Disinfection Of Medical Devices Research Articles

Study of the Effectiveness against Test Strain Mycobacterium terrae DSM 43227 of Some Substances Containing Fragment of Phenolic

Relevance. Multi-drug-resistant Mycobacterium tuberculosis has been an important problem in public health around the world. However, development of effective methods and means of disinfection is now extremely urgent. Phenol is probably the oldest known disinfectant. Disinfectants based on substances containing phenolic practically used in almost every countries of the worldwide for the disinfection of medical devices, surfaces and hand hygiene. Goal. Comparative study of the activity of certain disinfectants containing phenol fragment against the test strain. Materials and methods. Multi-drug-resistant M. terrae, M. avium-intracellulara and M. tuberculosis have similar characteristics of resistance to chemical disinfectants, herefore M. terrae DSM 43227 used as the test strain. We studied five used in Russia for the production of disinfectants and antiseptics. substances containing a phenolic. Results. The disinfectant effect of substances with phenol compounds was detected in lower concentrations (from 0.02% for 2-benzil-4-chlorphenol to 1.0% for ortophenylphenol) than with substances containing glutaraldehyde or chloramine B compounds. Conclusions. Saving disinfecting effectiveness at low concentrations of the active substances in the working solutions can be recommended disinfectants based on phenolic compounds for disinfection measures in the complex of measures for prevention of occurrence and spread of tuberculosis.

A review of heterogeneous photocatalysis for water and surface disinfection.

Photo-excitation of certain semiconductors can lead to the production of reactive oxygen species that can inactivate microorganisms. The mechanisms involved are reviewed, along with two important applications. The first is the use of photocatalysis to enhance the solar disinfection of water. It is estimated that 750 million people do not have accessed to an improved source for drinking and many more rely on sources that are not safe. If one can utilize photocatalysis to enhance the solar disinfection of water and provide an inexpensive, simple method of water disinfection, then it could help reduce the risk of waterborne disease. The second application is the use of photocatalytic coatings to combat healthcare associated infections. Two challenges are considered, i.e., the use of photocatalytic coatings to give “self-disinfecting” surfaces to reduce the risk of transmission of infection via environmental surfaces, and the use of photocatalytic coatings for the decontamination and disinfection of medical devices. In the final section, the development of novel photocatalytic materials for use in disinfection applications is reviewed, taking account of materials, developed for other photocatalytic applications, but which may be transferable for disinfection purposes.

Antiseptics and disinfectants in health care institutions: Modern principles of application

Skin antisepsis prior to invasive procedures, hand hygiene performed by health care workers, sterilization and disinfection of medical devices and environmental surfaces are the most important measures used to control nosocomial infections. Hand hygiene is the cheapest and most effective measure. Hand rubbing with an alcohol-based hand rub is recommended for the routine decontamination of hands. Hand washing with soap and water should be employed when hands are visibly soiled, and when exposure to Clostridium difficile infection is suspected or proven. Most alcohol based hand rubs are based on isopropanol, ethanol or n-propanol. The WHO published guidance recommend 20-30 seconds for routine hand rubbing. There are no recommendations stating that antimicrobial soaps are more effective than plain soaps. It is recommended to use alcohol-containing preparatory agents for skin preparation prior surgery, injections, incisions and punctures. Neutral pH detergent solutions are commonly used for cleaning equipment and instruments. Data did not clearly demonstrate that enzymatic cleaners are more effective than non-enzymatic cleaners. High level disinfection is safe procedure only if adequate products are properly used. There are no any special products for multidrug resistant bacteria.

Innate resistance to sporicides and potential failure to decontaminate

Bacterial spores are frequently intrinsically resistant to biocides and only a number of alkylating and oxidising biocides are sporicidal under certain conditions. Activity against spores is affected by several key factors such as concentration, exposure time, soiling, and the types of surface to be treated. Sporicidal efficacy is usually achieved after an exposure time of several minutes with a high concentration of a biocide. Failure to understand these factors will result in decreased sporicide activity and spore survival. Sporicides in healthcare settings are used for surface disinfection and for the high level disinfection of certain medical devices (e.g. endoscopes). With efficacy data in mind, sporicidal activity should be achieved for the disinfection of medical devices where both high concentration and long exposure time occur. However, for the disinfection of environmental surfaces, high concentration is not recommended, nor is long exposure time achievable. In this case, sporicidal activity is severely reduced and spore survival following treatment is to be expected and contributes to the explanation of spore persistence on surfaces.

