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1.
PLoS One ; 16(6): e0250854, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34086691

RESUMO

The use of personal protective equipment (PPE) has been considered the most effective way to avoid the contamination of healthcare workers by different microorganisms, including SARS-CoV-2. A spray disinfection technology (chamber) was developed, and its efficacy in instant decontamination of previously contaminated surfaces was evaluated in two exposure times. Seven test microorganisms were prepared and inoculated on the surface of seven types of PPE (respirator mask, face shield, shoe, glove, cap, safety glasses and lab coat). The tests were performed on previously contaminated PPE using a manikin with a motion device for exposure to the chamber with biocidal agent (sodium hypochlorite) for 10 and 30s. In 96.93% of the experimental conditions analyzed, the percentage reduction was >99% (the number of viable cells found on the surface ranged from 4.3x106 to <10 CFU/mL). The samples of E. faecalis collected from the glove showed the lowest percentages reduction, with 86.000 and 86.500% for exposure times of 10 and 30 s, respectively. The log10 reduction values varied between 0.85 log10 (E. faecalis at 30 s in glove surface) and 9.69 log10 (E. coli at 10 and 30 s in lab coat surface). In general, E. coli, S. aureus, C. freundii, P. mirabilis, C. albicans and C. parapsilosis showed susceptibility to the biocidal agent under the tested conditions, with >99% reduction after 10 and 30s, while E. faecalis and P. aeruginosa showed a lower susceptibility. The 30s exposure time was more effective for the inactivation of the tested microorganisms. The results show that the spray disinfection technology has the potential for instant decontamination of PPE, which can contribute to an additional barrier for infection control of healthcare workers in the hospital environment.


Assuntos
COVID-19/prevenção & controle , Descontaminação , Controle de Infecções , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Roupa de Proteção , Dispositivos de Proteção Respiratória , SARS-CoV-2 , Bactérias , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/transmissão , COVID-19/epidemiologia , COVID-19/transmissão , Descontaminação/instrumentação , Descontaminação/métodos , Humanos
2.
Adv Colloid Interface Sci ; 292: 102435, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33971389

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the novel coronavirus disease 2019 (COVID-19), has caused a global pandemic on a scale not seen for over a century. Increasing evidence suggests that respiratory droplets and aerosols are likely the most common route of transmission for SARS-CoV-2. Since the virus can be spread by presymptomatic and asymptomatic individuals, universal face masking has been recommended as a straightforward and low-cost strategy to mitigate virus transmission. Numerous governments and public health agencies around the world have advocated for or mandated the wearing of masks in public settings, especially in situations where social distancing is not possible. However, the efficacy of wearing a mask remains controversial. This interdisciplinary review summarizes the current, state-of-the-art understanding of mask usage against COVID-19. It covers three main aspects of mask usage amid the pandemic: quality standards for various face masks and their fundamental filtration mechanisms, empirical methods for quantitatively determining mask integrity and particle filtration efficiency, and decontamination methods that allow for the reuse of traditionally disposable N95 and surgical masks. The focus is given to the fundamental physicochemical and engineering sciences behind each aspect covered in this review, providing novel insights into the current understanding of mask usage to curb COVID-19 spread.


Assuntos
/transmissão , Descontaminação/métodos , Máscaras , Aerossóis , Humanos , Máscaras/normas
3.
Am J Disaster Med ; 16(1): 67-73, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33954977

RESUMO

BACKGROUND: Chemical, biological, radiologic, nuclear, and explosive (CBRNE) events threaten the health and integrity of human populations across the globe. Effective decontamination is a central component of CBRNE disaster response. OBJECTIVE: This paper provides an objective determination of wet decontamination effectiveness through the use of a liquid-based contaminant proxy and describes the mobilization and adaptation of easily available materials for the needs of decontamination in pediatric victims. METHODS: In this in-situ disaster simulation conducted at a pediatric hospital, decontamination effectiveness was determined through a liquid-based contaminant proxy, and standard burn charts to systematically estimate affected total body surface area (TBSA) in 39 adult simulated patients. Two independent raters evaluated TBSA covered by the contaminant before and after decontamination. RESULTS: On average, simulated patients had 59 percent (95 percent CI [53, 65]) of their TBSA covered by the simulated contaminant prior to decontamination. Following a wet decontamination protocol, the average reduction in TBSA contamination was 81 percent (95 percent CI [74, 88]). There was high inter-rater reliability for TBSA assessment (intraclass correlation coefficient = 0.83, 95 percent CI [0.68, 0.92]. A modified infant bath was tested during the simulated decontamination of infant mannequins and thereafter integrated to the local protocol. CONCLUSION: Wet decontamination can remove more than 80 percent of the initial contaminant found on adult simulated patients. The use of a liquid-based visual tool as a contaminant proxy enables the inexpensive evaluation of decontamination performance in a simulated setting. This paper also describes an innovative, low-cost adaptation of a local decontamination protocol to better meet pediatric needs.


