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Sultan Z, Li J, Pantelic J, Schiavon S. Particle characterization in commercial buildings: A cross-sectional study in 40 offices in Singapore. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172126. [PMID: 38569949 DOI: 10.1016/j.scitotenv.2024.172126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/10/2024] [Accepted: 03/29/2024] [Indexed: 04/05/2024]
Abstract
There is a knowledge gap in understanding how existing office buildings are protecting occupants from exposure to particles from both indoor and outdoor sources. We report a cross-sectional study involving weekly measurements of size-resolved indoor and outdoor particle concentrations in forty commercial building offices in Singapore. The outdoor and indoor particles size distributions were single mode with daytime peak number concentrations at 36.5 nm and 48.7 nm. Outdoor concentrations were significantly greater than indoors for all particle diameters. Indoor particle concentrations were generally low due to: 1) relatively high indoor particle removal (IPR) rates; 2) low indoor source strengths; and 3) low indoor particle of outdoor proportion (IPOP). We found that the ventilation system type had a substantial effect on indoor particle levels, IPR and IPOP. Through linear mixed model analyses, we identified dependencies of IPR rates with the use of MERV13 filters in supply air and filter maintenance frequency, IPOP with the use of MERV13 filters in the fresh air and supply air ducts and low particle source strength with regular daily cleaning presumably due to dust reservoir removal. Lastly, the contribution of outdoor sources was mainly seen for ultrafine and fine particles but less pronounced for coarse particles. This study provided detailed understanding of particle exposure in building offices and their influencing factors, facilitating future research on health impact of particle exposures.
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Affiliation(s)
- Zuraimi Sultan
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore.
| | - Jiayu Li
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore; University of California Berkeley, Center for the Built Environment, USA
| | - Jovan Pantelic
- Katholieke Universiteit Leuven, Belgium; Well Living Lab, USA
| | - Stefano Schiavon
- Berkeley Education Alliance for Research in Singapore (BEARS) Limited, Singapore; University of California Berkeley, Center for the Built Environment, USA
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2
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Teluguakula N, Chow VTK, Pandareesh MD, Dasegowda V, Kurrapotula V, Gopegowda SM, Radic M. SARS-CoV-2 and Influenza Co-Infection: Fair Competition or Sinister Combination? Viruses 2024; 16:793. [PMID: 38793676 PMCID: PMC11125941 DOI: 10.3390/v16050793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/11/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
The COVID-19 pandemic remains a serious public health problem globally. During winter influenza seasons, more aggressive SARS-CoV-2 infections and fatalities have been documented, indicating that influenza co-infections may significantly impact the disease outcome of COVID-19. Both influenza and SARS-CoV-2 viruses share many similarities in their transmission and their cellular tropism for replication in the human respiratory tract. However, the complex intricacies and multi-faceted dynamics of how the two pathogens interact to ensure their survival in the same lung microenvironment are still unclear. In addition, clinical studies on influenza co-infections in COVID-19 patients do not provide conclusive evidence of how influenza co-infection mechanistically modifies disease outcomes of COVID-19. This review discusses various viral as well as host factors that potentially influence the survival or synergism of these two respiratory pathogens in the infected lung microenvironment.
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Affiliation(s)
- Narasaraju Teluguakula
- Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, Mandya 571448, Karnataka, India; (M.D.P.); (V.D.); (V.K.); (S.M.G.)
- Department of Microbiology, Immunology and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA;
| | - Vincent T. K. Chow
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore 119228, Singapore;
| | - Mirazkar Dasharatharao Pandareesh
- Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, Mandya 571448, Karnataka, India; (M.D.P.); (V.D.); (V.K.); (S.M.G.)
- Department of Biochemistry, Adichunchanagiri School of Natural Sciences, Adichunchanagiri University, B.G Nagara 571448, Karnataka, India
| | - Venkatesha Dasegowda
- Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, Mandya 571448, Karnataka, India; (M.D.P.); (V.D.); (V.K.); (S.M.G.)
| | - Vidyasagar Kurrapotula
- Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, Mandya 571448, Karnataka, India; (M.D.P.); (V.D.); (V.K.); (S.M.G.)
| | - Shivaramu M. Gopegowda
- Adichunchanagiri Institute of Medical Sciences, Adichunchanagiri University, Mandya 571448, Karnataka, India; (M.D.P.); (V.D.); (V.K.); (S.M.G.)
| | - Marko Radic
- Department of Microbiology, Immunology and Biochemistry, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA;
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3
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Gibbons AM, Ohno PE. Relative Humidity-Dependent Phase Transitions in Submicron Respiratory Aerosols. J Phys Chem A 2024; 128:3015-3023. [PMID: 38593044 DOI: 10.1021/acs.jpca.4c00691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Respiratory viruses, such as influenza and severe acute respiratory syndrome coronavirus 2, represent a substantial public health burden and are largely transmitted through respiratory droplets and aerosols. Environmental factors such as relative humidity (RH) and temperature impact virus transmission rates, and a precise mechanistic understanding of the connection between these environmental factors and virus transmission would improve efforts to mitigate respiratory disease transmission. Previous studies on supermicrometer particles observed RH-dependent phase transitions and linked particle phase state to virus viability. Phase transitions in atmospheric aerosols are dependent on size in the submicrometer range, and actual respiratory particles are expelled over a large size range, including submicrometer aerosols that can transmit diseases over long distances. Here, we directly investigated the phase transitions of submicrometer model respiratory aerosols. A probe molecule, Nile red, was added to particle systems including multiple mucin/salt mixtures, a growth medium, and simulated lung fluid. For each system, the polarity-dependent fluorescence emission was measured following RH conditioning. Notably, the fluorescence measurements of mucin/NaCl and Dulbecco's modified Eagle's medium particles indicated that liquid-liquid phase separation (LLPS) also occurs in submicron particles, suggesting that LLPS can also impact the viability of viruses in submicron particles and thus affect aerosol virus transmission. Furthermore, the utility of fluorescence-based measurements to study submicrometer respiratory particle physicochemical properties in situ is demonstrated.
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Affiliation(s)
- Angel M Gibbons
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Paul E Ohno
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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4
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Zhang N, Yang X, Su B, Dou Z. Analysis of SARS-CoV-2 transmission in a university classroom based on real human close contact behaviors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170346. [PMID: 38281642 DOI: 10.1016/j.scitotenv.2024.170346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/29/2023] [Accepted: 01/19/2024] [Indexed: 01/30/2024]
Abstract
Due to high-population density, frequent close contact, possible poor ventilation, university classrooms are vulnerable for transmission of respiratory infectious diseases. Close contact and long-range airborne are possibly main routes for SARS-CoV-2 transmission. In this study, taking a university classroom in Beijing for example, close contact behaviors of students were collected through a depth-detection device, which could detect depth to each pixel of the image, based on semi-supervised learning. Finally, >23 h of video data were obtained. Using Computational Fluid Dynamics, the relationship between viral exposure and close contact behaviors (e.g. interpersonal distance, relative facial orientations, and relative positions) was established. A multi-route transmission model (short-range airborne, mucous deposition, and long-range airborne) of infectious diseases considering real close contact behaviors was developed. In the case of Omicron, the risk of infection in university classrooms and the efficacy of different interventions were assessed based on dose-response model. The average interpersonal distance in university classrooms is 0.9 m (95 % CI, 0.5 m-1.4 m), with the highest proportion of face-to-back contact at 87.0 %. The risk of infection of susceptible students per 45-min lesson was 1 %. The relative contributions of short-range airborne and long-range airborne transmission were 40.5 % and 59.5 %, respectively, and the mucous deposition was basically negligible. When all students are wearing N95 respirators, the infection risk could be reduced by 96 %, the relative contribution of long-range airborne transmission increases to 95.6 %. When the fresh air per capita in the classroom is 24 m3/h/person, the virus exposure could be decreased by 81.1 % compared to the real situation with 1.02 m3/h/person. In a classroom with an occupancy rate of 50 %, after optimized arrangement of student distribution, the infection risk could be decreased by 62 %.
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Affiliation(s)
- Nan Zhang
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Xueze Yang
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Boni Su
- China Electric Power Planning & Engineering Institute, Beijing, China
| | - Zhiyang Dou
- Department of Computer Science, The University of Hong Kong, Hong Kong, China.
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5
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Atamer Balkan B, Chang Y, Sparnaaij M, Wouda B, Boschma D, Liu Y, Yuan Y, Daamen W, de Jong MCM, Teberg C, Schachtschneider K, Sikkema RS, van Veen L, Duives D, ten Bosch QA. The multi-dimensional challenges of controlling respiratory virus transmission in indoor spaces: Insights from the linkage of a microscopic pedestrian simulation and SARS-CoV-2 transmission model. PLoS Comput Biol 2024; 20:e1011956. [PMID: 38547311 PMCID: PMC11003685 DOI: 10.1371/journal.pcbi.1011956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 04/09/2024] [Accepted: 02/29/2024] [Indexed: 04/11/2024] Open
Abstract
SARS-CoV-2 transmission in indoor spaces, where most infection events occur, depends on the types and duration of human interactions, among others. Understanding how these human behaviours interface with virus characteristics to drive pathogen transmission and dictate the outcomes of non-pharmaceutical interventions is important for the informed and safe use of indoor spaces. To better understand these complex interactions, we developed the Pedestrian Dynamics-Virus Spread model (PeDViS), an individual-based model that combines pedestrian behaviour models with virus spread models incorporating direct and indirect transmission routes. We explored the relationships between virus exposure and the duration, distance, respiratory behaviour, and environment in which interactions between infected and uninfected individuals took place and compared this to benchmark 'at risk' interactions (1.5 metres for 15 minutes). When considering aerosol transmission, individuals adhering to distancing measures may be at risk due to the buildup of airborne virus in the environment when infected individuals spend prolonged time indoors. In our restaurant case, guests seated at tables near infected individuals were at limited risk of infection but could, particularly in poorly ventilated places, experience risks that surpass that of benchmark interactions. Combining interventions that target different transmission routes can aid in accumulating impact, for instance by combining ventilation with face masks. The impact of such combined interventions depends on the relative importance of transmission routes, which is hard to disentangle and highly context dependent. This uncertainty should be considered when assessing transmission risks upon different types of human interactions in indoor spaces. We illustrated the multi-dimensionality of indoor SARS-CoV-2 transmission that emerges from the interplay of human behaviour and the spread of respiratory viruses. A modelling strategy that incorporates this in risk assessments can help inform policy makers and citizens on the safe use of indoor spaces with varying inter-human interactions.
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Affiliation(s)
- Büsra Atamer Balkan
- Quantitative Veterinary Epidemiology, Wageningen University & Research, Wageningen, The Netherlands
| | - You Chang
- Quantitative Veterinary Epidemiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Martijn Sparnaaij
- Department of Transport & Planning, Delft University of Technology, Delft, The Netherlands
| | - Berend Wouda
- Gamelab, Delft University of Technology, Delft, The Netherlands
| | - Doris Boschma
- Gamelab, Delft University of Technology, Delft, The Netherlands
| | - Yangfan Liu
- Quantitative Veterinary Epidemiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Yufei Yuan
- Department of Transport & Planning, Delft University of Technology, Delft, The Netherlands
| | - Winnie Daamen
- Department of Transport & Planning, Delft University of Technology, Delft, The Netherlands
| | - Mart C. M. de Jong
- Quantitative Veterinary Epidemiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Colin Teberg
- Steady State Scientific Computing, Chicago, Illinois, United States of America
| | | | | | - Linda van Veen
- Gamelab, Delft University of Technology, Delft, The Netherlands
| | - Dorine Duives
- Department of Transport & Planning, Delft University of Technology, Delft, The Netherlands
| | - Quirine A. ten Bosch
- Quantitative Veterinary Epidemiology, Wageningen University & Research, Wageningen, The Netherlands
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6
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Biney IN, Ari A, Barjaktarevic IZ, Carlin B, Christiani DC, Cochran L, Drummond MB, Johnson K, Kealing D, Kuehl PJ, Li J, Mahler DA, Martinez S, Ohar J, Radonovich LJ, Sood A, Suggett J, Tal-Singer R, Tashkin D, Yates J, Cambridge L, Dailey PA, Mannino DM, Dhand R. Guidance on Mitigating the Risk of Transmitting Respiratory Infections During Nebulization by the COPD Foundation Nebulizer Consortium. Chest 2024; 165:653-668. [PMID: 37977263 DOI: 10.1016/j.chest.2023.11.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023] Open
Abstract
BACKGROUND Nebulizers are used commonly for inhaled drug delivery. Because they deliver medication through aerosol generation, clarification is needed on what constitutes safe aerosol delivery in infectious respiratory disease settings. The COVID-19 pandemic highlighted the importance of understanding the safety and potential risks of aerosol-generating procedures. However, evidence supporting the increased risk of disease transmission with nebulized treatments is inconclusive, and inconsistent guidelines and differing opinions have left uncertainty regarding their use. Many clinicians opt for alternative devices, but this practice could impact outcomes negatively, especially for patients who may not derive full treatment benefit from handheld inhalers. Therefore, it is prudent to develop strategies that can be used during nebulized treatment to minimize the emission of fugitive aerosols, these comprising bioaerosols exhaled by infected individuals and medical aerosols generated by the device that also may be contaminated. This is particularly relevant for patient care in the context of a highly transmissible virus. RESEARCH QUESTION How can potential risks of infections during nebulization be mitigated? STUDY DESIGN AND METHODS The COPD Foundation Nebulizer Consortium (CNC) was formed in 2020 to address uncertainties surrounding administration of nebulized medication. The CNC is an international, multidisciplinary collaboration of patient advocates, pulmonary physicians, critical care physicians, respiratory therapists, clinical scientists, and pharmacists from research centers, medical centers, professional societies, industry, and government agencies. The CNC developed this expert guidance to inform the safe use of nebulized therapies for patients and providers and to answer key questions surrounding medication delivery with nebulizers during pandemics or when exposure to common respiratory pathogens is anticipated. RESULTS CNC members reviewed literature and guidelines regarding nebulization and developed two sets of guidance statements: one for the health care setting and one for the home environment. INTERPRETATION Future studies need to explore the risk of disease transmission with fugitive aerosols associated with different nebulizer types in real patient care situations and to evaluate the effectiveness of mitigation strategies.
