Role of the environment in the transmission of Clostridium difficile in health care facilities

Early identification of a ward-based outbreak of Clostridioides difficile using prospective multilocus sequence type-based Oxford Nanopore genomic surveillance

OBJECTIVE

To describe an outbreak of sequence type (ST)2 Clostridioides difficile infection (CDI) detected by a recently implemented multilocus sequence type (MLST)-based prospective genomic surveillance system using Oxford Nanopore Technologies (ONT) sequencing.

SETTING

Hemato-oncology ward of a public tertiary referral centre.

METHODS

From February 2022, we began prospectively sequencing all C. difficile isolated from inpatients at our institution on the ONT MinION device, with the output being an MLST. Bed-movement data are used to construct real-time ST-specific incidence charts based on ward exposures over the preceding three months.

RESULTS

Between February and October 2022, 76 of 118 (64.4%) CDI cases were successfully sequenced. There was wide ST variation across cases and the hospital, with only four different STs being seen in >4 patients. A clear predominance of ST2 CDI cases emerged among patients with exposure to our hemato-oncology ward between May and October 2022, which totalled ten patients. There was no detectable rise in overall CDI incidence for the ward or hospital due to the outbreak. Following a change in cleaning product to an accelerated hydrogen peroxide wipe and several other interventions, no further outbreak-associated ST2 cases were detected. A retrospective phylogenetic analysis using original sequence data showed clustering of the suspected outbreak cases, with the exception of two cases that were retrospectively excluded from the outbreak.

CONCLUSIONS

Prospective genomic surveillance of C. difficile using ONT sequencing permitted the identification of an outbreak of ST2 CDI that would have otherwise gone undetected.

The role of the hospital bed in hospital-onset Clostridioides difficile: A retrospective study with mediation analysis

OBJECTIVE

To determine whether residing in a hospital bed that previously held an occupant with Clostridioides difficile increases the risk of hospital-onset C. difficile infection (HO-CDI).

METHODS

In this retrospective cohort study, we used a real-time location system to track the movement of hospital beds in 2 academic hospitals from April 2018 to August 2019. We abstracted patient demographics, clinical characteristics, and C. difficile polymerase chain reaction (PCR) results from the medical record. We defined patients as being exposed to a potentially "contaminated" bed or room if, within the preceding 7 days from their HO-CDI diagnosis, they resided in a bed or room respectively, that held an occupant with C. difficile in the previous 90 days. We used multivariable logistic regression to determine whether residing in a contaminated bed was associated with HO-CDI after controlling for time at risk and requiring intensive care. We assessed mediation and interaction from a contaminated hospital room.

RESULTS

Of 25,032 hospital encounters with 18,860 unique patients, we identified 237 cases of HO-CDI. Exposure to a contaminated bed was associated with HO-CDI in unadjusted analyses (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.4-2.31) and adjusted analyses (OR, 1.5; 95% CI, 1.2-2.0). Most of this effect was due to both mediation from and interaction with a contaminated hospital room.

CONCLUSIONS

Residing in a hospital bed or room that previously had a patient with C. difficile increases the risk of HO-CDI. Increased attention to cleaning and disinfecting the healthcare environment may reduce hospital transmission of C. difficile.

Hygiene requirements for cleaning and disinfection of surfaces: recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

This recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) addresses not only hospitals, but also outpatient health care facilities and compiles current evidence. The following criteria are the basis for the indications for cleaning and disinfection: Infectious bioburden and tenacity of potential pathogens on surfaces and their transmission routes, influence of disinfecting surface cleaning on the rate of nosocomial infections, interruption of cross infections due to multidrug-resistant organisms, and outbreak control by disinfecting cleaning within bundles. The criteria for the selection of disinfectants are determined by the requirements for effectiveness, the efficacy spectrum, the compatibility for humans and the environment, as well as the risk potential for the development of tolerance and resistance. Detailed instructions on the organization and implementation of cleaning and disinfection measures, including structural and equipment requirements, serve as the basis for their implementation. Since the agents for surface disinfection and disinfecting surface cleaning have been classified as biocides in Europe since 2013, the regulatory consequences are explained. As possible addition to surface disinfection, probiotic cleaning, is pointed out. In an informative appendix (only in German), the pathogen characteristics for their acquisition of surfaces, such as tenacity, infectious dose and biofilm formation, and the toxicological and ecotoxicological characteristics of microbicidal agents as the basis for their selection are explained, and methods for the evaluation of the resulting quality of cleaning or disinfecting surface cleaning are presented.

Using a human-factors engineering approach to evaluate environmental cleaning in Veterans' Affairs acute and long-term care facilities: A qualitative analysis

BACKGROUND

Environmental cleaning is important in the interruption of pathogen transmission. Although prevention initiatives have targeted environmental cleaning, practice variations exist and compliance is low. Evaluation of human factors influencing variations in cleaning practices can be valuable in developing interventions to standardized practices. We conducted a work-system analysis using a human-factors engineering (HFE) framework to identify barriers and facilitators to environmental cleaning practices in acute and long-term care settings within the Veterans' Affairs health system.

METHODS

We conducted a qualitative study with key stakeholders at 3 VA facilities. We analyzed transcripts for thematic content and mapped themes to the HFE framework.

RESULTS

Staffing consistency was felt to improve cleaning practices and teamwork. We found that many environmental management service (EMS) staff were veterans who were motivated to serve fellow veterans, especially to prevent infections. However, hiring veterans comes with regulatory hurdles that affect staffing. Sites reported some form of monitoring their cleaning process, but there was variation in method and frequency. The EMS workload was affected by whether rooms were occupied by patients or were semiprivate rooms; both were reportedly more difficult to clean. Room design and surface finishes were identified as important to cleaning efficiency.

CONCLUSION

HFE work analysis identified barriers and facilitators to environmental cleaning. These findings highlight intervention entry points that may facilitate standardized work practices. There is a need to develop task-specific procedures such as cleaning occupied beds and semiprivate rooms. Future research should evaluate interventions that address these determinants of environmental cleaning.

Increasing ratio of opportunistic infections associated with sunshine exposure and economic level burdening Chinese inflammatory bowel disease hospitalized patients: the first nationwide survey from 2014 to 2019

BACKGROUND

The rising prevalence of opportunistic infections (OIs) in inflammatory bowel disease (IBD) in conjunction with the use of biologics/immunosuppressive agents has garnered attention. However, there is a dearth of research on OIs in Mainland China. This study seeks to evaluate the national ratio trend of OIs in IBD and elucidate the influence of economic and climate factors on IBD patients with OIs and their outcomes.

METHODS

The nationwide data was obtained from the Inpatient medical record home page via the Health Statistics and Information Reporting System (HSRS). Patients diagnosed with IBD were enlisted for participation, and their demographic and clinical information, encompassing infection type, surgical procedures, and expenses, were gathered. The National Bureau of Statistics provided data on monthly sunshine exposure hours and yearly Gross Domestic Product (GDP).

