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1.
Molecules ; 27(15)2022 Jul 26.
Article in English | MEDLINE | ID: covidwho-1994113

ABSTRACT

Some new N- and C-modified biomolecular peptide analogues of both VV-hemorphin-5 and VV-hemorphin-7 with varied amino acids (Cys, Glu, His), 1-adamantanecarboxylic acid, and niacin (nicotinic acid) were synthesized by solid-phase peptide synthesis-Fmoc (9-fluorenylmethoxy-carbonyl) chemistry and were characterized in water solutions with different pH using spectroscopic and electrochemical techniques. Basic physicochemical properties related to the elucidation of the peptide structure at physiological pH have been also studied. The results showed that the interaction of peptide compounds with light and electricity preserves the structural and conformational integrity of the compounds in the solutions. Moreover, textile cotton fibers were modified with the new compounds and the binding of the peptides to the surface of the material was proved by FTIR and SEM analysis. Washing the material with an alkaline soap solution did not show a violation of the modified structure of the cotton. Antiviral activity against the human respiratory syncytial virus (HRSV-S2) and human adenovirus serotype 5 (HAdV-5), the antimicrobial activity against B. cereus and P. aeruginosa used as model bacterial strains and cytotoxic effect of the peptide derivatives and modified cotton textile material has been evaluated. Antimicrobial tests showed promising activity of the newly synthesized compounds against the used Gram-positive and Gram-negative bacteria. The compounds C-V, H-V, AC-V, and AH-V were found slightly more active than NH7C and NCH7. The activity has been retained after the deposition of the compounds on cotton fibers.


Subject(s)
Anti-Infective Agents , Gram-Negative Bacteria , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Cotton Fiber , Gram-Positive Bacteria , Humans , Textiles
2.
Int J Biol Macromol ; 207: 100-109, 2022 May 15.
Article in English | MEDLINE | ID: covidwho-1814498

ABSTRACT

In this study, Cu/Zn galvanic electrodes were sputtered on the two surfaces of hydrophilic cotton fiber nonwovens (Cotton) to prepare hydro electroactive Cu/Cotton/Zn composites. When the Cu/Cotton/Zn was used as a functional layer in the face mask, the Cu/Zn galvanic electrodes can be spontaneously activated by water vapor molecules exhaled by the human body and generate galvanic current. Based on this, the hydro electroactive Cu/Cotton/Zn demonstrated excellent antibacterial activity against Escherichia coli and Staphylococcus aureus and could deactivate Enterovirus 71 (EV71) virions transmitted through the respiratory tract by 97.72% after 15 min of contact. Moreover, the Cu/Cotton/Zn did not affect the particle filtration efficiency and breathability of the face mask's polypropylene (PP) melt-blown layer. Furthermore, the cytotoxicity assessment of Cu/Cotton/Zn showed no cytotoxicity, indicating good biological security. Overall, the Cu/Cotton/Zn may provide a new approach to increase the antibacterial and antiviral performance of current personnel protective equipment on the market.


Subject(s)
Antiviral Agents , Cotton Fiber , Anti-Bacterial Agents/pharmacology , Antiviral Agents/pharmacology , Escherichia coli , Humans , Staphylococcus aureus , Zinc
3.
Int J Mol Sci ; 23(7)2022 Mar 25.
Article in English | MEDLINE | ID: covidwho-1785729

ABSTRACT

The development of affordable, effective, and environmentally friendly barrier fabrics is a current goal in antimicrobial textile development. The discovery of new routes to achieve non-toxic naturally occurring molecules with antimicrobial activity is of interest in the development of materials that promote wound healing, improve hygiene, and offer protection against nosocomial infection. Highly cleaned and sterile unbleached cotton has constituents that produce hydrogen peroxide at levels commensurate with those that favor cell signaling in wound healing. Here, we show the antimicrobial and antiviral properties of spunlaced griege cotton-containing nonwovens treated with ascorbic acid formulations. The mechanism of action occurs through the promotion of enhanced hydrogen peroxide activity. The levels of hydrogen peroxide activity afford antimicrobial activity against Gram-negative and Gram-positive bacteria and antiviral activity against MS2 bacteriophages. Spun-bond nonwoven unbleached cotton was treated with ascorbic acid using traditional pad-dry-cure methods. An assessment of antibacterial and antiviral activity against Staphylococcus aureus, Klebsiella pneumoniae, and MS2 bacteriophages with the AATCC 100 test method showed a 99.99% inhibitory activity. An approach to the covalent attachment of ascorbic to cellulose through citric acid crosslinking chemistry is also discussed. Thus, a simple, low-cost approach to antimicrobial and antiviral cotton-based nonwovens applicable to dressings, nosocomial barrier fabrics, and face masks can be adopted by combining ascorbic acid with spunlace greige cotton nonwoven fabrics.