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Affiliation(s)
- Isaac N Biney
- University Pulmonary and Critical Care, The University of Tennessee Graduate School of Medicine, Knoxville, TN.
| | - Arzu Ari
- Department of Respiratory Care and Texas State Sleep Center, Texas State University, Round Rock, TX
| | - Igor Z Barjaktarevic
- Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, University of California Los Angeles Health Sciences, Los Angeles, CA; Division of Liver and Pancreas Transplantation, David Geffen School of Medicine, University of California Los Angeles Health Sciences, Los Angeles, CA
| | - Brian Carlin
- Sleep Medicine and Lung Health Consultants LLC, Pittsburgh, PA
| | - David C Christiani
- Harvard T.H. Chan School of Public Health, Harvard Medical School, Cambridge, MA; Pulmonary and Critical Care Division, Massachusetts General Hospital, Boston, MA
| | | | - M Bradley Drummond
- Division of Pulmonary Diseases and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | | | | | | | - Jie Li
- Rush University, Chicago, IL
| | - Donald A Mahler
- Geisel School of Medicine at Dartmouth, Hanover, NH; Valley Regional Hospital, Claremont, NH
| | | | - Jill Ohar
- Bowman Gray Center for Medical Education, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Lewis J Radonovich
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
| | - Akshay Sood
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM
| | | | | | - Donald Tashkin
- Division of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, University of California Los Angeles Health Sciences, Los Angeles, CA
| | | | - Lisa Cambridge
- Medical Science & Pharmaceutical Alliances, PARI, Inc., Midlothian, VA
| | | | | | - Rajiv Dhand
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, The University of Tennessee Graduate School of Medicine, Knoxville, TN
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7
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Port JR, Morris DH, Riopelle JC, Yinda CK, Avanzato VA, Holbrook MG, Bushmaker T, Schulz JE, Saturday TA, Barbian K, Russell CA, Perry-Gottschalk R, Shaia C, Martens C, Lloyd-Smith JO, Fischer RJ, Munster VJ. Host and viral determinants of airborne transmission of SARS-CoV-2 in the Syrian hamster. eLife 2024; 12:RP87094. [PMID: 38416804 PMCID: PMC10942639 DOI: 10.7554/elife.87094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024] Open
Abstract
It remains poorly understood how SARS-CoV-2 infection influences the physiological host factors important for aerosol transmission. We assessed breathing pattern, exhaled droplets, and infectious virus after infection with Alpha and Delta variants of concern (VOC) in the Syrian hamster. Both VOCs displayed a confined window of detectable airborne virus (24-48 hr), shorter than compared to oropharyngeal swabs. The loss of airborne shedding was linked to airway constriction resulting in a decrease of fine aerosols (1-10 µm) produced, which are suspected to be the major driver of airborne transmission. Male sex was associated with increased viral replication and virus shedding in the air. Next, we compared the transmission efficiency of both variants and found no significant differences. Transmission efficiency varied mostly among donors, 0-100% (including a superspreading event), and aerosol transmission over multiple chain links was representative of natural heterogeneity of exposure dose and downstream viral kinetics. Co-infection with VOCs only occurred when both viruses were shed by the same donor during an increased exposure timeframe (24-48 hr). This highlights that assessment of host and virus factors resulting in a differential exhaled particle profile is critical for understanding airborne transmission.
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Affiliation(s)
- Julia R Port
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Dylan H Morris
- Department of Ecology and Evolutionary Biology, University of California, Los AngelesLos AngelesUnited States
| | - Jade C Riopelle
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Claude Kwe Yinda
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Victoria A Avanzato
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Myndi G Holbrook
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Trenton Bushmaker
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Jonathan E Schulz
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Taylor A Saturday
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Kent Barbian
- Rocky Mountain Research and Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Colin A Russell
- Department of Medical Microbiology | Amsterdam University Medical Center, University of AmsterdamAmsterdamNetherlands
| | - Rose Perry-Gottschalk
- Rocky Mountain Visual and Medical Arts Unit, Research Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Carl Shaia
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Craig Martens
- Rocky Mountain Research and Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - James O Lloyd-Smith
- Department of Ecology and Evolutionary Biology, University of California, Los AngelesLos AngelesUnited States
| | - Robert J Fischer
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
| | - Vincent J Munster
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of HealthHamiltonUnited States
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8
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Zhang Y, Shankar SN, Vass WB, Lednicky JA, Fan ZH, Agdas D, Makuch R, Wu CY. Air Change Rate and SARS-CoV-2 Exposure in Hospitals and Residences: A Meta-Analysis. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2024; 58:217-243. [PMID: 38764553 PMCID: PMC11101186 DOI: 10.1080/02786826.2024.2312178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 01/16/2024] [Indexed: 05/21/2024]
Abstract
As SARS-CoV-2 swept across the globe, increased ventilation and implementation of air cleaning were emphasized by the US CDC and WHO as important strategies to reduce the risk of inhalation exposure to the virus. To assess whether higher ventilation and air cleaning rates lead to lower exposure risk to SARS-CoV-2, 1274 manuscripts published between April 2020 and September 2022 were screened using key words "airborne SARS-CoV-2 or "SARS-CoV-2 aerosol". Ninety-three studies involved air sampling at locations with known sources (hospitals and residences) were selected and associated data were compiled. Two metrics were used to assess exposure risk: SARS-CoV-2 concentration and SARS-CoV-2 detection rate in air samples. Locations were categorized by type (hospital or residence) and proximity to the sampling location housing the isolated/quarantined patient (primary or secondary). The results showed that hospital wards had lower airborne virus concentrations than residential isolation rooms. A negative correlation was found between airborne virus concentrations in primary-occupancy areas and air changes per hour (ACH). In hospital settings, sample positivity rates were significantly reduced in secondary-occupancy areas compared to primary-occupancy areas, but they were similar across sampling locations in residential settings. ACH and sample positivity rates were negatively correlated, though the effect was diminished when ACH values exceeded 8. While limitations associated with diverse sampling protocols exist, data considered by this meta-analysis support the notion that higher ACH may reduce exposure risks to the virus in ambient air.
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Affiliation(s)
- Yuetong Zhang
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida, USA
- Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columnia, Canada
| | - Sripriya Nannu Shankar
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida, USA
- Department of Environmental & Public Health Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - William B. Vass
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida, USA
| | - John A. Lednicky
- Department of Environmental and Global Health, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - Z. Hugh Fan
- Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | - Duzgun Agdas
- Engineering School of Sustainable Infrastructure & Environment, University of Florida, Gainesville, Florida, USA
| | - Robert Makuch
- Department of Biostatistics, Yale University School of Public Health, New Haven, Connecticut, USA
| | - Chang-Yu Wu
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida, USA
- Department of Chemical, Environmental, and Materials Engineering, University of Miami, Coral Gables, Florida, USA
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9
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Shrimpton AJ, Brown V, Vassallo J, Nolan JP, Soar J, Hamilton F, Cook TM, Bzdek BR, Reid JP, Makepeace CH, Deutsch J, Ascione R, Brown JM, Benger JR, Pickering AE. A quantitative evaluation of aerosol generation during cardiopulmonary resuscitation. Anaesthesia 2024; 79:156-167. [PMID: 37921438 PMCID: PMC10952244 DOI: 10.1111/anae.16162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2023] [Indexed: 11/04/2023]
Abstract
It is unclear if cardiopulmonary resuscitation is an aerosol-generating procedure and whether this poses a risk of airborne disease transmission to healthcare workers and bystanders. Use of airborne transmission precautions during cardiopulmonary resuscitation may confer rescuer protection but risks patient harm due to delays in commencing treatment. To quantify the risk of respiratory aerosol generation during cardiopulmonary resuscitation in humans, we conducted an aerosol monitoring study during out-of-hospital cardiac arrests. Exhaled aerosol was recorded using an optical particle sizer spectrometer connected to the breathing system. Aerosol produced during resuscitation was compared with that produced by control participants under general anaesthesia ventilated with an equivalent respiratory pattern to cardiopulmonary resuscitation. A porcine cardiac arrest model was used to determine the independent contributions of ventilatory breaths, chest compressions and external cardiac defibrillation to aerosol generation. Time-series analysis of participants with cardiac arrest (n = 18) demonstrated a repeating waveform of respiratory aerosol that mapped to specific components of resuscitation. Very high peak aerosol concentrations were generated during ventilation of participants with cardiac arrest with median (IQR [range]) 17,926 (5546-59,209 [1523-242,648]) particles.l-1 , which were 24-fold greater than in control participants under general anaesthesia (744 (309-2106 [23-9099]) particles.l-1 , p < 0.001, n = 16). A substantial rise in aerosol also occurred with cardiac defibrillation and chest compressions. In a complimentary porcine model of cardiac arrest, aerosol recordings showed a strikingly similar profile to the human data. Time-averaged aerosol concentrations during ventilation were approximately 270-fold higher than before cardiac arrest (19,410 (2307-41,017 [104-136,025]) vs. 72 (41-136 [23-268]) particles.l-1 , p = 0.008). The porcine model also confirmed that both defibrillation and chest compressions generate high concentrations of aerosol independent of, but synergistic with, ventilation. In conclusion, multiple components of cardiopulmonary resuscitation generate high concentrations of respiratory aerosol. We recommend that airborne transmission precautions are warranted in the setting of high-risk pathogens, until the airway is secured with an airway device and breathing system with a filter.