RESULTS

Findings indicate that between 2014 and 2019, a total of 381,752 patients with IBD were admitted to hospitals, with 364,249 patients lacking OIs and 17,503 patients presenting with OIs. The annual proportion of OIs exhibited an upward trend, rising from 3.54% in 2014 to 4.81% in 2019. There was a significant correlation observed between individuals who identified as male, those who visited hospitals in southern regions, or those originating from areas with lower GDP or shorter sunshine exposure hours, and a higher incidence of OIs. Among patients diagnosed with either Crohn's disease (CD) or ulcerative colitis (UC), Clostridium difficile was found to be the most prevalent infection, followed by Epstein-Barr virus and cytomegalovirus. Furthermore, the occurrence of OIs was found to be associated with an increased rate of surgical interventions in UC patients.

CONCLUSIONS

The rising prevalence of OIs among hospitalized patients with IBD necessitates heightened attention towards mitigating associated risk factors, particularly among IBD patients residing in less developed regions or experiencing limited exposure to sunlight. This approach aims to minimize hospital stays and associated costs.

Clostridioides difficile infections; new treatments and future perspectives

PURPOSE OF REVIEW

As a significant cause of global morbidity and mortality, Clostridioides difficile infections (CDIs) are listed by the Centres for Disease Control and prevention as one of the top 5 urgent threats in the USA. CDI occurs from gut microbiome dysbiosis, typically through antibiotic-mediated disruption; however, antibiotics are the treatment of choice, which can result in recurrent infections. Here, we highlight new treatments available and provide a perspective on different classes of future treatments.

RECENT FINDINGS

Due to the reduced risk of disease recurrence, the microbiome-sparing antibiotic Fidaxomicin has been recommended as the first-line treatment for C. difficile infection. Based on the success of faecal microbiota transplantations (FMT) in treating CDI recurrence, defined microbiome biotherapeutics offer a safer and more tightly controlled alterative as an adjunct to antibiotic therapy. Given the association between antibiotic-mediated dysbiosis of the intestinal microbiota and the recurrence of CDI, future prospective therapies aim to reduce the dependence on antibiotics for the treatment of CDI.

SUMMARY

With current first-in-line antibiotic therapy options associated with high levels of recurrent CDI, the availability of new generation targeted therapeutics can really impact treatment success. There are still unknowns about the long-term implications of these new CDI therapeutics, but efforts to expand the CDI treatment toolbox can offer multiple solutions for clinicians to treat this multifaceted infectious disease to reduce patient suffering.

Disinfection and sterilization: New technologies

BACKGROUND

Adherence to professional guidelines and/or manufacturer's instructions for use regarding proper disinfection and sterilization of medical devices is crucial to preventing cross transmission of pathogens between patients. Emerging pathogens (e.g., Candida auris) and complex medical devices provide new challenges.

METHODS

A search for published English articles on new disinfection and sterilization technologies was conducted by Google, Google scholar and PubMed.

RESULTS

Several new disinfection methods or products (e.g., electrostatic spraying, new sporicides, colorized disinfectants, "no touch" room decontamination, continuous room decontamination) and sterilization technologies (e.g., new sterilization technology for endoscopes) were identified.

CONCLUSIONS

These technologies should reduce patient risk.

úNo touch..Ñ methods for health care room disinfection: Focus on clinical trials

BACKGROUND

Hospital patient room surfaces are frequently contaminated with multidrug-resistant organisms. Since studies have demonstrated that inadequate terminal room disinfection commonly occurs, ..úno touch..Ñ methods of terminal room disinfection have been developed such as ultraviolet light (UV) devices and hydrogen peroxide (HP) systems.

METHODS

This paper reviews published clinical trials of ..úno touch..Ñ methods and ..úself-disinfecting..Ñ surfaces.

RESULTS

Multiple papers were identified including clinical trials of UV room disinfection devices (N.ß=.ß20), HP room disinfection systems (N.ß=.ß8), handheld UV devices (N.ß=.ß1), and copper-impregnated or coated surfaces (N.ß=.ß5). Most but not all clinical trials of UV devices and HP systems for terminal disinfection demonstrated a reduction of colonization/infection in patients subsequently housed in the room. Copper-coated surfaces were the only ..úself-disinfecting..Ñ technology evaluated by clinical trials. Results of these clinical trials were mixed.

DISCUSSION

Almost all clinical trials reviewed used a ..úweak..Ñ design (eg, before-after) and failed to assess potential confounders (eg, compliance with hand hygiene and environmental cleaning).

CONCLUSIONS

The evidence is strong enough to recommend the use of a ..úno-touch..Ñ method as an adjunct for outbreak control, mitigation strategy for high-consequence pathogens (eg, Candida auris or Ebola), or when there are an excessive endemic rates of multidrug-resistant organisms.

Frontline perspectives of C. difficile infection prevention practice implementation within veterans affairs health care facilities: A qualitative study

BACKGROUND

In 2012, the veteran's affairs (VA) multidrug-resistant organism (MDRO) Program Office launched a national Clostridioides difficile Infection (CDI) Prevention Initiative to address CDI as the most common cause of healthcare associated infections, mandating use of a VA CDI Bundle of prevention practices in inpatient facilities. We draw upon frontline worker perspectives to explore work system barriers and facilitators to the sustained implementation of the VA CDI Bundle using the systems engineering initiative for patient safety (SEIPS) framework.

METHODS

We interviewed 29 key stakeholders at 4 participating sites between October 2019-July 2021. Participants included infection prevention and control (IPC) leaders, nurses, physicians, and environmental management staff. Interviews were analyzed to identify themes and perceptions of facilitators and barriers to CDI prevention.

RESULTS

IPC leadership was most likely to know of the specific VA CDI Bundle components. Other participants demonstrated general knowledge of CDI prevention practices, with role-based variation in the depth of awareness of specific practices. Facilitators included leadership support, mandated CDI training and prevention practices, and readily available training from multiple sources. Barriers included limits to communication about facility or unit-level CDI rates, ambiguous communications about CDI prevention practice updates and VA mandates, and role-hierarchies that may limit team members' clinical contributions.

DISCUSSION

Recommendations include improving centrally-mandated clarity about and standardization of CDI prevention policies, including testing. Regular IPC training updates for all clinical stakeholders are also recommended.

CONCLUSIONS

A work system analysis using SEIPS identified barriers and facilitators to CDI prevention practices that could be addressed both nationally at the system level and locally at the facility level, specifically in the areas of communication and coordination.