Subject(s)
Anti-Infective Agents , Cotton Fiber , Adjuvants, Pharmaceutic , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Antiviral Agents , Ascorbic Acid/pharmacology , Gossypium , Hydrogen Peroxide , Textiles
4.
East. Mediterr. health j ; 28(2): 93-170, 2022-02.
Article in English | WHOIRIS | ID: gwh-352428

ABSTRACT

Eastern Mediterranean Health Journal is the official health journal published by the Eastern Mediterranean Regional Office of the World Health Organization. It is a forum for the presentation and promotion of new policies and initiatives in health services; and for the exchange of ideas concepts epidemiological data research findings and other information with special reference to the Eastern Mediterranean Region. It addresses all members of the health profession medical and other health educational institutes interested NGOs WHO Collaborating Centres and individuals within and outside the Region


المجلة الصحية لشرق المتوسط هى المجلة الرسمية التى تصدرعن المكتب الاقليمى لشرق المتوسط بمنظمة الصحة العالمية. وهى منبر لتقديم السياسات والمبادرات الجديدة فى الصحة العامة والخدمات الصحية والترويج لها، و لتبادل الاراء و المفاهيم والمعطيات الوبائية ونتائج الابحاث وغير ذلك من المعلومات، و خاصة ما يتعلق منها باقليم شرق المتوسط. وهى موجهة الى كل اعضاء المهن الصحية، والكليات الطبية وسائر المعاهد التعليمية، و كذا المنظمات غير الحكومية المعنية، والمراكز المتعاونة مع منظمة الصحة العالمية والافراد المهتمين بالصحة فى الاقليم و خارجه


La Revue de Santé de la Méditerranée Orientale est une revue de santé officielle publiée par le Bureau régional de l’Organisation mondiale de la Santé pour la Méditerranée orientale. Elle offre une tribune pour la présentation et la promotion de nouvelles politiques et initiatives dans le domaine de la santé publique et des services de santé ainsi qu’à l’échange d’idées de concepts de données épidémiologiques de résultats de recherches et d’autres informations se rapportant plus particulièrement à la Région de la Méditerranée orientale. Elle s’adresse à tous les professionnels de la santé aux membres des instituts médicaux et autres instituts de formation médico-sanitaire aux ONG Centres collaborateurs de l’OMS et personnes concernés au sein et hors de la Région


Subject(s)
Leprosy , COVID-19 , Alcohol Drinking , Pulmonary Disease, Chronic Obstructive , Immunization , Emergency Service, Hospital , Cotton Fiber , Clinical Clerkship , Personal Protective Equipment , Neglected Diseases , Betacoronavirus , Disease Outbreaks
5.
Int J Mol Sci ; 22(4)2021 Feb 23.
Article in English | MEDLINE | ID: covidwho-1389391

ABSTRACT

Endotoxin removal therapy with polymyxin B immobilized fiber column (PMX) has been clinically applied for sepsis and septic shock patients since 1994. The effectiveness and usefulness of this therapy have been demonstrated for more than a quarter of a century. However, a documented survival benefit has not yet been demonstrable in a large, multicenter, randomized and controlled trial. Following the findings derived from a large sepsis clinical trial with PMX in North America, a new trial is ongoing to determine if PMX has a long-term survival benefit when administered to septic patients. Another approach to support a survival benefit from intervention with PMX is to utilize a detailed analysis available from a large clinical data base. The endotoxin adsorption capacity of PMX columns in vitro and the effectiveness of PMX columns can be further demonstrable in animal models. The capability of PMX and details of its mechanism of action to intervene in the sepsis cascade and impede organ dysfunction in septic patients is not fully understood. The surface antigen expression in monocytes and neutrophils are improved after PMX therapy. Immunomodulatory effects as a result of endotoxin removal and/or other mechanisms of action have been suggested. These effects and other potential immune effects may explain some of the improved effects upon organ dysfunction of sepsis and septic shock patients. Endotoxemia may be involved in the pathophysiology of other diseases than sepsis. A rapid diagnostic method to detect and target endotoxemia could allow us to practice precision medicine and expand the clinical indications of endotoxin removal therapy.


