51
|
Baker MA, Rhee C, Tucker R, Badwaik A, Coughlin C, Holtzman MA, Hsieh C, Maguire A, Mermel Blaeser E, Seetharaman S, Solem O, Vaidya V, Klompas M. Rapid control of hospital-based SARS-CoV-2 Omicron clusters through daily testing and universal use of N95 respirators. Clin Infect Dis 2022; 75:e296-e299. [PMID: 35137035 PMCID: PMC8903387 DOI: 10.1093/cid/ciac113] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Indexed: 11/14/2022] Open
Abstract
The highly contagious SARS-CoV-2 Omicron variant increases risk for nosocomial transmission despite universal masking, admission testing, and symptom screening. We report large increases in hospital-onset infections and 2 unit-based clusters. The clusters rapidly abated after instituting universal N95 respirators and daily testing. Broader use of these strategies may prevent nosocomial transmissions.
Collapse
Affiliation(s)
- Meghan A Baker
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
- Infection Control Department, Dana Farber Cancer Institute, Boston, MA, USA
| | - Chanu Rhee
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | - Robert Tucker
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | - Amy Badwaik
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | - Cassie Coughlin
- Infection Control Department, Dana Farber Cancer Institute, Boston, MA, USA
| | - Meghan A Holtzman
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | - Candace Hsieh
- Infection Control Department, Dana Farber Cancer Institute, Boston, MA, USA
| | - Angela Maguire
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | | | | | - Ofelia Solem
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | - Vineeta Vaidya
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
| | - Michael Klompas
- Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, USA
- Infection Control Department, Brigham and Women’s Hospital, Boston, MA, USA
- Corresponding author: Michael Klompas MD, MPH Department of Population Medicine 401 Park Drive, Suite 401 East Boston, MA, 02215 USA
| |
Collapse
|
52
|
Coyle JP, Derk RC, Lindsley WG, Boots T, Blachere FM, Reynolds JS, McKinney WG, Sinsel EW, Lemons AR, Beezhold DH, Noti JD. Reduction of exposure to simulated respiratory aerosols using ventilation, physical distancing, and universal masking. INDOOR AIR 2022; 32:e12987. [PMID: 35225389 PMCID: PMC8988470 DOI: 10.1111/ina.12987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
To limit community spread of SARS-CoV-2, CDC recommends universal masking indoors, maintaining 1.8 m of physical distancing, adequate ventilation, and avoiding crowded indoor spaces. Several studies have examined the independent influence of each control strategy in mitigating transmission in isolation, yet controls are often implemented concomitantly within an indoor environment. To address the influence of physical distancing, universal masking, and ventilation on very fine respiratory droplets and aerosol particle exposure, a simulator that coughed and exhaled aerosols (the source) and a second breathing simulator (the recipient) were placed in an exposure chamber. When controlling for the other two mitigation strategies, universal masking with 3-ply cotton masks reduced exposure to 0.3-3 µm coughed and exhaled aerosol particles by >77% compared to unmasked tests, whereas physical distancing (0.9 or 1.8 m) significantly changed exposure to cough but not exhaled aerosols. The effectiveness of ventilation depended upon the respiratory activity, that is, coughing or breathing, as well as the duration of exposure time. Our results demonstrate that a layered mitigation strategy approach of administrative and engineering controls can reduce personal inhalation exposure to potentially infectious very fine respiratory droplets and aerosol particles within an indoor environment.
Collapse
Affiliation(s)
- Jayme P. Coyle
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Raymond C. Derk
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - William G. Lindsley
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Theresa Boots
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Francoise M. Blachere
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Jeffrey S. Reynolds
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Walter G. McKinney
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Erik W. Sinsel
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Angela R. Lemons
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - Donald H. Beezhold
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| | - John D. Noti
- Health Effects Laboratory DivisionCenters for Disease Control and PreventionNational Institute for Occupational Safety and HealthMorgantownWest VirginiaUSA
| |
Collapse
|
53
|
Blachere FM, Lemons AR, Coyle JP, Derk RC, Lindsley WG, Beezhold DH, Woodfork K, Duling MG, Boutin B, Boots T, Harris JR, Nurkiewicz T, Noti JD. Face mask fit modifications that improve source control performance. Am J Infect Control 2022; 50:133-140. [PMID: 34924208 PMCID: PMC8674119 DOI: 10.1016/j.ajic.2021.10.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND During the COVID-19 pandemic, face masks are used as source control devices to reduce the expulsion of respiratory aerosols from infected people. Modifications such as mask braces, earloop straps, knotting and tucking, and double masking have been proposed to improve mask fit however the data on source control are limited. METHODS The effectiveness of mask fit modifications was determined by conducting fit tests on human subjects and simulator manikins and by performing simulated coughs and exhalations using a source control measurement system. RESULTS Medical masks without modification blocked ≥56% of cough aerosols and ≥42% of exhaled aerosols. Modifying fit by crossing the earloops or placing a bracket under the mask did not increase performance, while using earloop toggles, an earloop strap, and knotting and tucking the mask increased performance. The most effective modifications for improving source control performance were double masking and using a mask brace. Placing a cloth mask over a medical mask blocked ≥85% of cough aerosols and ≥91% of exhaled aerosols. Placing a brace over a medical mask blocked ≥95% of cough aerosols and ≥99% of exhaled aerosols. CONCLUSIONS Fit modifications can greatly improve the performance of face masks as source control devices for respiratory aerosols.
Collapse
Affiliation(s)
- Francoise M Blachere
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV.
| | - Angela R Lemons
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Jayme P Coyle
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Raymond C Derk
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - William G Lindsley
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Donald H Beezhold
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Karen Woodfork
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV; Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, WV
| | - Matthew G Duling
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Brenda Boutin
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Theresa Boots
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - James R Harris
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Tim Nurkiewicz
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV; Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, WV
| | - John D Noti
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| |
Collapse
|
54
|
Wilson AM, Sleeth DK, Schaefer C, Jones RM. Transmission of Respiratory Viral Diseases to Health Care Workers: COVID-19 as an Example. Annu Rev Public Health 2022; 43:311-330. [DOI: 10.1146/annurev-publhealth-052120-110009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Health care workers (HCWs) can acquire infectious diseases, including coronavirus disease 2019 (COVID-19), from patients. Herein, COVID-19 is used with the source–pathway–receptor framework as an example to assess evidence for the role of aerosol transmission and indirect contact transmission of viral respiratory infectious diseases. Evidence for both routes is strong for COVID-19 and other respiratory viruses, but aerosol transmission is likely dominant for COVID-19. Key knowledge gaps about transmission processes and control strategies include the distribution of viable virus among respiratory aerosols of different sizes, the mechanisms and efficiency by which virus deposited on the facial mucous membrane moves to infection sites inside the body, and the performance of source controls such as face coverings and aerosol containment devices. To ensure that HCWs are adequately protected from infection, guidelines and regulations must be updated to reflect the evidence that respiratory viruses are transmitted via aerosols. Expected final online publication date for the Annual Review of Public Health, Volume 43 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Amanda M. Wilson
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, USA;, ,
- Department of Community, Environment and Policy, Mel and Enid Zuckerman College of Public Health, The University of Arizona, Tucson, Arizona, USA
| | - Darrah K. Sleeth
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, USA;, ,
| | - Camie Schaefer
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, USA;, ,
| | - Rachael M. Jones
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, USA;, ,
| |
Collapse
|
55
|
Bartels J, Estill CF, Chen IC, Neu D. Laboratory study of physical barrier efficiency for worker protection against SARS-CoV-2 while standing or sitting. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2022; 56:295-303. [PMID: 35677842 PMCID: PMC9170184 DOI: 10.1080/02786826.2021.2020210] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 05/30/2023]
Abstract
Transparent barriers were installed as a response to the SARS-COV-2 pandemic in many customer-facing industries. Transparent barriers are an engineering control that intercept particles traveling between customers and workers. Information on the effectiveness of these barriers against aerosols is limited. In this study, a cough simulator was used to represent a cough from a customer. Two optical particle counters were used (one on each side of the barrier, labeled customer and worker) to determine the number of particles that migrated around a transparent barrier. Ten configurations were tested with six replicates for both sitting and standing scenarios, representing nail salons and grocery stores, respectively. Barrier efficiency was calculated using a ratio of the particle count results (customer/worker). Barriers had better efficiency (up to 93%) when its top was 9 to 39 cm above cough height and its width was at least 91 cm. Barriers that extended 91 cm above table height for both scenarios blocked 71% or more of the particles between 0.35-0.725 μm and 68% for particles between 1 to 3 μm. A barrier that blocked an initial cough was effective at reducing particle counts. While the width of the barriers was not as significant as the height in determining barrier efficiency it is important that a barrier be placed where interactions between customers and workers are most frequent. Bystander exposure was not taken into consideration along with other limitations.