A review of Spaulding's classification system for effective cleaning, disinfection and sterilization of reusable medical devices: Viewed through a modern-day lens that will inform and enable future sustainability

Despite advances in medicine and innovations in many underpinning fields including disease prevention and control, the Spaulding classification system, originally proposed in 1957, remains widely used for defining the disinfection and sterilization of contaminated re-usable medical devices and surgical instruments. Screening PubMed and Scopus databases using a PRISMA guiding framework generated 272 relevant publications that were used in this review. Findings revealed that there is a need to evolve how medical devices are designed, and processed by cleaning, disinfection (and/or sterilization) to mitigate patient risks, including acquiring an infection. This Spaulding Classification remains in use as it is logical, easily applied and understood by users (microbiologists, epidemiologists, manufacturers, industry) and by regulators. However, substantial changes have occurred over the past 65 years that challenge interpretation and application of this system that includes inter alia emergence of new pathogens (viruses, mycobacteria, protozoa, fungi), a greater understanding of innate and adaptive microbial tolerance to disinfection, toxicity risks, increased number of vulnerable patients and associated patient procedures, and greater complexity in design and use of medical devices. Common cited examples include endoscopes that enable non- or minimal invasive procedures but are highly sophisticated with various types of materials (polymers, electronic components etc), long narrow channels, right angle and heat-sensitive components and various accessories (e.g., values) that can be contaminated with high levels of microbial bioburden and patient tissues after use. Contaminated flexible duodenoscopes have been a source of several significant infection outbreaks, where at least 9 reported cases were caused by multidrug resistant organisms [MDROs] with no obvious breach in processing detected. Despite this, there is evidence of the lack of attention to cleaning and maintenance of these devices and associated equipment. Over the last few decades there is increasing genomic evidence of innate and adaptive resistance to chemical disinfectant methods along with adaptive tolerance to environmental stresses. To reduce these risks, it has been proposed to elevate classification of higher-risk flexible endoscopes (such as duodenoscopes) from semi-critical [contact with mucous membrane and intact skin] to critical use [contact with sterile tissue and blood] that entails a transition to using low-temperature sterilization modalities instead of routinely using high-level disinfection; thus, increasing the margin of safety for endoscope processing. This timely review addresses important issues surrounding use of the Spaulding classification system to meet modern-day needs. It specifically addresses the need for automated, robust cleaning and drying methods combined with using real-time monitoring of device processing. There is a need to understand entire end-to-end processing of devices instead of adopting silo approaches that in the future will be informed by artificial intelligence and deep-learning/machine learning. For example, combinational solutions that address the formation of complex biofilms that harbour pathogenic and opportunistic microorganisms on the surfaces of processed devices. Emerging trends are addressed including future sustainability for the medical devices sector that can be enabled via a new Quintuple Helix Hub approach that combines academia, industry, healthcare, regulators, and society to unlock real world solutions.

Mitigating hospital-onset Clostridioides difficile: The impact of an optimized environmental hygiene program in eight hospitals

OBJECTIVE

To evaluate the impact of a standardized, process-validated intervention utilizing daily hospital-wide patient-zone sporicidal disinfectant cleaning on incidence density of healthcare-onset Clostridioides difficile infection (HO-CDI) standardized infection ratios (SIRs).

DESIGN

Multi-site, quasi-experimental study, with control hospitals and a nonequivalent dependent variable.

SETTING

The study was conducted across 8 acute-care hospitals in 6 states with stable endemic HO-CDI SIRs.

METHODS

Following an 18-month preintervention control period, each site implemented a program of daily hospital-wide sporicidal disinfectant patient zone cleaning. After a wash-in period, thoroughness of disinfection cleaning (TDC) was monitored prospectively and optimized with performance feedback utilizing a previously validated process improvement program. Mean HO-CDI SIRs were calculated by quarter for the pre- and postintervention periods for both the intervention and control hospitals. We used a difference-in-differences analysis to estimate the change in the average HO-CDI SIR and HO-CAUTI SIR for the pre- and postintervention periods.

RESULTS

Following the wash-in period, the TDC improved steadily for all sites and by 18 months was 93.6% for the group. The mean HO-CDI SIRs decreased from 1.03 to 0.6 (95% CI, 0.13-0.75; P = .009). In the adjusted difference-in-differences analysis in comparison to controls, there was a 0.55 reduction (95% CI, -0.77 to -0.32) in HO-CDI (P < .001) or a 50% relative decrease from baseline.

CONCLUSIONS

This study represents the first multiple-site, quasi-experimental study with control hospitals and a nonequivalent dependent variable to evaluate a 4-component intervention on HO-CDI. Following ongoing improvement in cleaning thoroughness, there was a sustained 50% decrease in HO-CDI SIRs compared to controls.

Evaluation of daily environmental cleaning and disinfection practices in veterans affairs acute and long-term care facilities: A mixed methods study

OBJECTIVES

To describe daily environmental cleaning and disinfection practices and their associations with cleaning rates while exploring contextual factors experienced by healthcare workers involved in the cleaning process.

METHODS

A convergent mixed methods approach using quantitative observations (ie, direct observation of environmental service staff performing environmental cleaning using a standardized observation form) and qualitative interviews (ie, semistructured interviews of key healthcare workers) across 3 Veterans Affairs acute and long-term care facilities.

RESULTS

Between December 2018 and May 2019 a total of sixty-two room observations (N = 3602 surfaces) were conducted. The average observed surface cleaning rate during daily cleaning in patient rooms was 33.6% for all environmental surfaces and 60.0% for high-touch surfaces (HTS). Higher cleaning rates were observed with bathroom surfaces (Odds Ratio OR = 3.23), HTSs (OR = 1.57), and reusable medical equipment (RME) (OR = 1.40). Lower cleaning rates were observed when cleaning semiprivate rooms (OR = 0.71) and rooms in AC (OR = 0.56). In analysis stratified by patient presence (ie, present, or absent) in the room during cleaning, patient absence was associated with higher cleaning rates for HTSs (OR = 1.71). In addition, the odds that bathroom surfaces being cleaned more frequently than bedroom surfaces decreased (OR = 1.97) as well as the odds that private rooms being cleaned more frequently than semi-private rooms also decreased (OR = 0.26; 0.07-0.93). Between January and June 2019 eighteen qualitative interviews were conducted and found key themes (ie, patient presence and semiprivate rooms) as potential barriers to cleaning; this supports findings from the quantitative analysis.

CONCLUSION

Overall observed rates of daily cleaning of environmental surfaces in both acute and long-term care was low. Standardized environmental cleaning practices to address known barriers, specifically cleaning practices when patients are present in rooms and semi-private rooms are needed to achieve improvements in cleaning rates.

Inanimate Surfaces as a Source of Hospital Infections Caused by Fungi, Bacteria and Viruses with Particular Emphasis on SARS-CoV-2

The carriers of nosocomial infections are the hands of medical personnel and inanimate surfaces. Both hands and surfaces may be contaminated as a result of contact with the patient, their body fluids, and touching contaminated surfaces in the patient’s surroundings. Visually clean inanimate surfaces are an important source of pathogens. Microorganisms have properties thanks to which they can survive in unfavorable conditions, from a few days to several months. Bacteria, viruses and fungi are able to transmit from inanimate surfaces to the skin of the patient and the medical staff. These pathogens include SARS-CoV-2, which can survive on various types of inanimate surfaces, being a potential source of infection. By following the recommendations related to washing and disinfecting hands and surfaces, and using appropriate washing and disinfecting agents with a broad biocidal spectrum, high material compatibility and the shortest duration of action, we contribute to breaking the chain of nosocomial infections.