Subject(s)
Cotton Fiber , Endotoxins/blood , Endotoxins/isolation & purification , Hemoperfusion/methods , Immobilization/methods , Polymyxin B/chemistry , Sepsis/therapy , Shock, Septic/therapy , Adsorption , Animals , COVID-19/therapy , Endotoxemia/blood , Endotoxemia/therapy , Humans , Idiopathic Pulmonary Fibrosis/drug therapy , Idiopathic Pulmonary Fibrosis/therapy , Immobilization/instrumentation , Sepsis/blood , Shock, Septic/blood
6.
ACS Appl Mater Interfaces ; 13(26): 30317-30325, 2021 Jul 07.
Article in English | MEDLINE | ID: covidwho-1387130

ABSTRACT

Influenza A viruses (IAV) and SARS-CoV-2 can spread via liquid droplets and aerosols. Face masks and other personal protective equipment (PPE) can act as barriers that prevent the spread of these viruses. However, IAV and SARS-CoV-2 are stable for hours on various materials, which makes frequent and correct disposal of these PPE important. Metal ions embedded into PPE may inactivate respiratory viruses, but confounding factors such as adsorption of viruses make measuring and optimizing the inactivation characteristics difficult. Here, we used polyamide 6.6 (PA66) fibers containing embedded zinc ions and systematically investigated if these fibers can adsorb and inactivate SARS-CoV-2 and IAV H1N1 when woven into a fabric. We found that our PA66-based fabric decreased the IAV H1N1 and SARS-CoV-2 titer by approximately 100-fold. Moreover, we found that the zinc content and the virus inactivating property of the fabric remained stable over 50 standardized washes. Overall, these results provide insights into the development of reusable PPE that offer protection against RNA virus spread.


Subject(s)
Influenza A virus/physiology , Nylons/pharmacology , SARS-CoV-2/physiology , Textiles , Virus Inactivation/drug effects , Zinc/pharmacology , Adsorption , Animals , Chlorocebus aethiops , Cotton Fiber , Dogs , HEK293 Cells , Humans , Influenza A virus/drug effects , Ions , Madin Darby Canine Kidney Cells , Polypropylenes/pharmacology , SARS-CoV-2/drug effects , Vero Cells , Viral Load , Zinc Oxide/pharmacology
7.
ACS Appl Bio Mater ; 4(7): 5471-5484, 2021 07 19.
Article in English | MEDLINE | ID: covidwho-1337090

ABSTRACT

Centers for Disease Control and Prevention (CDC) warns the use of one-way valves or vents in face masks for potential threat of spreading COVID-19 through expelled respiratory droplets. Here, we have developed a nanoceutical cotton fabric duly sensitized with non-toxic zinc oxide nanomaterial for potential use as a membrane filter in the one-way valve for the ease of breathing without the threat of COVID-19 spreading. A detailed computational study revealed that zinc oxide nanoflowers (ZnO NFs) with almost two-dimensional petals trap SARS-CoV-2 spike proteins, responsible to attach to ACE-2 receptors in human lung epithelial cells. The study also confirmed significant denaturation of the spike proteins on the ZnO surface, revealing removal of the virus upon efficient trapping. Following the computational study, we have synthesized ZnO NF on a cotton matrix using a hydrothermal-assisted strategy. Electron-microscopic, steady-state, and picosecond-resolved spectroscopic studies confirm attachment of ZnO NF to the cotton (i.e., cellulose) matrix at the atomic level to develop the nanoceutical fabric. A detailed antimicrobial assay using Pseudomonas aeruginosa bacteria (model SARS-CoV-2 mimic) reveals excellent antimicrobial efficiency of the developed nanoceutical fabric. To our understanding, the nanoceutical fabric used in the one-way valve of a face mask would be the choice to assure breathing comfort along with source control of COVID-19 infection. The developed nanosensitized cloth can also be used as an antibacterial/anti CoV-2 washable dress material in general.


