils, Minimum Entropy Decomposition, QIIME2 (for alpha and beta diversity), LEfSe and ANCOM-BC for taxonomic differential abundance and ADONIS to test for differences in beta diversity (p<0.05).

RESULTS

Porous surfaces had more bacterial DNA compared to non-porous surfaces (median non-porous = 0.0016ng/μL, 95%CI = 0.0077-0.00024ng/μL, N = 15; porous = 0.0084 ng/μL, 95%CI = 0.0046-0.019 ng/μL, N = 18. p = 0.0066,DNA. Samples clustered by type of surface with non-porous surfaces further differentiated by those contacted by hand versus foot. ADONIS two-way ANOVA showed that the interaction of porosity and contact frequency (but neither alone) had a significant effect on 16S communities (F = 1.7234, R2 = 0.0609, p = 0.032).

DISCUSSION

Porosity of surfaces and the way they are contacted may play an underestimated, but important role in microbial contamination. Additional research involving a broader range of clinics is required to confirm results. Results suggest that surface and contact-specific cleaning and hygiene measures may be needed for optimal sanitization in outpatient REHAB clinics.

Dissemination of methicillin-resistant Staphylococcus aureus and bacteriophage MS2 from floors in long-term care facility resident rooms

We demonstrated that methicillin-resistant Staphylococcus aureus (MRSA) contamination on floors in the rooms of colonized long-term care facility residents was frequently transferred by shoes to adjacent patient rooms. A benign virus inoculated onto the floor was transferred to floors and high-touch surfaces in adjacent rooms and the nursing station. These results suggest that shoes may serve as a vector for dissemination of healthcare-associated pathogens from rooms of MRSA-colonized patients.

A randomized trial to determine whether wearing slippers reduces transfer of bacteriophage MS2 from floors to patients and surfaces in hospital rooms

In a randomized trial, patients wearing slippers whenever out of bed transferred bacteriophage MS2 from hospital room floors to patients and surfaces significantly less often than controls not provided with slippers. Wearing slippers could provide a simple means to reduce the risk for acquisition of healthcare-associated pathogens from contaminated floors.

Registration: ClinicalTrials.gov; NCT04935892

A randomized trial of ultraviolet-C (UV-C) light versus sodium hypochlorite delivered by an electrostatic sprayer for adjunctive decontamination of hospital rooms

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.

Review of decontamination protocols for shared non-critical objects in 35 policies of UK NHS Acute Care Organisations

BACKGROUND

Decontamination of non-critical objects shared by patients is key in reducing HAIs, but it is a complex process that needs precise guidance from UK NHS Acute Care Organisations (ACOs).

AIM

To review the indications given by NHS ACOs' policies regarding the decontamination of shared non-critical devices.

METHODS

Detailed lists of decontamination protocols for shared non-critical objects were retrieved from cleaning, disinfection, and decontamination policies of 35 NHS ACOs. Three parameters were considered for each object: decontamination method, decontamination frequency and person responsible for decontamination.

FINDINGS

1279 decontamination protocols regarding 283 different shared non-critical objects were retrieved. 689 (54%) did not indicate the person responsible for decontamination, while only 425 (33%), were complete, giving indications for all three parameters analysed. Only 2.5% (32/1279) decontamination protocols were complete and identical in two policies. In policies where cleaning represented the major decontamination method, chemical disinfection was rarely mentioned and vice versa. A general agreement among policies can be found for four main decontamination methods (detergent and water, detergent wipes, disinfectant wipes, use of disposable items), two decontamination frequencies (between events, daily) and two responsible person designations (nurses, domestic staff).

CONCLUSIONS

Decontamination protocol policies for shared non-critical objects had some similarities but did not concur on how each individual object should be decontaminated. The lack of clear indications regarding the person responsible for the decontamination process put at risk the ability of policies to serve as guidance.