Collapse
Affiliation(s)
- Jacob Bartels
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA
| | - Cheryl Fairfield Estill
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA
| | - I-Chen Chen
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA
| | - Dylan Neu
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, Ohio, USA
| |
Collapse
|
56
|
Du Puis JL, Forstenhausler L, Goodge K, Maher M, Frey M, Baytar F, Park H. Cloth face mask fit and function for children part one: design exploration. FASHION AND TEXTILES 2022; 9:14. [PMCID: PMC9107347 DOI: 10.1186/s40691-022-00287-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Commercially available children’s cloth masks range widely in material type and fabric structures, methods of construction, layering, and shape, and there is a lack of sizing systems, anthropometric data or guidelines specifically targeting the fit assessment and design of cloth face masks for children 4-6 years old. To better identify and understand the cloth face mask fit and functional needs of children ages 4-6 years old, the researchers embarked on interdisciplinary in-depth study to investigate commercial market offerings of children’s face masks, identify consumer perspectives, and explore mask design improvements through design research. By triangulating results from survey feedback, commercial market content analysis, and wear trial observations, the researchers were able to identify important design criteria that can be used in the improvement of children’s cloth face mask design: size, comfort, dexterity, movement, and thermal comfort. These criteria were used to iteratively develop new mask prototypes involving a 3D printed head form, traditional sewing and hand patternmaking skills, and the creation of multiple mask versions to explore the design criteria listed above. The designs were interpreted through Bye’s (2010) Problem-Based Design Research (PBDR) framework, which identifies common design research practices in the field on a spectrum and situates PBDR as a process centered on a problem as impetus for design through which artifacts are developed.
Collapse
Affiliation(s)
- Jenny Leigh Du Puis
- Cornell University, T-41 Human Ecology Building, 37 Forest Home Dr, Ithaca, NY 14853 USA
| | - Lauren Forstenhausler
- Cornell University, 255 Human Ecology Building, 37 Forest Home Dr, Ithaca, NY 14853 USA
| | - Katarina Goodge
- Cornell University, 150 Human Ecology Building, 37 Forest Home Dr, Ithaca, NY 14853 USA
| | - Mona Maher
- Cornell University, 112 Human Ecology Building, 37 Forest Home Dr., Ithaca, NY 14853 USA
| | - Margaret Frey
- Cornell University, 235 Human Ecology Building, 37 Forest Home Dr, Ithaca, NY 14853 USA
| | - Fatma Baytar
- Cornell University, 133 Human Ecology Building, 37 Forest Home Dr., Ithaca, NY 14853 USA
| | - Huiju Park
- Cornell University, 131 Human Ecology Building, 37 Forest Home Dr, Ithaca, NY 14853 USA
| |
Collapse
|
57
|
Acuti Martellucci C, Flacco ME, Martellucci M, Violante FS, Manzoli L. Inhaled CO 2 Concentration While Wearing Face Masks: A Pilot Study Using Capnography. ENVIRONMENTAL HEALTH INSIGHTS 2022. [PMID: 36133777 DOI: 10.1101/2022.05.10.22274813] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND Face masks are recommended based on the assumption that they protect against SARS-CoV-2 transmission, however studies on their potential side effects are still lacking. We aimed to evaluate the inhaled air carbon dioxide (CO2) concentration, when wearing masks. METHODS We measured end-tidal CO2 using professional side-stream capnography, with water-removing tubing, (1) without masks, (2) wearing a surgical mask, and (3) wearing a FFP2 respirator (for 5 minutes each while seated after 10 minutes of rest), in 146 healthy volunteers aged 10 to 90 years, from the general population of Ferrara, Italy. The inhaled air CO2 concentration was computed as: ([mask volume × end-tidal CO2] + [tidal volume - mask volume] × ambient air CO2)/tidal volume. RESULTS With surgical masks, the mean CO2 concentration was 7091 ± 2491 ppm in children, 4835 ± 869 in adults, and 4379 ± 978 in the elderly. With FFP2 respirators, this concentration was 13 665 ± 3655 in children, 8502 ± 1859 in adults, and 9027 ± 1882 in the elderly. The proportion showing a CO2 concentration higher than the 5000 ppm (8-hour average) acceptable threshold for workers was 41.1% with surgical masks, and 99.3% with FFP2 respirators. Adjusting for age, gender, BMI, and smoking, the inhaled air CO2 concentration significantly increased with increasing respiratory rate (mean 10 837 ±3712 ppm among participants ⩾18 breaths/minute, with FFP2 respirators), and among the minors. CONCLUSION If these results are confirmed, the current guidelines on mask-wearing should be reevaluated.
Collapse
Affiliation(s)
| | - Maria Elena Flacco
- Department of Environmental and Prevention Sciences, University of Ferrara, Ferrara, Italy
| | - Mosè Martellucci
- Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Francesco Saverio Violante
- Occupational Health Unit, Sant'Orsola Malpighi University Hospital, University of Bologna, Bologna, Italy
| | - Lamberto Manzoli
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| |
Collapse
|
58
|
Ataei M, Shirazi FM, Nakhaee S, Abdollahi M, Mehrpour O. Assessment of cloth masks ability to limit Covid-19 particles spread: a systematic review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:1645-1676. [PMID: 34689269 PMCID: PMC8541808 DOI: 10.1007/s11356-021-16847-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 09/28/2021] [Indexed: 05/10/2023]
Abstract
After the spread of Covid 19 worldwide, the use of cloth masks increased significantly due to a shortage of medical masks. Meanwhile, there were different opinions about the effectiveness of these masks and, so far, no study has been done to find the best fabric masks. This study reviews and summarizes all studies related to fabric masks' effectiveness and various fabrics against coronavirus. This systematic review is based on PRISMA rules. Two researchers separately examined three databases: PubMed, Scopus, and Web of Science. Laboratory and clinical studies were included. After extracting the articles, their quality was assessed with the Joanna Briggs Institute (JBI) tool. In addition to efficacy, other factors, including the penetration of masks, pressure drop, and quality factor, were examined to select the best fabrics. Of the 42 studies selected, 39 were laboratory studies, and 3 were clinical studies. Among the various fabrics examined, cotton quilt 120 thread per inch (TPI), copy paper (bonded), hybrid of cotton with chiffon/ silk, and flannel filtration were found to have over 90% effectiveness in the particle size range of Covid-19. The results and comparison of different factors (pressure drop, filtration efficacy, penetration, filtration quality, and fit factor have been evaluated) showed that among different fabrics, hybrid masks, 2-layered cotton quilt, 2-layered 100% cotton, cotton flannel, and hairy tea towel + fleece sweater had the best performance. Clinical studies have not explicitly examined cloth masks' effectiveness in Covid-19, so the effectiveness of these types of masks for Covid 19 is questionable, and more studies are needed.
Collapse
Affiliation(s)
- Mahshid Ataei
- Medical Toxicology and Drug Abuse Research Center (MTDRC), Birjand University of Medical Sciences (BUMS), Birjand, Iran
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), and Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Farshad M Shirazi
- Arizona Poison & Drug Information Center, University of Arizona, College of Pharmacy and University of Arizona College of Medicine, Tucson, AZ, USA
| | - Samaneh Nakhaee
- Medical Toxicology and Drug Abuse Research Center (MTDRC), Birjand University of Medical Sciences (BUMS), Birjand, Iran
| | - Mohammad Abdollahi
- Toxicology and Diseases Group, Pharmaceutical Sciences Research Center (PSRC), The Institute of Pharmaceutical Sciences (TIPS), and Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Omid Mehrpour
- Medical Toxicology and Drug Abuse Research Center (MTDRC), Birjand University of Medical Sciences (BUMS), Birjand, Iran.
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA.
| |
Collapse
|
59
|
Bueno de Mesquita PJ, Delp WW, Chan WR, Bahnfleth WP, Singer BC. Control of airborne infectious disease in buildings: Evidence and research priorities. INDOOR AIR 2022; 32:e12965. [PMID: 34816493 DOI: 10.1111/ina.12965] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/07/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Abstract
The evolution of SARS-CoV-2 virus has resulted in variants likely to be more readily transmitted through respiratory aerosols, underscoring the increased potential for indoor environmental controls to mitigate risk. Use of tight-fitting face masks to trap infectious aerosol in exhaled breath and reduce inhalation exposure to contaminated air is of critical importance for disease control. Administrative controls including the regulation of occupancy and interpersonal spacing are also important, while presenting social and economic challenges. Indoor engineering controls including ventilation, exhaust, air flow control, filtration, and disinfection by germicidal ultraviolet irradiation can reduce reliance on stringent occupancy restrictions. However, the effects of controls-individually and in combination-on reducing infectious aerosol transfer indoors remain to be clearly characterized to the extent needed to support widespread implementation by building operators. We review aerobiologic and epidemiologic evidence of indoor environmental controls against transmission and present a quantitative aerosol transfer scenario illustrating relative differences in exposure at close-interactive, room, and building scales. We identify an overarching need for investment to implement building controls and evaluate their effectiveness on infection in well-characterized and real-world settings, supported by specific, methodological advances. Improved understanding of engineering control effectiveness guides implementation at scale while considering occupant comfort, operational challenges, and energy costs.