Subject(s)
Anti-Infective Agents/chemistry , COVID-19/prevention & control , Nanostructures/chemistry , Anti-Infective Agents/metabolism , Anti-Infective Agents/pharmacology , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , COVID-19/virology , Cotton Fiber/analysis , Humans , Masks , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/metabolism , Recycling , Respiratory Aerosols and Droplets/virology , SARS-CoV-2/drug effects , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Zinc Oxide/chemistry
8.
mSphere ; 6(2)2021 04 28.
Article in English | MEDLINE | ID: covidwho-1207482

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) persists on stainless steel and plastic for up to 7 days, suggesting that coronavirus disease 2019 (COVID-19) could be spread by fomite transmission. There is limited research on the stability of SARS-CoV-2 on textiles, with the risk of textiles acting as fomites not being well understood. To date, there does not appear to be any published research on the stability of coronaviruses during laundering, which is required to determine the efficacy of current laundering policies in the decontamination of health care textiles. The aim of this study was to investigate the environmental stability of human coronaviruses HCoV-OC43 and HCoV-229E on different textile fiber types and the persistence of HCoV-OC43 on textiles during domestic and industrial laundering. This study demonstrated that human coronaviruses (5 log10 50% tissue culture infective doses [TCID50]) remain infectious on polyester for ≥72 h, cotton for ≥24 h, and polycotton for ≥6 h; HCoV-OC43 was also able to transfer from polyester to PVC or polyester after 72 h. Under clean conditions, HCoV-OC43 was not detectable on cotton swatches laundered with industrial and domestic wash cycles without temperature and detergent (≥4.57-log10-TCID50 reduction), suggesting that the dilution and agitation of wash cycles are sufficient to remove human coronaviruses from textiles. In the presence of interfering substances (artificial saliva), ≤1.78 log10 TCID50 HCoV-OC43 was detected after washing domestically without temperature and detergent, unlike industrial laundering, where the virus was completely removed. However, no infectious HCoV-OC43 was detected when washed domestically with detergent.IMPORTANCE Synthetic textiles such as polyester could potentially act as fomites of human coronaviruses, indicating the importance of infection control procedures during handling of contaminated textiles prior to laundering. This study provides novel evidence that human coronaviruses can persist on textiles for up to 3 days and are readily transferred from polyester textile to other surfaces after 72 h of incubation. This is of particular importance for the domestic laundering of contaminated textiles such as health care uniforms in the United Kingdom and United States, where there may be a risk of cross-contaminating the domestic environment. It was demonstrated that human coronaviruses are removed from contaminated textiles by typical domestic and commercial wash cycles, even at low temperatures without detergent, indicating that current health care laundering policies are likely sufficient in the decontamination of SARS-CoV-2 from textiles.


Subject(s)
COVID-19/transmission , Common Cold/transmission , Coronavirus 229E, Human/drug effects , Coronavirus OC43, Human/drug effects , Detergents/pharmacology , Textiles/virology , Cell Line , Cotton Fiber/virology , Fomites/virology , Humans , Laundering , Polyesters , SARS-CoV-2/drug effects
9.
Int J Biol Macromol ; 181: 990-1002, 2021 Jun 30.
Article in English | MEDLINE | ID: covidwho-1188608

ABSTRACT

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). We succeeded in preparing disinfectant cellulose-based wipes treated with antimicrobial and antiviral silver nanoparticles to be used for prevention of contamination and transmission of several pathogenic viruses and microbes to human in critical areas such as hospitals and healthcare centers especially coronavirus. In this work, the antimicrobial and antiviral activities of silver nanoparticles (AgNPs) prepared with four different techniques were investigated for the utilization as a disinfectant for cellulose-based wipes. These four methods are namely; 1) trisodium citrate with cotton yarn as a reducing agent, 2) preparing AgNP's using aqueous solution of PVA in the presence of glucose, 3) trisodium citrate with cotton fabric as a reducing agent, and 4) photochemical reaction of polyacrylic acid and silver nitrate solution. Polyester/viscose blended spunlace nonwoven fabrics as cellulose based fabrics were treated with the prepared silver nanoparticles to be used as surfaces disinfection wipes. The properties of the nonwoven fabrics were examined including thickness, tensile strength in dry and wet conditions in both machine direction (MD) and cross-machine direction (CMD), bursting strength, air permeability, water permeability and surface wettability. Characterization of the AgNPs was carried out in terms of UV-VIS spectroscopy, TEM, SEM, and Zeta potential analysis. The assessment of AgNPs active solutions for antimicrobial and antiviral activities was evaluated. The results obtained from the analyses of the AgNPs samples prepared with different techniques showed good uniformity and stability of the particles, as well uniform coating of the AgNPs on the fibers. Additionally, there is a significant effect of the AgNPs preparation method on their disinfectant performance that proved its effectiveness against coronavirus (MERS-CoV), S. aureus and B. subtilis as Gram-positive bacteria, E. coli and P. mirabilis as Gram-negative bacteria, A. niger and C. albicans fungi.


