Biofilms on medical instruments and surfaces: Do they interfere with instrument reprocessing and surface disinfection.

BACKGROUND: Biofilms are surface-attached communities of bacteria embedded in an extracellular matrix. This matrix shields the resident cells from desiccation, chemical perturbation, invasion by other bacteria, and confers reduced susceptibility to antibiotics and disinfectants. There is growing evidence that biofilms on medical instruments (especially endoscopes) and environmental surfaces interfere with cleaning and disinfection. METHODS: The English literature on the impact of biofilms in medicine was reviewed with a focus on the impact of biofilms on reusable semicritical medical instruments and hospital environmental surfaces. RESULTS: Biofilms are frequently present on hospital environmental surfaces and reusable medical equipment. Important health care...associated pathogens that readily form biofilms on environmental surfaces include Staphylococcus aureus, Pseudomonas aeruginosa, and Candida auris. Evidence has demonstrated that biofilms interfere with cleaning and disinfection. DISCUSSION: New technologies such as ..úself-disinfecting..Ñ surfaces or continuous room disinfection systems may reduce or disrupt biofilm formation and are under study to reduce the impact of the contaminated surface environment on health care...associated infections. CONCLUSIONS: Future research is urgently needed to develop methods to reduce or eliminate biofilms from forming on implantable medical devices, reusable medical equipment, and hospital surfaces.

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.

Role of the contaminated environment in transmission of multidrug-resistant organisms in nursing homes and infection prevention.

BACKGROUND: With aging of the population in the United States, there are more people in long-term care facilities than in hospitals. Nursing home residents have a high prevalence of colonization with multidrug-resistant organisms (MDROs). A shared environment with vulnerable patients can facilitate intra- and inter-facility transmission of MDROs. The aim of this paper is to examine the role of the nursing home environment in MDRO transmission and provide infection prevention strategies. METHODS: We searched the published literature and reviewed selected articles on contamination, transmission, and infection associated with the nursing home environment. RESULTS: Nursing home residents were frequently colonized with MDROs, leading to contamination of the surrounding environment with the same pathogen. Surface contamination with MDROs was common in nursing home patient rooms, and to a substantial but lesser frequency in common rooms. Shared rooms were a risk factor for MDRO transmission between patients. CONCLUSIONS: Since outbreaks and infections via the environmental contamination cause substantial burden of morbidity and mortality in the nursing home residents, it is essential for healthcare personnel to recognize the role of the nursing home environment in infection transmission and adhere to the current infection prevention guidelines for cleaning and disinfection of environmental surfaces.

Evaluation of antibiotic-resistant bacteria in home kitchens and bathrooms: Is there a link between home disinfectant use and antibiotic resistance?

OBJECTIVE: To determine the relationship between home disinfectant use and the prevalence of antibiotic resistance among environmental isolates of human pathogens. METHODS: Bacteria were cultured from 5 kitchen and 5 bathroom sites using quantitative methods. Antibiotic susceptibility was determined by standard methods. Home disinfectant use was assessed via a questionnaire. RESULTS: The overall total mean log10 counts (total CFU) for the kitchen and bathroom were 4.31 and 4.88, respectively. Gram-positive bacteria were more common in the bathroom (4.05) than in the kitchen (3.60), while Gram-negative bacilli were more common in the kitchen (4.23) than in the bathroom (3.86). The sink and bath drains were the most contaminated sites with 6.16-log10 of total CFU and 6.6-log10 in the kitchen and bathroom, respectively. Households reported cleaning frequency with a variety of commercial products. Most respondents used antibacterial products (eg, soaps, surface disinfectants) in the home. Antibiotic-resistant pathogens were infrequently isolated in the homes evaluated. CONCLUSIONS: Compared to pathogens causing community-acquired clinical infections in the ICARE study, pathogens isolated from households are less likely to demonstrate antibiotic resistance. In addition, no relationship between antibacterial use or frequency of cleaning or disinfection and antibiotic resistance was revealed.

Emerging infectious diseases, focus on infection prevention, environmental survival and germicide susceptibility: SARS-CoV-2, Mpox, and Candida auris.

BACKGROUND: New and emerging infectious diseases continue to represent a public health threat. Emerging infectious disease threats include pathogens increasing in range (eg, Mpox), zoonotic microbes jumping species lines to cause sustained infections in humans via person-to-person transmission (SARS-CoV-2) and multidrug-resistant pathogens (eg, Candida auris). MATERIALS AND METHODS: We searched the published English literature and reviewed the selected articles on SARS-CoV-2, Mpox, and Candida auris with a focus on environmental survival, contamination of the patient's hospital environment, susceptibility of the pathogen to antiseptics and disinfectants and infection prevention recommendations. RESULTS: All three pathogens (ie, SARS-CoV-2, Mpox, and Candida auris) can survive on surfaces for minutes to hours and for Mpox and C auris for days. Currently available antiseptics (eg, 70%-90% alcohol hand hygiene products) are active against SARS-CoV-2, Mpox and C auris. The U.S Environmental Protection Agency provides separate lists of surface disinfectants active against SARS-CoV-2, Mpox, and C auris. DISCUSSION: The risk of environment-to-patient transmission of SARS-CoV-2, Mpox and Candida auris, is very low, low-moderate and high, respectively. In the absence of appropriate patient isolation and use of personal protection equipment, the risk of patient-to-health care provider transmission of SARS-CoV-2, Mpox, and C auris is high, moderate and low, respectively. CONCLUSIONS: Appropriate patient isolation, use of personal protective equipment by health care personnel, hand hygiene, and surface disinfection can protect patients and health care personnel from acquiring SARS-CoV-2, Mpox, and C auris from infected patients.

