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1.
Artigo em Inglês | MEDLINE | ID: mdl-34208169

RESUMO

The increasing number of endoscopic procedures performed and their increasing invasiveness mean that endoscopy of the gastrointestinal tract is associated with the risk of transmitting pathogenic microorganisms through infected equipment or contact with other patients and medical staff. In order to ensure protection of the health of both patients and medical staff, endoscopy laboratories should meet high hygiene standards. The results of tests of the microbiological cleanliness of surfaces and equipment of an endoscopic examination laboratory performed in the period from January to December 2019 at the Provincial Clinical Hospital No. 2 in Rzeszow were assessed retrospectively. Samples for testing were collected by swabbing from places where microbiological contamination was the most likely and cleaning was the most difficult. In the analyzed period, a total of 86 samples were collected for microbiological tests, of which positive results accounted for 6.9%. Positive results were obtained mainly from swabs collected from wet surfaces (66.7%). Most of the isolated microorganisms were Gram-negative bacteria (66.7% of all positive tests) and they were: Acinetobacter junii, Ralstonia pickettii, and Achromobacter denitrificans. The condition of the microbiological cleanliness of the surfaces and equipment of the endoscopic examination laboratory was satisfactory. A very low level of microbiological contamination of the tested items indicates occasional shortcomings in the decontamination processes. Since microorganisms isolated from the collected samples may be the cause of infection in patients and medical personnel, it is necessary to verify the decontamination procedures applied and to continue periodic microbiological monitoring of their effectiveness.


Assuntos
Endoscopia , Laboratórios , Acinetobacter , Contaminação de Equipamentos , Humanos , Polônia , Estudos Retrospectivos
2.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34259620

RESUMO

Introduction. The presence of Candida biofilms in medical devices is a concerning and important clinical issue for haemodialysis patients who require constant use of prosthetic fistulae and catheters.Hypothesis/Gap Statement. This prolonged use increases the risk of candidaemia due to biofilm formation. PH151 and clioquinol are 8-hydroxyquinoline derivatives that have been studied by our group and showed interesting anti-Candida activity.Aim. This study evaluated the biofilm formation capacity of Candida species on polytetrafluoroethylene (PTFE) and polyurethane (PUR) and investigated the synergistic effects between the compounds PH151 and clioquinol and fluconazole, amphotericin B and caspofungin against biofilm cells removed from those materials. Further, the synergistic combination was evaluated in terms of preventing biofilm formation on PTFE and PUR discs.Methodology. Susceptibility testing was performed for planktonic and biofilm cells using the broth microdilution method. The checkerboard method and the time-kill assay were used to evaluate the interactions between antifungal agents. Antibiofilm activity on PTFE and PUR materials was assessed to quantify the prevention of biofilm formation.Results. Candida albicans, Candida glabrata and Candida tropicalis showed ability to form biofilms on both materials. By contrast, Candida parapsilosis did not demonstrate this ability. Synergistic interaction was observed when PH151 was combined with fluconazole in 77.8 % of isolates and this treatment was shown to be concentration- and time-dependent. On the other hand, indifferent interactions were predominantly observed with the other combinations. A reduction in biofilm formation on PUR material of more than 50 % was observed when using PH151 combined with fluconazole.Conclusion. PH151 demonstrated potential as a local treatment for use in a combination therapy approach against Candida biofilm formation on haemodialysis devices.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Contaminação de Equipamentos/prevenção & controle , Fluconazol/farmacologia , Sulfonamidas/farmacologia , Candida/classificação , Candida/fisiologia , Candidíase/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Oxiquinolina/farmacologia , Diálise Renal
3.
Artigo em Inglês | MEDLINE | ID: mdl-34281001