Collapse
Affiliation(s)
| | - William W Delp
- Indoor Environment Group, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Wanyu R Chan
- Indoor Environment Group, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - William P Bahnfleth
- Department of Architectural Engineering, Pennsylvania State University, State College, Pennsylvania, USA
| | - Brett C Singer
- Indoor Environment Group, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| |
Collapse
|
60
|
Coyle JP, Derk RC, Lindsley WG, Blachere FM, Boots T, Lemons AR, Martin SB, Mead KR, Fotta SA, Reynolds JS, McKinney WG, Sinsel EW, Beezhold DH, Noti JD. Efficacy of Ventilation, HEPA Air Cleaners, Universal Masking, and Physical Distancing for Reducing Exposure to Simulated Exhaled Aerosols in a Meeting Room. Viruses 2021; 13:2536. [PMID: 34960804 PMCID: PMC8707272 DOI: 10.3390/v13122536] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/07/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022] Open
Abstract
There is strong evidence associating the indoor environment with transmission of SARS-CoV-2, the virus that causes COVID-19. SARS-CoV-2 can spread by exposure to droplets and very fine aerosol particles from respiratory fluids that are released by infected persons. Layered mitigation strategies, including but not limited to maintaining physical distancing, adequate ventilation, universal masking, avoiding overcrowding, and vaccination, have shown to be effective in reducing the spread of SARS-CoV-2 within the indoor environment. Here, we examine the effect of mitigation strategies on reducing the risk of exposure to simulated respiratory aerosol particles within a classroom-style meeting room. To quantify exposure of uninfected individuals (Recipients), surrogate respiratory aerosol particles were generated by a breathing simulator with a headform (Source) that mimicked breath exhalations. Recipients, represented by three breathing simulators with manikin headforms, were placed in a meeting room and affixed with optical particle counters to measure 0.3-3 µm aerosol particles. Universal masking of all breathing simulators with a 3-ply cotton mask reduced aerosol exposure by 50% or more compared to scenarios with simulators unmasked. While evaluating the effect of Source placement, Recipients had the highest exposure at 0.9 m in a face-to-face orientation. Ventilation reduced exposure by approximately 5% per unit increase in air change per hour (ACH), irrespective of whether increases in ACH were by the HVAC system or portable HEPA air cleaners. The results demonstrate that mitigation strategies, such as universal masking and increasing ventilation, reduce personal exposure to respiratory aerosols within a meeting room. While universal masking remains a key component of a layered mitigation strategy of exposure reduction, increasing ventilation via system HVAC or portable HEPA air cleaners further reduces exposure.
Collapse
Affiliation(s)
- Jayme P. Coyle
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Raymond C. Derk
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - William G. Lindsley
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Francoise M. Blachere
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Theresa Boots
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Angela R. Lemons
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Stephen B. Martin
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA;
| | - Kenneth R. Mead
- Division of Field Studies and Engineering, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Cincinnati, OH 45226, USA;
| | - Steven A. Fotta
- Facilities Management Office, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA;
| | - Jeffrey S. Reynolds
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Walter G. McKinney
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Erik W. Sinsel
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - Donald H. Beezhold
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| | - John D. Noti
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA; (J.P.C.); (R.C.D.); (F.M.B.); (T.B.); (A.R.L.); (J.S.R.); (W.G.M.); (E.W.S.); (D.H.B.); (J.D.N.)
| |
Collapse
|
61
|
Freeman AL, Parker S, Noakes C, Fitzgerald S, Smyth A, Macbeth R, Spiegelhalter D, Rutter H. Expert elicitation on the relative importance of possible SARS-CoV-2 transmission routes and the effectiveness of mitigations. BMJ Open 2021; 11:e050869. [PMID: 34853105 PMCID: PMC8637346 DOI: 10.1136/bmjopen-2021-050869] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/26/2021] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVES To help people make decisions about the most effective mitigation measures against SARS-CoV-2 transmission in different scenarios, the likelihoods of transmission by different routes need to be quantified to some degree (however uncertain). These likelihoods need to be communicated in an appropriate way to illustrate the relative importance of different routes in different scenarios, the likely effectiveness of different mitigation measures along those routes, and the level of uncertainty in those estimates. In this study, a pragmatic expert elicitation was undertaken to supply the underlying quantitative values to produce such a communication tool. PARTICIPANTS Twenty-seven individual experts from five countries and many scientific disciplines provided estimates. OUTCOME MEASURES Estimates of transmission parameters, assessments of the quality of the evidence, references to relevant literature, rationales for their estimates and sources of uncertainty. RESULTS AND CONCLUSION The participants' responses showed that there is still considerable disagreement among experts about the relative importance of different transmission pathways and the effectiveness of different mitigation measures due to a lack of empirical evidence. Despite these disagreements, when pooled, the majority views on each parameter formed an internally consistent set of estimates (for example, that transmission was more likely indoors than outdoors, and at closer range), which formed the basis of a visualisation to help individuals and organisations understand the factors that influence transmission and the potential benefits of different mitigation measures.
Collapse
Affiliation(s)
- Alexandra Lj Freeman
- Winton Centre for Risk & Evidence Communication, University of Cambridge, Cambridge, UK
| | - Simon Parker
- Defence Science and Technology Laboratory, Salisbury, UK
| | | | - Shaun Fitzgerald
- Centre for Climate Repair at Cambridge, University of Cambridge, Cambridge, UK
| | | | | | - David Spiegelhalter
- Winton Centre for Risk & Evidence Communication, University of Cambridge, Cambridge, UK
| | | |
Collapse
|
62
|
Elastomeric Respirators for COVID-19 and the Next Respiratory Virus Pandemic: Essential Design Elements. Anesthesiology 2021; 135:951-962. [PMID: 34666348 DOI: 10.1097/aln.0000000000004005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Respiratory viruses are transmitted via respiratory particles that are emitted when people breath, speak, cough, or sneeze. These particles span the size spectrum from visible droplets to airborne particles of hundreds of nanometers. Barrier face coverings ("cloth masks") and surgical masks are loose-fitting and provide limited protection from airborne particles since air passes around the edges of the mask as well as through the filtering material. Respirators, which fit tightly to the face, provide more effective respiratory protection. Although healthcare workers have relied primarily on disposable filtering facepiece respirators (such as N95) during the COVID-19 pandemic, reusable elastomeric respirators have significant potential advantages for the COVID-19 and future respiratory virus pandemics. However, currently available elastomeric respirators were not designed primarily for healthcare or pandemic use and require further development to improve their suitability for this application. The authors believe that the development, implementation, and stockpiling of improved elastomeric respirators should be an international public health priority.
Collapse
|
63
|
Li R, Zhang M, Wu Y, Tang P, Sun G, Wang L, Mandal S, Wang L, Lang J, Passalacqua A, Subramaniam S, Song G. What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues. Polymers (Basel) 2021; 13:4165. [PMID: 34883668 PMCID: PMC8659889 DOI: 10.3390/polym13234165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 02/07/2023] Open
Abstract
Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.