Assuntos
Queimaduras , Planejamento em Desastres , Desastres , Adulto , Criança , Descontaminação , Humanos , Lactente , Reprodutibilidade dos Testes
4.
Antimicrob Resist Infect Control ; 10(1): 82, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044893

RESUMO

Aerosolization may occur during reprocessing of medical devices. With the current coronavirus disease 2019 pandemic, it is important to understand the necessity of using respirators in the cleaning area of the sterile processing department. To evaluate the presence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) in the air of the sterile processing department during the reprocessing of contaminated medical devices. Air and surface samples were collected from the sterile processing department of two teaching tertiary hospitals during the reprocessing of respiratory equipment used in patients diagnosed with coronavirus disease 2019 and from intensive care units during treatment of these patients. SARS-CoV-2 was detected only in 1 air sample before the beginning of decontamination process. Viable severe acute respiratory syndrome coronavirus 2 RNA was not detected in any sample collected from around symptomatic patients or in sterile processing department samples. The cleaning of respiratory equipment does not cause aerosolization of SARS-CoV-2. We believe that the use of medical masks is sufficient while reprocessing medical devices during the coronavirus disease 2019 pandemic.


Assuntos
Aerossóis , Descontaminação , Reutilização de Equipamento , Equipamento de Proteção Individual/virologia , SARS-CoV-2/isolamento & purificação , Microbiologia do Ar , Estudos Transversais , Equipamentos e Provisões Hospitalares/virologia , RNA Viral/isolamento & purificação , Centros de Atenção Terciária , Ventiladores Mecânicos/virologia
5.
Antimicrob Resist Infect Control ; 10(1): 83, 2021 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-34051855

RESUMO

BACKGROUND: With the current SARS-CoV-2 pandemic, many healthcare facilities are lacking a steady supply of masks worldwide. This emergency situation warrants the taking of extraordinary measures to minimize the negative health impact from an insufficient supply of masks. The decontamination, and reuse of healthcare workers' N95/FFP2 masks is a promising solution which needs to overcome several pitfalls to become a reality. AIM: The overall aim of this article is to provide the reader with a quick overview of the various methods for decontamination and the potential issues to be taken into account when deciding to reuse masks. Ultraviolet germicidal irradiation (UVGI), hydrogen peroxide, steam, ozone, ethylene oxide, dry heat and moist heat have all been methods studied in the context of the pandemic. The article first focuses on the logistical implementation of a decontamination system in its entirety, and then aims to summarize and analyze the different available methods for decontamination. METHODS: In order to have a clear understanding of the research that has already been done, we conducted a systematic literature review for the questions: what are the tested methods for decontaminating N95/FFP2 masks, and what impact do those methods have on the microbiological contamination and physical integrity of the masks? We used the results of a systematic review on the methods of microbiological decontamination of masks to make sure we covered all of the recommended methods for mask reuse. To this systematic review we added articles and studies relevant to the subject, but that were outside the limits of the systematic review. These include a number of studies that performed important fit and function tests on the masks but took their microbiological outcomes from the existing literature and were thus excluded from the systematic review, but useful for this paper. We also used additional unpublished studies and internal communication from the University of Geneva Hospitals and partner institutions. RESULTS: This paper analyzes the acceptable methods for respirator decontamination and reuse, and scores them according to a number of variables that we have defined as being crucial (including cost, risk, complexity, time, etc.) to help healthcare facilities decide which method of decontamination is right for them. CONCLUSION: We provide a resource for healthcare institutions looking at making informed decisions about respirator decontamination. This informed decision making will help to improve infection prevention and control measures, and protect healthcare workers during this crucial time. The overall take home message is that institutions should not reuse respirators unless they have to. In the case of an emergency situation, there are some safe ways to decontaminate them.