医療用器材の消毒・滅菌方法の改善に関する検討 : 院内各部署における実態調査から

医療用器材の消毒・滅菌方法の改善に関する検討 : 院内各部署における実態調査から

Evaluation of a New Desktop Washer-Disinfector for the Viral Disinfection of Medical Devices

Evaluation of a New Desktop Washer-Disinfector for the Viral Disinfection of Medical Devices

Infecção por micobactérias de crescimento rápido após procedimentos videocirúrgicos - a hipótese do glutaraldeído

Between August 2006 and February 2007, in the state of Rio de Janeiro, Brazil, a massive outbreak of RGM infections after video laparoscopy was mainly associated to the recently described Mycobacterium massiliense species. All confirmed and probable cases reports described the use of high-level disinfection of medical devices by using 2% glutaraldehyde (2% GA) for 30 min before the surgical procedures. We investigated the susceptibility of the M. massiliense isolates recovered during the outbreak to high-level disinfection after 30 min, 1h, 6h and 10h of exposure to the commercial disinfectants. Reference strains for official mycobactericidal tests such as Mycobacterium abscessus, Mycobacterium bovis, Mycobacterium chelonae, Mycobacterium neoaurum and Mycobacterium smegmatis were included as controls. Although all the reference strains were eliminated in 30 min of exposure to 2% GA, we observed the recovery of all M. massiliense clinical isolates even after 10h of exposure. This study suggests that failures in high-level disinfection and the high tolerance of these M. massiliense clinical strains to the 2% GA were strongly associated to the magnitude of the outbreak.

Antimicrobial efficacy of chlorhexidine digluconate alone and in combination with eucalyptus oil, tea tree oil and thymol against planktonic and biofilm cultures of Staphylococcus epidermidis

Effective skin antisepsis and disinfection of medical devices are key factors in preventing many healthcare-acquired infections associated with skin microorganisms, particularly Staphylococcus epidermidis. The aim of this study was to investigate the antimicrobial efficacy of chlorhexidine digluconate (CHG), a widely used antiseptic in clinical practice, alone and in combination with tea tree oil (TTO), eucalyptus oil (EO) and thymol against planktonic and biofilm cultures of S. epidermidis. Antimicrobial susceptibility assays against S. epidermidis in a suspension and in a biofilm mode of growth were performed with broth microdilution and ATP bioluminescence methods, respectively. Synergy of antimicrobial agents was evaluated with the chequerboard method. CHG exhibited antimicrobial activity against S. epidermidis in both suspension and biofilm (MIC 2-8 mg/L). Of the essential oils thymol exhibited the greatest antimicrobial efficacy (0.5-4 g/L) against S. epidermidis in suspension and biofilm followed by TTO (2-16 g/L) and EO (4-64 g/L). MICs of CHG and EO were reduced against S. epidermidis biofilm when in combination (MIC of 8 reduced to 0.25-1 mg/L and MIC of 32-64 reduced to 4 g/L for CHG and EO, respectively). Furthermore, the combination of EO with CHG demonstrated synergistic activity against S. epidermidis biofilm with a fractional inhibitory concentration index of <0.5. The results from this study suggest that there may be a role for essential oils, in particular EO, for improved skin antisepsis when combined with CHG.

Outbreaks associated with contaminated antiseptics and disinfectants.