Collapse
Affiliation(s)
- Rui Li
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Mengying Zhang
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Yulin Wu
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Peixin Tang
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA; (P.T.); (G.S.)
| | - Gang Sun
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA; (P.T.); (G.S.)
| | - Liwen Wang
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Sumit Mandal
- Department of Design, Housing and Merchandising, Oklahoma State University, Stillwater, OK 74078, USA;
| | - Lizhi Wang
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, Ames, IA 50010, USA;
| | - James Lang
- Department of Kinesiology, Iowa State University, Ames, IA 50010, USA;
| | - Alberto Passalacqua
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA; (A.P.); (S.S.)
| | - Shankar Subramaniam
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA; (A.P.); (S.S.)
| | - Guowen Song
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| |
Collapse
|
64
|
Grinshpun SA, Yermakov M. Technical note: Impact of face covering on aerosol transport patterns during coughing and sneezing. JOURNAL OF AEROSOL SCIENCE 2021; 158:105847. [PMID: 34305164 PMCID: PMC8279921 DOI: 10.1016/j.jaerosci.2021.105847] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 05/02/2023]
Abstract
COVID-19 is spread via different routes, including virus-laden airborne particles generated by human respiratory activities. In addition to large droplets, coughing and sneezing produce a lot of small aerosol particles. While face coverings are believed to reduce the aerosol transmission, information about their outward effectiveness is limited. Here, we determined the aerosol concentration patterns around a coughing and sneezing manikin and established spatial zones representing specific elevations of the aerosol concentration relative to the background. Real-time measurements of sub-micrometer aerosol particles were performed in the vicinity of the manikin. The tests were carried out without any face covering and with three different types of face covers: a safety faceshield, low-efficiency facemask and high-efficiency surgical mask. With no face covering, the simulated coughing and sneezing created a powerful forward-propagating fine aerosol flow. At 6 ft forward from the manikin head, the aerosol concentration was still 20-fold above the background. Adding a face covering reconfigured the forward-directed aerosol transmission pattern. The tested face coverings were found capable of mitigating the risk of coronavirus transmission; their effectiveness is dependent on the protective device. The outward leakage associated with a specific face covering was shown to be a major determinant of the exposure level for a person standing or seating next to or behind the coughing or sneezing "spreader" in a bus/train/aircraft/auditorium setting. Along with reports recently published in the literature, the study findings help assess the infectious dose and ultimately health risk for persons located within a 6-ft radius around the "spreader."
Collapse
Affiliation(s)
- Sergey A Grinshpun
- Center for Health-Related Aerosol Studies, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Michael Yermakov
- Center for Health-Related Aerosol Studies, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| |
Collapse
|
65
|
Chazelet S, Pacault S. Efficiency of Community Face Coverings and Surgical Masks to Limit the Spread of Aerosol. Ann Work Expo Health 2021; 66:495-509. [PMID: 34668014 DOI: 10.1093/annweh/wxab089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 09/14/2021] [Accepted: 09/24/2021] [Indexed: 11/14/2022] Open
Abstract
In the current pandemic context of COVID-19, people wear different types of masks, particularly in their workplace, to limit the spread of the virus. Depending on their activity and work environment, employees are required to wear community face coverings, cloth masks with a transparent windows, surgical masks, reusable masks, or respirators. The objective of this study was to evaluate the efficiency as source control of these masks, i.e., when worn to protect the environment from the spread of particles emitted by the wearer. An experimental test bench including a dummy head and a breathing simulator associated with a DEHS droplet generator emitting 1 or 3 µm particles in the exhaled stream is used. Source control efficiency is calculated from the total flux of particles emitted in the test section without and with a mask. Seventeen models of masks are tested. Three breathing rate conditions were studied: from rest to heavy breathing, with average rates of 13, 27, and 45 L/min. Source control efficiencies vary from one mask to another. Among community face coverings (seven models) the values ranged from 15.6 to 33.8% for a medium intensity breath. The efficiencies of surgical masks (three models) ranged from 17.4 to 28.3% for the same breathing cycle. The community face coverings and the disposable surgical masks present equivalent values of source control efficiency, respectively, 25.9 and 24.1% at 1 µm and 31.5 and 23.2% at 3 µm. The respirators show higher source control efficiency than the other types of masks (76.7% at 1 µm and 82.5% at 3 µm). The statistical analysis of the data shows no effect of the breathing flow rate and an interaction effect between mask type and particle size. No differences in source control were found for the two particle sizes or the different experimental breathing rates for the respirators and the surgical masks. But the community face coverings and the cloth masks with transparent window present a source control efficiency which increases with the particle size. Varying levels of efficiency were measured with higher source control for respirators than for other types of masks. In the context of a respiratory protection programme, they can provide an effective barrier to the spread of the virus. But these results show also that no mask can stop all the particles emitted by its wearer. Regardless of the type of mask, other barrier measures (ventilation, social distancing, and hygiene) are then necessary.
Collapse
Affiliation(s)
- Sandrine Chazelet
- National Institute for Research and Safety, Process Engineering Department, 1, rue du Morvan - CS 60027 - 54519 Vandoeuvre Cedex, France
| | - Stephanie Pacault
- National Institute for Research and Safety, Process Engineering Department, 1, rue du Morvan - CS 60027 - 54519 Vandoeuvre Cedex, France
| |
Collapse
|
66
|
Kurabuchi T, Yanagi U, Ogata M, Otsuka M, Kagi N, Yamamoto Y, Hayashi M, Tanabe S. Operation of air‐conditioning and sanitary equipment for SARS‐CoV‐2 infectious disease control. JAPAN ARCHITECTURAL REVIEW 2021; 4:608-620. [PMCID: PMC8420534 DOI: 10.1002/2475-8876.12238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/17/2021] [Indexed: 06/15/2023]
Abstract
It is still undetermined if the main infection route of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the virus that leads to coronavirus disease 2019 (COVID‐19), is infection through droplet, contact, or airborne transmission. However, confined spaces with poor ventilation are cited as a risk factor for group outbreaks, and there is growing interest in the effects of intervention through the appropriate operation of air‐conditioning and sanitary equipment to reduce the risk of airborne transmission. This study first offers an outline of the characteristics of the novel coronavirus disease and the cluster outbreak case reports that have been clarified until now. Subsequently, we describe the appropriate operating conditions for building equipment that are effective in reducing the risk of infection and also highlight specificities for each building use based on the guidance provided by healthcare institutions and with reference to the standard recommendations by Western academic societies related to building equipment.
Collapse
Affiliation(s)
- Takashi Kurabuchi
- Department of ArchitectureFaculty of EngineeringTokyo University of ScienceTokyoJapan
| | - U. Yanagi
- School of ArchitectureKogakuin UniversityTokyoJapan
| | - Masayuki Ogata
- Department of ArchitectureFaculty of Urban Environmental SciencesTokyo Metropolitan UniversityTokyoJapan
| | - Masayuki Otsuka
- College of Architecture and Environmental DesignKanto Gakuin UniversityYokohamaJapan
| | - Naoki Kagi
- School of Environment and SocietyTokyo Institute of TechnologyTokyoJapan
| | | | | | | |
Collapse
|
67
|
Desforges M, Gurdasani D, Hamdy A, Leonardi AJ. Uncertainty around the Long-Term Implications of COVID-19. Pathogens 2021; 10:1267. [PMID: 34684216 PMCID: PMC8536991 DOI: 10.3390/pathogens10101267] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 01/08/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 231 million people globally, with more than 4.7 million deaths recorded by the World Health Organization as of 26 September 2021. In response to the pandemic, some countries (New Zealand, Vietnam, Taiwan, South Korea and others) have pursued suppression strategies, so-called Zero COVID policies, to drive and maintain infection rates as close to zero as possible and respond aggressively to new cases. In comparison, European countries and North America have adopted mitigation strategies (of varying intensity and effectiveness) that aim primarily to prevent health systems from being overwhelmed. With recent advances in our understanding of SARS-CoV-2 and its biology, and the increasing recognition there is more to COVID-19 beyond the acute infection, we offer a perspective on some of the long-term risks of mutational escape, viral persistence, reinfection, immune dysregulation and neurological and multi-system complications (Long COVID).
Collapse
Affiliation(s)
- Marc Desforges
- Centre Hospitalier Universitaire Ste-Justine and Faculté de Médecine, Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | | | - Adam Hamdy
- Panres Pandemic Research, Newport TF10 8PG, UK;
| | - Anthony J. Leonardi
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA;
| |
Collapse
|
68
|
Siwal SS, Chaudhary G, Saini AK, Kaur H, Saini V, Mokhta SK, Chand R, Chandel UK, Christie G, Thakur VK. Key ingredients and recycling strategy of personal protective equipment (PPE): Towards sustainable solution for the COVID-19 like pandemics. JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 2021; 9:106284. [PMID: 34485055 PMCID: PMC8404393 DOI: 10.1016/j.jece.2021.106284] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/26/2021] [Accepted: 08/25/2021] [Indexed: 05/24/2023]
Abstract
The COVID-19 pandemic has intensified the complications of plastic trash management and disposal. The current situation of living in fear of transmission of the COVID-19 virus has further transformed our behavioural models, such as regularly using personal protective equipment (PPE) kits and single-use applications for day to day needs etc. It has been estimated that with the passage of the coronavirus epidemic every month, there is expected use of 200 billion pieces of single-use facemasks and gloves. PPE are well established now as life-saving items for medicinal specialists to stay safe through the COVID-19 pandemic. Different processes such as glycolysis, hydrogenation, aminolysis, hydrolysis, pyrolysis, and gasification are now working on finding advanced technologies to transfer waste PPE into value-added products. Here, in this article, we have discussed the recycling strategies of PPE, important components (such as medical gloves, gowns, masks & respirators and other face and eye protection) and the raw materials used in PPE kits. Further, the value addition methods to recycling the PPE kits, chemical & apparatus used in recycling and recycling components into value-added products. Finally, the biorenewable materials in PPE for textiles components have been discussed along with concluded remarks.