Assuntos
COVID-19/prevenção & controle , Descontaminação/métodos , Reutilização de Equipamento , Respiradores N95/normas , SARS-CoV-2 , Óxido de Etileno/farmacologia , Pessoal de Saúde , Humanos , Peróxido de Hidrogênio/farmacologia , Respiradores N95/virologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/efeitos da radiação , Vapor , Raios Ultravioleta
6.
Artigo em Inglês | MEDLINE | ID: mdl-33946831

RESUMO

Aerosol generation and a wide range of pathogens originating from the oral cavity of the patient contaminate various surfaces of the dental clinic. The aim was to determine the efficacy of vaporized hydrogen peroxide fogging on pathogens related to the dental environment and its possible application in dentistry. PICOS statement (Population, Intervention, Comparison/Control, Outcome and Study design statement) was used in the review. Six electronic databases were searched for articles published from 2010 to 2020. Articles written in English reporting vaporized hydrogen peroxide on pathogens deemed to be relevant to the dental environment were assessed. The quality of the studies was assessed using the risk-of-bias assessment tool designed for the investigation of vaporized hydrogen peroxide application in dentistry. A total of 17 studies were included in the qualitative synthesis. The most commonly reported single bacterial pathogen was Methicillin-resistant Staphylococcus aureus in five studies, and the viruses Feline calicivirus, Human norovirus, and Murine norovirus were featured in three studies. The results of the studies reporting the log kill were sufficient for all authors to conclude that vaporized hydrogen peroxide generation was effective for the assessed pathogens. The studies that assessed aerosolized hydrogen peroxide found a greater log kill with the use of vaporized hydrogen peroxide generators. The overarching conclusion was that hydrogen peroxide delivered as vaporized hydrogen peroxide was an effective method to achieve large levels of log kill on the assessed pathogens. The hydrogen peroxide vapor generators can play a role in dental bio-decontamination. The parameters must be standardized and the efficacy assessed to perform bio-decontamination for the whole clinic. For vaporized hydrogen peroxide generators to be included in the dental bio-decontamination regimen, certain criteria should be met. These include the standardization and efficacy assessment of the vaporized hydrogen peroxide generators in dental clinics.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Norovirus , Vírus , Animais , Gatos , Descontaminação , Humanos , Peróxido de Hidrogênio , Camundongos
7.
Bioresour Technol ; 332: 125121, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33845314

RESUMO

Currently, there is a lack of an efficient, environmentally-benign and sustainable industrial decontamination strategy to steadily achieve improved astaxanthin production from Haematococcus pluvialis under large-scale outdoor conditions. Here, this study demonstrates for the first time that a CaCO3 biomineralization-based decontamination strategy (CBDS) is highly efficient in selectively eliminating algicidal microorganisms, such as bacteria and fungi, during large-scale H. pluvialis cultivation under autotrophic and mixotrophic conditions, thereby augmenting the astaxanthin productivity. Under outdoor AT and MT conditions, the average astaxanthin productivity of H. pluvialis using CBDS in a closed photobioreactor system was substantially increased by 14.85- (1.19 mg L-1 d-1) and 13.65-fold (2.43 mg L-1 d-1), respectively, compared to the contaminated H. pluvialis cultures. Given the exponentially increasing demand of astaxanthin, a natural anti-viral, anti-inflammatory, and antioxidant drug, CBDS will be a technology of interest in H. pluvialis-based commercial astaxanthin production which has been hindered by the serious biological contaminations.


Assuntos
Clorófitas , Biomassa , Biomineralização , Descontaminação , Xantofilas
8.
Artigo em Inglês | MEDLINE | ID: mdl-33802722

RESUMO

Planning for major incidents involving the release of hazardous chemicals has been informed by a multi-disciplinary research agenda which has sought to inform all aspects of emergency response, but with a focus in recent years on mass casualty decontamination. In vitro and human volunteer studies have established the relative effectiveness of different decontamination protocols for a range of chemical agents. In parallel, a programme of research has focused on communicating with and managing large numbers of contaminated casualties at the scene of an incident. We present an accessible overview of the evidence underpinning current casualty decontamination strategies. We highlight where research outcomes can directly inform response planning, including the critical importance of beginning the decontamination process as soon as possible, the benefits of early removal of contaminated clothing, the evidence under-pinning dry and wet decontamination and how effective communication is essential to any decontamination response. We identify a range of priority areas for future research including establishing the significance of the 'wash-in' effect and developing effective strategies for the decontamination of hair. We also highlight several areas of future methodological development, such as the need for novel chemical simulants. Whilst considerable progress has been made towards incorporating research outcomes into operational policy and practice, we outline how this developing evidence-base might be used to inform future iterations of mass casualty decontamination guidance.