Evaluation of an aerosolized hydrogen peroxide disinfection system for the reduction of Clostridioides difficile hospital infection rates over a 10 year period

BACKGROUND

Clostridioides difficile infections (CDI) cause significant morbidity and mortality in healthcare facilities worldwide. We examined the use of an aerosolized hydrogen peroxide (aHP) disinfection system for reduction of CDI rates.

METHODS

We conducted a retrospective analysis of CDI rates at an acute care facility over a 10-year period. The first 5-year period investigated the before and after implementation of an aHP system followed by another 5-year period of continued use on CDI rates.

RESULTS

The before and after period showed a reduction in CDI rates from 4.6 per 10,000 patient days down to 2.7 per 10,000 patient days after implementation (P < .001). The second study period for the continued aHP use exhibited a consistent decrease in CDI rates to 1.4 per 10,000 patient days at the end of the study.

CONCLUSIONS

The addition of a touchless aHP whole room disinfection system as part of terminal cleaning resulted in a significant reduction in CDI rates that have been sustained year after year.

Engaging veterans in identifying key elements of environmental cleaning and disinfection for preventing healthcare-associated infections: A qualitative study

BACKGROUND

Environmental cleaning and disinfection are important for preventing healthcare-associated infections (HAIs) via contaminated surfaces. Hospital cleanliness plays a large role in patient perception and satisfaction regarding their healthcare. However, patient perceptions of environmental cleaning procedures remain unclear. The objective of the study was to engage patients in achieving patient-centered care and examine patient perspectives on environmental cleaning work systems in healthcare.

METHODS

A qualitative descriptive study was conducted using semi-structured interviews with hospitalized patients at a Midwestern Veterans Administration Hospital. Interviews were audio recorded, transcribed, then coded to identify recurring themes.

RESULTS

Fifteen patient interview were conducted. Patients reported expecting a clean hospital room. Some patients expressed feeling "in the way" during cleaning, possibly rushing cleaning procedures. Patients expressed confidence in Environmental Management Service (EMS) staff's skilled work and noted "soft skills" as desirable attributes, including camaraderie which can develop between Veteran patients and Veteran staff during room cleaning.

CONCLUSIONS

Patients identified environmental cleaning as a priority for HAI patient-centered infection prevention practices. Cleaning occupied rooms may be an important entry point for intervention to address actual or perceived disruption to patients or build upon Veteran peer relationships. Cleaning procedures may become more patient-centric if cleaning procedures were explained and based on patient preferences.

A systematic review and meta-analysis of decontamination methods to prevent hospital environmental contamination and transmission of Clostridioidesdifficile

The current guidelines suggest that hospital rooms previously occupied with Clostridioides difficile infection (CDI) patients should be decontaminated with recommended decontamination methods because C. difficile can persist on surfaces despite adherence to the recommended procedures. Recently, ultraviolet (UV) light and hydrogen peroxide have increasingly been used as innovative decontamination methods. Hence, we conducted a systematic review and meta-analysis to investigate which decontamination methods are effective in reducing environmental C. difficile contamination. We systematically searched the EMBASE, PubMed, CINAHL, Scopus, and Ichushi until March 11, 2021. We evaluated the efficacy of decontamination methods in terms of the frequency of C. difficile contamination on high-touch surfaces in hospital rooms and the incidence of hospital-acquired C. difficile infection. Among the 15 studies retrieved in our meta-analysis, eight evaluated decontamination methods with the frequency of C. difficile detection among samples after disinfection procedures, and eight reported the number of hospital-acquired CDI cases. Pooled analysis indicated that hydrogen peroxide significantly reduced the frequency of environmental C. difficile contamination, compared with hypochlorite (odds ratios [OR]: 0.12; 95% confidence interval [CI]: 0.07-0.23). Additionally, hydrogen peroxide reduced the incidence of hospital-acquired CDI compared to other methods (OR: 0.52; 95% CI: 0.28-0.96). Decontamination with UV significantly reduced the incidence of hospital-acquired CDI compared to hypochlorite (OR 0.52, 95% CI 0.28-0.96). The use of hydrogen peroxide and UV can help prevent environmental C. difficile contamination and transmission in healthcare facilities.

Comparing approaches for modelling indirect contact transmission of infectious diseases

Mathematical models describing indirect contact transmission are an important component of infectious disease mitigation and risk assessment. A model that tracks microorganisms between compartments by coupled ordinary differential equations or a Markov chain is benchmarked against a mechanistic interpretation of the physical transfer of microorganisms from surfaces to fingers and subsequently to a susceptible person's facial mucosal membranes. The primary objective was to compare these models in their estimates of doses and changes in microorganism concentrations on hands and fomites over time. The abilities of the models to capture the impact of episodic events, such as hand hygiene, and of contact patterns were also explored. For both models, greater doses were estimated for the asymmetrical scenarios in which a more contaminated fomite was touched more often. Differing representations of hand hygiene in the Markov model did not notably impact estimated doses but affected pathogen concentration dynamics on hands. When using the Markov model, losses due to hand hygiene should be handled as separate events as opposed to time-averaging expected losses. The discrete event model demonstrated the effect of hand-to-mouth contact timing on the dose. Understanding how model design influences estimated doses is important for advancing models as reliable risk assessment tools.

Health Care Environmental Hygiene: New Insights and Centers for Disease Control and Prevention Guidance

Recent research has significantly clarified the impact of optimizing patient-zone environmental hygiene. New insights into the environmental microbial epidemiology of many hospital-associated pathogens, especially Clostridioides difficile, have clarified and quantified the role of ongoing occult pathogen transmission from the near-patient environment. The recent development of safe, broadly effective surface chemical disinfectants has led to new opportunities to broadly enhance environmental hygiene in all health care settings. The Centers for Disease Control and Prevention has recently developed a detailed guidance to assist all health care settings in implementing optimized programs to mitigate health care-associated pathogen transmission from the near-patient surfaces.

Mathematically modeling the effect of touch frequency on the environmental transmission of Clostridioides difficile in healthcare settings

Clostridioides difficile, formerly Clostridium difficile, is the leading cause of infectious diarrhea and one of the most common healthcare acquired infections in United States hospitals. C. difficile persists well in healthcare environments because it forms spores that can survive for long periods of time and can be transmitted to susceptible patients through contact with contaminated hands and fomites, objects or surfaces that can harbor infectious agents. Fomites can be classified as high-touch or low-touch based on the frequency they are contacted. The mathematical model in this study investigates the relative contribution of high-touch and low-touch fomites on new cases of C. difficile colonization among patients of a hospital ward. The dynamics of transmission are described by a system of ordinary differential equations representing four patient population classes and two pathogen environmental reservoirs. Parameters that have a significant effect on incidence, as determined by a global sensitivity analysis, are varied in stochastic simulations of the system to identify feasible strategies to prevent disease transmission. Results indicate that on average, under one-quarter of asymptomatically colonized patients are exposed to C. difficile via low-touch fomites. In comparison, over three-quarters of colonized patients are colonized through high-touch fomites, despite additional cleaning of high-touch fomites. Increased contacts with high-touch fomites increases the contribution of these fomites to the incidence of colonized individuals and decreasing the duration of a hospital visit reduces the amount of pathogen in the environment. Thus, enhanced efficacy of disinfection upon discharge and extra cleaning of high-touch fomites, reduced contact with high-touch fomites, and higher discharge rates, among other control measures, could lead to a decrease in the incidence of colonized individuals.