Subject(s)
COVID-19/prevention & control , Cellulose/chemistry , Coronavirus/drug effects , Disinfectants/chemistry , Metal Nanoparticles/chemistry , SARS-CoV-2/drug effects , Silver/chemistry , Acrylic Resins/chemistry , Anti-Bacterial Agents/chemistry , Anti-Infective Agents/chemistry , Antiviral Agents/chemistry , Citrates/chemistry , Cotton Fiber , Fungi/drug effects , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Green Chemistry Technology , Microbial Sensitivity Tests , Silver Nitrate/chemistry
10.
JAMA Netw Open ; 4(3): e212574, 2021 03 01.
Article in English | MEDLINE | ID: covidwho-1126330

ABSTRACT

Importance: Face masks are recommended to prevent transmission of coronavirus disease 2019 (COVID-19); however, there is scarce evidence on their protection efficacy and ways to improve it. Objective: To determine the proportion of improper face mask use, the factors associated with face mask protection efficacy, and ways to improve efficacy. Design, Setting, and Participants: This population-based cross-sectional study was conducted in China from July to August 2020 in 5 kinds of public places. Participants included convenience samples of individuals wearing face masks and able to taste the check solution. Exposures: Demographic and socioeconomic characteristics, including sex, age, and education level; information on face mask model and the worn duration was recorded. Main Outcomes and Measures: The main outcome as airtightness, assessed by detecting face-to-face mask gaps, movement of cotton fiber placed at the face mask edges, and using a qualitative fit test with a bitter solution spray. Masks were further assessed for whether sealing the upper face mask edge with an adhesive tape strip was associated with improved face mask airtightness. Results: Among 6003 face mask wearers enrolled, the mean (SD) age of participants was 31.1 (13.7) years, and 3047 participants (50.8%) were female. The first qualitative fit test found air leakage in 2754 participants (45.9%; 95% CI, 44.6%-47.1%), which was mostly attributable to gaps at the upper face mask edge. After sealing the upper face mask edge with an adhesive tape strip, 69.7% (95% CI, 68.0%-71.5%) of masks that had exhibited leakage became airtight in the second qualitative fit test, and the rate of airtightness reached 96.2% (95% CI, 95.4%-96.8%) in a third qualitative fit test after new surgical face masks with tape on the upper edge were provided to those who had not converted initially. The tape was well tolerated; overall, 6 participants (1.2%) reported a rash and 24 participants (5.8%) reported significant discomfort. Conclusions and Relevance: In this study of face mask fit among participants in China, although most people used face masks in public places, compromised protection due to suboptimal airtightness was common. The simple approach of sealing the upper edge of the face mask with an adhesive tape strip was associated with substantially improved its airtightness.


Subject(s)
COVID-19/prevention & control , Cotton Fiber , Disposable Equipment , Masks , N95 Respirators , Adult , COVID-19/transmission , China , Cross-Sectional Studies , Female , Humans , Male , SARS-CoV-2 , Young Adult
11.
Anal Chem ; 93(3): 1826-1833, 2021 01 26.
Article in English | MEDLINE | ID: covidwho-997756

ABSTRACT

Collection of nasopharyngeal samples using swabs followed by the transfer of the virus into a solution and an RNA extraction step to perform reverse transcription polymerase chain reaction (PCR) is the primary method currently used for the diagnosis of COVID-19. However, the need for several reagents and steps and the high cost of PCR hinder its worldwide implementation to contain the outbreak. Here, we report a cotton-tipped electrochemical immunosensor for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus antigen. Unlike the reported approaches, we integrated the sample collection and detection tools into a single platform by coating screen-printed electrodes with absorbing cotton padding. The immunosensor was fabricated by immobilizing the virus nucleocapsid (N) protein on carbon nanofiber-modified screen-printed electrodes which were functionalized by diazonium electrografting. The detection of the virus antigen was achieved via swabbing followed by competitive assay using a fixed amount of N protein antibody in the solution. A square wave voltammetric technique was used for the detection. The limit of detection for our electrochemical biosensor was 0.8 pg/mL for SARS-CoV-2, indicating very good sensitivity for the sensor. The biosensor did not show significant cross-reactivity with other virus antigens such as influenza A and HCoV, indicating high selectivity of the method. Moreover, the biosensor was successfully applied for the detection of the virus antigen in spiked nasal samples showing excellent recovery percentages. Thus, our electrochemical immunosensor is a promising diagnostic tool for the direct rapid detection of the COVID-19 virus that requires no sample transfer or pretreatment.