Evidence Map and Systematic Review of Disinfection Efficacy on Environmental Surfaces in Healthcare Facilities

Healthcare-associated infections (HAIs) contribute to patient morbidity and mortality with an estimated 1.7 million infections and 99,000 deaths costing USD $28-34 billion annually in the United States alone. There is little understanding as to if current environmental surface disinfection practices reduce pathogen load, and subsequently HAIs, in critical care settings. This evidence map includes a systematic review on the efficacy of disinfecting environmental surfaces in healthcare facilities. We screened 17,064 abstracts, 635 full texts, and included 181 articles for data extraction and study quality assessment. We reviewed ten disinfectant types and compared disinfectants with respect to study design, outcome organism, and fourteen indictors of study quality. We found important areas for improvement and gaps in the research related to study design, implementation, and analysis. Implementation of disinfection, a determinant of disinfection outcomes, was not measured in most studies and few studies assessed fungi or viruses. Assessing and comparing disinfection efficacy was impeded by study heterogeneity; however, we catalogued the outcomes and results for each disinfection type. We concluded that guidelines for disinfectant use are primarily based on laboratory data rather than a systematic review of in situ disinfection efficacy. It is critically important for practitioners and researchers to consider system-level efficacy and not just the efficacy of the disinfectant.

Microbial bioburden of inpatient and outpatient areas beyond patient hospital rooms

OBJECTIVE

To investigate the frequency of environmental contamination in hospital areas outside patient rooms and in outpatient healthcare facilities.

DESIGN

Culture survey.

SETTING

This study was conducted across 4 hospitals, 4 outpatient clinics, and 1 surgery center.

METHODS

We conducted 3 point-prevalence culture surveys for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridioides difficile, Candida spp, and gram-negative bacilli including Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumanii, and Stenotrophomonas maltophilia in each facility. In hospitals, high-touch surfaces were sampled from radiology, physical therapy, and mobile equipment and in emergency departments, waiting rooms, clinics, and endoscopy facilities. In outpatient facilities, surfaces were sampled in exam rooms including patient and provider areas, patient bathrooms, and waiting rooms and from portable equipment. Fluorescent markers were placed on high-touch surfaces and removal was assessed 1 day later.

RESULTS

In the hospitals, 110 (9.4%) of 1,195 sites were positive for 1 or more bacterial pathogens (range, 5.3%-13.7% for the 4 hospitals) and 70 (5.9%) were positive for Candida spp (range, 3.7%-5.9%). In outpatient facilities, 31 of 485 (6.4%) sites were positive for 1 or more bacterial pathogens (range, 2% to 14.4% for the 5 outpatient facilities) and 50 (10.3%) were positive for Candida spp (range, 3.9%-23.3%). Fluorescent markers had been removed from 33% of sites in hospitals (range, 28.4%-39.7%) and 46.3% of sites in outpatient clinics (range, 7.4%-82.8%).

CONCLUSIONS

Surfaces in hospitals outside patient rooms and in outpatient facilities are frequently contaminated with healthcare-associated pathogens. Improvements in cleaning and disinfection practices are needed to reduce contamination.

Antibacterial Treatment of Selected High-Touch Objects and Surfaces within Provision of Nursing Care in Terms of Prevention of Healthcare-Associated Infections

Prevention of healthcare-associated infections is an important part of providing nursing care. High-touch objects and surfaces that can be contaminated with various bacteria are matters of concern. The possibility of reducing contamination is the use of antibacterial and hydrophobic nanolayers. The aim of this study was to determine, by means of an experimental method, the microbial efficacy of applied antibacterial and hydrophobic nanolayers on high-touch objects and surfaces used in nursing practice in a regional hospital in the Czech Republic. The results show that the antibacterial efficacy of the applied nanolayer was not demonstrated. Furthermore, the results show that selected objects and surfaces can always be contaminated by bacterial agents in about 1/3 of cases. It is mainly contamination with nonpathogenic bacteria; however, the presence of pathogenic bacteria, such as Staphylococcus aureus, has also been detected. The results of this study pinpoint the importance of following the basic rules for the use of decontaminated objects and surfaces used to provide healthcare.

Methicillin-resistant Staphylococcus aureus contamination of hospital-use-only mobile phones and efficacy of 222-nm ultraviolet disinfection

BACKGROUND

Mobile phones may be contaminated with nosocomial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to investigate the MRSA contamination rate on doctors' hospital-use-only mobile phones and the efficacy of 222-nm ultraviolet light (UV) disinfection.

METHODS

We investigated the MRSA contamination rate of doctors' hospital-use-only mobile phones, as well as the reduction in MRSA counts on plastic plates and aerobic bacteria (AB) on mobile phones before and after exposure to 222-nm UV irradiation.