Collapse
Affiliation(s)
- Samarjeet Singh Siwal
- Department of Chemistry, M.M. Engineering College, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana 133207, India
| | - Gauri Chaudhary
- Department of Chemistry, M.M. Engineering College, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana 133207, India
| | - Adesh Kumar Saini
- Department of Biotechnology, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana 133207, India
| | - Harjot Kaur
- Department of Chemistry, M.M. Engineering College, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana 133207, India
| | - Vipin Saini
- Department of Pharmacy, Maharishi Markandeshwar University, Kumarhatti, Solan, Himachal Pradesh, 173229, India
| | - Sudesh Kumar Mokhta
- Department of Environment, Science & Technology, Government of Himachal Pradesh, 171001, India
| | - Ramesh Chand
- Department of Health and Family Welfare, Government of Himachal Pradesh, 171001, India
| | - U K Chandel
- Department of surgery, Indira Gandhi Medical College and Hospital (IGMC), Shimla, Himachal Pradesh 171001, India
| | - Graham Christie
- Institute of Biotechnology, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
| | - Vijay Kumar Thakur
- Biorefining and Advanced Materials Research Center, SRUC, Kings Buildings, Edinburgh EH9 3JG, UK
- Enhanced Composites and Structures Center, School of Aerospace, Transport and Manufacturing, Cranfield University, Bedfordshire MK43 0AL, UK
- Faculty of Materials Science and Applied Chemistry Institute of Polymer Materials, Riga Technical University, P.Valdena 3/7, LV, 1048 Riga, Latvia
- Department of Mechanical Engineering, School of Engineering, Shiv Nadar University, Uttar Pradesh 201314, India
- School of Engineering, University of Petroleum & Energy Studies (UPES), Dehradun, Uttarakhand, India
| |
Collapse
|
69
|
Hartvigsen G. Network assessment and modeling the management of an epidemic on a college campus with testing, contact tracing, and masking. PLoS One 2021; 16:e0257052. [PMID: 34534212 PMCID: PMC8448338 DOI: 10.1371/journal.pone.0257052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/22/2021] [Indexed: 01/12/2023] Open
Abstract
There remains a great challenge to minimize the spread of epidemics, especially in high-density communities such as colleges and universities. This is particularly true on densely populated, residential college campuses. To construct class and residential networks data from a four-year, residential liberal arts college with 5539 students were obtained from SUNY College at Geneseo, a rural, residential, undergraduate institution in western NY, USA. Equal-sized random networks also were created for each day. Different levels of compliance with mask use (none to 100%), mask efficacy (50% to 100%), and testing frequency (daily, or every 2, 3, 7, 14, 28, or 105 days) were assessed. Tests were assumed to be only 90% accurate and positive results were used to isolate individuals. The effectiveness of contact tracing, and the effect of quarantining neighbors of infectious individuals, was tested. The structure of the college course enrollment and residence networks greatly influenced the dynamics of the epidemics, as compared to the random networks. In particular, average path lengths were longer in the college networks compared to random networks. Students in larger majors generally had shorter average path lengths than students in smaller majors. Average transitivity (clustering) was lower on days when students most frequently were in class (MWF). Degree distributions were generally large and right skewed, ranging from 0 to 719. Simulations began by inoculating twenty students (10 exposed and 10 infectious) with SARS-CoV-2 on the first day of the fall semester and ended once the disease was cleared. Transmission probability was calculated based on an R0 = 2.4. Without interventions epidemics resulted in most students becoming infected and lasted into the second semester. On average students in the college networks experienced fewer infections, shorter duration, and lower epidemic peaks when compared to the dynamics on equal-sized random networks. The most important factors in reducing case numbers were the proportion masking and the frequency of testing, followed by contact tracing and mask efficacy. The paper discusses further high-order interactions and other implications of non-pharmaceutical interventions for disease transmission on a residential college campus.
Collapse
Affiliation(s)
- Gregg Hartvigsen
- Biology Department, SUNY Geneseo, Geneseo, NY, United States of America
| |
Collapse
|
70
|
Crawford MJ, Ramezani S, Jabbari R, Pathak P, Cho HJ, Kim BN, Choi H. Development of a novel self-sanitizing mask prototype to combat the spread of infectious disease and reduce unnecessary waste. Sci Rep 2021; 11:18213. [PMID: 34521866 PMCID: PMC8440541 DOI: 10.1038/s41598-021-97357-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/23/2021] [Indexed: 12/04/2022] Open
Abstract
With the spread of COVID-19, significant emphasis has been placed on mitigation techniques such as mask wearing to slow infectious disease transmission. Widespread use of face coverings has revealed challenges such as mask contamination and waste, presenting an opportunity to improve the current technologies. In response, we have developed the Auto-sanitizing Retractable Mask Optimized for Reusability (ARMOR). ARMOR is a novel, reusable face covering that can be quickly disinfected using an array of ultraviolet C lamps contained within a wearable case. A nanomembrane UVC sensor was used to quantify the intensity of germicidal radiation at 18 different locations on the face covering and determine the necessary exposure time to inactivate SARS-CoV-2 in addition to other viruses and bacteria. After experimentation, it was found that ARMOR successfully provided germicidal radiation to all areas of the mask and will inactivate SARS-CoV-2 in approximately 180 s, H1N1 Influenza in 130 s, and Mycobacterium tuberculosis in 113 s, proving that this design is effective at eliminating a variety of pathogens and can serve as an alternative to traditional waste-producing disposable face masks. The accessibility, ease of use, and speed of sanitization supports the wide application of ARMOR in both clinical and public settings.
Collapse
Affiliation(s)
- Matthew J Crawford
- Department of Biomedical Sciences, University of Central Florida, Orlando, 32816, USA
| | - Sepehr Ramezani
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, 32816, USA
| | | | - Pawan Pathak
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, 32816, USA
| | - Hyoung J Cho
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, 32816, USA
| | - Brian N Kim
- Department of Electrical and Computer Engineering, University of Central Florida, Orlando, 32816, USA
| | - Hwan Choi
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, 32816, USA.
| |
Collapse
|
71
|
Ngonghala CN, Knitter JR, Marinacci L, Bonds MH, Gumel AB. Assessing the impact of widespread respirator use in curtailing COVID-19 transmission in the USA. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210699. [PMID: 34527275 PMCID: PMC8424336 DOI: 10.1098/rsos.210699] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/25/2021] [Indexed: 05/14/2023]
Abstract
Dynamic models are used to assess the impact of three types of face masks (cloth masks, surgical/procedure masks and respirators) in controlling the COVID-19 pandemic in the USA. We showed that the pandemic would have failed to establish in the USA if a nationwide mask mandate, based on using respirators with moderately high compliance, had been implemented during the first two months of the pandemic. The other mask types would fail to prevent the pandemic from becoming established. When mask usage compliance is low to moderate, respirators are far more effective in reducing disease burden. Using data from the third wave, we showed that the epidemic could be eliminated in the USA if at least 40% of the population consistently wore respirators in public. Surgical masks can also lead to elimination, but requires compliance of at least 55%. Daily COVID-19 mortality could be eliminated in the USA by June or July 2021 if 95% of the population opted for either respirators or surgical masks from the beginning of the third wave. We showed that the prospect of effective control or elimination of the pandemic using mask-based strategy is greatly enhanced if combined with other non-pharmaceutical interventions (NPIs) that significantly reduce the baseline community transmission. By slightly modifying the model to include the effect of a vaccine against COVID-19 and waning vaccine-derived and natural immunity, this study shows that the waning of such immunity could trigger multiple new waves of the pandemic in the USA. The number, severity and duration of the projected waves depend on the quality of mask type used and the level of increase in the baseline levels of other NPIs used in the community during the onset of the third wave of the pandemic in the USA. Specifically, no severe fourth or subsequent wave of the pandemic will be recorded in the USA if surgical masks or respirators are used, particularly if the mask use strategy is combined with an increase in the baseline levels of other NPIs. This study further emphasizes the role of human behaviour towards masking on COVID-19 burden, and highlights the urgent need to maintain a healthy stockpile of highly effective respiratory protection, particularly respirators, to be made available to the general public in times of future outbreaks or pandemics of respiratory diseases that inflict severe public health and socio-economic burden on the population.