Environmental Contamination of Contact Precaution and Non-Contact Precaution Patient Rooms in Six Acute Care Facilities

BACKGROUND

Environmental contamination is an important source of hospital multidrug-resistant organism (MDRO) transmission. Factors such as patient MDRO contact precautions (CP) status, patient proximity to surfaces, and unit type likely influence MDRO contamination and bacterial bioburden levels on patient room surfaces. Identifying factors associated with environmental contamination in patient rooms and on shared unit surfaces could help identify important environmental MDRO transmission routes.

METHODS

Surfaces were sampled from MDRO CP and non-CP rooms, nursing stations, and mobile equipment in acute care, intensive care, and transplant units within 6 acute care hospitals using a convenience sampling approach blinded to cleaning events. Precaution rooms had patients with clinical or surveillance tests positive for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, carbapenem-resistant Enterobacteriaceae or Acinetobacter within the previous 6 months, or Clostridioides difficile toxin within the past 30 days. Rooms not meeting this definition were considered non-CP rooms. Samples were cultured for the above MDROs and total bioburden.

RESULTS

Overall, an estimated 13% of rooms were contaminated with at least 1 MDRO. MDROs were detected more frequently in CP rooms (32% of 209 room-sample events) than non-CP rooms (12% of 234 room-sample events). Surface bioburden did not differ significantly between CP and non-CP rooms or MDRO-positive and MDRO-negative rooms.

CONCLUSIONS

CP room surfaces are contaminated more frequently than non-CP room surfaces; however, contamination of non-CP room surfaces is not uncommon and may be an important reservoir for ongoing MDRO transmission. MDRO contamination of non-CP rooms may indicate asymptomatic patient MDRO carriage, inadequate terminal cleaning, or cross-contamination of room surfaces via healthcare personnel hands.

Persistence of Pathogens on Inanimate Surfaces: A Narrative Review

For the prevention of infectious diseases, knowledge about transmission routes is essential. In addition to respiratory, fecal-oral, and sexual transmission, the transfer of pathogens via surfaces plays a vital role for human pathogenic infections-especially nosocomial pathogens. Therefore, information about the survival of pathogens on surfaces can have direct implications on clinical measures, including hygiene guidelines and disinfection strategies. In this review, we reviewed the existing literature regarding viral, bacterial, and fungal persistence on inanimate surfaces. In particular, the current knowledge of the survival time and conditions of clinically relevant pathogens is summarized. While many pathogens persist only for hours, common nosocomial pathogens can survive for days to weeks under laboratory conditions and thereby potentially form a continuous source of transmission if no adequate inactivation procedures are performed.

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.

The effect of copper-oxide-treated soft and hard surfaces on the incidence of healthcare-associated infections: a two-phase study

BACKGROUND

Copper-oxide-impregnated linens and hard surfaces within the hospital environment have emerged as a novel technology to reduce environmental contamination and thereby potentially reduce the risk of healthcare-associated infections (HCAIs).

METHODS

This was a two-phase study. Phase 1 was a prospective, cluster-randomized, cross-over clinical trial in which one pod (eight beds) of our general ICU (GICU) utilized copper-oxide-impregnated linens whereas the other pod (eight beds) used standard hospital linens. Phase 2 was a two-year before-after study, following the relocation of three ICUs into a new ICU tower in which all the hard surfaces were treated with copper oxide (in addition to copper-impregnated linens). HCAIs were recorded using the National Healthcare Safety Network definitions.

FINDINGS

A total of 1282 patients were enrolled in phase 1. There was no difference in the rate of HCAI between the patients who received standard compared with copper oxide linen. In phase 2 there was a significant reduction in the number of infections due to Clostridioides difficile (2.4 per 1000 vs 0.7 per 1000 patient-days; incidence rate ratio: 3.3; 95% confidence interval: 1.4-8.7; P = 0.002) but no difference in the rate of central-line-associated bloodstream infections nor of catheter-associated urinary tract infections.

CONCLUSION

Copper-oxide-impregnated linens alone had no effect on the rate of HCAI. Our data suggest that copper-oxide-treated hard surfaces reduced the rate of infections due to C. difficile; however, important confounders cannot be excluded.

Clostridioides difficile contamination in a clinical microbiology laboratory?

OBJECTIVES

Clostridioides difficile infection has traditionally been considered to be transmitted predominantly within health-care settings. It is not recognized as a pathogen that presents a risk of laboratory acquisition. Data on laboratory contamination and acquisition by laboratory personnel are lacking. Our objective was to assess environmental contamination by C. difficile and its potential for transmission in a clinical microbiology laboratory.

METHODS

Laboratory surfaces were screened for C. difficile. Samples were taken in areas that handle C. difficile isolates (high-exposure (HE) areas), areas adjacent to HE areas or those processing faecal samples (medium-exposure (ME) areas), and areas that do not process faecal samples or C. difficile isolates (low-exposure (LE) areas). We examined C. difficile carriage (hands/rectal samples) of laboratory workers.

RESULTS

A total of 140 environmental samples were collected from two HE areas (n = 56), two ME areas (n = 56) and two LE areas (n = 28). Overall, 37.8% (37/98) of surfaces were contaminated with C. difficile, and 17.3% (17/98) with toxigenic C. difficile (TCD). HE areas were significantly more contaminated with TCD than LE areas (38.1% (16/42) versus 0.0% (0/14), p 0.005) and ME areas (38.1% (16/42) versus 2.4% (1/42), p <0.001). Hands were colonized with TCD in 11.8% (4/34) of cases. We found no rectal carriage of C. difficile.

CONCLUSIONS

We found a significant proportion of laboratory surfaces to be contaminated with toxigenic C. difficile, as well as hand colonization of laboratory personnel. We recommend specific control measures for high-risk areas and laboratory personnel working in these areas.

Novel Visualization of Clostridium difficile Infections in Intensive Care Units

BACKGROUND

Accurate and timely surveillance and diagnosis of healthcare-facility onset Clostridium difficile infection (HO-CDI) is vital to controlling infections within the hospital, but there are limited tools to assist with timely outbreak investigations.

OBJECTIVES

To integrate spatiotemporal factors with HO-CDI cases and develop a map-based dashboard to support infection preventionists (IPs) in performing surveillance and outbreak investigations for HO-CDI.

METHODS

Clinical laboratory results and Admit-Transfer-Discharge data for admitted patients over two years were extracted from the Information Warehouse of a large academic medical center and processed according to Center for Disease Control (CDC) National Healthcare Safety Network (NHSN) definitions to classify Clostridium difficile infection (CDI) cases by onset date. Results were validated against the internal infection surveillance database maintained by IPs in Clinical Epidemiology of this Academic Medical Center (AMC). Hospital floor plans were combined with HO-CDI case data, to create a dashboard of intensive care units. Usability testing was performed with a think-aloud session and a survey.