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Affiliation(s)
- A. J. Shrimpton
- Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - V. Brown
- Critical Care, South Western Ambulance Service NHS Foundation TrustUK
- Great Western Air Ambulance CharityBristolUK
| | - J. Vassallo
- Institute of Naval MedicineGosportUK
- Academic Department of Military Emergency MedicineRoyal Centre for Defence MedicineBirminghamUK
| | - J. P. Nolan
- University of Warwick, Warwick Medical SchoolCoventryUK
- Department of Anaesthesia and Intensive Care MedicineRoyal United HospitalBathUK
| | - J. Soar
- Department of Anaesthesia and Intensive Care MedicineNorth Bristol NHS TrustBristolUK
| | - F. Hamilton
- MRC Integrative Epidemiology UnitUniversity of BristolUK
| | - T. M. Cook
- Department of Anaesthesia and Intensive Care MedicineRoyal United HospitalBathUK
| | - B. R. Bzdek
- School of ChemistryUniversity of BristolBristolUK
| | - J. P. Reid
- School of ChemistryUniversity of BristolBristolUK
| | - C. H. Makepeace
- Langford Vets and Translational Biomedical Research CentreUniversity of BristolUK
| | - J. Deutsch
- Langford Vets and Translational Biomedical Research CentreUniversity of BristolUK
| | - R. Ascione
- Translational Biomedical Research CentreUniversity of BristolBristolUK
- University Hospital Bristol Weston NHS TrustBristolUK
| | - J. M. Brown
- Department of Anaesthesia and Intensive Care MedicineNorth Bristol NHS TrustBristolUK
| | - J. R. Benger
- Faculty of Health and Applied SciencesUniversity of the West of EnglandBristolUK
| | - A. E. Pickering
- Department of AnaesthesiaUniversity Hospitals Bristol and WestonBristolUK
- Anaesthesia, Pain and Critical Care Sciences, School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
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10
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Banholzer N, Schmutz R, Middelkoop K, Hella J, Egger M, Wood R, Fenner L. Airborne transmission risks of tuberculosis and COVID-19 in schools in South Africa, Switzerland, and Tanzania: Modeling of environmental data. PLOS GLOBAL PUBLIC HEALTH 2024; 4:e0002800. [PMID: 38236801 PMCID: PMC10796007 DOI: 10.1371/journal.pgph.0002800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 12/18/2023] [Indexed: 01/22/2024]
Abstract
The COVID-19 pandemic renewed interest in airborne transmission of respiratory infections, particularly in congregate indoor settings, such as schools. We modeled transmission risks of tuberculosis (caused by Mycobacterium tuberculosis, Mtb) and COVID-19 (caused by SARS-CoV-2) in South African, Swiss and Tanzanian secondary schools. We estimated the risks of infection with the Wells-Riley equation, expressed as the median with 2.5% and 97.5% quantiles (credible interval [CrI]), based on the ventilation rate and the duration of exposure to infectious doses (so-called quanta). We computed the air change rate (ventilation) using carbon dioxide (CO2) as a tracer gas and modeled the quanta generation rate based on reported estimates from the literature. The share of infectious students in the classroom is determined by country-specific estimates of pulmonary TB. For SARS-CoV-2, the number of infectious students was estimated based on excess mortality to mitigate the bias from country-specific reporting and testing. Average CO2 concentration (parts per million [ppm]) was 1,610 ppm in South Africa, 1,757 ppm in Switzerland, and 648 ppm in Tanzania. The annual risk of infection for Mtb was 22.1% (interquartile range [IQR] 2.7%-89.5%) in South Africa, 0.7% (IQR 0.1%-6.4%) in Switzerland, and 0.5% (IQR 0.0%-3.9%) in Tanzania. For SARS-CoV-2, the monthly risk of infection was 6.8% (IQR 0.8%-43.8%) in South Africa, 1.2% (IQR 0.1%-8.8%) in Switzerland, and 0.9% (IQR 0.1%-6.6%) in Tanzania. The differences in transmission risks primarily reflect a higher incidence of SARS-CoV-2 and particularly prevalence of TB in South Africa, but also higher air change rates due to better natural ventilation of the classrooms in Tanzania. Global comparisons of the modeled risk of infectious disease transmission in classrooms can provide high-level information for policy-making regarding appropriate infection control strategies.
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Affiliation(s)
- Nicolas Banholzer
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Remo Schmutz
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Keren Middelkoop
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Desmond Tutu Health Centre, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Jerry Hella
- Ifakara Health Institute, Dar-es-Salaam, Tanzania
| | - Matthias Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Centre for Infectious Disease Epidemiology & Research, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Desmond Tutu Health Centre, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Lukas Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
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11
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Alsved M, Nyström K, Thuresson S, Nygren D, Patzi-Churqui M, Hussein T, Fraenkel CJ, Medstrand P, Löndahl J. Infectivity of exhaled SARS-CoV-2 aerosols is sufficient to transmit covid-19 within minutes. Sci Rep 2023; 13:21245. [PMID: 38040798 PMCID: PMC10692216 DOI: 10.1038/s41598-023-47829-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/18/2023] [Indexed: 12/03/2023] Open
Abstract
Exhaled SARS-CoV-2-containing aerosols contributed significantly to the rapid and vast spread of covid-19. However, quantitative experimental data on the infectivity of such aerosols is missing. Here, we quantified emission rates of infectious viruses in exhaled aerosol from individuals within their first days after symptom onset from covid-19. Six aerosol samples from three individuals were culturable, of which five were successfully quantified using TCID50. The source strength of the three individuals was highest during singing, when they exhaled 4, 36, or 127 TCID50/s, respectively. Calculations with an indoor air transmission model showed that if an infected individual with this emission rate entered a room, a susceptible person would inhale an infectious dose within 6 to 37 min in a room with normal ventilation. Thus, our data show that exhaled aerosols from a single person can transmit covid-19 to others within minutes at normal indoor conditions.
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Affiliation(s)
- Malin Alsved
- Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Box 118, 22100, Lund, Sweden.
| | - Kristina Nyström
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 41346, Gothenburg, Sweden
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 41346, Gothenburg, Sweden
| | - Sara Thuresson
- Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Box 118, 22100, Lund, Sweden
| | - David Nygren
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, 22100, Lund, Sweden
| | - Marianela Patzi-Churqui
- Department of Clinical Microbiology, Sahlgrenska University Hospital, Region Västra Götaland, 41346, Gothenburg, Sweden
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, 41346, Gothenburg, Sweden
| | - Tareq Hussein
- Environmental and Atmospheric Research Laboratory (EARL), Department of Physics, School of Science, The University of Jordan, Amman, 11942, Jordan
- Institute for Atmospheric and Earth System Research (INAR/Physics), University of Helsinki, 00014, Helsinki, Finland
| | - Carl-Johan Fraenkel
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, 22100, Lund, Sweden
- Department of Clinical Microbiology and Infection Control, Region Skåne, 22185, Lund, Sweden
| | - Patrik Medstrand
- Department of Translational Medicine, Clinical Virology, Lund University, 22100, Lund, Sweden
- SciLifeLab, Lund University, 22100, Lund, Sweden
| | - Jakob Löndahl
- Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Lund University, Box 118, 22100, Lund, Sweden.
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12
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Sobek E, Elias DA. Bipolar ionization rapidly inactivates real-world, airborne concentrations of infective respiratory viruses. PLoS One 2023; 18:e0293504. [PMID: 37992037 PMCID: PMC10664916 DOI: 10.1371/journal.pone.0293504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 10/05/2023] [Indexed: 11/24/2023] Open
Abstract
The SARS-CoV-2 (COVID-19) pandemic has highlighted the urgent need for strategies that rapidly inactivate airborne respiratory viruses and break the transmission cycle of indoor spaces. Air ions can reduce viable bacteria, mold, and virus counts, however, most studies use small test enclosures with target microbes and ion sources in close vicinity. To evaluate ion performance in real-world spaces, experiments were conducted in a large, room-size BSL-3 Chamber. Negative and positive ions were delivered simultaneously using a commercially available bipolar air ion device. The device housed Needle Point Bipolar ionization (NPBI) technology. Large chamber studies often use unrealistically high virus concentrations to ensure measurable virus is present at the trial end. However, excessively high viral concentrations bias air cleaning devices towards underperformance. Hence, devices that provide a substantial impact for protecting occupants in real-world spaces with real-world virus concentrations are often dismissed as poor performers. Herein, both real-world and excessive virus concentrations were studied using Influenza A and B, Human Respiratory Syncytial Virus (RSV), and the SARS-CoV-2 Alpha and Delta strains. The average ion concentrations ranged from 4,100 to 24,000 per polarity over 60-minute and 30-minute time trials. The reduction rate was considerably greater for trials that used real-world virus concentrations, reducing infectivity for Influenza A and B, RSV, and SARS-CoV-2 Delta by 88.3-99.98% in 30 minutes, whereas trials using in-excess concentrations showed 49.5-61.2% in 30 minutes. These findings strongly support the addition of NPBI ion technology to building management strategies aimed to protect occupants from contracting and spreading infective respiratory viruses indoors.
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Affiliation(s)
- Edward Sobek
- Global Plasma Solutions, Charlotte, NC, United States of America
| | - Dwayne A. Elias
- Elias Consulting, LLC, Knoxville, TN, United States of America
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13
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Garrett TJ, Coatsworth H, Mahmud I, Hamerly T, Stephenson CJ, Ayers JB, Yazd HS, Miller MR, Lednicky JA, Dinglasan RR. Niclosamide as a chemical probe for analyzing SARS-CoV-2 modulation of host cell lipid metabolism. Front Microbiol 2023; 14:1251065. [PMID: 37901834 PMCID: PMC10603251 DOI: 10.3389/fmicb.2023.1251065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/15/2023] [Indexed: 10/31/2023] Open
Abstract
Introduction SARS-CoV-2 subverts host cell processes to facilitate rapid replication and dissemination, and this leads to pathological inflammation. Methods We used niclosamide (NIC), a poorly soluble anti-helminth drug identified initially for repurposed treatment of COVID-19, which activates the cells' autophagic and lipophagic processes as a chemical probe to determine if it can modulate the host cell's total lipid profile that would otherwise be either amplified or reduced during SARS-CoV-2 infection. Results Through parallel lipidomic and transcriptomic analyses we observed massive reorganization of lipid profiles of SARS-CoV-2 infected Vero E6 cells, especially with triglycerides, which were elevated early during virus replication, but decreased thereafter, as well as plasmalogens, which were elevated at later timepoints during virus replication, but were also elevated under normal cell growth. These findings suggested a complex interplay of lipid profile reorganization involving plasmalogen metabolism. We also observed that NIC treatment of both low and high viral loads does not affect virus entry. Instead, NIC treatment reduced the abundance of plasmalogens, diacylglycerides, and ceramides, which we found elevated during virus infection in the absence of NIC, resulting in a significant reduction in the production of infectious virions. Unexpectedly, at higher viral loads, NIC treatment also resulted in elevated triglyceride levels, and induced significant changes in phospholipid metabolism. Discussion We posit that future screens of approved or new partner drugs should prioritize compounds that effectively counter SARS-CoV-2 subversion of lipid metabolism, thereby reducing virus replication, egress, and the subsequent regulation of key lipid mediators of pathological inflammation.
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Affiliation(s)
- Timothy J. Garrett
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
- Southeast Center for Integrated Metabolomics, Clinical and Translational Science Institute, University of Florida, Gainesville, FL, United States
| | - Heather Coatsworth
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Iqbal Mahmud
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
- Southeast Center for Integrated Metabolomics, Clinical and Translational Science Institute, University of Florida, Gainesville, FL, United States
| | - Timothy Hamerly
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Caroline J. Stephenson
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States
| | - Jasmine B. Ayers
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Hoda S. Yazd
- Department of Chemistry, University of Florida, Gainesville, FL, United States
| | - Megan R. Miller
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - John A. Lednicky
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States
| | - Rhoel R. Dinglasan
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
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14
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Hamilton V, Sheikh S, Szczepanska A, Maskell N, Hamilton F, Reid JP, Bzdek BR, Murray JRD. Diathermy and bone sawing are high aerosol yield procedures. Bone Joint Res 2023; 12:636-643. [PMID: 37813391 PMCID: PMC10562079 DOI: 10.1302/2046-3758.1210.bjr-2023-0028.r1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/11/2023] Open
Abstract
Aims Orthopaedic surgery uses many varied instruments with high-speed, high-impact, thermal energy and sometimes heavy instruments, all of which potentially result in aerosolization of contaminated blood, tissue, and bone, raising concerns for clinicians' health. This study quantifies the aerosol exposure by measuring the number and size distribution of the particles reaching the lead surgeon during key orthopaedic operations. Methods The aerosol yield from 17 orthopaedic open surgeries (on the knee, hip, and shoulder) was recorded at the position of the lead surgeon using an Aerodynamic Particle Sizer (APS; 0.5 to 20 μm diameter particles) sampling at 1 s time resolution. Through timestamping, detected aerosol was attributed to specific procedures. Results Diathermy (electrocautery) and oscillating bone saw use had a high aerosol yield (> 100 particles detected per s) consistent with high exposure to aerosol in the respirable range (< 5 µm) for the lead surgeon. Pulsed lavage, reaming, osteotome use, and jig application/removal were medium aerosol yield (10 to 100 particles s-1). However, pulsed lavage aerosol was largely attributed to the saline jet, osteotome use was always brief, and jig application/removal had a large variability in the associated aerosol yield. Suctioning (with/without saline irrigation) had a low aerosol yield (< 10 particles s-1). Most surprisingly, other high-speed procedures, such as drilling and screwing, had low aerosol yields. Conclusion This work suggests that additional precautions should be recommended for diathermy and bone sawing, such as enhanced personal protective equipment or the use of suction devices to reduce exposure.