RESUMO

Preventable neonatal deaths due to prematurity, perinatal events, and infections are the leading causes of under-five mortality. The vast majority of these deaths are in resource-limited areas. Deaths due to infection have been associated with lack of access to clean water, overcrowded nurseries, and improper disinfection (reprocessing) of equipment, including vital resuscitation equipment. Reprocessing has recently come to heightened attention, with the COVID-19 pandemic bringing this issue to the forefront across all economic levels; however, it is particularly challenging in low-resource settings. In 2015, Eslami et al. published a letter to the editor in Resuscitation, highlighting concerns about the disinfection of equipment being used to resuscitate newborns in Kenya. To address the issue of improper disinfection, the global health nongovernment organization PATH gathered a group of experts and, due to lack of best-practice evidence, published guidelines with recommendations for reprocessing of neonatal resuscitation equipment in low-resource areas. The guidelines follow the gold-standard principle of high-level disinfection; however, there is ongoing concern that the complexity of the guideline would make feasibility and sustainability difficult in the settings for which it was designed. Observations from hospitals in Kenya and Malawi reinforce this concern. The purpose of this review is to discuss why proper disinfection of equipment is important, why this is challenging in low-resource settings, and suggestions for solutions to move forward.


Assuntos
COVID-19 , Desinfecção , Contaminação de Equipamentos , Feminino , Humanos , Recém-Nascido , Quênia , Malaui , Pandemias , Gravidez , Ressuscitação , SARS-CoV-2
4.
BMC Infect Dis ; 21(1): 681, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34256724

RESUMO

BACKGROUND: Mobile phones used by healthcare workers (HCWs) are contaminated with bacteria, but the posterior surface of smartphones has rarely been studied. The aim of this study was to compare the prevalence of microbial contamination of touchscreens and posterior surfaces of smartphones owned by HCWs. METHODS: A cross-sectional study of smartphones used by HCWs employed at two intensive care units at a Japanese tertiary care hospital was performed. Bacteria on each surface of the smartphones were isolated separately. The primary outcomes were the prevalence of microbial contamination on each surface of smartphones and associated bacterial species. Fisher's exact test was used to compare dichotomous outcomes. RESULTS: Eighty-four HCWs participated in this study. The touchscreen and posterior surface were contaminated in 27 (32.1%) and 39 (46.4%) smartphones, respectively, indicating that the posterior surface was more frequently contaminated (p = 0.041). Bacillus species and coagulase-negative staphylococci were isolated from each surface of the smartphones. CONCLUSIONS: The posterior surface of a smartphone was more significantly contaminated with bacteria than the touchscreen, regardless of having a cover. Therefore, routine cleaning of the posterior surface of a smartphone is recommended.


Assuntos
Bacillus/isolamento & purificação , Contaminação de Equipamentos , Pessoal de Saúde/estatística & dados numéricos , Smartphone , Staphylococcus/isolamento & purificação , Infecção Hospitalar/prevenção & controle , Estudos Transversais , Contaminação de Equipamentos/prevenção & controle , Contaminação de Equipamentos/estatística & dados numéricos , Humanos , Controle de Infecções/métodos , Unidades de Terapia Intensiva/estatística & dados numéricos , Japão , Prevalência
5.
Front Cell Infect Microbiol ; 11: 670211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222041

RESUMO

The contamination of dental unit waterlines (DUWLs) is a serious problem and directly affects the dental care. This study aims to explore the microbial community of biofilm in DUWL from different specialties and investigate the associated factors. A total of 36 biofilm samples from 18 DUWL of six specialties (i.e., prosthodontics, orthodontics, pediatrics, endodontics, oral surgery, and periodontics) at two time points (i.e., before and after daily dental practice) were collected with a novel method. Genomic DNA of samples was extracted, and then 16S ribosomal DNA (rDNA) (V3-V4 regions) and ITS2 gene were amplified and sequenced. Kruskal-Wallis and Wilcoxon rank test were adopted for statistical analysis. Microbial community with high diversity of bacteria (631 genera), fungi (193 genera), and viridiplantae was detected in the biofilm samples. Proteobacteria was the dominant bacteria (representing over 65.74-95.98% of the total sequences), and the dominant fungi was Ascomycota (93.9-99.3%). Microorganisms belonging to multiple genera involved in human diseases were detected including 25 genera of bacteria and eight genera of fungi, with relative abundance of six genera over 1% (i.e., Acinetobacter, Pseudomonas, Enterobacter, Aspergillus, Candida, and Penicillium). The biofilm microbiome may be influenced by the characteristics of dental specialty and routine work to some extent. The age of dental chair unit and overall number of patients had the strongest impact on the overall bacteria composition, and the effect of daily dental practices (associated with number of patients and dental specialty) on the fungi composition was the greatest. For the first time, biofilm in DUWL related to dental specialty was comprehensively evaluated, with more abundance of bacterial and fungal communities than in water samples. Biofilm accumulation with daily work and multiple kinds of opportunistic pathogen emphasized the infectious risk with dental care and the importance of biofilm control.