Assuntos
Vazamento de Resíduos Químicos , Planejamento em Desastres , Incidentes com Feridos em Massa , Descontaminação , Emergências , Substâncias Perigosas , Humanos
9.
Int J Oral Maxillofac Implants ; 36(2): 271-280, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909716

RESUMO

PURPOSE: Assessment of in vitro efficacy of three different nonsurgical implant surface decontamination methods in three peri-implant bone defect simulation models. MATERIALS AND METHODS: A total of 180 implants were allocated to differently angulated (30, 60, and 90 degrees) peri-implant bone defect resin models, each covered by a mucosa mask. All implants were stained with indelible red color and assigned to one of the three defect models. In each simulated bone defect group, 20 implants were decontaminated for 2 minutes with a curette (CUR), sonic scaler (SOSC), or air-powder abrasion device (APA) with glycine powder. Photos were taken from both sides of each implant to measure the percentage of uncleaned implant surface area. Scanning electron microscopy (SEM) was used to assess the implant surface for morphologic damage. RESULTS: Among the three defect angulations, a significantly different cleaning efficacy (P < .001) for each treatment method was found (30 degrees: CUR [67.33%], SOSC [62.70%], APA [39.33%]; 60 degrees: CUR [61.59%], SOSC [54.31%], APA [23.91%]; 90 degrees: CUR [66.82%], SOSC [55.77%], APA [28.03%]). SEM did not show any considerable surface damage after APA treatment in comparison with after CUR or SOSC. CONCLUSION: Air-powder abrasion proved to be the most efficient nonsurgical treatment device for each type of defect in this in vitro model with the least noticeable surface change. No decontamination method resulted in complete cleaning of the color remnants on the implant surface.


Assuntos
Implantes Dentários , Peri-Implantite , Descontaminação , Humanos , Microscopia Eletrônica de Varredura , Peri-Implantite/terapia , Pós , Propriedades de Superfície , Titânio
10.
Artigo em Inglês | MEDLINE | ID: mdl-33802332

RESUMO

Background: Health care systems in the United States are continuously expanding and contracting spaces to treat patients with coronavirus disease 2019 (COVID-19) in intensive care units (ICUs). As a result, hospitals must effectively decontaminate and contain severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in constructed and deconstructed ICUs that care for patients with COVID-19. We assessed decontamination of a COVID-19 ICU and examined the containment efficacy of combined contact and droplet precautions in creating and maintaining a SARS-CoV-2-negative ICU "antechamber". Methods: To examine the efficacy of chemical decontamination, we used high-density, semi-quantitative environmental sampling to detect SARS-CoV-2 on surfaces in a COVID-19 ICU and COVID-19 ICU antechamber. Quantitative real-time polymerase chain reaction was used to measure viral RNA on surfaces. Viral location mapping revealed the distribution of viral RNA in the COVID-19 ICU and COVID-19 ICU antechamber. Results were further assessed using loop-mediated isothermal amplification. Results: We collected 224 surface samples pre-decontamination and 193 samples post-decontamination from a COVID-19 ICU and adjoining COVID-19 ICU antechamber. We found that 46% of antechamber objects were positive for SARS-CoV-2 pre-decontamination despite the construction of a swinging door barrier system, implementation of contact precautions, and installation of high-efficiency particulate air filters. The object positivity rate reduced to 32.1% and viral particle rate reduced by 95.4% following decontamination. Matched items had an average of 432.2 ± 2729 viral copies/cm2 pre-decontamination and 19.2 ± 118 viral copies/cm2 post-decontamination, demonstrating significantly reduced viral surface distribution (p < 0.0001). Conclusions: Environmental sampling is an effective method for evaluating decontamination protocols and validating measures used to contain SARS-CoV-2 viral particles. While chemical decontamination effectively removes detectable viral RNA from surfaces, our approach to droplet/contact containment with an antechamber was not highly effective. These data suggest that hospitals should plan for the potential of aerosolized virions when creating strategies to contain SARS-CoV-2.