RESULTS

The simple classification algorithm identified all 265 HO-CDI cases from 1/1/15-11/30/15 with a positive predictive value (PPV) of 96.3%. When applied to data from 2014, the PPV was 94.6% All users "strongly agreed" that the dashboard would be a positive addition to Clinical Epidemiology and would enable them to present Hospital Acquired Infection (HAI) information to others more efficiently.

CONCLUSIONS

The CDI dashboard demonstrates the feasibility of mapping clinical data to hospital patient care units for more efficient surveillance and potential outbreak investigations.

Characterization of Clostridioides difficile isolates recovered from hospitalized patients and the hospitals environment and air: A multicenter study

In healthcare settings, contamination of environment with toxigenic and hypervirulent Clostridioides difficile strains is a serious concern. Here, we assessed whether patients with C. difficile have a role to play in the dissemination of C. difficile in our settings or other sources are implicated in its circulation. A total of 700 fecal specimens and 1435 environmental samples from surfaces, equipment and air of rooms occupied by patients suspected of C. difficile infection were taken from 4 tertiary hospitals in Tehran, Iran between April 2016 and August 2017. Antibiotic susceptibility testing and detection of resistance genes were performed for the environmental isolates. The clinical and environmental isolates of C. difficile were subjected to Pulsed Field Gel Electrophoresis (PFGE) analysis. Forty three (6.14%) and 2 (0.13%) isolates of C. difficile were recovered from the clinical and environmental samples, respectively. In the clinical settings, 2 patients were suspected of recurrent C. difficile infection. Thirty distinct pulsotypes were found among the C. difficile isolates including 28 singletons and 2 common types. One of the two environmental isolates was isolated from floor in the Medical ward, of pulsotype/ribotype/toxinotype PT10/New ribotype/toxinotype V, harbored cdtA/B and tcdC-A, and resistant to ciprofloxacin. The other one was isolated from air of a room in ICU, assigned to PT11/RT001/toxinotype 0, belonged to tcdC-sc3 genotypes and resistant to metronidazole. The environmental isolates did not generate amplicons in PCR assays targeting vanA and nim genes. This study provided evidence for dissemination of genetically diverse strains of C. difficile in hospitalized patients, presence of C. difficile in hospital air, existence of binary toxin positive/antibiotic-resistant isolate on the floor and intra-hospital dissemination of this pathogen.

Interlaboratory reproducibility of a test method following 4-field test methodology to evaluate the susceptibility of Clostridium difficile spores

BACKGROUND

Sporicidal surface disinfection is recommended to control transmission of Clostridium difficile in healthcare facilities. EN 17126 provides a method to determine the sporicidal activity in suspension and has been approved as a European standard. In addition, a sporicidal surface test has been proposed.

AIM

To determine the interlaboratory reproducibility of a test method for evaluating the susceptibility of a C. difficile spore preparation to a biocidal formulation following the 4-field test (EN 16615 methodology).

METHODS

Nine laboratories participated. C. difficile NCTC 13366 spores were used. Glutaraldehyde (1% and 6%; 15 min) and peracetic acid (PAA; 0.01% and 0.04%; 15 min) were used to determine the spores' susceptibility in suspension in triplicate.

FINDINGS

One-percent glutaraldehyde revealed a mean decimal log₁₀ reduction of 1.03 with variable results in the nine laboratories (0.37-1.49) and a reproducibility of 0.38. The effect of 6% glutaraldehyde was stronger (mean: 2.05; range: 0.96-4.29; reproducibility: 0.86). PAA revealed similar results. An exemplary biocidal formulation based on 5% PAA was used at 0.5% (non-effective concentration) and 4% (effective concentration) to determine the sporicidal efficacy (4-field test) under clean conditions in triplicate with a contact time of 15 min. When used at 0.5% it demonstrated an overall log₁₀ reduction of 2.68 (range: 2.35-3.57) and at 4% of 4.61 (range: 3.82-5.71). The residual contamination on the three primarily uncontaminated test fields was <50 cfu/25 cm² in one out of nine laboratories (0.5%) and in seven out of nine laboratories (4%).

CONCLUSION

The interlaboratory reproducibility seems to be robust.

Toilet plume aerosol generation rate and environmental contamination following bowl water inoculation with Clostridium difficile spores

INTRODUCTION

Clostridium difficile is the leading cause of health care-associated gastric illness. Environmental contamination with C difficile spores is a risk factor for contact transmission, and toilet flushing causes such contamination. This work explores toilet contamination persistence and environmental contamination produced over a series of flushes after contamination.

METHODS

A flushometer toilet was seeded with C difficile spores in a sealed chamber. The toilet was flushed 24times, with postflush bowl water samples and settle plates periodically collected for culturing and counting. Air samples were collected after each of 12 flushes using rotating plate impactors.

RESULTS

Spores were present in bowl water even after 24 flushes. Large droplet spore deposition accumulated over the 24-flush period. Droplet nuclei spore bioaerosol was produced over at least 12 flushes.

CONCLUSIONS

Toilets contaminated with C difficile spores are a persistent source of environmental contamination over an extended number of flushes.

ASID/ACIPC position statement - Infection control for patients with Clostridium difficile infection in healthcare facilities

BACKGROUND

In 2011, the Australasian Society for Infectious Diseases (ASID) and the Australian Infection Control Association (AICA), now known as the Australasian College of Infection Prevention and Control (ACIPC), produced a position statement on infection control requirements for preventing and controlling Clostridium difficile infection (CDI) in healthcare settings.

METHODS

The statement updated in 2017 to reflect new literature available .The authors reviewed the 2011 position statement and critically appraised new literature published between 2011 and 2017 and relevant current infection control guidelines to identify where new evidence had become available or best practice had changed.

RESULTS

The position statement was updated incorporating the new findings. A draft version of the updated position statement was circulated for consultation to members of ASID and ACIPC. The authors responded to all comments received and updated the position statement.

CONCLUSIONS

This updated position statement emphasizes the importance of health service organizations having evidence-based infection prevention and control programs and comprehensive antimicrobial stewardship programs, to ensure the risk of C. difficile acquisition, transmission and infection is minimised.

Health care-associated infections - an overview

Health care-associated infections (HCAIs) are infections that occur while receiving health care, developed in a hospital or other health care facility that first appear 48 hours or more after hospital admission, or within 30 days after having received health care. Multiple studies indicate that the common types of adverse events affecting hospitalized patients are adverse drug events, HCAIs, and surgical complications. The US Center for Disease Control and Prevention identifies that nearly 1.7 million hospitalized patients annually acquire HCAIs while being treated for other health issues and that more than 98,000 patients (one in 17) die due to these. Several studies suggest that simple infection-control procedures such as cleaning hands with an alcohol-based hand rub can help prevent HCAIs and save lives, reduce morbidity, and minimize health care costs. Routine educational interventions for health care professionals can help change their hand-washing practices to prevent the spread of infection. In support of this, the WHO has produced guidelines to promote hand-washing practices among member countries.