The Centers for Disease Control and Prevention (CDC) has estimated that health care-associated infections account for an estimated 1.7 million infections, 99,000 deaths, and $4.5 billion in excess health care costs annually (16). The key interventions used to control health care-associated infections include surveillance (27, 33), isolation of patients with communicable diseases (26) or multidrug-resistant pathogens (81), proper skin antisepsis prior to invasive procedures and hand hygiene by health care workers (12), and appropriate disinfection and sterilization of medical devices and environmental surfaces (73, 75, 79). Multiple nosocomial outbreaks have resulted from inadequate antisepsis or disinfection. Inadequate skin antisepsis may result from a lack of intrinsic antimicrobial activity of the antiseptic, a resistant pathogen, overdilution of the antiseptic, or the use of a contaminated antiseptic. The inadequate disinfection of medical devices or environmental surfaces may result from a lack of intrinsic antimicrobial activity of the disinfectant, an incorrect choice of a disinfectant, a resistant pathogen, overdilution of the disinfectant, an inadequate duration of disinfection, a lack of contact between the disinfectant and the microbes, or the use of a contaminated disinfectant. Editorials have noted that contaminated antiseptics and disinfectants have been the occasional vehicles of hospital infections for more than 50 years (20, 72, 76). This paper concisely reviews nosocomial outbreaks associated with the use of a microbiologically contaminated germicide and focuses on the currently recommended germicides.

New methods for the disinfection of medical devices potentially contaminated by prion

New methods for the disinfection of medical devices potentially contaminated by prion

Carrier Tests to Assess Microbicidal Activities of Chemical Disinfectants for Use on Medical Devices and Environmental Surfaces

For well over a decade, many deficiencies have been identified in current AOAC methods used to assess the microbicidal activities of chemical disinfectants on medical devices and environmental surfaces. This report discusses the development of quantitative carrier tests (QCT) designed to address these concerns. Decontamination of surfaces with dried inocula is invariably more difficult than when microorganisms are in suspension. For medical device as well as environmental decontamination, microbicides are used on contaminated surfaces, thus making it necessary to evaluate their microbicidal action on representative carrier materials contaminated with a dried challenge microorganism(s). Our approach is a 2-tiered QCT. The first tier (QCT-1) uses relatively ideal conditions to assess performance of the microbicide for screening purposes; the test uses smooth glass surfaces and quantities of disinfectant in excess of those likely to be experienced in the field. The second tier of testing (QCT-2) is more stringent because it uses (1) disks of brushed stainless steel as carriers, (2) only 50 microL of the test formulation on each carrier as compared to 1 mL in QCT-1, and (3) an added soil load to simulate the presence of residual body fluids or accumulated surface dirt. This review also discusses the factors that affect disinfection of medical devices and environmental surfaces in the context of the methodology used to evaluate the potency of microbicides. Specific recommendations for discussion are included, and performance criteria are suggested based on a risk-reduction approach for different classes of disinfectants. The focus is on improving the relevance of the test methodology to actual field use of disinfectants for devices and facilities in health care, and potentially in other settings. It is hoped that this review and its recommendations will initiate needed discussion and resolution of the many issues identified.

Nosocomial infections due to nontuberculous mycobacteria.

Nontuberculous mycobacteria (NTM) are ubiquitous in the environment and cause colonization, infection, and pseudo-outbreaks in health care settings. Data suggest that the frequency of nosocomial outbreaks due to NTM may be increasing, and reduced hot water temperatures may be partly responsible for this phenomenon. Attention to adequate high-level disinfection of medical devices and the use of sterile reagents and biologicals will prevent most outbreaks. Because NTM cannot be eliminated from the hospital environment, and because they present an ongoing potential for infection, NTM should be considered in all cases of nosocomial infection, and careful surveillance must be used to identify potential outbreaks. Analysis of the species of NTM and the specimen source may assist in determining the significance of a cluster of isolates. Once an outbreak or pseudo-outbreak is suspected, molecular techniques should be applied promptly to determine the source and identify appropriate control measures.

