A study of the effect of clinical washing decontamination process on corrosion resistance of Martensitic Stainless Steel 420

Corrosion of surgical instruments provides a seat for contamination and prevents proper sterilisation, placing both patients and medical staff at risk of infection. Corrosion can also compromise the structural integrity of instruments and lead to mechanical failure in use. It is essential to understand the various factors affecting corrosion resistance of surgical instruments and how it can be minimised.This paper investigates the effect on corrosion resistance from the clinical washing decontamination (WD) process, specifically by studying the changes in surface roughness and Cr/Fe ratio. Results indicate that the WD process provides a positive effect on smooth polished samples, while a lesser positive effect was observed on rough reflection reduced samples.</p

Increasing the frequency of hand washing by healthcare workers does not lead to commensurate reductions in staphylococcal infection in a hospital ward

Hand hygiene is generally considered to be the most important measure that can be applied to prevent the spread of healthcare-associated infection (HAI). Continuous emphasis on this intervention has lead to the widespread opinion that HAI rates can be greatly reduced by increased hand hygiene compliance alone. However, this assumes that the effectiveness of hand hygiene is not constrained by other factors and that improved compliance in excess of a given level, in itself, will result in a commensurate reduction in the incidence of HAI. However, several researchers have found the law of diminishing returns to apply to hand hygiene, with the greatest benefits occurring in the first 20% or so of compliance, and others have demonstrated that poor cohorting of nursing staff profoundly influences the effectiveness of hand hygiene measures. Collectively, these findings raise intriguing questions about the extent to which increasing compliance alone can further reduce rates of HAI. In order to investigate these issues further, we constructed a deterministic Ross-Macdonald model and applied it to a hypothetical general medical ward. In this model the transmission of staphylococcal infection was assumed to occur after contact with the transiently colonized hands of HCWs, who, in turn, acquire contamination only by touching colonized patients. The aim of the study was to evaluate the impact of imperfect hand cleansing on the transmission of staphylococcal infection and to identify, whether there is a limit, above which further hand hygiene compliance is unlikely to be of benefit. The model demonstrated that if transmission is solely via the hands of HCWs, it should, under most circumstances, be possible to prevent outbreaks of staphylococcal infection from occurring at a hand cleansing frequencies <50%, even with imperfect hand hygiene. The analysis also indicated that the relationship between hand cleansing efficacy and frequency is not linear - as efficacy decreases, so the hand cleansing frequency required to ensure R0<1 increases disproportionately. Although our study confirmed hand hygiene to be an effective control measure, it demonstrated that the law of diminishing returns applies, with the greatest benefit derived from the first 20% or so of compliance. Indeed, our analysis suggests that there is little benefit to be accrued from very high levels of hand cleansing and that in most situations compliance >40% should be enough to prevent outbreaks of staphylococcal infection occurring, if transmission is solely via the hands of HCWs. Furthermore we identified a non-linear relationship between hand cleansing efficacy and frequency, suggesting that it is important to maximise the efficacy of the hand cleansing process

Efficiency of disinfectants against Rotavirus in the presence and absence of organic matter

Rotavirus is an enteric pathogen that causes morbidity and mortality in young mammals, including pigs. Outbreaks of rotavirus on commercial farms have a significant economic impact in terms of losses in production. Effective cleaning and disinfection along with good farm management can reduce rotavirus contamination in the environment, and decrease the chance of outbreaks of disease. This study investigated the efficacy of six commercial disinfectants against MS2 bacteriophage and Group A porcine rotavirus, in the presence of high and low levels of organic matter to simulate the farm environment. A phenolic-based disinfectant (Bi-OO-cyst) was effective at all levels of organic matter concentrations. Iodophore based disinfectants did not have a significant virucidal effect against rotavirus under any conditions. For peroxygen compound-based disinfectants and glutaraldehyde-based disinfectants, organic matter load made a significant difference in reducing efficacy. This highlights the importance of thorough cleaning with detergent before disinfection to reduce viral contamination on the farm and decrease rotavirus disease incidence in pigs

A Review of Single-Use and Reusable Gowns and Drapes in Health Care

Gowns and drapes are used widely in healthcare facilities. Gowns have been used to minimize the risk of disease acquisition by healthcare providers, to reduce the risk of patient-to-patient transmission, and during invasive procedures to aid in maintaining a sterile field. Drapes have been used during invasive procedures to maintain the sterility of environmental surfaces, equipment, and patients. This article reviews the use of gowns and drapes in healthcare facilities, including the characteristics, costs, benefits, and barrier effectiveness of single-use and reusable products. Currently, gowns protect healthcare personnel performing invasive procedures from contact with bloodborne pathogens. Although gowns have been recommended to prevent patient-to-patient transmission in certain settings (eg, neonatal intensive care unit) and for certain patients (eg, those infected with vancomycin-resistant enterococci), scientific studies have produced mixed results of their efficacy. While appropriate use of drapes during invasive procedures is recommended widely as an aid in minimizing contamination of the operative field, the efficacy of this practice in reducing surgical-site infections has not been assessed by scientific studies. Based on an evaluation of the functional requirements, environmental impact, and economics of gowns and drapes, clear superiority of either reusable or single-use gowns and drapes cannot be demonstrated. The selection of particular gowns and drapes by individual healthcare facilities requires an assessment of the facility's requirements, available products, and costs and should be based on the desired characteristics of an ideal gown or drape as defined in this paper