Subject(s)
COVID-19/diagnosis , Cotton Fiber , Electrochemical Techniques/methods , Immunoassay/methods , SARS-CoV-2/isolation & purification , Antibodies, Viral/immunology , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Carbon/chemistry , Coronavirus Nucleocapsid Proteins/chemistry , Coronavirus Nucleocapsid Proteins/immunology , Electrochemical Techniques/instrumentation , Electrodes , Gossypium/chemistry , Humans , Immobilized Proteins/chemistry , Immobilized Proteins/immunology , Immunoassay/instrumentation , Limit of Detection , Nanofibers/chemistry , Phosphoproteins/chemistry , Phosphoproteins/immunology , SARS-CoV-2/immunology
12.
JAMA Intern Med ; 181(4): 463-469, 2021 04 01.
Article in English | MEDLINE | ID: covidwho-966088

ABSTRACT

Importance: During the coronavirus disease 2019 (COVID-19) pandemic, the general public has been advised to wear masks or improvised face coverings to limit transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there has been considerable confusion and disagreement regarding the degree to which masks protect the wearer from airborne particles. Objectives: To evaluate the fitted filtration efficiency (FFE) of various consumer-grade and improvised face masks, as well as several popular modifications of medical procedure masks that are intended to improve mask fit or comfort. Design, Setting, and Participants: For this study conducted in a research laboratory between June and August 2020, 7 consumer-grade masks and 5 medical procedure mask modifications were fitted on an adult male volunteer, and FFE measurements were collected during a series of repeated movements of the torso, head, and facial muscles as outlined by the US Occupational Safety and Health Administration Quantitative Fit Testing Protocol. The consumer-grade masks tested included (1) a 2-layer nylon mask with ear loops that was tested with an optional aluminum nose bridge and filter insert in place, (2) a cotton bandana folded diagonally once (ie, "bandit" style) or in a (3) multilayer rectangle according to the instructions presented by the US Surgeon General, (4) a single-layer polyester/nylon mask with ties, (5) a polypropylene mask with fixed ear loops, (6) a single-layer polyester gaiter/neck cover balaclava bandana, and (7) a 3-layer cotton mask with ear loops. Medical procedure mask modifications included (1) tying the mask's ear loops and tucking in the side pleats, (2) fastening ear loops behind the head with 3-dimensional-printed ear guards, (3) fastening ear loops behind the head with a claw-type hair clip, (4) enhancing the mask/face seal with rubber bands over the mask, and (5) enhancing the mask/face seal with a band of nylon hosiery over the fitted mask. Main Outcomes and Measures: The primary study outcome was the measured FFE of common consumer-grade and improvised face masks, as well as several popular modifications of medical procedure masks. Results: The mean (SD) FFE of consumer grade masks tested on 1 adult male with no beard ranged from 79.0% (4.3%) to 26.5% (10.5%), with the 2-layer nylon mask having the highest FFE. Unmodified medical procedure masks with ear loops had a mean (SD) FFE of 38.5% (11.2%). All modifications evaluated in this study increased procedure mask FFE (range [SD], 60.3% [11.1%] to 80.2% [3.1%]), with a nylon hosiery sleeve placed over the procedure mask producing the greatest improvement. Conclusions and Relevance: While modifications to improve medical procedure mask fit can enhance the filtering capability and reduce inhalation of airborne particles, this study demonstrates that the FFEs of consumer-grade masks available to the public are, in many cases, nearly equivalent to or better than their non-N95 respirator medical mask counterparts.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , Masks , Adult , Cotton Fiber , Equipment Design , Filtration/instrumentation , Humans , Male , Nylons , Polyesters , Polypropylenes , Protective Clothing
13.
Nano Lett ; 20(10): 7642-7647, 2020 10 14.
Article in English | MEDLINE | ID: covidwho-801587