Assuntos
Descontaminação , Humanos , Unidades de Terapia Intensiva , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico
11.
Mar Drugs ; 19(4)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923695

RESUMO

Biofilm in dental unit water lines may pose a health risk to patients and dental practitioners. An AdiC-like quorum quenching enzyme, YtnP, was cloned from a deep-sea probiotic Bacillus velezensis, and heterologously expressed in E. coli to examine the application on the improvement of hygiene problems caused by biofilm infection of Pseudomonas aeruginosa in dental units. Pseudomonas bacteria were isolated from dental chair units and used to grow static biofilms in the laboratory. A water filter system was designed to test the antifouling activity of YtnP in Laboratory, to simulate the biofilm contamination on water filter in dental unit water lines. The results demonstrated that the enzyme of YtnP was able to degrade the N-acyl homoserine lactones, significantly inhibited the EPS generation, biofilm formation, and virulence factors production (pyocyanin and rhamnolipid) of P. aeruginosa, and was efficient on the antifouling against P. aeruginosa. The findings in this study indicated the possibility of YtnP as novel disinfectant reagent for hygiene treatment in dental units.


Assuntos
Antibacterianos/farmacologia , Bacillus/enzimologia , Proteínas de Bactérias/farmacologia , Hidrolases de Éster Carboxílico/farmacologia , Descontaminação , Instituições Odontológicas , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Microbiologia da Água , Purificação da Água , Abastecimento de Água , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/isolamento & purificação , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Hidrolases de Éster Carboxílico/isolamento & purificação , Pseudomonas aeruginosa/crescimento & desenvolvimento
12.
J Hosp Infect ; 112: 108-113, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33864891

RESUMO

BACKGROUND: The presence of coronaviruses on surfaces in the patient environment is a potential source of indirect transmission. Manual cleaning and disinfection measures do not always achieve sufficient removal of surface contamination. This increases the importance of automated solutions in the context of final disinfection of rooms in the hospital setting. Ozone is a highly effective disinfectant which, combined with high humidity, is an effective agent against respiratory viruses. Current devices allow continuous nebulization for high room humidity as well as ozone production without any consumables. AIM: In the following study, the effectiveness of a fully automatic room decontamination system based on ozone was tested against bacteriophage Φ6 (phi 6) and bovine coronavirus L9, as surrogate viruses for the pandemic coronavirus SARS-CoV-2. METHODS: For this purpose, various surfaces (ceramic tile, stainless steel surface and furniture board) were soiled with the surrogate viruses and placed at two different levels in a gas-tight test room. After using the automatic decontamination device according to the manufacturer's instructions, the surrogate viruses were recovered from the surfaces and examined by quantitative cultures. Then, reduction factors were calculated. FINDINGS: The ozone-based room decontamination device achieved virucidal efficacy (reduction factor >4 log10) against both surrogate organisms regardless of the different surfaces and positions confirming a high activity under the used conditions. CONCLUSION: Ozone is highly active against SARS-CoV-2 surrogate organisms. Further investigations are necessary for a safe application and efficacy in practice as well as integration into routine processes.


Assuntos
Automação/instrumentação , Desinfetantes/farmacologia , Desinfecção/instrumentação , Desinfecção/métodos , Ozônio/farmacologia , Animais , Bacteriófagos/efeitos dos fármacos , Bovinos , Coronavirus Bovino/efeitos dos fármacos , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/virologia , Descontaminação/instrumentação , Descontaminação/métodos , Equipamentos e Provisões Hospitalares/virologia , Hospitais , Humanos , /efeitos dos fármacos
13.
Sci Total Environ ; 784: 147108, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-33892326

RESUMO

Contaminant removal from wastewater using natural biosorbents has been widely studied as a suitable and environmentally benign alternative for conventional techniques. Currently, researchers are working on various biomass-based composites for wastewater remediation to improve the performance of natural biosorbents. This review takes into focus a wide range of biomass-based composites like hydrogel composites, metal oxide composites, magnetic composites, polymer composites, carbon nanotubes (CNTs) and graphene composites, metal organic framework composites (MOFs) and clay composites for the removal of various contaminants from wastewater. It is evident from the literature survey that the composite fabrication involves the modification of morphological and textural features of the biomass which results in significant enhancement of adsorption capacity. Apart from this, regeneration of the used biomass-based composite is also studied in depth in order to overcome the problem of solid waste generation. This review would prove to be beneficial for researchers who are currently focusing on the development of cost-effective, easily available, recyclable biomass-based composites with enhanced adsorption capacities for wastewater treatment.