Disinfection, sterilization and antisepsis: An overview.

BACKGROUND: Each year in the United States there are approximately 100,000,000 outpatient/inpatient surgical procedures. Each of these procedures involves contact by a medical device or surgical instrument with a patient's sterile tissue and/or mucous membrane. A major risk of all such procedures is the introduction of infection. METHODS: We searched published literature for articles on the use and effectiveness of disinfectants, sterilization methods and antiseptics. RESULTS: The level of disinfection is dependent on the intended use of the object: critical (items that contact sterile tissue such as surgical instruments), semicritical (items that contact mucous membrane such as endoscopes), and noncritical (devices that contact only intact skin such as stethoscopes) items require sterilization, high-level disinfection and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Antiseptics are essential to infection prevention as part of a hand hygiene program as well as other uses such as surgical hand antisepsis and pre-operative patient skin preparation. CONCLUSIONS: When properly used, disinfection and sterilization can ensure the safe use of invasive and non-invasive medical devices. Cleaning should always precede high-level disinfection and sterilization. Strict adherence to current disinfection and sterilization guidelines is essential to prevent patient infections and exposures to infectious agents.

Sterilization of 20 billion medical devices by ethylene oxide (ETO): Consequences of ETO closures and alternative sterilization technologies/solutions.

BACKGROUND: To prevent healthcare-associated infections, it is essential that critical medical devices be sterilized before use. Although there are several sterilization technologies for medical devices, only ethylene oxide (ETO) sterilization has virtually universal material compatibility. METHODS: We searched the published English literature (Google, Google scholar and PubMed) for articles on the sterilization of medical devices by ethylene oxide, the consequences of ETO closures, and alternative sterilization technologies/solutions. RESULTS: ETO's compatibility and effectiveness with medical products allows for sterilization of many medical devices that would otherwise be rendered ineffective or unsafe if sterilized with an alternative method. CONCLUSIONS: At present, there are no alternatives to ETO that provide the same sterility assurance and result in the same device performance as ETO; therefore, it is likely irreplaceable for years.

Risk of disease transmission to patients from "contaminated" surgical instruments and immediate use steam sterilization.

BACKGROUND: There are several sources of pathogens that cause surgical site infections (SSI) to include the patients endogenous microflora and exogenous sources (e.g., air, surfaces, staff, surgical equipment). METHODS: We searched the published English literature (Google, Google Scholar, PubMed) for articles on reprocessing surgical instruments, effectiveness of sterilization methods, microbial load on surgical instruments, frequency of "contaminated" instruments, and the infection risk associated with "contaminated" surgical instruments and immediate use steam sterilization. RESULTS: There is substantial redundancy in instrument reprocessing to include: even if a patient was exposed to a "contaminated" instrument, the decontamination and sterilization process would have removed and/or inactivated the contaminating pathogens due to the exceptional effectiveness of the manual and mechanical cleaning (i.e., washer-disinfector) and the remarkable robustness of sterilization technology; and the low-level of microorganisms on surgical instruments after use and before cleaning. CONCLUSIONS: A critical review of the literature suggests that the risk of acquiring an SSI from instruments used in surgery is essentially zero if the sterilization cycle is validated.

Reprocessing semicritical items: An overview and an update on the shift from HLD to sterilization for endoscopes.

BACKGROUND: Semicritical medical devices are defined as items that come into contact with mucous membranes or nonintact skin (e.g., gastrointestinal endoscopes, endocavitary probes). Such medical devices require minimally high-level disinfection. METHODS: Analyze the methods used to reprocess semicritical medical devices and identify methods and new technologies to reduce the risk of infection. RESULTS: The reprocessing methods for semicritical medical devices is described as well as a shift from high-level disinfection to sterilization for lumened endoscopes. CONCLUSIONS: Strict adherence to current guidelines and transition to sterilization for endoscopes is required as more outbreaks have been linked to inadequately disinfected endoscopes and other semicritical items than any other reusable medical devices.

Inactivation and/or physical removal of Candida auris from floors by detergent cleaner, disinfectants, microfiber, and ultraviolet C light (UV-C).

Contaminated surfaces may be a source of transmission for the globally emerging pathogen, Candida auris. Because floors may be a source of C. auris contamination on hands, strategies for inactivating or removing C. auris from floors were investigated. A sporicidal disinfectant and UV-C were most effective in inactivating C. auris on floors.

Transfer efficiency of an enveloped virus, human coronavirus 229E, from various hard surface fomites to finger pads of the hands.