RESULTS

Five (10%) of the 50 mobile phones investigated were contaminated with MRSA. Exposure to 0.1 mJ/cm² 222-nm UVC irradiation for 1.5 and 2.5 min (9 and 15 mJ/cm²) achieved mean log₁₀ MRSA colony-forming units reductions of 2.91 and 3.95, respectively. Exposure to 9 mJ/cm² 222-nm UVC irradiation (0.1 mW/cm² for 1.5 minutes) significantly reduced AB contamination on mobile phones (P < .001).

CONCLUSIONS

The use of 222-nm UV disinfection resulted in effective in vitro reduction of MRSA and significantly reduced AB contamination of mobile phone surfaces.

Evaluation of a continuously active disinfectant for decontamination of portable medical equipment

A single spray application of a continuously active disinfectant on portable equipment resulted in significant reductions in aerobic colony counts over 7 days and in recovery of Staphylococcus aureus and enterococci: 3 of 93 cultures (3%) versus 11 of 97 (11%) and 20 of 97 (21%) in quaternary ammonium disinfectant and untreated control groups, respectively.

Timing and route of contamination of hospitalized patient rooms with healthcare-associated pathogens

OBJECTIVE

To investigate the timing and routes of contamination of the rooms of patients newly admitted to the hospital.

DESIGN

Observational cohort study and simulations of pathogen transfer.

SETTING

A Veterans' Affairs hospital.

PARTICIPANTS

Patients newly admitted to the hospital with no known carriage of healthcare-associated pathogens.

METHODS

Interactions between the participants and personnel or portable equipment were observed, and cultures of high-touch surfaces, floors, bedding, and patients' socks and skin were collected for up to 4 days. Cultures were processed for Clostridioides difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). Simulations were conducted with bacteriophage MS2 to assess plausibility of transfer from contaminated floors to high-touch surfaces and to assess the effectiveness of wearing slippers in reducing transfer.

RESULTS

Environmental cultures became positive for at least 1 pathogen in 10 (59%) of the 17 rooms, with cultures positive for MRSA, C. difficile, and VRE in the rooms of 10 (59%), 2 (12%), and 2 (12%) participants, respectively. For all 14 instances of pathogen detection, the initial site of recovery was the floor followed in a subset of patients by detection on sock bottoms, bedding, and high-touch surfaces. In simulations, wearing slippers over hospital socks dramatically reduced transfer of bacteriophage MS2 from the floor to hands and to high-touch surfaces.

CONCLUSIONS

Floors may be an underappreciated source of pathogen dissemination in healthcare facilities. Simple interventions such as having patients wear slippers could potentially reduce the risk for transfer of pathogens from floors to hands and high-touch surfaces.

Quantitative characterization of high-touch surfaces in emergency departments and hemodialysis facilities

An observational study was conducted to characterize high-touch surfaces in emergency departments and hemodialysis facilities. Certain surfaces were touched with much greater frequency than others. A small number of surfaces accounted for the majority of touch episodes. Prioritizing disinfection of these surfaces may reduce pathogen transmission within healthcare environments.

Use of viral DNA surrogate markers to study routes of transmission of healthcare-associated pathogens

BACKGROUND

The hands of healthcare personnel are the most important source for transmission of healthcare-associated pathogens. The role of contaminated fomites such as portable equipment, stethoscopes, and clothing of personnel in pathogen transmission is unclear.

OBJECTIVE

To study routes of transmission of cauliflower mosaic virus DNA markers from 31 source patients and from environmental surfaces in their rooms.

DESIGN

A 3-month observational cohort study.

SETTING

A Veterans' Affairs hospital.

METHODS

After providing care for source patients, healthcare personnel were observed during interactions with subsequent patients. Putative routes of transmission were identified based on recovery of DNA markers from sites of contact with the patient or environment. To assess plausibility of fomite-mediated transmission, we assessed the frequency of transfer of methicillin-resistant Staphylococcus aureus (MRSA) from the skin of 25 colonized patients via gloved hands versus fomites.

RESULTS

Of 145 interactions involving contact with patients and/or the environment, 41 (28.3%) resulted in transfer of 1 or both DNA markers to the patient and/or the environment. The DNA marker applied to patients' skin and clothing was transferred most frequently by stethoscopes, hands, and portable equipment, whereas the marker applied to environmental surfaces was transferred only by hands and clothing. The percentages of MRSA transfer from the skin of colonized patients via gloved hands, stethoscope diaphragms, and clothing were 52%, 40%, and 48%, respectively.