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Affiliation(s)
| | | | | | - Nick Maskell
- Bristol Medical School, University of Bristol, Bristol, UK
| | | | | | | | - James R. D. Murray
- Bristol Medical School, University of Bristol, Bristol, UK
- Avon Orthopaedic Centre, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
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15
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Port JR, Morris DH, Riopelle JC, Yinda CK, Avanzato VA, Holbrook MG, Bushmaker T, Schulz JE, Saturday TA, Barbian K, Russell CA, Perry-Gottschalk R, Shaia CI, Martens C, Lloyd-Smith JO, Fischer RJ, Munster VJ. Host and viral determinants of airborne transmission of SARS-CoV-2 in the Syrian hamster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2022.08.15.504010. [PMID: 36032963 PMCID: PMC9413705 DOI: 10.1101/2022.08.15.504010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
It remains poorly understood how SARS-CoV-2 infection influences the physiological host factors important for aerosol transmission. We assessed breathing pattern, exhaled droplets, and infectious virus after infection with Alpha and Delta variants of concern (VOC) in the Syrian hamster. Both VOCs displayed a confined window of detectable airborne virus (24-48 h), shorter than compared to oropharyngeal swabs. The loss of airborne shedding was linked to airway constriction resulting in a decrease of fine aerosols (1-10μm) produced, which are suspected to be the major driver of airborne transmission. Male sex was associated with increased viral replication and virus shedding in the air. Next, we compared the transmission efficiency of both variants and found no significant differences. Transmission efficiency varied mostly among donors, 0-100% (including a superspreading event), and aerosol transmission over multiple chain links was representative of natural heterogeneity of exposure dose and downstream viral kinetics. Co-infection with VOCs only occurred when both viruses were shed by the same donor during an increased exposure timeframe (24-48 h). This highlights that assessment of host and virus factors resulting in a differential exhaled particle profile is critical for understanding airborne transmission.
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Affiliation(s)
- Julia R. Port
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Dylan H. Morris
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - Jade C. Riopelle
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Claude Kwe Yinda
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Victoria A. Avanzato
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Myndi G. Holbrook
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Trenton Bushmaker
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Jonathan E. Schulz
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Taylor A. Saturday
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Kent Barbian
- Rocky Mountain Research and Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Colin A. Russell
- Department of Medical Microbiology | Amsterdam University Medical Center, University of Amsterdam
| | - Rose Perry-Gottschalk
- Rocky Mountain Visual and Medical Arts Unit, Research Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Carl I. Shaia
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Craig Martens
- Rocky Mountain Research and Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - James O. Lloyd-Smith
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - Robert J. Fischer
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Vincent J. Munster
- Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
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16
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Luong Nguyen LB, Goupil de Bouillé J, Menant L, Noret M, Dumas A, Salmona M, Le Goff J, Delaugerre C, Crépey P, Zeggagh J. A randomised controlled trial to study the transmission of SARS-CoV-2 and other respiratory viruses during indoor clubbing events (ANRS0066s ITOC study). Clin Infect Dis 2023; 77:ciad603. [PMID: 37795682 PMCID: PMC10724450 DOI: 10.1093/cid/ciad603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 07/05/2023] [Accepted: 10/04/2023] [Indexed: 10/06/2023] Open
Abstract
BACKGROUND In the context of the circulation of the SARS-CoV-2 B.1.617.2 (Delta) variant, vaccination re-authorised mass indoor gatherings. The "Indoor Transmission of COVID-19" (ITOC) trial (ClinicalTrials.gov, NCT05311865) aimed to assess the risk of transmission of SARS-CoV-2 and other respiratory viruses during an indoor clubbing event among participants fully-vaccinated against COVID-19. METHODS ITOC, a randomised, controlled trial in the Paris region (France), enrolled healthy volunteers aged 18-49 years, fully-vaccinated against COVID-19, with no co-morbidities or symptoms, randomised 1:1 to be interventional group "attendees" or control "non-attendees". The intervention, a 7-hour indoor event in a nightclub at full capacity, with no masking, prior SARS-CoV-2 test result or social distancing required. The primary-outcome measure was the numbers of RT-PCR-determined SARS-CoV-2-positive subjects on self-collected saliva 7 days post-gathering in the per-protocol population. Secondary endpoints focused on 20 other respiratory viruses. RESULTS Healthy participants (n = 1,216) randomised 2:1 by blocks up to 10, 815 attendees and 401 non-attendees, yielding 529 and 287 subjects, respectively, with day-7 saliva samples. One day-7 sample from each group was positive. Looking at all respiratory viruses together, the clubbing event was associated with an increased risk of infection of 1.59 [95% CI 1.04-2.61]. CONCLUSIONS In the context of low Delta-VOC circulation, no evidence of SARS-CoV-2 transmission among asymptomatic and vaccinated participants was found, but the risk of other respiratory virus transmission was higher.
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Affiliation(s)
- Liem Binh Luong Nguyen
- CIC Cochin Pasteur, Hôpital Cochin Port-Royal, AP-HP, Université de Paris Cité, Paris, France
| | - Jeanne Goupil de Bouillé
- Service de Maladies Infectieuses et Tropicales, Hôpital Avicenne, AP-HP, Bobigny, France
- LEPS Laboratoire Éducations et Promotion de Santé, Université Paris 13, Bobigny, France
| | - Lola Menant
- Université de Rennes, EHESP, CNRS, Inserm, Arènes—UMR 6051, RSMS—U 1309, Rennes, France
| | - Marion Noret
- Réseau National de Recherche Clinique en Infectiologie (RENARCI), Service de Maladies Infectieuses et Tropicales, Hôpital Saint-Louis, AP-HP, Paris, France
| | - Audrey Dumas
- ANRS∣Emerging Infectious Diseases, Paris, France
| | - Maud Salmona
- Service de Virologie, Hôpital Saint-Louis, AP-HP, Université de Paris Cité, Paris, France
| | - Jérôme Le Goff
- Service de Virologie, Hôpital Saint-Louis, AP-HP, Université de Paris Cité, Paris, France
| | - Constance Delaugerre
- Service de Virologie, Hôpital Saint-Louis, AP-HP, Université de Paris Cité, Paris, France
| | - Pascal Crépey
- Université de Rennes, EHESP, CNRS, Inserm, Arènes—UMR 6051, RSMS—U 1309, Rennes, France
| | - Jeremy Zeggagh
- Service de Maladies Infectieuses et Tropicales, Hôpital Saint-Louis, AP-HP, Paris, France
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17
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Thibon C, Vecellio L, Belkhir L, Dubus JC, Robert A, Kabamba B, Reychler G. There Is a Risk of Spread During a Nebulization Session in a Patient with COVID-19. J Aerosol Med Pulm Drug Deliv 2023; 36:268-274. [PMID: 37610849 DOI: 10.1089/jamp.2023.0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/25/2023] Open
Abstract
Introduction: A hypothetical risk of SARS-CoV-2 airborne transmission through nebulization was suggested based on a potential environmental contamination by the fugitive aerosol emitted in the environment during the procedure. The aim of this study was to verify this risk from the fugitive aerosol emitted by COVID-19 patients during one nebulization session. Methods: In this cohort study, COVID-19 patients treated with nebulization were recruited at their admission to the hospital. Patients had to perform a nebulization session while a BioSampler® and a pump were used to vacuum the fugitive aerosol and collect it for SARS-CoV-2 RNA detection. Results: Ten consecutive patients hospitalized with COVID-19 were recruited. The median viral load was 6.5 × 106 copies/mL. Two out of the 10 samples from the fugitive aerosol collected were positive to SARS-CoV-2. Conclusion: The risk of fugitive aerosol contamination with SARS-CoV-2 during nebulization has now been verified.
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Affiliation(s)
- Christophe Thibon
- Secteur de Kinésithérapie et Ergothérapie, Cliniques Universitaires Saint-Luc, Brussels, Belgium
- Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium
- Service de Pneumologie, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Laurent Vecellio
- PST A, Université de Tours, Tours, France
- Group Aerosoltherapy GAT of the French Language Respiratory Society-Société de Pneumologie de Langue Française SPLF, Paris, France
| | - Leila Belkhir
- Department of Internal Medicine, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Jean-Christophe Dubus
- Group Aerosoltherapy GAT of the French Language Respiratory Society-Société de Pneumologie de Langue Française SPLF, Paris, France
- Unité de Pneumologie Pédiatrique, Centre Hospitalo-Universitaire (CHU) Timone-Enfants, Marseille, France
- Aix Marseille Université, IRD, AP-HM, MEPHI, IHU-Méditerranée Infection, Marseille, France
| | - Annie Robert
- Pole épidémiologie et biostatistique, Institut de recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Benoît Kabamba
- Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium
- Department of Microbiology, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Gregory Reychler
- Secteur de Kinésithérapie et Ergothérapie, Cliniques Universitaires Saint-Luc, Brussels, Belgium
- Institut de Recherche Expérimentale et Clinique (IREC), Université Catholique de Louvain, Brussels, Belgium
- Service de Pneumologie, Cliniques universitaires Saint-Luc, Brussels, Belgium
- Group Aerosoltherapy GAT of the French Language Respiratory Society-Société de Pneumologie de Langue Française SPLF, Paris, France
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18
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Chow VTK, Tay DJW, Chen MIC, Tang JW, Milton DK, Tham KW. Influenza A and B Viruses in Fine Aerosols of Exhaled Breath Samples from Patients in Tropical Singapore. Viruses 2023; 15:2033. [PMID: 37896810 PMCID: PMC10612062 DOI: 10.3390/v15102033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/29/2023] Open
Abstract
Influenza is a highly contagious respiratory illness that commonly causes outbreaks among human communities. Details about the exact nature of the droplets produced by human respiratory activities such as breathing, and their potential to carry and transmit influenza A and B viruses is still not fully understood. The objective of our study was to characterize and quantify influenza viral shedding in exhaled aerosols from natural patient breath, and to determine their viral infectivity among participants in a university cohort in tropical Singapore. Using the Gesundheit-II exhaled breath sampling apparatus, samples of exhaled breath of two aerosol size fractions ("coarse" > 5 µm and "fine" ≤ 5 µm) were collected and analyzed from 31 study participants, i.e., 24 with influenza A (including H1N1 and H3N2 subtypes) and 7 with influenza B (including Victoria and Yamagata lineages). Influenza viral copy number was quantified using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Infectivity of influenza virus in the fine particle fraction was determined by culturing in Madin-Darby canine kidney cells. Exhaled influenza virus RNA generation rates ranged from 9 to 1.67 × 105 and 10 to 1.24 × 104 influenza virus RNA copies per minute for the fine and coarse aerosol fractions, respectively. Compared to the coarse aerosol fractions, influenza A and B viruses were detected more frequently in the fine aerosol fractions that harbored 12-fold higher viral loads. Culturable virus was recovered from the fine aerosol fractions from 9 of the 31 subjects (29%). These findings constitute additional evidence to reiterate the important role of fine aerosols in influenza transmission and provide a baseline range of influenza virus RNA generation rates.
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Affiliation(s)
- Vincent T. K. Chow
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore;
| | - Douglas Jie Wen Tay
- Infectious Diseases Translational Research Program, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore;
| | - Mark I. C. Chen
- Research Office, National Centre for Infectious Diseases, Singapore 308442, Singapore;
| | - Julian W. Tang
- Department of Respiratory Sciences, University of Leicester, Leicester LE1 7RH, UK;
| | - Donald K. Milton
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD 20742, USA;
| | - Kwok Wai Tham
- Department of the Built Environment, College of Design and Engineering, National University of Singapore, Singapore 117356, Singapore
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Lane G, Zhou G, Hultquist JF, Simons LM, Redondo RL, Ozer EA, McCarthy DM, Ison MG, Achenbach CJ, Wang X, Wai CM, Wyatt E, Aalsburg A, Yang Q, Noto T, Alisoltani A, Ysselstein D, Awatramani R, Murphy R, Theron G, Zelano C. Quantity of SARS-CoV-2 RNA copies exhaled per minute during natural breathing over the course of COVID-19 infection. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.09.06.23295138. [PMID: 37732212 PMCID: PMC10508818 DOI: 10.1101/2023.09.06.23295138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
SARS-CoV-2 is spread through exhaled breath of infected individuals. A fundamental question in understanding transmission of SARS-CoV-2 is how much virus an individual is exhaling into the environment while they breathe, over the course of their infection. Research on viral load dynamics during COVID-19 infection has focused on internal swab specimens, which provide a measure of viral loads inside the respiratory tract, but not on breath. Therefore, the dynamics of viral shedding on exhaled breath over the course of infection are poorly understood. Here, we collected exhaled breath specimens from COVID-19 patients and used RTq-PCR to show that numbers of exhaled SARS-CoV-2 RNA copies during COVID-19 infection do not decrease significantly until day 8 from symptom-onset. COVID-19-positive participants exhaled an average of 80 SARS-CoV-2 viral RNA copies per minute during the first 8 days of infection, with significant variability both between and within individuals, including spikes over 800 copies a minute in some patients. After day 8, there was a steep drop to levels nearing the limit of detection, persisting for up to 20 days. We further found that levels of exhaled viral RNA increased with self-rated symptom-severity, though individual variation was high. Levels of exhaled viral RNA did not differ across age, sex, time of day, vaccination status or viral variant. Our data provide a fine-grained, direct measure of the number of SARS-CoV-2 viral copies exhaled per minute during natural breathing-including 312 breath specimens collected multiple times daily over the course of infection-in order to fill an important gap in our understanding of the time course of exhaled viral loads in COVID-19.