Impact of antimicrobial wipes compared with hypochlorite solution on environmental surface contamination in a health care setting: A double-crossover study

OBJECTIVE

Antimicrobial wipes are increasingly used in health care settings. This study evaluates, in a clinical setting, the efficacy of sporicidal wipes versus a cloth soaked in a 1,000 ppm chlorine solution.

INTERVENTION

A double-crossover study was performed on 2 different surgical and cardiovascular wards in a 1,000-bed teaching hospital over 29 weeks. The intervention period that consisted of surface decontamination with the preimpregnated wipe or cloth soaked in chlorine followed a 5-week baseline assessment of microbial bioburden on surfaces. Environmental samples from 11 surfaces were analyzed weekly for their microbial content.

RESULTS

A total of 1,566 environmental samples and 1,591 ATP swabs were analyzed during the trial. Overall, there were significant differences in the recovery of total aerobic bacteria (P < .001), total anaerobic bacteria (P < .001), and ATP measurement (P < .001) between wards and between the different parts of the crossover study. Generally, the use of wipes produced the largest reduction in the total aerobic and anaerobic counts when compared with the baseline data or the use of 1,000 ppm chlorine. Collectively, the introduction of training plus daily wipe disinfection significantly reduced multidrug-resistant organisms recovered from surfaces. Reversion to using 1,000 ppm chlorine resulted in the number of sites positive for multidrug-resistant organisms rising again.

CONCLUSIONS

This double-crossover study is the first controlled field trial comparison of using preimpregnated wipes versus cotton cloth dipped into a bucket of hypochlorite to decrease surface microbial bioburden. The results demonstrate the superiority of the preimpregnated wipes in significantly decreasing microbial bioburden from high-touch surfaces.

Impact of test protocols and material binding on the efficacy of antimicrobial wipes

BACKGROUND

The use of effective cleaning/disinfectant products is important to control pathogens on healthcare surfaces. With the increasing number of wipe products available, there is a concern that combination of a formulation with the wrong material will decrease the efficacy of the product. This study aimed to use a range of efficacy test protocols to determine the efficacy of four formulations before and after binding to three commonly used wiping materials.

METHODS

Two quaternary ammonium (QAC)-based products, one hydrogen-peroxide-based product and one neutral cleaner were combined with microfibre, cotton or non-woven materials and tested for efficacy against Pseudomonas aeruginosa and Staphylococcus aureus with two surface tests (ASTM E2197-17 and EN13697-15) and two 'product' tests (ASTM E2967-15 and EN16615-15).

FINDINGS

Overall, the impact of using different materials on formulation efficacy was limited, except for an alkyl(C_12-16)dimethylbenzylammonium chloride-based product used at 0.5% v/v. The hydrogen peroxide product was the most efficacious regardless of the material used. The results from wipe test ASTM E2967-15 were consistent with those from the surface tests, but not with EN16615-15 which was far less stringent.

CONCLUSIONS

The use of different wiping cloth materials may not impact severely on the efficacy of potent disinfectants, despite the absorption of different volumes of formulation by the materials. QAC-based formulations may be at higher risk when a low concentration is used. There were large differences in efficacy depending on the standard test performed, highlighting the need for more stringency in choosing the test to make a product claim on label.

Preventable Patient Harm: a Multidisciplinary, Bundled Approach to Reducing Clostridium difficile Infections While Using a Glutamate Dehydrogenase/Toxin Immunochromatographic Assay/Nucleic Acid Amplification Test Diagnostic Algorithm

Health care facility-onset Clostridium difficile infections (HO-CDI) are an important national problem, causing increased morbidity and mortality. HO-CDI is an important metric for the Center for Medicare and Medicaid Service's (CMS) performance measures. Hospitals that fall into the worst-performing quartile in preventing hospital-acquired infections, including HO-CDI, may lose millions of dollars in reimbursement. Under pressure to reduce CDI and without a clear optimal method for C. difficile detection, health care facilities are questioning how best to use highly sensitive nucleic acid amplification tests (NAATs) to aid in the diagnosis of CDI. Our institution has used a two-step glutamate dehydrogenase (GDH)/toxin immunochromatographic assay/NAAT algorithm since 2009. In 2016, our institution set an organizational goal to reduce our CDI rates by 10% by July 2017. We achieved a statistically significant reduction of 42.7% in our HO-CDI rate by forming a multidisciplinary group to implement and monitor eight key categories of infection prevention interventions over a period of 13 months. Notably, we achieved this reduction without modifying our laboratory algorithm. Significant reductions in CDI rates can be achieved without altering sensitive laboratory testing methods.

Factors associated with an outbreak of hospital-onset, healthcare facility-associated Clostridium difficile infection (HO-HCFA CDI) in a Mexican tertiary care hospital: A case-control study

Objective

To identify clinical and environmental factors associated with an outbreak of hospital-onset, healthcare facility-associated Clostridium difficile infection (HO-HCFA CDI).

Design

Case-control study.

Setting

Public, acute care, academic tertiary referral center in Mexico.

Patients

Adults hospitalized ≥48 hours between January 2015 and December 2016 were included. Cases were patients with a first episode of HO-HCFA CDI. Controls were patients with any other diagnosis; they were randomly selected from the hospital discharge database and matched in a 1:2 manner according to the date of diagnosis of case ± 10 days. Variables with p<0.1 were considered for multivariable analysis.

Results

One hundred and fifty-five cases and 310 controls were included. Variables independently associated with HO-HCFA CDI were: exposure to both ciprofloxacin and proton pump inhibitor (PPI) within the last 3 months (OR = 8.07, 95% CI = 1.70–38.16), febrile neutropenia (OR = 4.61, 95% CI = 1.37–15.46), intraabdominal infection (OR = 2.06, 95% CI = 0.95–4.46), referral from other hospitals (OR = 1.99, 95% CI = 0.98–4.05) and an increasing number of antibiotics previously used (OR = 1.28, 95% CI = 1.13–1.46).

Conclusions

Multiple factors were found to be associated with the first episode of HO-HCFA CDI in the setting of an outbreak; of the modifiable risk factors, prior exposure to both ciprofloxacin and PPI was the most important. Referral from other hospitals was an environmental risk factor that deserves further study.

'No touch' technologies for environmental decontamination: focus on ultraviolet devices and hydrogen peroxide systems

PURPOSE OF REVIEW

This article reviews 'no touch' methods for disinfection of the contaminated surface environment of hospitalized patients' rooms. The focus is on studies that assessed the effectiveness of ultraviolet (UV) light devices, hydrogen peroxide systems, and self-disinfecting surfaces to reduce healthcare-associated infections (HAIs).

RECENT FINDINGS

The contaminated surface environment in hospitals plays an important role in the transmission of several key nosocomial pathogens including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., Clostridium difficile, Acinetobacter spp., and norovirus. Multiple clinical trials have now demonstrated the effectiveness of UV light devices and hydrogen peroxide systems to reduce HAIs. A limited number of studies have suggested that 'self-disinfecting' surfaces may also decrease HAIs.