Assuntos
Nanotubos de Carbono , Poluentes Químicos da Água , Adsorção , Biomassa , Descontaminação , Águas Residuárias
14.
Water Sci Technol ; 83(7): 1662-1676, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33843750

RESUMO

In the present study, adsorption of colour and other pollutants from agro-based paper mill effluent onto fabricated coal fly ash nanoparticles (CFA-N) have been investigated. Response surface methodology was applied to evaluate the operational conditions for maximum ouster of colour from effluent by nano structured CFA-N. Maximum reduction in colour (92.45%) and other pollutants were obtained at optimum conditions: 60 min interaction time, 60 g/L adsorbent dosage and 80 rpm agitation rate. The regression coefficient values (adjusted R2 = 0.7169; predicted R2 = 0.7539) established harmony between predicted and the experimental data. The adsorption equilibrium results matched perfectly with both Langmuir and Freundlich isotherms with maximum adsorption capacity of 250 platinum-cobalt/g. Additionally, the efficacy of CFA-N was also assessed in a continuous column mode. Furthermore, the feasibility of treated effluent for irrigation purpose was checked by growing the plant Solanum lycopersicum. Overall, the findings demonstrated the outstanding role of inexpensive and abundantly available CFA-N in treatment of paper mill effluent to the required compliance levels.


Assuntos
Cinza de Carvão , Poluentes Químicos da Água , Adsorção , Carvão Mineral , Descontaminação , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
15.
Medicine (Baltimore) ; 100(13): e25285, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33787613

RESUMO

ABSTRACT: Surface treatment of medical devices may be a way of avoiding the need for replacement of these devices and the comorbidities associated with infection. The aim of this study was to evaluate whether pre- and postcontamination washing of 2 prostheses with different textures can decrease bacterial contamination.The following microorganisms were evaluated: Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Enterococcus faecalis. Silicone and expanded polytetrafluoroethylene vascular prostheses were used and divided into 3 groups: prostheses contaminated; prostheses contaminated and treated before contamination; and prostheses contaminated and treated after contamination. Treatments were performed with antibiotic solution, chlorhexidine and lidocaine. After one week of incubation, the prostheses were sown in culture medium, which was incubated for 48 hours. The area of colony formation was evaluated by fractal dimension, an image analysis tool.The antibiotic solution inhibited the growth of S epidermidis and chlorhexidine decrease in 53% the colonization density for S aureus in for both prostheses in the pre-washing. In postcontamination washing, the antibiotic solution inhibited the growth of all bacteria evaluated; there was a 60% decrease in the colonization density of S aureus and absence of colonization for E faecalis with chlorhexidine; and lidocaine inhibited the growth of S aureus in both prostheses.Antibiotic solution showed the highest efficiency in inhibiting bacterial growth, especially for S epidermidis, in both washings. Lidocaine was able to reduce colonization by S aureus in post-contamination washing, showing that it can be used as an alternative adjuvant treatment in these cases.


Assuntos
Prótese Vascular/microbiologia , Descontaminação/métodos , Desinfetantes/administração & dosagem , Infecções Relacionadas à Prótese/prevenção & controle , Antibacterianos/administração & dosagem , Contagem de Colônia Microbiana , Enterococcus faecalis/crescimento & desenvolvimento , Humanos , Lidocaína/administração & dosagem , Politetrafluoretileno , Desenho de Prótese , Infecções Relacionadas à Prótese/microbiologia , Proteus mirabilis/crescimento & desenvolvimento , Silicones , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento
16.
PLoS One ; 16(3): e0248487, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33735216