Efficacy of Improved Hydrogen Peroxide against Important Healthcare-Associated Pathogens

This study was designed to test in vitro efficacy of 2 improved hydrogen peroxide (HP) products against 3 standard HP products and 1 quaternary ammonium compound. Improved HP is significantly superior to standard HP at the same concentration and can be used for disinfection of environmental surfaces or noncritical patient care items

Efficacy of a Washer-Disinfector in Eliminating Healthcare-Associated Pathogens from Surgical Instruments

This study was designed to test the efficacy of a washer-disinfector in eliminating selected healthcare-associated pathogens from surgical instruments. Our results showed that a washer-disinfector was extremely effective in eliminating microorganisms (&gt;7-log 10 reduction), including vegetative and spore-forming bacteria, from experimentally contaminated instruments. The washer-disinfector remained effective in eliminating microorganisms in the absence of enzymatic cleaners and detergents. Infect Control Hosp Epidemiol 2014;35(7):883–88

Effectiveness of a hydrogen peroxide mist (Trophon) system in inactivating healthcare pathogens on surface and endocavitary probes

they are considered noncritical and require at least low-level disinfection between patients. Endocavitary probes (eg, transvaginal, transrectal, or transesophageal probes) are considered semicritical because they have direct contact with mucous membranes (eg, vagina, rectum, or pharynx) or nonintact skin. While one could argue that the use of the probe cover changes the category for the endocavitary probe, the Centers for Disease Control and Prevention (CDC) guideline for disinfection and sterilization recommends that a new condom/probe cover should be used for each patient, and because condoms/probe covers and low-level disinfection may fail, high-level disinfection of the probe should be performed. The relevance of this recommendation is reinforced by the finding that sterile ultrasound probe covers and condoms can have a perforation rate from 0% to 81% before and after use. These studies underscore the need for high-level disinfection of endocavitary probes between examinations.Ultrasound probes are used in sonographic scanning and are commonly used as either surface probes or endocavitary probes. Surface probes are used on intact skin, such as the abdome

Antimicrobial mechanisms of ortho-phthalaldehyde action

Biocides generally have multiple biochemical targets. Such a feature easily entangles the analysis of the mechanisms of antimicrobial action. In this study, the action of the dialdehyde biocide ortho-phtalaldehyde (OPA), on bacteria, was investigated using the Gram-negative Pseudomonas fluorescens. The targets of the biocide action were studied using different bacterial physiological indices. The respiratory activity, membrane permeabilization, physico-chemical characterization of the bacterial surfaces, outer membrane proteins (OMP) expression, concomitant influence of pH, contact time and presence of bovine serum albumin (BSA) on respiratory activity, morphological changes and OPA-DNA interactions were assessed for different OPA concentrations. With the process conditions used, the minimum inhibitory concentration was 1500 mg/l, the concentration to promote total loss of bacterial culturability was 65 mg/l and the concentration needed to inactivate respiratory activity was 80 mg/l. These data are evidence that culturability and respiratory activity were markedly affected by the biocide. OPA lead, moreover, to a significant change in cell surface hydrophobicity and induced propidium iodide uptake. Such results suggest cytoplasmic membrane damage, although no release of ATP was detected. At pH 5, the bactericidal action of OPA was stronger, though not influenced by BSA presence. Nevertheless, at pH 9, BSA noticeably (p < 0.05) impaired biocide action. A time- dependent effect in OPA action was evident when contemplating respiratory activity variation, mainly for the lower exposure times. Scanning electron microscopy allowed to detect bacterial morphological changes, translated on cellular elongation, for OPA concentrations higher than 100 mg/l. Interferences at DNA level were, however, restricted to extreme biocide concentrations. The overall bactericidal events occurred without detectable OMP expression changes. In conclusion, the results indicated a sequence of events responsible for the antimicrobial action of OPA: it binds to membrane receptors due to cross-linkage; impairs the membrane functions allowing the biocide to enter through the permeabilized membrane; it interacts with intracellular reactive molecules, such as RNA, compromising the growth cycle of the cells and, at last, with DNA.Fundação para a Ciência e a Tecnologia (FCT

‘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