Collapse
Affiliation(s)
- Calistus N. Ngonghala
- Department of Mathematics, University of Florida, Gainesville, FL, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - James R. Knitter
- Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Lucas Marinacci
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Matthew H. Bonds
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, USA
| | - Abba B. Gumel
- School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ, USA
- Department of Mathematics and Applied Mathematics, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
72
|
Segaloff HE, Cole D, Rosenblum HG, Lee CC, Morgan CN, Remington P, Pitts C, Kelly P, Baggott J, Bateman A, Somers T, Ruff J, Payne D, Desamu-Thorpe R, Foster MA, Currie DW, Abedi GR, Westergaard R, Hsu CH, Tate JE, Kirking HL. Risk Factors for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection and Presence of Anti-SARS-CoV-2 Antibodies Among University Student Dormitory Residents, September-November 2020. Open Forum Infect Dis 2021; 8:ofab405. [PMID: 34552995 PMCID: PMC8436379 DOI: 10.1093/ofid/ofab405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 07/29/2021] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks occurred at universities during Fall 2020, but little is known about risk factors for campus-associated infections or immunity provided by anti-SARS-CoV-2 antibodies in young adults. METHODS We conducted surveys and serology tests among students living in dormitories in September and November to examine infection risk factors and antibody presence. Using campus weekly reverse-transcription polymerase chain reaction (RT-PCR) test results, the relationship between survey responses, SARS-CoV-2 antibodies, and infections was assessed. RESULTS Of 6136 students, 1197 completed the survey and 572 also completed serologic testing in September compared with 517 and 414 in November, respectively. Participation in fraternity or sorority events (adjusted risk ratio [aRR], 1.9 [95% confidence interval {CI}, 1.4-2.5]) and frequent alcohol consumption (aRR, 1.6 [95% CI, 1.2-2.2]) were associated with SARS-CoV-2 infection. Mask wearing during social events (aRR, 0.6 [95% CI, .6-1.0]) was associated with decreased risk. None of the 20 students with antibodies in September tested positive for SARS-CoV-2 during the semester, while 27.8% of students who tested RT-PCR positive tested negative for antibodies in November. CONCLUSIONS Frequent drinking and attending social events were associated with SARS-CoV-2 infection. Antibody presence in September appeared to be protective from reinfection, but this finding was not statistically significant.
Collapse
Affiliation(s)
- Hannah E Segaloff
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta Georgia, USA
- Wisconsin Department of Health Services, Madison, Wisconsin, USA
| | - Devlin Cole
- Wisconsin Department of Health Services, Madison, Wisconsin, USA
- School of Medicine and Public Health, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Hannah G Rosenblum
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta Georgia, USA
| | - Christine C Lee
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Laboratory Leadership Service, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Clint N Morgan
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Patrick Remington
- School of Medicine and Public Health, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Collin Pitts
- School of Medicine and Public Health, University of Wisconsin–Madison, Madison, Wisconsin, USA
- University Health Services, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Patrick Kelly
- School of Medicine and Public Health, University of Wisconsin–Madison, Madison, Wisconsin, USA
- University Health Services, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Jake Baggott
- University Health Services, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Allen Bateman
- Wisconsin State Laboratory of Hygiene, Madison, Wisconsin, USA
| | - Tarah Somers
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jeanne Ruff
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta Georgia, USA
| | - David Payne
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Laboratory Leadership Service, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Rodel Desamu-Thorpe
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Monique A Foster
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Dustin W Currie
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta Georgia, USA
| | - Glen R Abedi
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ryan Westergaard
- Wisconsin Department of Health Services, Madison, Wisconsin, USA
- School of Medicine and Public Health, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Christopher H Hsu
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jaqueline E Tate
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Hannah L Kirking
- COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| |
Collapse
|
73
|
Jin Z, Jorns A, Yim W, Wing R, Mantri Y, Zhou J, Zhou J, Wu Z, Moore C, Penny WF, Jokerst JV. Mapping Aerosolized Saliva on Face Coverings for Biosensing Applications. Anal Chem 2021; 93:11025-11032. [PMID: 34309356 PMCID: PMC8543450 DOI: 10.1021/acs.analchem.1c02399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Facemasks in congregate settings prevent the transmission of SARS-CoV-2 and help control the ongoing COVID-19 global pandemic because face coverings can arrest transmission of respiratory droplets. While many groups have studied face coverings as personal protective equipment, these respiratory droplets can also serve as a diagnostic fluid to report on health state; surprisingly, studies of face coverings from this perspective are quite limited. Here, we determined the concentration and distribution of aerosolized saliva (via α-amylase levels) captured on various face coverings. Our results showed that α-amylase accumulated on face coverings in a time-dependent way albeit at different levels, e.g., neck gaiters and surgical masks captured about 3-fold more α-amylase than cloth masks and N95 respirators. In addition, the saliva aerosols were primarily detected on the inner layer of multilayered face coverings. We also found that the distribution of salivary droplets on the mask correlated with the morphologies of face coverings as well as their coherence to the face curvature. These findings motivated us to extend this work and build multifunctional sensing strips capable of detecting biomarkers in situ to create "smart" masks. The work highlights that face coverings are promising platforms for biofluid collection and colorimetric biosensing, which bode well for developing surveillance tools for airborne diseases.
Collapse
Affiliation(s)
- Zhicheng Jin
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Alec Jorns
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Wonjun Yim
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, United States
| | - Ryan Wing
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Yash Mantri
- Department of Bioengineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Jiajing Zhou
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Jingcheng Zhou
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Zhuohong Wu
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - Colman Moore
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
| | - William F Penny
- Division of Cardiology, University of California, San Diego, San Diego, California 92161, United States
| | - Jesse V Jokerst
- Department of NanoEngineering, University of California, San Diego, La Jolla, California 92093, United States
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, United States
- Department of Radiology, University of California, San Diego, La Jolla, California 92093, United States
| |
Collapse
|
74
|
Lindsley WG, Beezhold DH, Coyle J, Derk RC, Blachere FM, Boots T, Reynolds JS, McKinney WG, Sinsel E, Noti JD. Efficacy of universal masking for source control and personal protection from simulated cough and exhaled aerosols in a room. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2021; 18:409-422. [PMID: 34161193 PMCID: PMC8355198 DOI: 10.1080/15459624.2021.1939879] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Face masks reduce the expulsion of respiratory aerosols produced during coughs and exhalations ("source control"). Factors such as the directions in which people are facing (orientation) and separation distance also affect aerosol dispersion. However, it is not clear how the combined effects of masking, orientation, and distance affect the exposure of individuals to respiratory aerosols in indoor spaces. We placed a respiratory aerosol simulator ("source") and a breathing simulator ("recipient") in a 3 m × 3 m chamber and measured aerosol concentrations for different combinations of masking, orientation, and separation distance. When the simulators were front-to-front during coughing, masks reduced the 15-min mean aerosol concentration at the recipient by 92% at 0.9 and 1.8 m separation. When the simulators were side-by-side, masks reduced the concentration by 81% at 0.9 m and 78% at 1.8 m. During breathing, masks reduced the aerosol concentration by 66% when front-to-front and 76% when side-by-side at 0.9 m. Similar results were seen at 1.8 m. When the simulators were unmasked, changing the orientations from front-to-front to side-by-side reduced the cough aerosol concentration by 59% at 0.9 m and 60% at 1.8 m. When both simulators were masked, changing the orientations did not significantly change the concentration at either distance during coughing or breathing. Increasing the distance between the simulators from 0.9 m to 1.8 m during coughing reduced the aerosol concentration by 25% when no masks were worn but had little effect when both simulators were masked. During breathing, when neither simulator was masked, increasing the separation reduced the concentration by 13%, which approached significance, while the change was not significant when both source and recipient were masked. Our results show that universal masking reduces exposure to respiratory aerosol particles regardless of the orientation and separation distance between the source and recipient.
Collapse
Affiliation(s)
- William G Lindsley
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Donald H Beezhold
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Jayme Coyle
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Raymond C Derk
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Francoise M Blachere
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Theresa Boots
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Jeffrey S Reynolds
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Walter G McKinney
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Erik Sinsel
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - John D Noti
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| |
Collapse
|
75
|
Stephan-Odenthal M. [Urological practice in the corona pandemic]. Aktuelle Urol 2021; 52:332-337. [PMID: 34318461 DOI: 10.1055/a-1426-9037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The Corona-Pandemic is an additional challenge for urological practice, as most urological patients are in the high-risk group for a severe course of COVID19 disease due to their age and accompanying illnesses. The most effective protective measures are prioritised reduction in patient contacts with the help of telemedical contacts and the consistent wearing of FFP2-masks during direct contact. Further measures such as access controls, protective walls and air-filtering can further reduce the risk of infection. Ultimately, only a nationwide vaccination programm will result in the removal of pandemic-related restrictions for further urological treatment.