RESUMO

A gas-phase Advanced Oxidation Process (gAOP) was evaluated for decontaminating N95 and surgical masks. The continuous process was based on the generation of hydroxyl-radicals via the UV-C (254 nm) photo-degradation of hydrogen peroxide and ozone. The decontamination efficacy of the gAOP was dependent on the orientation of the N95 mask passing through the gAOP unit with those positioned horizontally enabling greater exposure to hydroxyl-radicals compared to when arranged vertically. The lethality of gAOP was independent of the applied hydrogen peroxide concentration (2-6% v/v) but was significantly (P<0.05) higher when H2O2 was introduced into the unit at 40 ml/min compared to 20 ml/min. A suitable treatment for N95 masks was identified as 3% v/v hydrogen peroxide delivered into the gAOP reactor at 40 ml/min with continuous introduction of ozone gas and a UV-C dose of 113 mJ/cm2 (30 s processing time). The treatment supported >6 log CFU decrease in Geobacillus stearothermophilus endospores, > 8 log reduction of human coronavirus 229E, and no detection of Escherichia coli K12 on the interior and exterior of masks. There was no negative effect on the N95 mask fitting or particulate efficacy after 20 passes through the gAOP system. No visual changes or hydrogen peroxide residues were detected (<1 ppm) in gAOP treated masks. The optimized gAOP treatment could also support >6 log CFU reduction of endospores inoculated on the interior or exterior of surgical masks. G. stearothermophilus Apex spore strips could be applied as a biological indicator to verify the performance of gAOP treatment. Also, a chemical indicator based on the oxidative polymerization of pyrrole was found suitable for reporting the generation of hydroxyl-radicals. In conclusion, gAOP is a verifiable treatment that can be applied to decontaminate N95 and surgical masks without any negative effects on functionality.


Assuntos
Descontaminação/métodos , Máscaras/virologia , Gases/química , Humanos , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Oxirredução , Ozônio/química , Fotólise
17.
Emerg Infect Dis ; 27(4): 1229-1231, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33755002

RESUMO

Severe acute respiratory syndrome coronavirus 2 can persist on surfaces, suggesting possible surface-mediated transmission of this pathogen. We found that fomites might be a substantial source of transmission risk, particularly in schools and child daycares. Combining surface cleaning and decontamination with mask wearing can help mitigate this risk.


Assuntos
Transmissão de Doença Infecciosa/prevenção & controle , Fômites/virologia , Controle de Infecções , /isolamento & purificação , Idoso , Número Básico de Reprodução , /prevenção & controle , /virologia , Criança , Creches/normas , Descontaminação/métodos , Contaminação de Equipamentos/prevenção & controle , Desinfecção das Mãos/métodos , Humanos , Controle de Infecções/instrumentação , Controle de Infecções/métodos , Máscaras , Casas de Saúde/normas , Instituições Acadêmicas/normas , Estados Unidos/epidemiologia
18.
JAMA ; 325(13): 1296-1317, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33656543

RESUMO

Importance: The COVID-19 pandemic has resulted in a persistent shortage of personal protective equipment; therefore, a need exists for hospitals to reprocess filtering facepiece respirators (FFRs), such as N95 respirators. Objective: To perform a systematic review to evaluate the evidence on effectiveness and feasibility of different processes used for decontaminating N95 respirators. Evidence Review: A search of PubMed and EMBASE (through January 31, 2021) was completed for 5 types of respirator-decontaminating processes including UV irradiation, vaporized hydrogen peroxide, moist-heat incubation, microwave-generated steam, and ethylene oxide. Data were abstracted on process method, pathogen removal, mask filtration efficiency, facial fit, user safety, and processing capability. Findings: Forty-two studies were included that examined 65 total types of masks. All were laboratory studies (no clinical trials), and 2 evaluated respirator performance and fit with actual clinical use of N95 respirators. Twenty-seven evaluated UV germicidal irradiation, 19 vaporized hydrogen peroxide, 9 moist-heat incubation, 10 microwave-generated steam, and 7 ethylene oxide. Forty-three types of N95 respirators were treated with UV irradiation. Doses of 1 to 2 J/cm2 effectively sterilized most pathogens on N95 respirators (>103 reduction in influenza virus [4 studies], MS2 bacteriophage [3 studies], Bacillus spores [2 studies], Escherichia virus MS2 [1 study], vesicular stomatitis virus [1 study], and Middle East respiratory syndrome virus/SARS-CoV-1 [1 study]) without degrading respirator components. Doses higher than 1.5 to 2 J/cm2 may be needed based on 2 studies demonstrating greater than 103 reduction in SARS-CoV-2. Vaporized hydrogen peroxide eradicated the pathogen in all 7 efficacy studies (>104 reduction in SARS-CoV-2 [3 studies] and >106 reduction of Bacillus and Geobacillus stearothermophilus spores [4 studies]). Pressurized chamber systems with higher concentrations of hydrogen peroxide caused FFR damage (6 studies), while open-room systems did not degrade respirator components. Moist heat effectively reduced SARS-CoV-2 (2 studies), influenza virus by greater than 104 (2 studies), vesicular stomatitis virus (1 study), and Escherichia coli (1 study) and preserved filtration efficiency and facial fit for 11 N95 respirators using preheated containers/chambers at 60 °C to 85 °C (5 studies); however, diminished filtration performance was seen for the Caron incubator. Microwave-generated steam (1100-W to 1800-W devices; 40 seconds to 3 minutes) effectively reduced pathogens by greater than 103 (influenza virus [2 studies], MS2 bacteriophage [3 studies], and Staphylococcus aureus [1 study]) and maintained filtration performance in 10 N95 respirators; however, damage was noted in least 1 respirator type in 4 studies. In 6 studies, ethylene oxide preserved respirator components in 16 N95 respirator types but left residual carcinogenic by-product (1 study). Conclusions and Relevance: Ultraviolet germicidal irradiation, vaporized hydrogen peroxide, moist heat, and microwave-generated steam processing effectively sterilized N95 respirators and retained filtration performance. Ultraviolet irradiation and vaporized hydrogen peroxide damaged respirators the least. More research is needed on decontamination effectiveness for SARS-CoV-2 because few studies specifically examined this pathogen.