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20
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McCarthy MW. Paxlovid as a potential treatment for long COVID. Expert Opin Pharmacother 2023; 24:1839-1843. [PMID: 37731377 DOI: 10.1080/14656566.2023.2262387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 09/20/2023] [Indexed: 09/22/2023]
Abstract
INTRODUCTION On 31 July 2023, the United States Department of Health and Human Services announced the formation of the Office of Long COVID Research and Practice and the United States National Institutes of Health opened enrollment for RECOVER-Vital, a randomized study to evaluate new treatment options for long Coronavirus (long COVID). AREAS COVERED The RECOVER Initiative is a $1.15 billion research platform intended to describe, categorize, treat, and prevent long-term symptoms following infection by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‑CoV‑2), the virus that causes Coronavirus (COVID-19). More than 200 symptoms have been associated with long COVID, potentially affecting nearly all body systems, and current estimates suggest that between 7 million and 23 million Americans have developed long COVID. However, there are no approved treatments for this condition. EXPERT OPINION The first prospective, randomized study of the RECOVER research initiative, RECOVER-Vital, will evaluate the SARS-CoV-2 antiviral nirmatrelvir/ritonavir (Paxlovid) as a potential treatment for long COVID. This manuscript explores what is known about Paxlovid to treat and prevent long COVID and examines the rationale for addressing this condition with an antiviral agent.
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21
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Yao Y, Cui Y, Gao X, Qian Y, Hu B. Contamination of personal protective equipment and environmental surfaces in Fangcang shelter hospitals. Am J Infect Control 2023; 51:926-930. [PMID: 36435405 PMCID: PMC9683851 DOI: 10.1016/j.ajic.2022.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 11/17/2022] [Accepted: 11/17/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Fangcang shelter hospitals emerged as a new public health concept after COVID-19. Data regarding contamination of Fangcang shelter environments remains scarce. This study aims to investigate the extent of SARS-CoV-2 contamination on personal protective equipment and surfaces in Fangcang hospitals. METHODS Between March and May 2022, during wave of omicron variant, a prospective study was conducted in 2 Fangcang hospitals in Shanghai, China. Swabs of personal protective equipment worn and environmental surfaces of contaminated areas, doffing rooms, and potentially contaminated areas were collected. SARS-CoV-2 RNA was detected by reverse transcription quantitative polymerase chain reaction. If viral RNA was detected, sampling was repeated after cleaning and disinfection. RESULTS A total of 602 samples were collected. 13.3% of the personal protective equipment were contaminated. Positive rate was higher in the contaminated areas (48.4%) than in the doffing rooms (11.7%) and the potentially contaminated areas (0; P<.05). Contamination was highest in patient occupied areas (67.5%). After cleaning, samples taken at previously contaminated surfaces are all negative. CONCLUSIONS SARS-CoV-2 RNA contamination is prevalent in Fangcang hospitals and healthcare workers are under risk of infection. Potentially contaminated areas and surfaces after cleaning and disinfection are negative, underlying the importance of infection control policy.
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Affiliation(s)
- Yumeng Yao
- Department of Infectious Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yangwen Cui
- Department of Infection Control and Management, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaodong Gao
- Department of Infection Control and Management, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yiyi Qian
- Department of Infectious Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Bijie Hu
- Department of Infectious Diseases, Zhongshan Hospital, Fudan University, Shanghai, China; Department of Infection Control and Management, Zhongshan Hospital, Fudan University, Shanghai, China.
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22
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Zhou J, Singanayagam A, Goonawardane N, Moshe M, Sweeney FP, Sukhova K, Killingley B, Kalinova M, Mann AJ, Catchpole AP, Barer MR, Ferguson NM, Chiu C, Barclay WS. Viral emissions into the air and environment after SARS-CoV-2 human challenge: a phase 1, open label, first-in-human study. THE LANCET. MICROBE 2023; 4:e579-e590. [PMID: 37307844 PMCID: PMC10256269 DOI: 10.1016/s2666-5247(23)00101-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/14/2023] [Accepted: 03/16/2023] [Indexed: 06/14/2023]
Abstract
BACKGROUND Effectively implementing strategies to curb SARS-CoV-2 transmission requires understanding who is contagious and when. Although viral load on upper respiratory swabs has commonly been used to infer contagiousness, measuring viral emissions might be more accurate to indicate the chance of onward transmission and identify likely routes. We aimed to correlate viral emissions, viral load in the upper respiratory tract, and symptoms, longitudinally, in participants who were experimentally infected with SARS-CoV-2. METHODS In this phase 1, open label, first-in-human SARS-CoV-2 experimental infection study at quarantine unit at the Royal Free London NHS Foundation Trust, London, UK, healthy adults aged 18-30 years who were unvaccinated for SARS-CoV-2, not previously known to have been infected with SARS-CoV-2, and seronegative at screening were recruited. Participants were inoculated with 10 50% tissue culture infectious dose of pre-alpha wild-type SARS-CoV-2 (Asp614Gly) by intranasal drops and remained in individual negative pressure rooms for a minimum of 14 days. Nose and throat swabs were collected daily. Emissions were collected daily from the air (using a Coriolis μ air sampler and directly into facemasks) and the surrounding environment (via surface and hand swabs). All samples were collected by researchers, and tested by using PCR, plaque assay, or lateral flow antigen test. Symptom scores were collected using self-reported symptom diaries three times daily. The study is registered with ClinicalTrials.gov, NCT04865237. FINDINGS Between March 6 and July 8, 2021, 36 participants (ten female and 26 male) were recruited and 18 (53%) of 34 participants became infected, resulting in protracted high viral loads in the nose and throat following a short incubation period, with mild-to-moderate symptoms. Two participants were excluded from the per-protocol analysis owing to seroconversion between screening and inoculation, identified post hoc. Viral RNA was detected in 63 (25%) of 252 Coriolis air samples from 16 participants, 109 (43%) of 252 mask samples from 17 participants, 67 (27%) of 252 hand swabs from 16 participants, and 371 (29%) of 1260 surface swabs from 18 participants. Viable SARS-CoV-2 was collected from breath captured in 16 masks and from 13 surfaces, including four small frequently touched surfaces and nine larger surfaces where airborne virus could deposit. Viral emissions correlated more strongly with viral load in nasal swabs than throat swabs. Two individuals emitted 86% of airborne virus, and the majority of airborne virus collected was released on 3 days. Individuals who reported the highest total symptom scores were not those who emitted most virus. Very few emissions occurred before the first reported symptom (7%) and hardly any before the first positive lateral flow antigen test (2%). INTERPRETATION After controlled experimental inoculation, the timing, extent, and routes of viral emissions was heterogeneous. We observed that a minority of participants were high airborne virus emitters, giving support to the notion of superspreading individuals or events. Our data implicates the nose as the most important source of emissions. Frequent self-testing coupled with isolation upon awareness of first symptoms could reduce onward transmissions. FUNDING UK Vaccine Taskforce of the Department for Business, Energy and Industrial Strategy of Her Majesty's Government.
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Affiliation(s)
- Jie Zhou
- Section of Virology, Imperial College London, London, UK
| | - Anika Singanayagam
- Section of Adult Infectious Disease, Imperial College London, London, UK
| | | | - Maya Moshe
- Section of Virology, Imperial College London, London, UK
| | | | - Ksenia Sukhova
- Section of Virology, Imperial College London, London, UK
| | - Ben Killingley
- Department of Infectious Diseases, University College London Hospital, London, UK
| | | | | | | | - Michael R Barer
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Neil M Ferguson
- Department of Infectious Disease, and MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK
| | - Christopher Chiu
- Section of Adult Infectious Disease, Imperial College London, London, UK
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23
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Zhang N, Liu L, Dou Z, Liu X, Yang X, Miao D, Guo Y, Gu S, Li Y, Qian H, Wei J. Close contact behaviors of university and school students in 10 indoor environments. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:132069. [PMID: 37463561 DOI: 10.1016/j.jhazmat.2023.132069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/24/2023] [Accepted: 07/13/2023] [Indexed: 07/20/2023]
Abstract
Close contact routes, including short-range airborne and large-droplet routes, play an important role in the transmission of SARS-CoV-2 in indoor environments. However, the exposure risk of such routes is difficult to quantify due to the lack of data on the close contact behavior of individuals. In this study, a digital wearable device, based on semi-supervised learning, was developed to automatically record human close contact behavior. We collected 337,056 s of indoor close contact of school and university students from 194.5 h of depth video recordings in 10 types of indoor environments. The correlation between aerosol exposure and close contact behaviors was then evaluated. Individuals in restaurants had the highest close contact ratio (64%), as well as the highest probability of face-to-face pattern (78%) during close contact. Accordingly, university students showed greater exposure potential in dormitories than school students in homes, however, a lower exposure was observed in classrooms and postgraduate student offices in comparison with school students in classrooms. In addition, restaurants had the highest aerosol exposure volume for both short-range inhalation and direct deposition on the facial mucosa. Thus, the classroom was established as the primary indoor environment where school students are exposed to aerosols.
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Affiliation(s)
- Nan Zhang
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Li Liu
- School of Architecture, Tsinghua University, Beijing, China
| | - Zhiyang Dou
- Department of Computer Science, The University of Hong Kong, Hong Kong, China
| | - Xiyue Liu
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Xueze Yang
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Doudou Miao
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Yong Guo
- Department of Building Science, Tsinghua University, Beijing, China
| | - Silan Gu
- Thee First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Yuguo Li
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China
| | - Hua Qian
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Jianjian Wei
- Institute of Refrigeration and Cryogenics, Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Zhejiang University, Hangzhou, China.
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24
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Dommer A, Wauer NA, Angle KJ, Davasam A, Rubio P, Luo M, Morris CK, Prather KA, Grassian VH, Amaro RE. Revealing the Impacts of Chemical Complexity on Submicrometer Sea Spray Aerosol Morphology. ACS CENTRAL SCIENCE 2023; 9:1088-1103. [PMID: 37396863 PMCID: PMC10311664 DOI: 10.1021/acscentsci.3c00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Indexed: 07/04/2023]
Abstract
Sea spray aerosol (SSA) ejected through bursting bubbles at the ocean surface is a complex mixture of salts and organic species. Submicrometer SSA particles have long atmospheric lifetimes and play a critical role in the climate system. Composition impacts their ability to form marine clouds, yet their cloud-forming potential is difficult to study due to their small size. Here, we use large-scale molecular dynamics (MD) simulations as a "computational microscope" to provide never-before-seen views of 40 nm model aerosol particles and their molecular morphologies. We investigate how increasing chemical complexity impacts the distribution of organic material throughout individual particles for a range of organic constituents with varying chemical properties. Our simulations show that common organic marine surfactants readily partition between both the surface and interior of the aerosol, indicating that nascent SSA may be more heterogeneous than traditional morphological models suggest. We support our computational observations of SSA surface heterogeneity with Brewster angle microscopy on model interfaces. These observations indicate that increased chemical complexity in submicrometer SSA leads to a reduced surface coverage by marine organics, which may facilitate water uptake in the atmosphere. Our work thus establishes large-scale MD simulations as a novel technique for interrogating aerosols at the single-particle level.