Collapse
|
76
|
Escandón K, Rasmussen AL, Bogoch II, Murray EJ, Escandón K, Popescu SV, Kindrachuk J. COVID-19 false dichotomies and a comprehensive review of the evidence regarding public health, COVID-19 symptomatology, SARS-CoV-2 transmission, mask wearing, and reinfection. BMC Infect Dis 2021; 21:710. [PMID: 34315427 PMCID: PMC8314268 DOI: 10.1186/s12879-021-06357-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Scientists across disciplines, policymakers, and journalists have voiced frustration at the unprecedented polarization and misinformation around coronavirus disease 2019 (COVID-19) pandemic. Several false dichotomies have been used to polarize debates while oversimplifying complex issues. In this comprehensive narrative review, we deconstruct six common COVID-19 false dichotomies, address the evidence on these topics, identify insights relevant to effective pandemic responses, and highlight knowledge gaps and uncertainties. The topics of this review are: 1) Health and lives vs. economy and livelihoods, 2) Indefinite lockdown vs. unlimited reopening, 3) Symptomatic vs. asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, 4) Droplet vs. aerosol transmission of SARS-CoV-2, 5) Masks for all vs. no masking, and 6) SARS-CoV-2 reinfection vs. no reinfection. We discuss the importance of multidisciplinary integration (health, social, and physical sciences), multilayered approaches to reducing risk ("Emmentaler cheese model"), harm reduction, smart masking, relaxation of interventions, and context-sensitive policymaking for COVID-19 response plans. We also address the challenges in understanding the broad clinical presentation of COVID-19, SARS-CoV-2 transmission, and SARS-CoV-2 reinfection. These key issues of science and public health policy have been presented as false dichotomies during the pandemic. However, they are hardly binary, simple, or uniform, and therefore should not be framed as polar extremes. We urge a nuanced understanding of the science and caution against black-or-white messaging, all-or-nothing guidance, and one-size-fits-all approaches. There is a need for meaningful public health communication and science-informed policies that recognize shades of gray, uncertainties, local context, and social determinants of health.
Collapse
Affiliation(s)
- Kevin Escandón
- School of Medicine, Universidad del Valle, Cali, Colombia.
| | - Angela L Rasmussen
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada
- Georgetown Center for Global Health Science and Security, Georgetown University, Washington, DC, USA
| | - Isaac I Bogoch
- Division of Infectious Diseases, University of Toronto, Toronto General Hospital, Toronto, Canada
| | - Eleanor J Murray
- Department of Epidemiology, Boston University School of Public Health, Boston, USA
| | - Karina Escandón
- Department of Anthropology, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Saskia V Popescu
- Georgetown Center for Global Health Science and Security, Georgetown University, Washington, DC, USA
- Schar School of Policy and Government, George Mason University, Fairfax, VA, USA
| | - Jason Kindrachuk
- Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
77
|
Wilson AM, Jones RM, Lugo Lerma V, Abney SE, King MF, Weir MH, Sexton JD, Noakes CJ, Reynolds KA. Respirators, face masks, and their risk reductions via multiple transmission routes for first responders within an ambulance. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2021; 18:345-360. [PMID: 34129448 DOI: 10.1080/15459624.2021.1926468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
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.
Collapse
Affiliation(s)
- Amanda M Wilson
- Rocky Mountain Center for Occupational and Environmental Health, University of Utah, Salt Lake City, Utah
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, Utah
| | - Rachael M Jones
- Rocky Mountain Center for Occupational and Environmental Health, University of Utah, Salt Lake City, Utah
- Department of Family and Preventive Medicine, School of Medicine, University of Utah, Salt Lake City, Utah
| | - Veronica Lugo Lerma
- Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona
| | - Sarah E Abney
- Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona
- Department of Environmental Science, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona
| | | | - Mark H Weir
- Divison of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, Ohio
| | - Jonathan D Sexton
- Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona
| | | | - Kelly A Reynolds
- Department of Community, Environment, and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona
| |
Collapse
|
78
|
Ogbuoji EA, Zaky AM, Escobar IC. Advanced Research and Development of Face Masks and Respirators Pre and Post the Coronavirus Disease 2019 (COVID-19) Pandemic: A Critical Review. Polymers (Basel) 2021; 13:1998. [PMID: 34207184 PMCID: PMC8235328 DOI: 10.3390/polym13121998] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 12/05/2022] Open
Abstract
The outbreak of the COVID-19 pandemic, in 2020, has accelerated the need for personal protective equipment (PPE) masks as one of the methods to reduce and/or eliminate transmission of the coronavirus across communities. Despite the availability of different coronavirus vaccines, it is still recommended by the Center of Disease Control and Prevention (CDC), World Health Organization (WHO), and local authorities to apply public safety measures including maintaining social distancing and wearing face masks. This includes individuals who have been fully vaccinated. Remarkable increase in scientific studies, along with manufacturing-related research and development investigations, have been performed in an attempt to provide better PPE solutions during the pandemic. Recent literature has estimated the filtration efficiency (FE) of face masks and respirators shedding the light on specific targeted parameters that investigators can measure, detect, evaluate, and provide reliable data with consistent results. This review showed the variability in testing protocols and FE evaluation methods of different face mask materials and/or brands. In addition to the safety requirements needed to perform aerosol viral filtration tests, one of the main challenges researchers currently face is the inability to simulate or mimic true aerosol filtration scenarios via laboratory experiments, field tests, and in vitro/in vivo investigations. Moreover, the FE through the mask can be influenced by different filtration mechanisms, environmental parameters, filtration material properties, number of layers used, packing density, fiber charge density, fiber diameter, aerosol type and particle size, aerosol face velocity and concentration loadings, and infectious concentrations generated due to different human activities. These parameters are not fully understood and constrain the design, production, efficacy, and efficiency of face masks.
Collapse
Affiliation(s)
- Ebuka A. Ogbuoji
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA;
| | - Amr M. Zaky
- BioMicrobics Inc., 16002 West 110th Street, Lenexa, KS 66219, USA;
| | - Isabel C. Escobar
- Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506, USA;
| |
Collapse
|
79
|
Lindsley WG, Blachere FM, Beezhold DH, Law BF, Derk RC, Hettick JM, Woodfork K, Goldsmith WT, Harris JR, Duling MG, Boutin B, Nurkiewicz T, Boots T, Coyle J, Noti JD. A comparison of performance metrics for cloth masks as source control devices for simulated cough and exhalation aerosols. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2021; 55:1125-1142. [PMID: 35923216 PMCID: PMC9345405 DOI: 10.1080/02786826.2021.1933377] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Universal mask wearing is recommended to help control the spread of COVID-19. Masks reduce the expulsion of aerosols of respiratory fluids into the environment (called source control) and offer some protection to the wearer. Masks are often characterized using filtration efficiency, airflow resistance, and manikin or human fit factors, which are standard metrics used for personal protective devices. However, none of these metrics are direct measurements of how effectively a mask blocks coughed and exhaled aerosols. We studied the source control performance of 15 cloth masks (face masks, neck gaiters, and bandanas), two medical masks, and two N95 filtering facepiece respirators by measuring their ability to block aerosols ≤ 7 μm expelled during simulated coughing and exhalation (called source control collection efficiency). These measurements were compared with filtration efficiencies, airflow resistances, and fit factors measured on manikin headforms and humans. Collection efficiencies for the cloth masks ranged from 17% to 71% for coughing and 35% to 66% for exhalation. Filtration efficiencies for the cloth masks ranged from 1.4% to 98%, while the fit factors were 1.3 to 7.4 on headforms and 1.0 to 4.0 on human subjects. The Spearman's rank correlation coefficients between the source control collection efficiencies and the standard metrics ranged from 0.03 to 0.68 and were significant in all but two cases. However, none of the standard metrics were strongly correlated with source control performance. A better understanding of the relationships between source control collection efficiency, filtration efficiency, airflow resistance, and fit factor is needed.