CONCLUSIONS

Fomites such as stethoscopes, clothing, and portable equipment may be underappreciated sources of pathogen transmission. Simple interventions such as decontamination of fomites between patients could reduce the risk for transmission.

Environmental Surface Hygiene in the OR: Strategies for Reducing the Transmission of Health Care-Associated Infections

Health care-associated infections (HAIs) cost billions of dollars annually in the United States and cause patient morbidity and mortality. There is increasing evidence that environmental surfaces in the OR setting, including anesthesia work areas, can harbor pathogens that can lead to HAIs. Patient-care equipment used routinely in the OR, such as electrocardiograph wires, blood pressure cuffs, pulse oximetry probes, and monitor cables, can become contaminated with pathogens during surgical procedures; without proper cleaning and disinfection between procedures, these items pose a risk for pathogen transmission and subsequent patient infections. This article discusses the association between contaminated surfaces in the OR and the risk for HAIs. It is essential that perioperative nurses, environmental services personnel, anesthesia technicians, and anesthesia professionals properly disinfect environmental surfaces to prevent HAIs.

Efficacy of a multi-purpose high level disinfection cabinet against Candida auris and other health care-associated pathogen

Portable equipment and other small devices used in health care are a potential source for dissemination of pathogens. We demonstrated that a high-level disinfection cabinet using ultrasonic submicron droplets of peracetic acid and hydrogen peroxide was effective against methicillin-resistant Staphylococcus aureus, Clostridiodes difficile spores, the nonenveloped virus bacteriophage MS2, and Candida auris on steel disk carriers. The device also eliminated Candida auris inoculated on real-world items of portable equipment.

Hospital MRSA outbreaks: Multiplex PCR-reverse line blot binary typing as a screening method for WGS, and the role of the environment in transmission

BACKGROUND

Whole-genome sequencing (WGS) can provide useful information on methicillin-resistant Staphylococcus aureus (MRSA) transmission in hospitals. However, it is expensive and laborious, especially for environmental screening programs which generate large numbers of isolates. Multiplex PCR-reverse line blot binary typing (mPCR-RLB BT) is a rapid, high throughput, inexpensive typing method which could be useful to screen isolates for WGS. This study assessed the strategy of screening isolates with mPCR-RLB BT to reduce the need for WGS; and to assess the role of the environment in transmission.

METHODS

MRSA transmission in a Burns Unit and its related Intensive Care Unit was studied. mPCR-RLB BT was performed on 238 isolates; this, combined with epidemiological data, was used to choose 97 isolates for WGS.

RESULTS

Relationships between isolates by WGS demonstrated several outbreaks. There was a significant contribution of environmental isolates to transmission, and several problem areas were identified. There was a substantial cost saving from screening isolates with mPCR-RLB BT.

CONCLUSIONS

The use of an inexpensive, rapid screening method for MRSA typing is useful to reduce expenditure and time spent on hospital infection control programs, and reductions are likely to be even more considerable in a non-outbreak setting. Environmental screening and WGS are useful to determine exact sources of transmission to focus mitigation strategies.

In Vitro Bactericidal Effects of Photodynamic Therapy Combined with Four Tetracyclines against Clostridioides difficile KCTC5009 in Planktonic Cultures

Surface disinfection in health-care facilities is critical to prevent dissemination of Clostridioides difficile (C. difficile). Tetracyclines (TCs) are broad-spectrum antibiotics that are associated with a low risk of development of C. difficile infection (CDI) and are used as photosensitizers (PS) in photodynamic therapy (PDT). We evaluated whether TCs may be useful environmental cleansing agents. We compared the in vitro ability to kill C. difficile of four TCs (TC, doxycycline, minocycline, and tigecycline) combined with PDT using ultraviolet A (UVA). We included chitosan, a cationic material, as a booster to increase the photodynamic bactericidal efficacy of TCs. PDT-induced bactericidal effects were assessed by the number of viable cells and the degree of DNA damage and membrane integrity. To avoid the intrinsic antibacterial activity of TCs at high concentrations, we used low concentrations of TCs (0.05 and 0.1 mg/mL). The bactericidal effect of treatment with chitosan plus PDT was over 100 times higher than that with PDT alone for each of the four TCs. DNA damage measured by ethidium bromide monoazide and real-time quantitative polymerase chain reaction was also greater for PDT plus chitosan treatment than for PDT alone or under control conditions: the threshold cycle (Ct) values for the control, PDT, and PDT plus chitosan were 14.67 ± 0.22, 20.46 ± 0.12, and 25.54 ± 0.17, respectively. All four TCs caused similar levels of severe cell membrane damage during PDT compared with control conditions. These data suggest that PDT combined with any of the four TCs plus chitosan might be an available tool to kill efficiently planktonic form of C. difficile.