Assuntos
Microbiota , Microbiologia da Água , Biofilmes , Criança , Contagem de Colônia Microbiana , Contaminação de Equipamentos , Humanos
6.
J Occup Environ Hyg ; 18(7): 345-360, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34129448

RESUMO

First responders may have high SARS-CoV-2 infection risks due to working with potentially infected patients in enclosed spaces. The study objective was to estimate infection risks per transport for first responders and quantify how first responder use of N95 respirators and patient use of cloth masks can reduce these risks. A model was developed for two Scenarios: an ambulance transport with a patient actively emitting a virus in small aerosols that could lead to airborne transmission (Scenario 1) and a subsequent transport with the same respirator or mask use conditions, an uninfected patient; and remaining airborne SARS-CoV-2 and contaminated surfaces due to aerosol deposition from the previous transport (Scenario 2). A compartmental Monte Carlo simulation model was used to estimate the dispersion and deposition of SARS-CoV-2 and subsequent infection risks for first responders, accounting for variability and uncertainty in input parameters (i.e., transport duration, transfer efficiencies, SARS-CoV-2 emission rates from infected patients, etc.). Infection risk distributions and changes in concentration on hands and surfaces over time were estimated across sub-Scenarios of first responder respirator use and patient cloth mask use. For Scenario 1, predicted mean infection risks were reduced by 69%, 48%, and 85% from a baseline risk (no respirators or face masks used) of 2.9 × 10-2 ± 3.4 × 10-2 when simulated first responders wore respirators, the patient wore a cloth mask, and when first responders and the patient wore respirators or a cloth mask, respectively. For Scenario 2, infection risk reductions for these same Scenarios were 69%, 50%, and 85%, respectively (baseline risk of 7.2 × 10-3 ± 1.0 × 10-2). While aerosol transmission routes contributed more to viral dose in Scenario 1, our simulations demonstrate the ability of face masks worn by patients to additionally reduce surface transmission by reducing viral deposition on surfaces. Based on these simulations, we recommend the patient wear a face mask and first responders wear respirators, when possible, and disinfection should prioritize high use equipment.


Assuntos
COVID-19/transmissão , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Máscaras/virologia , Respiradores N95/virologia , SARS-CoV-2 , Aerossóis , Microbiologia do Ar , Ambulâncias , COVID-19/prevenção & controle , Simulação por Computador , Socorristas , Contaminação de Equipamentos , Humanos , Método de Monte Carlo , Dispositivos de Proteção Respiratória/virologia , Comportamento de Redução do Risco , Transporte de Pacientes
7.
Artigo em Inglês | MEDLINE | ID: mdl-34065424

RESUMO

Water in dental unit waterlines (DUWL) represents a risk for vulnerable patients if its microbiological quality is not controlled. The aim of this prospective study was to evaluate two systems for its management under real conditions: Hygowater® and IGN Calbenium®. Samples of the output water of DUWL were obtained for 5 previously contaminated units connected to Hygowater®, and 5 non-contaminated units connected to IGN Calbenium®, which was already effective for more than 1 year, as a control group. Samples were regularly collected up to 6 months after the implementation of Hygowater®, and were then cultured and analyzed. With IGN Calbenium®, except for a technical problem and a sample result in one unit at 6 months (Heterotrophic Plate Count (HPC) at 37 °C of 66 colony forming units (cfu)/mL), the results showed an absence of contamination. Hygowater® took a couple of weeks to be effective on initially contaminated DUWL (over 200 cfu/mL for all the units), then showed its efficacy for 2 months (HPC at 37 °C with a mean of 40.2 ufc/mL, and HPC at 22 °C with a mean of 0.2 ufc/mL). At 6 months, results were satisfactory for HPC at 22 °C (mean of 12 ufc/mL), but HPC at 37 °C gave non-satisfactory results for 4 of the 5 units (mean of 92.2 ufc/mL). Both systems have an effect on the microbiological quality of DUWL. IGN Calbenium® appears to be more reliable on a long-term basis.