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25
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Shinde M, Lavania M, Rawal J, Chavan N, Shinde P. Evaluation of droplet digital qRT-PCR (dd qRT-PCR) for quantification of SARS CoV-2 RNA in stool and urine specimens of COVID-19 patients. Front Med (Lausanne) 2023; 10:1148688. [PMID: 37469662 PMCID: PMC10352106 DOI: 10.3389/fmed.2023.1148688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/09/2023] [Indexed: 07/21/2023] Open
Abstract
Introduction There have been a few reports of viral load detection in stool and urine samples of patients with coronavirus disease 2019 (COVID-19), and the transmission of the virus through faecal oral route. For clinical diagnosis and treatment, the widely used reverse transcription-polymerase chain reaction (qRT-PCR) method has some limitations. Methods The aim of our study to assess the presence and concentration of SARS CoV-2 RNA in stool and urine samples from COVID-19 patients with mild, moderate, and severe disease, we compared a traditional qRT-PCR approach with a ddPCR. ddPCR and qRT-PCR-based target gene analysis were performed on 107 COVID-19-confirmed patients paired samples (N1 and N2). The MagMax magnetic beads base method was used to isolate RNA. Real-time qRT-PCR and dd PCR were performed on all patients. Results and Discussion The average cycle threshold (Ct) of qRT-PCR was highly correlated with the average copy number of 327.10 copies/l analyzed in ddPCR. In ddPCR, urine samples showed 27.1% positivity while for stool it was 100%. Conclusion This study's findings not only show that SARS CoV-2 is present in urine and faeces, but also suggest that low concentrations of the viral target ddPCR make it easier to identify positive samples and help resolve for cases of inconclusive diagnosis.
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26
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Armand P, Tâche J. 3D modelling and simulation of the impact of wearing a mask on the dispersion of particles carrying the SARS-CoV-2 virus in a railway transport coach. Sci Rep 2023; 13:8929. [PMID: 37264020 DOI: 10.1038/s41598-023-35025-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 05/11/2023] [Indexed: 06/03/2023] Open
Abstract
Even though the Covid-19 pandemic seems to be stagnating or decreasing across the world, a resurgence of the disease or the occurrence of other epidemics caused by the aerial dissemination of pathogenic biological agents cannot be ruled out. These agents, in particular the virions of the Covid-19 disease, are found in the particles originating from the sputum of infected symptomatic or asymptomatic people. In previous research, we made use of a three-dimensional Computational Fluid Dynamics (CFD) model to simulate particle transport and dispersion in ventilated semi-confined spaces. By way of illustration, we considered a commuter train coach in which an infected passenger emitted droplets (1 and 10 µm) and drops (100 and 1000 µm) while breathing and coughing. Using an Eulerian approach and a Lagrangian approach, we modelled the dispersion of the particles in the turbulent flow generated by the ventilation of the coach. The simulations returned similar results from both approaches and clearly demonstrated the very distinct aerodynamics of the aerosol of airborne droplets and, at the other end of the spectrum, of drops falling or behaving like projectiles depending on their initial velocity. That numerical study considered passengers without protective masks. In this new phase of research, we first used literature data to develop a model of a typical surgical mask for use on a digital manikin representing a human. Next, we resumed the twin experiment of the railway coach, but this time, the passengers (including the infected one) were provided with surgical masks. We compared the spatial and temporal distributions of the particles depending on whether the spreader passenger wore a mask at all, and whether the mask was perfectly fitted (without leaks) or worn loosely (with leaks). Beyond demonstrating the obvious value of wearing a mask in limiting the dissemination of particles, our model and our simulations allow a quantification of the ratio of particles suspended in the coach depending on whether the infected passenger wears a mask or not. Moreover, the calculations carried out constitute only one illustrative application among many others, not only in public transport, but in any other public or private ventilated space on the basis of the same physical models and digital twins of the places considered. CFD therefore makes it possible to estimate the criticality of the occupation of places by people with or without a mask and to recommend measures in order to limit aerial contamination by any kind of airborne pathogen, such as the virions of Covid-19.
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Moschovis PP, Lombay J, Rooney J, Schenkel SR, Singh D, Rezaei SJ, Salo N, Gong A, Yonker LM, Shah J, Hayden D, Hibberd PL, Demokritou P, Kinane TB. The effect of activity and face masks on exhaled particles in children. Pediatr Investig 2023; 7:75-85. [PMID: 37324601 PMCID: PMC10262878 DOI: 10.1002/ped4.12376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 01/29/2023] [Indexed: 06/17/2023] Open
Abstract
Importance Despite the high burden of respiratory infections among children, the production of exhaled particles during common activities and the efficacy of face masks in children have not been sufficiently studied. Objective To determine the effect of type of activity and mask usage on exhaled particle production in children. Methods Healthy children were asked to perform activities that ranged in intensity (breathing quietly, speaking, singing, coughing, and sneezing) while wearing no mask, a cloth mask, or a surgical mask. The concentration and size of exhaled particles were assessed during each activity. Results Twenty-three children were enrolled in the study. Average exhaled particle concentration increased by intensity of activity, with the lowest particle concentration during tidal breathing (1.285 particles/cm3 [95% CI 0.943, 1.627]) and highest particle concentration during sneezing (5.183 particles/cm3 [95% CI 1.911, 8.455]). High-intensity activities were associated with an increase primarily in the respirable size (≤ 5 µm) particle fraction. Surgical and cloth masks were associated with lower average particle concentration compared to no mask (P = 0.026 for sneezing). Surgical masks outperformed cloth masks across all activities, especially within the respirable size fraction. In a multivariable linear regression model, we observed significant effect modification of activity by age and by mask type. Interpretation Similar to adults, children produce exhaled particles that vary in size and concentration across a range of activities. Production of respirable size fraction particles (≤ 5 µm), the dominant mode of transmission of many respiratory viruses, increases significantly with coughing and sneezing and is most effectively reduced by wearing surgical face masks.
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Affiliation(s)
- Peter P. Moschovis
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Jesiel Lombay
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Jennifer Rooney
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Sara R. Schenkel
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Dilpreet Singh
- Department of Environmental HealthHarvard T. H. Chan School of Public HealthBostonMassachusettsUSA
- Department of Mechanical and Aerospace EngineeringRutgers University School of Public HealthNew BrunswickNew JerseyUSA
| | - Shawheen J. Rezaei
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Nora Salo
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Amanda Gong
- David Geffen School of Medicinethe University of California Los AngelesLos AngelesCaliforniaUSA
| | - Lael M. Yonker
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Jhill Shah
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Douglas Hayden
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Patricia L. Hibberd
- Department of Global HealthBoston University School of Public HealthBostonMassachusettsUSA
| | - Philip Demokritou
- Department of Environmental HealthHarvard T. H. Chan School of Public HealthBostonMassachusettsUSA
- Department of Mechanical and Aerospace EngineeringRutgers University School of Public HealthNew BrunswickNew JerseyUSA
| | - T. Bernard Kinane
- Department of PediatricsMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
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28
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Peng Y, Yao M. Quantitatively Visualizing Airborne Disease Transmission Risks of Different Exhalation Activities through CO 2 Imaging. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6865-6875. [PMID: 37074044 PMCID: PMC10124748 DOI: 10.1021/acs.est.2c08503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/23/2023] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
Aerosol transmission has played a leading role in COVID-19 pandemic. However, there is still a poor understanding about how it is transmitted. This work was designed to study the exhaled breath flow dynamics and transmission risks under different exhaling modes. Using an infrared photography device, exhaled flow characteristics of different breathing activities, such as deep breathing, dry coughing, and laughing, together with the roles of mouth and nose were characterized by imaging CO2 flow morphologies. Both mouth and nose played an important role in the disease transmission though in the downward direction for the nose. In contrast to the trajectory commonly modeled, the exhaled airflows appeared with turbulent entrainments and obvious irregular movements, particularly the exhalations involving mouth were directed horizontal and had a higher propagation capacity and transmission risk. While the cumulative risk was high for deep breathing, those transient ones from dry coughing, yawning, and laughing were also shown to be significant. Various protective measures including masks, canteen table shields, and wearable devices were visually demonstrated to be effective for altering the exhaled flow directions. This work is useful to understanding the risk of aerosol infection and guiding the formulation of its prevention and control strategies. Experimental data also provide important information for refining model boundary conditions.
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Affiliation(s)
- Yijiao Peng
- State Key Joint Laboratory of Environmental Simulation and
Pollution Control, College of Environmental Sciences and Engineering, Peking
University, Beijing 100871, China
| | - Maosheng Yao
- State Key Joint Laboratory of Environmental Simulation and
Pollution Control, College of Environmental Sciences and Engineering, Peking
University, Beijing 100871, China
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29
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Parhizkar H, Fretz M, Laguerre A, Stenson J, Corsi RL, Van Den Wymelenberg KG, Gall ET. A novel VOC breath tracer method to evaluate indoor respiratory exposures in the near- and far-fields; implications for the spread of respiratory viruses. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2023; 33:339-346. [PMID: 36424424 PMCID: PMC9686220 DOI: 10.1038/s41370-022-00499-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 05/24/2023]
Abstract
BACKGROUND Several studies suggest that far-field transmission (>6 ft) explains a significant number of COVID-19 superspreading outbreaks. OBJECTIVE Therefore, quantifying the ratio of near- and far-field exposure to emissions from a source is key to better understanding human-to-human airborne infectious disease transmission and associated risks. METHODS In this study, we used an environmentally-controlled chamber to measure volatile organic compounds (VOCs) released from a healthy participant who consumed breath mints, which contained unique tracer compounds. Tracer measurements were made at 0.76 m (2.5 ft), 1.52 m (5 ft), 2.28 m (7.5 ft) from the participant, as well as in the exhaust plenum of the chamber. RESULTS We observed that 0.76 m (2.5 ft) trials had ~36-44% higher concentrations than other distances during the first 20 minutes of experiments, highlighting the importance of the near-field exposure relative to the far-field before virus-laden respiratory aerosol plumes are continuously mixed into the far-field. However, for the conditions studied, the concentrations of human-sourced tracers after 20 minutes and approaching the end of the 60-minute trials at 0.76 m, 1.52 m, and 2.28 m were only ~18%, ~11%, and ~7.5% higher than volume-averaged concentrations, respectively. SIGNIFICANCE This study suggests that for rooms with similar airflow parameters disease transmission risk is dominated by near-field exposures for shorter event durations (e.g., initial 20-25-minutes of event) whereas far-field exposures are critical throughout the entire event and are increasingly more important for longer event durations. IMPACT STATEMENT We offer a novel methodology for studying the fate and transport of airborne bioaerosols in indoor spaces using VOCs as unique proxies for bioaerosols. We provide evidence that real-time measurement of VOCs can be applied in settings with human subjects to estimate the concentration of bioaerosol at different distances from the emitter. We also improve upon the conventional assumption that a well-mixed room exhibits instantaneous and perfect mixing by addressing spatial distances and mixing over time. We quantitatively assessed the exposure levels to breath tracers at alternate distances and provided more insights into the changes on "near-field to far-field" ratios over time. This method can be used in future to estimate the benefits of alternate environmental conditions and occupant behaviors.
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Affiliation(s)
- Hooman Parhizkar
- Institute for Health and the Built Environment, University of Oregon, Portland, OR, 97209, USA
- Energy Studies in Buildings Laboratory, University of Oregon, Eugene, OR, 97403, USA
| | - Mark Fretz
- Institute for Health and the Built Environment, University of Oregon, Portland, OR, 97209, USA
- Energy Studies in Buildings Laboratory, University of Oregon, Eugene, OR, 97403, USA
- Biology and the Built Environment Center, University of Oregon, Eugene, OR, 97403, USA
| | - Aurélie Laguerre
- Department of Mechanical and Materials Engineering, Portland State University, Portland, OR, 97201, USA
| | - Jason Stenson
- Institute for Health and the Built Environment, University of Oregon, Portland, OR, 97209, USA
- Energy Studies in Buildings Laboratory, University of Oregon, Eugene, OR, 97403, USA
| | - Richard L Corsi
- Department of Civil and Environmental Engineering, University of California, Davis, Davis, CA, 95616, USA
| | - Kevin G Van Den Wymelenberg
- Institute for Health and the Built Environment, University of Oregon, Portland, OR, 97209, USA.
- Energy Studies in Buildings Laboratory, University of Oregon, Eugene, OR, 97403, USA.