ABSTRACT

Shortages in the availability of personal protective face masks during the COVID-19 pandemic required many to fabricate masks and filter inserts from available materials. While the base filtration efficiency of a material is of primary importance when a perfect seal is possible, ideal fit is not likely to be achieved by the average person preparing to enter a public space or even a healthcare worker without fit-testing before each shift. Our findings suggest that parameters including permeability and pliability can play a strong role in the filtration efficiency of a mask fabricated with various filter media, and that the filtration efficiency of loosely fitting masks/respirators against ultrafine particulates can drop by more than 60% when worn compared to the ideal filtration efficiency of the base material. Further, a test method using SARS-CoV-2 virion-sized silica nanoaerosols is demonstrated to assess the filtration efficiency against nanoparticulates that follow air currents associated with mask leakage.


Subject(s)
Betacoronavirus , Coronavirus Infections/prevention & control , Filtration/instrumentation , Masks , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Respiratory Protective Devices , Textiles , Aerosols , Air Microbiology , Betacoronavirus/ultrastructure , COVID-19 , Coronavirus Infections/transmission , Coronavirus Infections/virology , Cotton Fiber , Filtration/statistics & numerical data , Humans , Inhalation Exposure , Nanoparticles , Particle Size , Permeability , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , SARS-CoV-2 , Silicon Dioxide
14.
BMJ Open ; 10(9): e039424, 2020 09 22.
Article in English | MEDLINE | ID: covidwho-788150

ABSTRACT

OBJECTIVE: We examined the ability of fabrics which might be used to create home-made face masks to filter out ultrafine (0.02-0.1 µm) particles at the velocity of adult human coughing. METHODS: Twenty commonly available fabrics and materials were evaluated for their ability to reduce air concentrations of ultrafine particles at coughing face velocities. Further assessment was made on the filtration ability of selected fabrics while damp and of fabric combinations which might be used to construct home-made masks. RESULTS: Single fabric layers blocked a range of ultrafine particles. When fabrics were layered, a higher percentage of ultrafine particles were filtered. The average filtration efficiency of single layer fabrics and of layered combination was found to be 35% and 45%, respectively. Non-woven fusible interfacing, when combined with other fabrics, could add up to 11% additional filtration efficiency. However, fabric and fabric combinations were more difficult to breathe through than N95 masks. CONCLUSIONS: The current coronavirus pandemic has left many communities without access to N95 face masks. Our findings suggest that face masks made from layered common fabric can help filter ultrafine particles and provide some protection for the wearer when commercial face masks are unavailable.


Subject(s)
Coronavirus Infections/transmission , Cough , Masks/supply & distribution , Materials Testing , Particulate Matter , Pneumonia, Viral/transmission , Textiles , Air Filters , Betacoronavirus , COVID-19 , Cellulose , Coronavirus Infections/prevention & control , Cotton Fiber , Humans , Nylons , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Polyesters , Polyurethanes , Respiratory Protective Devices/supply & distribution , SARS-CoV-2 , Wool Fiber
15.
Front Cell Infect Microbiol ; 10: 356, 2020.
Article in English | MEDLINE | ID: covidwho-642075

ABSTRACT

CDC and WHO guidelines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis only recommend synthetic fiber swabs for nasopharyngeal (NP) sampling. We show that cotton-tipped plastic swabs do not inhibit PCR and have equivalent performance to rayon swabs. Cotton-tipped plastic swabs are massively produced worldwide and would prevent swab supply shortages under the current high SARS-CoV-2 testing demands, particularly in developing countries.


Subject(s)
Betacoronavirus/isolation & purification , Clinical Laboratory Techniques/instrumentation , Coronavirus Infections/diagnosis , Diagnostic Equipment/supply & distribution , Disposable Equipment/supply & distribution , Pneumonia, Viral/diagnosis , Real-Time Polymerase Chain Reaction/instrumentation , Betacoronavirus/genetics , COVID-19 , COVID-19 Testing , Cellulose/supply & distribution , Clinical Laboratory Techniques/methods , Coronavirus Infections/virology , Cotton Fiber/supply & distribution , Humans , Nasopharynx , Pandemics , Plastics/supply & distribution , Pneumonia, Viral/virology , RNA, Viral/analysis , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2 , Specimen Handling/instrumentation , Specimen Handling/methods
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