Assuntos
Microbiologia da Água , Água , Biofilmes , Contagem de Colônia Microbiana , Equipamentos Odontológicos , Contaminação de Equipamentos , Humanos , Estudos Prospectivos
8.
Viruses ; 13(6)2021 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067345

RESUMO

The SARS-CoV-2 pandemic has highlighted the need for protective and effective personal protective equipment (PPE). Research has shown that SARS-CoV-2 can survive on personal protective equipment, such as commonly used surgical masks. Methods are needed to inactivate virus on contaminated material. We show here that embedding viral-disinfecting compounds during the manufacturing of surgical masks inactivates a high dose (up to 1 × 105 pfu) of live, authentic SARS-CoV-2 within minutes.


Assuntos
Compostos de Amônio/farmacologia , Antivirais/farmacologia , Máscaras/virologia , SARS-CoV-2/efeitos dos fármacos , Inativação de Vírus , Contaminação de Equipamentos/prevenção & controle , Humanos
10.
Biomed Instrum Technol ; 55(s3): 12-16, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34153992

RESUMO

In 2015, the Food and Drug Administration (FDA) updated its guidance on test methods for cleaning validations for reusable medical devices. The changes include the condition and contamination of devices, test samples and controls, cleaning process performed during validation, extraction methods, and endpoints. This article reviews the FDA's changes to cleaning validations. Examples are presented using flexible endoscopes in order to provide a practical guide to performing cleaning validations.


Assuntos
Desinfecção , Contaminação de Equipamentos , Endoscópios , Contaminação de Equipamentos/prevenção & controle , Estados Unidos , United States Food and Drug Administration
11.
Rev Bras Enferm ; 74(2): e20201040, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-34076226

RESUMO

OBJECTIVES: to evaluate the results of two methods of hospital bedpan reprocessing. METHODS: cross-sectional study. Hospital bedpans containing a biological material contamination simulator or organic matter were submitted to manual cleaning followed by disinfection with 70% alcohol solution or thermodisinfection. Permanence of simulated contamination was evaluated by using the fluorescence technique and presence of organic matter was verified by carrying out the protein detection test. RESULTS: the contamination simulator was found in bedpans submitted to both processes. The seat was dirtier after manual cleaning (p=0.044) in comparison with the result obtained with thermodisinfection. Automatized decontamination led to worse results when compared to the manual procedure for the scoop and external bottom (p=0.000). The protein detection test was positive in two items after thermodisinfection. CONCLUSIONS: manual cleaning followed by rubbing with 70% alcohol solution proved more effective than automatized cleaning in the reprocessing of hospital bedpans. There are relevant issues regarding reuse of hospital bedpans.


Assuntos
Aparelho Sanitário , Infecção Hospitalar , Estudos Transversais , Desinfecção , Contaminação de Equipamentos , Reutilização de Equipamento , Hospitais , Humanos
13.
Optom Vis Sci ; 98(5): 512-517, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33973914