- Biology and the Built Environment Center, University of Oregon, Eugene, OR, 97403, USA.
| | - Elliott T Gall
- Department of Mechanical and Materials Engineering, Portland State University, Portland, OR, 97201, USA
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Banholzer N, Zürcher K, Jent P, Bittel P, Furrer L, Egger M, Hascher T, Fenner L. SARS-CoV-2 transmission with and without mask wearing or air cleaners in schools in Switzerland: A modeling study of epidemiological, environmental, and molecular data. PLoS Med 2023; 20:e1004226. [PMID: 37200241 PMCID: PMC10194935 DOI: 10.1371/journal.pmed.1004226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/28/2023] [Indexed: 05/20/2023] Open
Abstract
BACKGROUND Growing evidence suggests an important contribution of airborne transmission to the overall spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), in particular via smaller particles called aerosols. However, the contribution of school children to SARS-CoV-2 transmission remains uncertain. The aim of this study was to assess transmission of airborne respiratory infections and the association with infection control measures in schools using a multiple-measurement approach. METHODS AND FINDINGS We collected epidemiological (cases of Coronavirus Disease 2019 (COVID-19)), environmental (CO2, aerosol and particle concentrations), and molecular data (bioaerosol and saliva samples) over 7 weeks from January to March 2022 (Omicron wave) in 2 secondary schools (n = 90, average 18 students/classroom) in Switzerland. We analyzed changes in environmental and molecular characteristics between different study conditions (no intervention, mask wearing, air cleaners). Analyses of environmental changes were adjusted for different ventilation, the number of students in class, school and weekday effects. We modeled disease transmission using a semi-mechanistic Bayesian hierarchical model, adjusting for absent students and community transmission. Molecular analysis of saliva (21/262 positive) and airborne samples (10/130) detected SARS-CoV-2 throughout the study (weekly average viral concentration 0.6 copies/L) and occasionally other respiratory viruses. Overall daily average CO2 levels were 1,064 ± 232 ppm (± standard deviation). Daily average aerosol number concentrations without interventions were 177 ± 109 1/cm3 and decreased by 69% (95% CrI 42% to 86%) with mask mandates and 39% (95% CrI 4% to 69%) with air cleaners. Compared to no intervention, the transmission risk was lower with mask mandates (adjusted odds ratio 0.19, 95% CrI 0.09 to 0.38) and comparable with air cleaners (1.00, 95% CrI 0.15 to 6.51). Study limitations include possible confounding by period as the number of susceptible students declined over time. Furthermore, airborne detection of pathogens document exposure but not necessarily transmission. CONCLUSIONS Molecular detection of airborne and human SARS-CoV-2 indicated sustained transmission in schools. Mask mandates were associated with greater reductions in aerosol concentrations than air cleaners and with lower transmission. Our multiple-measurement approach could be used to continuously monitor transmission risk of respiratory infections and the effectiveness of infection control measures in schools and other congregate settings.
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Affiliation(s)
- Nicolas Banholzer
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Kathrin Zürcher
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Philipp Jent
- Department of Infectious Diseases, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Pascal Bittel
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Lavinia Furrer
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Matthias Egger
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
- Centre for Infectious Disease Epidemiology and Research, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Tina Hascher
- Institute of Educational Science, University of Bern, Bern, Switzerland
| | - Lukas Fenner
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
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Wu J, Weng W, Fu M, Li Y. Numerical study of transient indoor airflow and virus-laden droplet dispersion: Impact of interactive human movement. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161750. [PMID: 36690100 DOI: 10.1016/j.scitotenv.2023.161750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/29/2022] [Accepted: 01/17/2023] [Indexed: 06/17/2023]
Abstract
Human movement affects indoor airflow and the airborne transmission of respiratory infectious diseases, which has attracted scholars. However, the interactive airflow between moving and stationary people has yet to be studied in detail. This study used the numerical method validated by experimental data to explore the transient indoor airflow and virus-laden droplet dispersion in scenes with interactive human movement. Human-shaped numerical models and the dynamic mesh method were adopted to realize human movement in scenes with different lateral distances (0.2-1.2 m) between a moving person and stationary (standing/sitting) persons. The interactive human movement obviously impacts other persons' respiratory airflow, and the lateral fusion ranged about 0.6 m. The interactive human movement strengthens the indoor airflow convection, and some exhaled virus-laden droplets were carried into wake flow and enhanced long-range airborne transmission. The impact of interactive human movement on sitting patients' exhalation airflow seems more evident than on standing patients. The impact might last over 2 min after movement stopped, and people in the affected area might be at a higher exposure. The results can provide a reference for epidemic control in indoor environments.
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Affiliation(s)
- Jialin Wu
- Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of City Integrated Emergency Response Science, Tsinghua University, Beijing 100084, PR China
| | - Wenguo Weng
- Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of City Integrated Emergency Response Science, Tsinghua University, Beijing 100084, PR China.
| | - Ming Fu
- Hefei Institute for Public Safety Research, Tsinghua University, Hefei, Anhui Province 230601, PR China; Anhui Province Key Laboratory of Human Safety, Hefei, Anhui Province 230601, PR China
| | - Yayun Li
- Hefei Institute for Public Safety Research, Tsinghua University, Hefei, Anhui Province 230601, PR China; Anhui Province Key Laboratory of Human Safety, Hefei, Anhui Province 230601, PR China
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Chang Y, Wang Y, Li W, Wei Z, Tang S, Chen R. Mechanisms, Techniques and Devices of Airborne Virus Detection: A Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20085471. [PMID: 37107752 PMCID: PMC10138381 DOI: 10.3390/ijerph20085471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/13/2023] [Accepted: 04/03/2023] [Indexed: 05/11/2023]
Abstract
Airborne viruses, such as COVID-19, cause pandemics all over the world. Virus-containing particles produced by infected individuals are suspended in the air for extended periods, actually resulting in viral aerosols and the spread of infectious diseases. Aerosol collection and detection devices are essential for limiting the spread of airborne virus diseases. This review provides an overview of the primary mechanisms and enhancement techniques for collecting and detecting airborne viruses. Indoor virus detection strategies for scenarios with varying ventilations are also summarized based on the excellent performance of existing advanced comprehensive devices. This review provides guidance for the development of future aerosol detection devices and aids in the control of airborne transmission diseases, such as COVID-19, influenza and other airborne transmission viruses.
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Affiliation(s)
- Yuqing Chang
- Beijing Key Laboratory of Occupational Safety and Health, Institute of Urban Safety and Environmental Science, Beijing Academy of Science and Technology, Beijing 100054, China; (Y.C.); (Y.W.); (S.T.)
| | - Yuqian Wang
- Beijing Key Laboratory of Occupational Safety and Health, Institute of Urban Safety and Environmental Science, Beijing Academy of Science and Technology, Beijing 100054, China; (Y.C.); (Y.W.); (S.T.)
| | - Wen Li
- Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Beijing 100081, China; (W.L.); (Z.W.)
| | - Zewen Wei
- Department of Biomedical Engineering, School of Life Science, Beijing Institute of Technology, Beijing 100081, China; (W.L.); (Z.W.)
| | - Shichuan Tang
- Beijing Key Laboratory of Occupational Safety and Health, Institute of Urban Safety and Environmental Science, Beijing Academy of Science and Technology, Beijing 100054, China; (Y.C.); (Y.W.); (S.T.)
| | - Rui Chen
- Beijing Key Laboratory of Occupational Safety and Health, Institute of Urban Safety and Environmental Science, Beijing Academy of Science and Technology, Beijing 100054, China; (Y.C.); (Y.W.); (S.T.)
- Correspondence:
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Tharwat S, Eleraky ES, Adel T, Nassar MK, Saleh M. Attitudes and concerns regarding booster dose of COVID-19 vaccine among Egyptian patients with autoimmune and rheumatic diseases: a cross-sectional survey study. J Pharm Policy Pract 2023; 16:54. [PMID: 37020249 PMCID: PMC10075500 DOI: 10.1186/s40545-023-00558-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/25/2023] [Indexed: 04/07/2023] Open
Abstract
BACKGROUND COVID-19 booster dose vaccination acceptance and actual vaccination behavior is not known among Egyptian individuals with autoimmune and rheumatic diseases (ARDs). The aim of this study was to investigate the acceptability of booster dose of the COVID-19 vaccine, as well as the factors that drive and inhibit that acceptance among Egyptian patients diagnosed with ARDs. METHODS This interview-based, cross-sectional analytical study was carried out on ARD patients from 20 July to 20 November 2022. A questionnaire was created to assess sociodemographic and clinical data, as well as COVID-19 vaccination status and the intention to receive a COVID-19 vaccine booster dose, perception of health benefits of it in addition to the perceived barriers and/or concerns. RESULTS A total of 248 ARD patients were included, with a mean age of 39.8 years (SD = 13.2), and 92.3% were females. Among them, 53.6% were resistant to the COVID-19 booster dose, whereas 31.9% were acceptant and 14.5% were hesitant. Those who were administering corticosteroids and hydroxychloroquine shown significantly greater booster hesitancy and resistance (p = 0.010 and 0.004, respectively). The primary motivation for taking a booster dose among the acceptant group was own volition (92%). Most acceptants believed that booster dose can prevent serious infection (98.7%) and community spread (96.2%). Among the hesitant and resistant groups, the main concerns for booster dose were fear about its major adverse effects (57.4%) and long-term impact (45.6%). CONCLUSIONS There is a low acceptability rate of booster dose of COVID-19 vaccine among Egyptian patients with ARD diseases. Public health workers and policymakers need to make sure that all ARD patients get clear messages about accepting the COVID-19 booster dose.
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Affiliation(s)
- Samar Tharwat
- Rheumatology & Immunology Unit, Department of Internal Medicine, Faculty of Medicine, Mansoura University, El Gomhouria St., Mansoura, 35511, Dakahlia Governorate, Egypt.
- Department of Internal Medicine, Faculty of Medicine, Horus University, New Damietta, Egypt.
| | - Elshimaa Saad Eleraky
- Department of Internal Medicine, Faculty of Medicine, Horus University, New Damietta, Egypt
| | - Toqa Adel
- Faculty of Medicine, Menoufia University, Shebeen El-Kom, Egypt
| | - Mohammed Kamal Nassar
- Department of Internal Medicine, Faculty of Medicine, Horus University, New Damietta, Egypt
- Mansoura Nephrology and Dialysis Unit (MNDU), Department of Internal Medicine, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Marwa Saleh
- Mansoura Nephrology and Dialysis Unit (MNDU), Department of Internal Medicine, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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Fukuda K, Baba H, Yoshida M, Kitabayashi K, Katsushima S, Sonehara H, Mizuno K, Kanamori H, Tokuda K, Nakagawa A, Mizuno A. Novel Virus Air Sampler Based on Electrostatic Precipitation and Air Sampling of SARS-CoV-2. Microorganisms 2023; 11:microorganisms11040944. [PMID: 37110367 PMCID: PMC10143856 DOI: 10.3390/microorganisms11040944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/23/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
The assessment of airborne viruses in air is a critical step in the design of appropriate prevention and control measures. Hence, herein, we developed a novel wet-type electrostatic air sampler using a viral dissolution buffer containing a radical scavenging agent, and verified the concentration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in the air of hospital rooms inhabiting coronavirus disease 2019 (COVID-19) patients and public areas. RNA damage caused by corona discharge was negligible when Buffer AVL was used as the collecting electrode. The viral RNA concentration in the air of the room varied by patient: 3.9 × 103 copy/m3 on the 10th day after onset in a mild case and 1.3 × 103 copy/m3 on the 18th day in a severe case. Viral RNA levels were 7.8 × 102 and 1.9 × 102 copy/m3 in the air of the office and food court, respectively, where people removed their masks when eating and talking, but it remained undetected in the station corridor where all the people were wearing masks. The assessment of airborne SARS-CoV-2 RNA using the proposed sampler can serve as a basis for the safe discontinuation of COVID-19 isolation precautions to identify exposure hotspots and alert individuals at increased infection risks.