Assuntos
Descontaminação/métodos , Reutilização de Equipamento , Esterilização/métodos , Óxido de Etileno , Temperatura Alta , Humanos , Peróxido de Hidrogênio , Vapor , Esterilização/economia , Raios Ultravioleta
19.
Water Sci Technol ; 83(5): 985-992, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33724930

RESUMO

Active chlorine decontaminants like hypochlorite are used to destroy chemical warfare agents (CWAs) such as HD, VX and GD due to the former's strong oxidation capacity and high nucleophilicity. In this paper, experiments were performed to identify the main factors affecting agent recovery from decon water. Based on the results, a method to recover residual CWAs from hypochlorite decon water before quantitative determination by GC was developed. The results showed that the extraction solvent was a critical determinant of high CWA recovery. Dichloromethane was more suitable than petroleum either, especially for samples containing GD or low residual CWAs. For VX-containing samples, the use of an alkali solution improved VX recovery. Neutralization was also important for a high CWA recovery, especially for samples with low CWA concentrations and/or strong decontaminant reactivity. The use of 15% sodium sulfite as the neutralization solution gave the best results for hypochlorite decon water. When the optimized conditions of simultaneous sodium sulfite neutralization and dichloromethane extraction were used, the recovery of HD, VX and GD in hypochlorite decon water was greater than 85% at a concentration range of 20 mg/L to 10,000 mg/L.


Assuntos
Substâncias para a Guerra Química , Ácido Hipocloroso , Substâncias para a Guerra Química/análise , Descontaminação , Compostos Organotiofosforados , Água
20.
Rev Gaucha Enferm ; 42(spe): e20200146, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33787720

RESUMO

OBJECTIVE: To evaluate the protocols on decontamination/reuse of N95 masks available in the literature in times of the Covid-19 pandemic. METHOD: Integrative literature review, in the period from 2010 to 2020, on the databases MEDLINE/PubMed, Science Direct, Cochrane, SAGE journals, Web of Science, Scopus, Embase and Wiley, with the descriptors Masks AND Respiratory protective devices; Mask OR N95 AND Covid-19; N95 AND Respirators; Decontamination AND N95 AND Coronavirus; Facemask OR Pandemic. RESULTS: Twelve studies were included, of which 3 (30.0%) used ultraviolet germicidal irradiation and indicated mask deterioration between 2 and 10 cycles, 4 (40.0%) used hydrogen peroxide vapor, and seal loss varied from 5 to 20 cycles, 4 (33.3%) evaluated the structural integrity of the N95 mask through visual inspection and 6 (54.4%), its filtration efficiency. CONCLUSION: Reuse strategies to overcome a shortage of devices in the face of the pandemic challenge the current concept for good practices in health-product processing.


Assuntos
/epidemiologia , Descontaminação/métodos , Reutilização de Equipamento , Pandemias , Anti-Infecciosos Locais , Desinfetantes , Desinfecção/métodos , Óxido de Etileno , Filtração/instrumentação , Humanos , Peróxido de Hidrogênio , Raios Ultravioleta
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