RESUMO

SIGNIFICANCE: The results of this study demonstrate that Smart Touch Technology packaging, which is designed to reduce and simplify contact lens handling before insertion, is effective in reducing the frequency of bacterial contamination of the back surface of contact lenses after short-term wear. PURPOSE: The purpose of this study was to investigate the effect of lens packaging type, chelating agent, and finger contamination on microbial contamination on the back surface of worn soft contact lenses. METHODS: Twenty-five subjects completed each contralateral lens wear comparison in this randomized study: Smart Touch Technology versus conventional blister packaging for (1) silicone hydrogel lenses with ethylenediaminetetraacetic acid (EDTA) and (2) hydrogel lenses without EDTA in the packaging, and (3) silicone hydrogel lenses without EDTA versus hydrogel lenses with EDTA both in Smart Touch Technology packaging. Participants washed hands, underwent finger swabs, and inserted the lenses. After 45 minutes, lenses were removed aseptically and the posterior lens surfaces cultured. RESULTS: Thirty-eight subjects (average age, 30.9 ± 12.5 years) participated in this study. Overall, the level of back surface contamination was low for both lens materials, ranging from 0 to 43 colony-forming unit (CFU)/lens for the silicone hydrogel and 0 to 17 CFU/lens for the hydrogel lenses. The proportion of lenses with zero back surface contamination ranged from 16 to 64% for silicone hydrogel lenses and 28 to 64% for hydrogel lenses. Contact lenses from conventional packaging containing EDTA had 3.38 times increased risk (95% confidence interval [CI], 1.02 to 11.11; P = .05) of contamination being present compared with lenses from Smart Touch packaging with EDTA. Contact lenses from conventional packaging without EDTA had 3.4 times increased risk (95% CI, 1.02 to 11.36; P = .05) of contamination being present compared with Smart Touch packaging without EDTA, and silicone hydrogel lenses had a 6.28 times increased risk (95% CI, 1.65 to 23.81; P = .007) of contamination being present compared with hydrogels. The median (interquartile range) number of bacteria isolated from fingers used to perform lens insertion after handwashing but before lens insertion was not significantly different between the silicone hydrogel and hydrogel lenses (63.7 [204.2] vs. 59 [84.5], P = .09). Finger contamination was not significantly associated with lens contamination in the presence or absence of EDTA. CONCLUSIONS: Smart Touch Technology packaging was effective in reducing the proportion of contaminated lenses. Although silicone hydrogel lenses were more likely to be contaminated, the presence of EDTA ameliorated this effect. Finger contamination was not associated with lens contamination.


Assuntos
Lentes de Contato Hidrofílicas/microbiologia , Contaminação de Equipamentos/prevenção & controle , Embalagem de Produtos , Adolescente , Adulto , Idoso , Bactérias/isolamento & purificação , Soluções para Lentes de Contato , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
14.
New Microbiol ; 44(2): 117-124, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33978196

RESUMO

The highly structured biofilms on the surface of internal tubing are regarded as the most important source of water pollution in the dental unit waterline (DUWL). Herein, the study aimed to evaluate the anti-biofilm effect of combined application of chlorine-containing disinfectant with multi-enzyme detergent in the dental unit waterline. Six dental units were included and randomly divided into two groups - Group A was treated with chlorine-containing disinfectant and multi-enzyme detergent; Group B was treated only with chlorine-containing disinfectant as control. All groups were treated once a day for four weeks. The anti-biofilm effect was evaluated by heterotrophic plate counts in output water, structure of biofilms, and fluorescence density of biofilms before and after treatment. Abundant opportunistic bacteria forming dense biofilms were observed before treatment. After one week, scanning electron microscopy showed the extracellular polymeric substance of biofilms in Group A was partially destroyed. The biofilms of Group A were completely removed in the third week, while the biofilms of Group B were still present. The combined application of chlorine-containing disinfectant and multi-enzyme detergent achieved a satisfactory effect on biofilms removal, demonstrating this strategy may play a significant role in reducing contamination in the dental clinic.


Assuntos
Desinfetantes , Biofilmes , Cloro , Contagem de Colônia Microbiana , Equipamentos Odontológicos , Detergentes/farmacologia , Desinfetantes/farmacologia , Contaminação de Equipamentos , Matriz Extracelular de Substâncias Poliméricas , Humanos , Microbiologia da Água
15.
Water Res ; 200: 117205, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34058484