Respiratory viruses can be transmitted by fomite contact, but no data currently exist on the transfer of enveloped viruses. The transfer efficiency of human coronavirus from various hard surfaces ranged from 0.46% to 49.0%. This information can be used to model the fomite transmission of enveloped viruses.

Continuously active disinfectant inactivates severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and human coronavirus 229E two days after the disinfectant was applied and following wear exposures.

The surface environment in rooms of coronavirus disease 2019 (COVID-19) patients may be persistently contaminated despite disinfection. A continuously active disinfectant demonstrated excellent sustained antiviral activity following a 48-hour period of wear and abrasion exposures with reinoculations. Reductions of >4-log10 were achieved within a 1-minute contact time for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and the human coronavirus, 229E.

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.

A comparison of methods for microbiologic environmental sampling.

We compared the effectiveness of 4 sampling methods to recover Staphylococcus aureus, Klebsiella pneumoniae and Clostridioides difficile from contaminated environmental surfaces: cotton swabs, RODAC culture plates, sponge sticks with manual agitation, and sponge sticks with a stomacher. Organism type was the most important factor in bacterial recovery.

Waterborne Outbreaks in Hemodialysis Patients and Infection Prevention.

Individuals treated with dialysis are at high risk for healthcare-associated infections. We conducted a literature review of outbreaks associated with water in hemodialysis during years 2011-2021 to understand the role of water as a source of infections for patients receiving hemodialysis with a focus on the risks associated with dialysis water and dialysate. For dialysis patients, water and dialysate have been a source of healthcare-associated pathogens, including nontuberculous mycobacteria and gram-negative bacilli as well as systemic reactions due to gram-negative bacilli-associated endotoxin. Lapses in infection prevention practices and dialysis water management were primarily involved in waterborne outbreaks. Dialysis clinics should adhere to recommendations regarding monitoring and levels of bacteria and endotoxin in hemodialysis water and dialysate. Since hemodialysis patients are at increased risk of healthcare-associated infections, it is important for healthcare personnel to adhere to infection prevention guidelines in hemodialysis patient care, especially hand hygiene, aseptic technique, cleaning/disinfection, and water management.

Does blood on "dirty" instruments interfere with the effectiveness of sterilization technologies?

We evaluated the robustness of sterilization technologies when spores and bacteria were placed on "dirty" instruments and overlaid with blood. The results illustrate that steam sterilization is the most effective sterilization technology with the largest margin of safety, followed by ethylene oxide and hydrogen peroxide gas plasma.

Inactivation of Candida auris and Candida albicans by ultraviolet-C.

We evaluated the ability of an ultraviolet-C (UV-C) room decontamination device to kill Candida auris and C. albicans. With an organic challenge (fetal calf serum), the UV-C device demonstrated the following log10 reductions for C. auris of 4.57 and for C. albicans of 5.26 with direct line of sight, and log10 reductions for C. auris of 2.41 and for C. ablicans of 3.96 with indirect line of sight.

Impact of Oral Metronidazole, Vancomycin, and Fidaxomicin on Host Shedding and Environmental Contamination With Clostridioides difficile.

BACKGROUND: Shedding of Clostridioides difficile spores from infected individuals contaminates the hospital environment and contributes to infection transmission. We assessed whether antibiotic selection affects C. difficile shedding and contamination of the hospital environment. METHODS: In this prospective, unblinded, randomized controlled trial of hospitalized adults with C. difficile infection, patients were randomized 1:1:1 to receive fidaxomicin, oral vancomycin, or metronidazole. The primary outcome was change in environmental contamination rate during treatment. Secondary outcomes included stool shedding, total burden of contamination, and molecular relatedness of stool versus environmental C. difficile isolates. RESULTS: Of 33 patients enrolled, 31 (94%) completed the study. Fidaxomicin (-0.36 log10 colony-forming units [CFUs]/d [95% confidence interval (CI), -.52 to -.19]; P < .01) and vancomycin (-0.17 log10 CFUs/d [-.34 to -.01]; P = .05) were associated with more rapid decline in C. difficile shedding than metronidazole (-0.01 log10 CFUs/d [95% CI, -.10 to .08). Both vancomycin (6.3% [95% CI, 4.7-8.3) and fidaxomicin (13.1% [10.7-15.9]) were associated with lower rates of environmental contamination than metronidazole (21.4% [18.0-25.2]). With specific modeling of within-subject change over time, fidaxomicin (adjusted odds ratio, 0.83 [95% CI, .70-.99]; P = .04) was associated with more rapid decline in environmental contamination than vancomycin or metronidazole. Overall, 207 of 233 environmental C. difficile isolates (88.8%) matched patient stool isolates by ribotyping, without significant difference by treatment. CONCLUSIONS: Fidaxomicin, and to a lesser extent vancomycin, reduces C. difficile shedding and contamination of the hospital environment relative to metronidazole. Treatment choice may play a role in reducing healthcare-associated C. difficile transmission. CLINICAL TRIALS REGISTRATION: NCT02057198.