Freely Accessible Endoscope Channels Improve Efficacy of Cleaning

Inadequate cleaning and disinfection of medical devices, including flexible endoscopes, can result in the transmission of micro-organisms to patients. The aim of this study was to investigate the influence of the design of medical devices on the efficacy of manual cleaning of endoscope channels. The investigation was carried out using four endoscopes (two duodenoscopes and two gastroscopes). The air/water channels of one duodenoscope and one gastroscope were freely accessible and could be brushed. The instrumentation and the air/water channels were contaminated with blood containing Enterococcus faecium as a test organism. After manual cleaning of the channels by flushing and, where possible, brushing, the recovery rates for the test organism were studied. The comparable rates for recovery of the test organism after cleaning of the instrumentation channels proved that the method used was reproducible. With regard to the air/water channels, the rate of micro-organisms in the cleaning solution recovered after flushing alone was a maximum of 3 % relative to the rate detected after brushing and flushing. The data collected in the study show that only flushing channels that are not freely accessible resulted in significantly lower (P<0.001) recovery rates for the test organism. In practice, this means that contamination may remain in the channels, and it shows that the design of a medical device has an important influence on the reprocessing of reusable instruments such as flexible endoscopes.

INFECTION CONTROL CONCEPTS IN CRITICAL CARE

Patients with critical illnesses requiring aggressive medical intervention are at risk of acquiring serious nosocomial infection that may lead to increases in medical expenditures, morbidity, and mortality. Infection control in this population entails continuous surveillance for hospital-acquired infection, with investigation of outbreaks. Policies for effective antibiotic utilization, disinfection of medical devices and hospital environment, and patient isolation may limit nosocomial infection in this population. Finally, an effective infection control program should protect the health care worker from hospital-acquired infections through educational programs, routine health surveillance, vaccinations, and post-exposure care.

Modeling disease transmission and its prevention by disinfection

Preface 1. The transmission and prevention of disease C. J. Hurst and P. A. Murphy 2. Strategies for modeling microbial colonization of the human body in health and disease R. A. Ross and M T Lee 3. Role of pathogen monitoring in microbial risk assessment J. B. Rose, J. T. Lisle and C. N. Haas 4. Estimating the risk of acquiring infectious disease from ingestion of water C. J. Hurst, R. M. Clark and S. E. Regli 5. Bacterial resistance to potable water disinfectants M. H. Stewart and B. H. Olson 6. Preventing foodborne infectious disease C. J. Hurst 7. Disinfection of microbial aerosols S. Clark and P. Scarpino 8. Transmission of viral infections through animate and inanimate surfaces and infection control through chemical disinfection S. A. Sattar and V. S. Springthorpe 9. The role of chemical disinfectants in controlling bacterial contaminants on environmental surfaces D. J. Gaber, T. M. Cusack and E. Scott 10. Sterilization and disinfection of medical devices A. B. Margolin and V. C. Chamberlain 11. Ultraviolet light disinfection of water and wastewater P. F. Roessler and B. F. Severin 12. Thermal inactivation of microorganisms G. Le Jean and G. Abraham Index.

The infection control information system of the Hospital Infections Program, Centers for Disease Control and Prevention

In December 1990 the Investigation and Prevention Branch, Hospital Infections Program, Centers for Disease Control and Prevention (CDC), developed the Hospital Infections Program infection control information system (HIP ICIS) to respond more efficiently to more than 200 public inquiries (telephone or written) that HIP receives daily. The HIP ICIS allows anyone with a Touch-Tone telephone, fax machine, or computer to access CDC information that answers the most commonly asked questions from infection control practitioners and other health care workers. The HIP ICIS has received approximately 56,608 inquiries; of these, 33% were about CDC guidelines on prevention and control of nosocomial infections, 25% about issues related to HIV, 16% about sterilization and disinfection of medical devices, 8% about methicillin-resistant Staphylococcus aureus, 3% about long-term care facilities, and 17% about miscellaneous topics (e.g., nosocomial infection rates, infection control courses, and ventilation, construction, and renovation of hospitals). The HIP ICIS is an efficient method of providing infection control guidance to the infection control community. In this article, we a) review the history of the HIP ICIS, b) present data on HIP ICIS usage, c) summarize the current HIP ICIS contents, and d) present step-by-step instructions on how to access the HIP ICIS.