RESUMO

Dental unit water systems are prone to biofilm formation. During use of the dental unit, clumps of biofilm slough off and can subsequently be aerosolized and inhaled by both patient and staff, potentially causing infections. The aim of this study was to determine the microbial load and microbiome of dental unit water, in the Netherlands, and the factors influencing these parameters. In total, 226 dental units were sampled and heterotrophic plate counts (HPC) were determined on the traditional effluent sample. Of all dental units, 61% exceeded the recommended microbiological guidelines of 100 colony forming units per milliliter. In addition, the microbiome, with additional q-PCR analysis for specific species, was determined on an effluent sample taken immediately after an overnight stagnancy period, in which the biofilm is in its relaxed state. These relaxed biofilm samples showed that each dental unit had a unique microbiome. Legionella spp., amoeba and fungi were found in 71%, 43% and 98% of all units, respectively. The presence of amoeba was positively associated with nine bacterial biomarkers and correlated positively with bacterial and fungal DNA and Legionella spp. concentrations, but not with HPC. Only when adhering to disinfection protocols, statistically significant effects on the microbial load and microbiome were seen. The relaxed biofilm sample, in combination with molecular techniques gives better insight in the presence of opportunistic pathogens when compared to the heterotrophic plate counts. Infection control measures should focus on biofilm analysis and control in order to guarantee patient safety.


Assuntos
Legionella , Microbiota , Biofilmes , Contagem de Colônia Microbiana , Equipamentos Odontológicos , Desinfecção , Contaminação de Equipamentos , Humanos , Legionella/genética , Países Baixos , Microbiologia da Água
16.
Infect Control Hosp Epidemiol ; 42(6): 740-742, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34009112

RESUMO

Healthcare-acquired infections are a tremendous challenge to the US medical system. Stethoscopes touch many patients, but current guidance from the Centers for Disease Control and Prevention does not support disinfection between each patient. Stethoscopes are rarely disinfected between patients by healthcare providers. When cultured, even after disinfection, stethoscopes have high rates of pathogen contamination, identical to that of unwashed hands. The consequence of these practices may bode poorly in the coronavirus 2019 disease (COVID-19) pandemic. Alternatively, the CDC recommends the use of disposable stethoscopes. However, these instruments have poor acoustic properties, and misdiagnoses have been documented. They may also serve as pathogen vectors among staff sharing them. Disposable aseptic stethoscope diaphragm barriers can provide increased safety without sacrificing stethoscope function. We recommend that the CDC consider the research regarding stethoscope hygiene and effective solutions to contemporize this guidance and elevate stethoscope hygiene to that of the hands, by requiring stethoscope disinfection or change of disposable barrier between every patient encounter.


Assuntos
Contaminação de Equipamentos/prevenção & controle , Estetoscópios/normas , COVID-19/prevenção & controle , COVID-19/transmissão , Centers for Disease Control and Prevention, U.S./normas , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/virologia , Desinfecção/métodos , Equipamentos Descartáveis , Desinfecção das Mãos , Humanos , Guias de Prática Clínica como Assunto , Estetoscópios/efeitos adversos , Estetoscópios/virologia , Estados Unidos
17.
J Occup Environ Hyg ; 18(6): 265-275, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33989113

RESUMO

The COVID-19 pandemic has caused a high demand for respiratory protection among health care workers in hospitals, especially surgical N95 filtering facepiece respirators (FFRs). To aid in alleviating that demand, a survey of commercially available filter media was conducted to determine whether any could serve as a substitute for an N95 FFR while held in a 3D-printed mask (Stopgap Surgical Face Mask from the NIH 3D Print Exchange). Fourteen filter media types and eight combinations were evaluated for filtration efficiency, breathing resistance (pressure drop), and liquid penetration. Additional testing was conducted to evaluate two filter media disinfection methods in the event that the filters were reused in a hospital setting. Efficiency testing was conducted in accordance with the procedures established for approving an N95 FFR. One apparatus used a filter-holding device and another apparatus employed a manikin head to which the 3D-printed mask could be sealed. The filter media and combinations exhibited collection efficiencies varied between 3.9% and 98.8% when tested with a face velocity comparable to that of a standard N95 FFR at the 85 L min-1 used in the approval procedure. Breathing resistance varied between 10.8 to >637 Pa (1.1 to > 65 mm H2O). When applied to the 3D-printed mask efficiency decreased by an average of 13% and breathing resistance increased 4-fold as a result of the smaller surface area of the filter media when held in that mask compared to that of an N95 FFR. Disinfection by dry heat, even after 25 cycles, did not significantly affect filter efficiency and reduced viral infectivity by > 99.9%. However, 10 cycles of 59% vaporized H2O2 significantly (p < 0.001) reduced filter efficiency of the media tested. Several commercially available filter media were found to be potential replacements for the media used to construct the typical cup-like N95 FFR. However, their use in the 3D-printed mask demonstrated reduced efficiency and increased breathing resistance at 85 L min-1.