Bioburden Assessment by Passive Methods on a Clinical Pathology Service in One Central Hospital from Lisbon: What Can it Tell Us Regarding Patients and Staff Exposure?

The assessment and control of microbial contamination in health care facilities is presently a mandatory and vital part of strategies to prevent and control hospital-acquired infections. This study aims to assess the bioburden with two passive sampling methods (30 ventilations grids swabs and 16 electrostatic dust collectors (EDCs)) at Clinical Pathology Services. The fungal burden was characterized through molecular tools, antifungal resistance, and the mycotoxins and cytotoxicity profile. Total bacteria presented the highest prevalence in both matrixes, whereas Gram-bacteria presented the lowest. Swabs presented a higher prevalence (27.6%) for fungal burden. Chrysonilia sitophila presented the highest prevalence in swabs, whereas for EDCs, C. sitophila and Mucor sp. were the most prevalent. Concerning Aspergillus genera on swabs, section Flavi was the one with the highest prevalence (58.02%), whereas, for EDCs, section Versicolores was the only section observed (100%). Aspergillus section Fumigati was detected in 10 swabs and 7 EDC samples and Aspergillus section Versicolores was detected in one EDC sample. Fungal growth on azole-supplemented media was observed in eight EDC samples. No mycotoxins were detected in any of the samples. A low cytotoxic effect was observed in two sites upon incubation of collected samples with A549 and SK cells and in two other sites upon incubation of collected samples with SK cells only. A medium cytotoxic effect was observed with one EDC sample upon incubation with A549 cells. This study reinforces the need of determination of the azole resistance profile for fungal species and allowed a preliminary risk characterization regarding the cytotoxicity. An intervention including the use of a ultraviolet with wavelength between 200 nm and 280 nm (UVC)—emitting device and an increased maintenance and cleaning of the central heating, ventilation, and air conditioning (HVAC) systems should be ensured to promote the reduction of microbial contamination.

Community-acquired in name only: A cluster of carbapenem-resistant Acinetobacter baumannii in a burn intensive care unit and beyond

OBJECTIVE

To describe an investigation into 5 clinical cases of carbapenem-resistant Acinetobacter baumannii (CRAB).

DESIGN

Epidemiological investigation supplemented by whole-genome sequencing (WGS) of clinical and environmental isolates.

SETTING

A tertiary-care academic health center in Boston, Massachusetts.

PATIENTS OR PARTICIPANTS

Individuals identified with CRAB clinical infections.

METHODS

A detailed review of patient demographic and clinical data was conducted. Clinical isolates underwent phenotypic antimicrobial susceptibility testing and WGS. Infection control practices were evaluated, and CRAB isolates obtained through environmental sampling were assessed by WGS. Genomic relatedness was measured by single-nucleotide polymorphism (SNP) analysis.

RESULTS

Four clinical cases spanning 4 months were linked to a single index case; isolates differed by 1-7 SNPs and belonged to a single cluster. The index patient and 3 case patients were admitted to the same room prior to their development of CRAB infection, and 2 case patients were admitted to the same room within 48 hours of admission. A fourth case patient was admitted to a different unit. Environmental sampling identified highly contaminated areas, and WGS of 5 environmental isolates revealed that they were highly related to the clinical cluster.

CONCLUSIONS

We report a cluster of highly resistant Acinetobacter baumannii that occurred in a burn ICU over 5 months and then spread to a separate ICU. Two case patients developed infections classified as community acquired under standard epidemiological definitions, but WGS revealed clonality, highlighting the risk of burn patients for early-onset nosocomial infections. An extensive investigation identified the role of environmental reservoirs.

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.