Collapse
Affiliation(s)
- William G. Lindsley
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Francoise M. Blachere
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Donald H. Beezhold
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Brandon F. Law
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Raymond C. Derk
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Justin M. Hettick
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Karen Woodfork
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - William T. Goldsmith
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - James R. Harris
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Matthew G. Duling
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Brenda Boutin
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Timothy Nurkiewicz
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - Theresa Boots
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Jayme Coyle
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - John D. Noti
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| |
Collapse
|
80
|
Cappa CD, Asadi S, Barreda S, Wexler AS, Bouvier NM, Ristenpart WD. Expiratory aerosol particle escape from surgical masks due to imperfect sealing. Sci Rep 2021; 11:12110. [PMID: 34103573 PMCID: PMC8187651 DOI: 10.1038/s41598-021-91487-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/27/2021] [Indexed: 01/20/2023] Open
Abstract
Wearing surgical masks or other similar face coverings can reduce the emission of expiratory particles produced via breathing, talking, coughing, or sneezing. Although it is well established that some fraction of the expiratory airflow leaks around the edges of the mask, it is unclear how these leakage airflows affect the overall efficiency with which masks block emission of expiratory aerosol particles. Here, we show experimentally that the aerosol particle concentrations in the leakage airflows around a surgical mask are reduced compared to no mask wearing, with the magnitude of reduction dependent on the direction of escape (out the top, the sides, or the bottom). Because the actual leakage flowrate in each direction is difficult to measure, we use a Monte Carlo approach to estimate flow-corrected particle emission rates for particles having diameters in the range 0.5-20 μm. in all orientations. From these, we derive a flow-weighted overall number-based particle removal efficiency for the mask. The overall mask efficiency, accounting both for air that passes through the mask and for leakage flows, is reduced compared to the through-mask filtration efficiency, from 93 to 70% for talking, but from only 94-90% for coughing. These results demonstrate that leakage flows due to imperfect sealing do decrease mask efficiencies for reducing emission of expiratory particles, but even with such leakage surgical masks provide substantial control.
Collapse
Affiliation(s)
- Christopher D Cappa
- Department of Civil and Environmental Engineering, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA.
| | - Sima Asadi
- Department of Chemical Engineering, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Av., Cambridge, MA, 02139, USA
| | - Santiago Barreda
- Department of Linguistics, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
| | - Anthony S Wexler
- Department of Chemical Engineering, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
- Department of Mechanical and Aerospace Engineering, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
- Air Quality Research Center, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
- Department of Land, Air and Water Resources, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
| | - Nicole M Bouvier
- Department of Medicine, Division of Infectious Diseases, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, New York, NY, 10029, USA
- Department Microbiology, Icahn School of Medicine at Mount Sinai, 1 Gustave Levy Place, New York, NY, 10029, USA
| | - William D Ristenpart
- Department of Chemical Engineering, University of California Davis, 1 Shields Ave., Davis, CA, 95616, USA
| |
Collapse
|
81
|
Affiliation(s)
- John T Brooks
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jay C Butler
- Centers for Disease Control and Prevention, Atlanta, Georgia
| |
Collapse
|
82
|
Lindsley WG, Blachere FM, Beezhold DH, Law BF, Derk RC, Hettick JM, Woodfork K, Goldsmith WT, Harris JR, Duling MG, Boutin B, Nurkiewicz T, Noti JD. A comparison of performance metrics for cloth face masks as source control devices for simulated cough and exhalation aerosols. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2021:2021.02.16.21251850. [PMID: 33619500 PMCID: PMC7899465 DOI: 10.1101/2021.02.16.21251850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Universal mask wearing is recommended by the Centers for Disease Control and Prevention to help control the spread of COVID-19. Masks reduce the expulsion of respiratory aerosols (called source control) and offer some protection to the wearer. However, masks vary greatly in their designs and construction materials, and it is not clear which are most effective. Our study tested 15 reusable cloth masks (which included face masks, neck gaiters, and bandanas), two medical masks, and two N95 filtering facepiece respirators as source control devices for aerosols ≤ 7 µm produced during simulated coughing and exhalation. These measurements were compared with the mask filtration efficiencies, airflow resistances, and fit factors. The source control collection efficiencies for the cloth masks ranged from 17% to 71% for coughing and 35% to 66% for exhalation. The filtration efficiencies of the cloth masks ranged from 1.4% to 98%, while the fit factors were 1.3 to 7.4 on an elastomeric manikin headform and 1.0 to 4.0 on human test subjects. The correlation coefficients between the source control efficacies and the other performance metrics ranged from 0.31 to 0.66 and were significant in all but one case. However, none of the alternative metrics were strong predictors of the source control performance of cloth masks. Our results suggest that a better understanding of the relationships between source control performance and metrics like filtration efficiency, airflow resistance, and fit factor are needed to develop simple methods to estimate the effectiveness of masks as source control devices for respiratory aerosols.
Collapse
Affiliation(s)
- William G. Lindsley
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Francoise M. Blachere
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Donald H. Beezhold
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Brandon F. Law
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Raymond C. Derk
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Justin M. Hettick
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Karen Woodfork
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - William T. Goldsmith
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - James R. Harris
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Matthew G. Duling
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Brenda Boutin
- National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Timothy Nurkiewicz
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - John D. Noti
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| |
Collapse
|
83
|
Wendling JM, Fabacher T, Pébaÿ PP, Cosperec I, Rochoy M. Experimental Efficacy of the Face Shield and the Mask against Emitted and Potentially Received Particles. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:1942. [PMID: 33671300 PMCID: PMC7922468 DOI: 10.3390/ijerph18041942] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/09/2021] [Accepted: 02/10/2021] [Indexed: 01/03/2023]
Abstract
There is currently not sufficient evidence to support the effectiveness of face shields for source control. In order to evaluate the comparative barrier performance effect of face masks and face shields, we used an aerosol generator and a particle counter to evaluate the performance of the various devices in comparable situations. We tested different configurations in an experimental setup with manikin heads wearing masks (surgical type I), face shields (22.5 cm high with overhang under the chin of 7 cm and circumference of 35 cm) on an emitter or a receiver manikin head, or both. The manikins were face to face, 25 cm apart, with an intense particle emission (52.5 L/min) for 30 s. The particle counter calculated the total cumulative particles aspirated on a volume of 1.416 L In our experimental conditions, when the receiver alone wore a protection, the face shield was more effective (reduction factor = 54.8%), while reduction was lower with a mask (reduction factor = 21.8%) (p = 0.002). The wearing of a protective device by the emitter alone reduced the level of received particles by 96.8% for both the mask and face shield (p = NS). When both the emitter and receiver manikin heads wore a face shield, the protection allowed for better results in our experimental conditions: 98% reduction for the face shields versus 97.3% for the masks (p = 0.01). Face shields offered an even better barrier effect than the mask against small inhaled particles (<0.3 µm-0.3 to 0.5 µm-0.5 to 1 µm) in all configurations. Therefore, it would be interesting to include face shields as used in our experimental study as part of strategies to reduce transmission within the community setting.
Collapse
Affiliation(s)
| | - Thibaut Fabacher
- Department of Public Health, GMRC, CHRU, F-67000 Strasbourg, France;
| | | | | | - Michaël Rochoy
- General Medicine Department, University Lille, CERIM, ULR 2694, F-59000 Lille, France
| |
Collapse
|
84
|
Ishii K, Ohno Y, Oikawa M, Onishi N. Relationship between human exhalation diffusion and posture in face-to-face scenario with utterance. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2021; 33:027101. [PMID: 33746491 PMCID: PMC7976045 DOI: 10.1063/5.0038380] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/07/2021] [Indexed: 05/04/2023]
Abstract
Because of the COVID-19, the world has been affected significantly. Not only health and medical problems but also the decline in life quality and economic activity due to the suspension of social activities cannot be disregarded. It is assumed that the virus is transmitted through coughing and sneezing; however, the possibility of airborne infection by aerosols containing viruses scattered in the air has become a popular topic recently. In airborne infections, the risk of infection increases when the mucous membrane is exposed to exhaled aerosols for a significant amount of time. Therefore, in this study, we visualize human breath using the smoke of electronic cigarettes as tracer particles. Exhalation when speaking was visualized for four human posture patterns. The result shows that the exhaled breath is affected by the body wall temperature; it rises when it remains in the boundary layer by wearing a mask. On the other hand, without a mask, it initially flows downward due to the structure of the nose and mouth, so it flows downward due to inertia and diffuses randomly. This finding is effective in reducing the risk of infection during face-to-face customer service.
Collapse
Affiliation(s)
- Keiko Ishii
- Department of Mechanical Engineering, College of
Science and Engineering, Aoyama Gakuin University, 5-10-1, Fuchnobe,
Sagamihara 252-5258, Japan
| | - Yoshiko Ohno
- Yamano College of Aesthetics, 530,
Yarimizu, Hachioji, Tokyo 192-0396, Japan
| | - Maiko Oikawa
- Yamano College of Aesthetics, 530,
Yarimizu, Hachioji, Tokyo 192-0396, Japan
| | - Noriko Onishi
- Yamano College of Aesthetics, 530,
Yarimizu, Hachioji, Tokyo 192-0396, Japan
| |
Collapse
|