SUMMARY

Many studies have demonstrated that terminal cleaning and disinfection with germicides is often inadequate and leaves environmental surfaces contaminated with important nosocomial pathogens. 'No touch' methods of room decontamination (i.e., UV devices and hydrogen peroxide systems) have been demonstrated to reduce key nosocomial pathogens on inoculated test surfaces and on environmental surfaces in actual patient rooms. Further UV devices and hydrogen peroxide systems have been demonstrated to reduce HAI. A validated 'no touch' device or system should be used for terminal room disinfection following discharge of patients on contact precautions. The use of a 'self-disinfecting' surface to reduce HAI has not been convincingly demonstrated.

Long-acting water-stable organosilane agent and its sustained effect on reducing microbial load in an intensive care unit

BACKGROUND

Contaminated hospital surfaces contribute significantly to the transmission of health care-associated infections. Although disinfectants reduce bioburden by up to 99%, bacterial growth can rebound within hours to precleaning levels. We tested the effectiveness of an innovative, long-acting water-stable organosilane (WSO) to achieve sustained decreases in bioburden on hard surfaces.

METHODS

A 5-month prospective, randomized, double-blind controlled study was performed. Eighteen intensive care unit rooms were randomly divided into placebo or treatment groups. Hard surfaces in all rooms were cleaned using the same protocol, except the placebo surfaces were cleaned with an inert saline solution and the treatment surfaces were treated with the WSO. Binomial regression with repeated measures were used to assess mean reductions in total bioburden as measured by colony forming units.

RESULTS

The placebo resulted in average reductions in total colony forming units of 35% to 40% (relative risk reduction [RRR], 0.65; P < .01) and the WSO group averaged reductions of colony forming units by 66% to 99% (RRR, 0.55; P < .001). Total Staphylococcus aureus increased among the placebo rooms 30% (RRR, 0.69; P < .001), whereas in treatment rooms there was a reduction of 50%-60% (RRR, 0.57; P < .01). Although both sets of rooms saw reductions in bioburden or colony forming units, application of the WSO resulted in larger reductions. There was also greater variability in reductions in the placebo arm.

CONCLUSION

This is the first randomized, double-blind controlled study of an innovative WSO on high-touch hard surfaces at risk for high bioburdens. Sustained reductions of bioburden with the monthly application of this unique WSO may be associated with significant reductions in the risk of health care-associated infections.

Molecular detection of Clostridium difficile on inert surfaces from a Costa Rican hospital during and after an outbreak

BACKGROUND

Hospital transmission of Clostridium difficile is fostered by contamination of surfaces and medical equipment with spores highly resistant to disinfectants and regular cleaning procedures. Despite the outbreaks and fatalities that C difficile causes, its epidemiology has not been studied in hospitals from middle- and low-income countries. To tackle this knowledge gap, the detection frequency of C difficile DNA on inert surfaces of a major Costa Rican hospital during and after an outbreak was compared.

METHODS

We used a presence-absence real-time polymerase chain reaction to detect a fragment of the tpi gene of C difficile on 21 surface samples collected during an outbreak and 54 surface samples taken 2 years later at the same hospital.

RESULTS

C difficile DNA was detected in 40% of the 75 environmental samples analyzed. Whereas 71% of the samples collected during the outbreak were positive, only 28% of the samples obtained 2 years after the outbreak gave the same result. This 2.5× ratio was maintained when the comparison was restricted to the wards that were sampled both during and after the outbreak (72% vs 35%, P = .016).

CONCLUSIONS

Our results show that environmental surfaces in the hospital analyzed are continuously being contaminated with C difficile DNA and that their level of contamination is higher during an outbreak than after it.

Disinfection and Sterilization in Health Care Facilities: An Overview and Current Issues

When properly used, disinfection and sterilization can ensure the safe use of invasive and noninvasive medical devices. The method of disinfection and sterilization depends on the intended use of the medical device: critical items (contact sterile tissue) must be sterilized before use; semicritical items (contact mucous membranes or nonintact skin) must be high-level disinfected; and noncritical items (contact intact skin) should receive low-level disinfection. Cleaning should always precede high-level disinfection and sterilization. Current disinfection and sterilization guidelines must be strictly followed.

Clostridium difficile Infection in Special High-Risk Populations

Antibiotic use continues to be the most important risk factor for the development of Clostridium difficile infection (CDI) through disruption of the indigenous microbiota of the colon. This factor, together with environmental contamination, makes hospital and other healthcare facilities the perfect breeding ground for the infection. Several groups of patients are exposed to the hospital environment and, at the same time, affected by conditions that can make CDI more prevalent, more severe or make it present a different clinical picture. The list of such conditions appears too extensive to be reviewed in a single article. Nevertheless, several groups, including the critically ill, oncological patients, solid organ and hematopoietic transplant recipients, patients with inflammatory bowel disease, patients with kidney disease and pregnant women, have generated more attention and have been studied in more detail. On the other hand, pediatric patients constitute a controversial group because the large number of asymptomatic carriers makes interpretation of clinical findings and diagnostic tests difficult, as is the development of an appropriate approach to treatment. We present an in-depth discussion of CDI in these high-risk populations and we also review the issue of CDI in pediatric patients.

Monitoring and improving the effectiveness of surface cleaning and disinfection

Disinfection of noncritical environmental surfaces and equipment is an essential component of an infection prevention program. Noncritical environmental surfaces and noncritical medical equipment surfaces may become contaminated with infectious agents and may contribute to cross-transmission by acquisition of transient hand carriage by health care personnel. Disinfection should render surfaces and equipment free of pathogens in sufficient numbers to prevent human disease (ie, hygienically clean).

Impact of a Probiotic-Based Cleaning Intervention on the Microbiota Ecosystem of the Hospital Surfaces: Focus on the Resistome Remodulation

Background

Contamination of hospital surfaces by clinically-relevant pathogens represents a major concern in healthcare facilities, due to its impact on transmission of healthcare-associated infections (HAIs) and to the growing drug resistance of HAI-associated pathogens. Routinely used chemical disinfectants show limitations in controlling pathogen contamination, due to their inefficacy in preventing recontamination and selection of resistant strains. Recently we observed that an innovative approach, based on a cleanser added with spores of non-pathogenic probiotic Bacilli, was effective in stably counteracting the growth of several pathogens contaminating hospital surfaces.

Methods

Here, we wanted to study the impact of the Bacillus-based cleanser on the drug-resistance features of the healthcare pathogens population. In parallel, the ability of cleanser-derived Bacilli to infect hospitalized patients was also investigated.

Results

Collected data showed that Bacilli spores can germinate on dry inanimate surfaces, generating the bacterial vegetative forms which counteract the growth of pathogens and effectively substitute for them on treated surfaces. Strikingly, this procedure did not select resistant species, but conversely induced an evident decrease of antibiotic resistance genes in the contaminating microbial population. Also importantly, all the six HAI-positive patients hosted in the treated areas resulted negative for probiotic Bacilli, thus adding evidences to their safety-to-use.

Conclusions

These results indicate that this probiotic-based procedure is active not only in controlling surface microbial contamination but also in lowering drug-resistant species, suggesting that it may have relevant clinical and therapeutical implications for the management of HAIs.