Assuntos
COVID-19/prevenção & controle , Desinfecção/normas , Contaminação de Equipamentos/prevenção & controle , Teste de Materiais/normas , Respiradores N95/virologia , Exposição Ocupacional/prevenção & controle , Pandemias/prevenção & controle , Poluentes Ocupacionais do Ar/análise , Análise de Falha de Equipamento/estatística & dados numéricos , Guias como Assunto , Humanos , Exposição por Inalação/análise , SARS-CoV-2
18.
Infect Dis Now ; 51(3): 219-227, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33934808

RESUMO

The novel human coronavirus SARS-CoV-2 has been responsible for a worldwide pandemic. Although media transmission through contaminated surfaces is one of the most recognized ways of transmission, the study on the number and viability of viruses surviving on a surface after leaving the host represents a "blind spot" in current research. In this paper we have reviewed studies on the physical process of droplet evaporation on media surfaces, and analyzed the recent literature related to experiments on the decay of the viral concentration and infectious activity of SARS-CoV-2 and other viruses on those surface and in the air. The huge differences in the risk of media transmission of large saliva and sputum droplets were analyzed in terms of time elapsed. Due to the rapid decrease of water content in the evaporated droplets and the increased concentration of each component, the living environment of the virus tended to deteriorate sharply, and virus concentration plummeted within a few minutes. Although a virus can be detected in a matter of hours, tens of hours, or days, the risk of transmission is negligible compared to when it first left the host. This study suggests that the key to prevention and control is to start from the source, the earlier the better. It is extremely important to develop good public health habits, wear masks, and wash hands frequently. That said, excessive disinfection and sterilization of surfaces during a later period may have adverse effects.


Assuntos
COVID-19/transmissão , Transmissão de Doença Infecciosa , Muco/virologia , SARS-CoV-2/fisiologia , Saliva/virologia , Escarro/virologia , Fenômenos Fisiológicos Virais , Microbiologia do Ar , Bactérias/isolamento & purificação , COVID-19/virologia , Tosse , Dessecação , Transmissão de Doença Infecciosa/prevenção & controle , Contaminação de Equipamentos , Fômites , Humanos , Umidade , Higiene , Tamanho da Partícula , Respiração , Risco , SARS-CoV-2/isolamento & purificação , Espirro , Fala , Temperatura , Fatores de Tempo , Carga Viral , Vírus/isolamento & purificação
20.
Cytometry A ; 99(1): 81-89, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-34038035

RESUMO

The COVID-19 pandemic has brought biosafety to the forefront of many life sciences. The outbreak has compelled research institutions to re-evaluate biosafety practices and potential at-risk areas within research laboratories and more specifically within Shared Resource Laboratories (SRLs). In flow cytometry facilities, biological safety assessment encompasses known hazards based on the biological sample and associated risk group, as well as potential or unknown hazards, such as aerosol generation and instrument "failure modes." Cell sorting procedures undergo clearly defined biological safety assessments and adhere to well-established biosafety guidelines that help to protect SRL staff and users against aerosol exposure. Conversely, benchtop analyzers are considered low risk due to their low sample pressure and enclosed fluidic systems, although there is little empirical evidence to support this assumption of low risk. To investigate this, we evaluated several regions on analyzers using the Cyclex-d microsphere assay, a recently established method for cell sorter aerosol containment testing. We found that aerosol and/or droplet hazards were detected on all benchtop analyzers predominantly during operation in "failure modes." These results indicate that benchtop analytical cytometers present a more complicated set of risks than are commonly appreciated.


Assuntos
COVID-19/prevenção & controle , Separação Celular/instrumentação , Contenção de Riscos Biológicos , Contaminação de Equipamentos/prevenção & controle , Citometria de Fluxo/instrumentação , Pessoal de Laboratório , Exposição Ocupacional/efeitos adversos , Saúde do Trabalhador , Aerossóis , COVID-19/transmissão , Humanos , Medição de Risco , Fatores de Risco
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