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Affiliation(s)
- Kyohei Fukuda
- AMANO Co., Ltd., 275 Mamedocho, Kohoku-ku, Yokohama 222-8558, Japan
| | - Hiroaki Baba
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Mie Yoshida
- AMANO Co., Ltd., 275 Mamedocho, Kohoku-ku, Yokohama 222-8558, Japan
| | | | | | - Hiroki Sonehara
- Genome Clinic Co., Ltd., 2-5-1 Chuo, Chuo-ku, Chiba 260-0013, Japan
| | - Kazue Mizuno
- MRC LLC, 5-29-12, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Preferred Networks, Inc., 1-6-1 Otemachi Building, Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Hajime Kanamori
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Koichi Tokuda
- Department of Infectious Diseases, Internal Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Atsuhiro Nakagawa
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan
| | - Akira Mizuno
- AMANO Co., Ltd., 275 Mamedocho, Kohoku-ku, Yokohama 222-8558, Japan
- MRC LLC, 5-29-12, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Sah GP, Kovalick G, Chopyk J, Kuo P, Huang L, Ghatbale P, Das P, Realegeno S, Knight R, Gilbert JA, Pride DT. Characterization of SARS-CoV-2 Distribution and Microbial Succession in a Clinical Microbiology Testing Facility during the SARS-CoV-2 Pandemic. Microbiol Spectr 2023; 11:e0450922. [PMID: 36916973 PMCID: PMC10100919 DOI: 10.1128/spectrum.04509-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 02/11/2023] [Indexed: 03/15/2023] Open
Abstract
The exchange of microbes between humans and the built environment is a dynamic process that has significant impact on health. Most studies exploring the microbiome of the built environment have been predicated on improving our understanding of pathogen emergence, persistence, and transmission. Previous studies have demonstrated that SARS-CoV-2 presence significantly correlates with the proportional abundance of specific bacteria on surfaces in the built environment. However, in these studies, SARS-CoV-2 originated from infected patients. Here, we perform a similar assessment for a clinical microbiology lab while staff were handling SARS-CoV-2 infected samples. The goal of this study was to understand the distribution and dynamics of microbial population on various surfaces within different sections of a clinical microbiology lab during a short period of 2020 Coronavirus disease (COVID-19) pandemic. We sampled floors, benches, and sinks in 3 sections (bacteriology, molecular microbiology, and COVID) of an active clinical microbiology lab over a 3-month period. Although floor samples harbored SARS-CoV-2, it was rarely identified on other surfaces, and bacterial diversity was significantly greater on floors than sinks and benches. The floors were primarily colonized by bacteria common to natural environments (e.g., soils), and benchtops harbored a greater proportion of human-associated microbes, including Staphylococcus and Streptococcus. Finally, we show that the microbial composition of these surfaces did not change over time and remained stable. Despite finding viruses on the floors, no lab-acquired infections were reported during the study period, which suggests that lab safety protocols and sanitation practices were sufficient to prevent pathogen exposures. IMPORTANCE For decades, diagnostic clinical laboratories have been an integral part of the health care systems that perform diagnostic tests on patient's specimens in bulk on a regular basis. Understanding their microbiota should assist in designing and implementing disinfection, and cleaning regime in more effective way. To our knowledge, there is a lack of information on the composition and dynamics of microbiota in the clinical laboratory environments, and, through this study, we have tried to fill that gap. This study has wider implications as understanding the makeup of microbes on various surfaces within clinical laboratories could help identify any pathogenic bacterial taxa that could have colonized these surfaces, and might act as a potential source of laboratory-acquired infections. Mapping the microbial community within these built environments may also be critical in assessing the reliability of laboratory safety and sanitation practices to lower any potential risk of exposures to health care workers.
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Affiliation(s)
- Govind Prasad Sah
- Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Grace Kovalick
- Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Jessica Chopyk
- Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Peiting Kuo
- Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Lina Huang
- Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Pooja Ghatbale
- Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Promi Das
- Department of Pediatrics, University of California San Diego, San Diego, California, USA
- Center for Microbiome Innovation, University of California San Diego, San Diego, California, USA
| | - Susan Realegeno
- Department of Pathology, University of California San Diego, San Diego, California, USA
| | - Rob Knight
- Department of Pediatrics, University of California San Diego, San Diego, California, USA
- Center for Microbiome Innovation, University of California San Diego, San Diego, California, USA
- Department of Bioengineering, University of California San Diego, San Diego, California, USA
- Department of Computer Science & Engineering, University of California San Diego, San Diego, California, USA
| | - Jack A. Gilbert
- Department of Pediatrics, University of California San Diego, San Diego, California, USA
- Center for Microbiome Innovation, University of California San Diego, San Diego, California, USA
- Scripps Institution of Oceanography and Department of Pediatrics, University of California San Diego, San Diego, California, USA
| | - David T. Pride
- Department of Pathology, University of California San Diego, San Diego, California, USA
- Department of Medicine, University of California San Diego, San Diego, California, USA
- Center for Microbiome Innovation, University of California San Diego, San Diego, California, USA
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Wang Y, Wei J, Gao CX, Jin T, Liu L. Tracing the origin of large respiratory droplets by their deposition characteristics inside the respiratory tract during speech. BUILDING SIMULATION 2023; 16:781-794. [PMID: 37101943 PMCID: PMC10009356 DOI: 10.1007/s12273-022-0982-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 05/28/2023]
Abstract
Origin of differently sized respiratory droplets is fundamental for clarifying their viral loads and the sequential transmission mechanism of SARS-CoV-2 in indoor environments. Transient talking activities characterized by low (0.2 L/s), medium (0.9 L/s), and high (1.6 L/s) airflow rates of monosyllabic and successive syllabic vocalizations were investigated by computational fluid dynamics (CFD) simulations based on a real human airway model. SST k-ω model was chosen to predict the airflow field, and the discrete phase model (DPM) was used to calculate the trajectories of droplets within the respiratory tract. The results showed that flow field in the respiratory tract during speech is characterized by a significant laryngeal jet, and bronchi, larynx, and pharynx-larynx junction were main deposition sites for droplets released from the lower respiratory tract or around the vocal cords, and among which, over 90% of droplets over 5 µm released from vocal cords deposited at the larynx and pharynx-larynx junction. Generally, droplets' deposition fraction increased with their size, and the maximum size of droplets that were able to escape into external environment decreased with the airflow rate. This threshold size for droplets released from the vocal folds was 10-20 µm, while that for droplets released from the bronchi was 5-20 µm under various airflow rates. Besides, successive syllables pronounced at low airflow rates promoted the escape of small droplets, but do not significantly affect the droplet threshold diameter. This study indicates that droplets larger than 20 µm may entirely originate from the oral cavity, where viral loads are lower; it provides a reference for evaluating the relative importance of large-droplet spray and airborne transmission route of COVID-19 and other respiratory infections.
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Affiliation(s)
- Yihan Wang
- Institute of Refrigeration and Cryogenics, Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Zhejiang University, Hangzhou, 310000 China
| | - Jianjian Wei
- Institute of Refrigeration and Cryogenics, Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Zhejiang University, Hangzhou, 310000 China
| | - Caroline X. Gao
- Public Health and Preventive Medicine, Monash University, Melbourne, VIC 3004 Australia
| | - Tao Jin
- Institute of Refrigeration and Cryogenics, Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Zhejiang University, Hangzhou, 310000 China
| | - Li Liu
- Department of Building Science, Tsinghua University, Beijing, 100084 China
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Lai J, Coleman KK, Tai SHS, German J, Hong F, Albert B, Esparza Y, Srikakulapu AK, Schanz M, Maldonado IS, Oertel M, Fadul N, Gold TL, Weston S, Mullins K, McPhaul KM, Frieman M, Milton DK. Exhaled Breath Aerosol Shedding of Highly Transmissible Versus Prior Severe Acute Respiratory Syndrome Coronavirus 2 Variants. Clin Infect Dis 2023; 76:786-794. [PMID: 36285523 PMCID: PMC9620356 DOI: 10.1093/cid/ciac846] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 10/14/2022] [Accepted: 10/21/2022] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Aerosol inhalation is recognized as the dominant mode of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Three highly transmissible lineages evolved during the pandemic. One hypothesis to explain increased transmissibility is that natural selection favors variants with higher rates of viral aerosol shedding. However, the extent of aerosol shedding of successive SARS-CoV-2 variants is unknown. We aimed to measure the infectivity and rate of SARS-CoV-2 shedding into exhaled breath aerosol (EBA) by individuals during the Delta and Omicron waves and compared those rates with those of prior SARS-CoV-2 variants from our previously published work. METHODS Individuals with coronavirus disease 2019 (COVID-19) (n = 93; 32 vaccinated and 20 boosted) were recruited to give samples, including 30-minute breath samples into a Gesundheit-II EBA sampler. Samples were quantified for viral RNA using reverse-transcription polymerase chain reaction and cultured for virus. RESULTS Alpha (n = 4), Delta (n = 3), and Omicron (n = 29) cases shed significantly more viral RNA copies into EBAs than cases infected with ancestral strains and variants not associated with increased transmissibility (n = 57). All Delta and Omicron cases were fully vaccinated and most Omicron cases were boosted. We cultured virus from the EBA of 1 boosted and 3 fully vaccinated cases. CONCLUSIONS Alpha, Delta, and Omicron independently evolved high viral aerosol shedding phenotypes, demonstrating convergent evolution. Vaccinated and boosted cases can shed infectious SARS-CoV-2 via EBA. These findings support a dominant role of infectious aerosols in transmission of SARS-CoV-2. Monitoring aerosol shedding from new variants and emerging pathogens can be an important component of future threat assessments and guide interventions to prevent transmission.
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Affiliation(s)
- Jianyu Lai
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Kristen K Coleman
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - S H Sheldon Tai
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Jennifer German
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Filbert Hong
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Barbara Albert
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Yi Esparza
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Aditya K Srikakulapu
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Maria Schanz
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Isabel Sierra Maldonado
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Molly Oertel
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Naja Fadul
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - T Louie Gold
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Stuart Weston
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kristin Mullins
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kathleen M McPhaul
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
| | - Matthew Frieman
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Donald K Milton
- Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA
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Systematic Review of the Key Factors Influencing the Indoor Airborne Spread of SARS-CoV-2. Pathogens 2023; 12:pathogens12030382. [PMID: 36986304 PMCID: PMC10053454 DOI: 10.3390/pathogens12030382] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/19/2023] [Accepted: 02/20/2023] [Indexed: 03/06/2023] Open
Abstract
The COVID-19 pandemic due to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been plaguing the world since late 2019/early 2020 and has changed the way we function as a society, halting both economic and social activities worldwide. Classrooms, offices, restaurants, public transport, and other enclosed spaces that typically gather large groups of people indoors, and are considered focal points for the spread of the virus. For society to be able to go “back to normal”, it is crucial to keep these places open and functioning. An understanding of the transmission modes occurring in these contexts is essential to set up effective infection control strategies. This understanding was made using a systematic review, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement (PRISMA) 2020 guidelines. We analyze the different parameters influencing airborne transmission indoors, the mathematical models proposed to understand it, and discuss how we can act on these parameters. Methods to judge infection risks through the analysis of the indoor air quality are described. Various mitigation measures are listed, and their efficiency, feasibility, and acceptability are ranked by a panel of experts in the field. Thus, effective ventilation procedures controlled by CO2-monitoring, continued mask wearing, and a strategic control of room occupancy, among other measures, are put forth to enable a safe return to these essential places.
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Pan D, Williams CM, Decker J, Fletcher E, Sze S, Assadi S, Haigh R, Saleem B, Nazareth J, Garton NJ, Pareek M, Barer MR. Exhaled SARS-CoV-2 RNA viral load kinetics measured by facemask sampling associates with household transmission. Clin Microbiol Infect 2023; 29:254.e1-254.e6. [PMID: 35843566 PMCID: PMC9281452 DOI: 10.1016/j.cmi.2022.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/06/2022] [Accepted: 07/07/2022] [Indexed: 02/07/2023]
Abstract
OBJECTIVES No studies have examined longitudinal patterns of naturally exhaled SARS-CoV-2 RNA viral load (VL) during acute infection. We report this using facemask sampling (FMS) and assessed the relationship between emitted RNA VL and household transmission. METHODS Between December 2020 and February 2021, we recruited participants within 24 hours of a positive RT-qPCR on upper respiratory tract sampling (URTS) (day 0). Participants gave FMS (for 1 hour) and URTS (self-taken) on seven occasions up to day 21. Samples were analysed by RT-qPCR (from sampling matrix strips within the mask) and symptom diaries were recorded. Household transmission was assessed through reporting of positive URTS RT-qPCR in household contacts. RESULTS Analysis of 203 FMS and 190 URTS from 34 participants showed that RNA VL peaked within the first 5 days following sampling. Concomitant URTS, FMS RNA VL, and symptom scores, however, were poorly correlated, but a higher severity of reported symptoms was associated with FMS positivity up to day 5. Of 28 participants who had household contacts, 12 (43%) reported transmission. Frequency of household transmission was associated with the highest (peak) FMS RNA VL obtained (negative genome copies/strip: 0% household transmission; 1 to 1000 copies/strip: 20%; 1001 to 10 000 copies/strip: 57%; >10 000 copies/strip: 75%; p = 0.048; age adjusted OR of household transmission per log increase in copies/strip: 4.97; 95% CI, 1.20-20.55; p = 0.02) but not observed with peak URTS RNA VL. DISCUSSION Exhaled RNA VL measured by FMS is highest in early infection, can be positive in symptomatic patients with concomitantly negative URTS, and is strongly associated with household transmission.
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Affiliation(s)
- Daniel Pan
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Department of Infectious Diseases and HIV Medicine, University Hospitals of Leicester NHS Trust, Leicester, UK; Li Ka Shing Center for Health Information and Discovery, Oxford Big Data Institute, University of Oxford, UK.
| | - Caroline M Williams
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Department of Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Jonathan Decker
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Eve Fletcher
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Shirley Sze
- Department of Cardiovascular Sciences, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Sara Assadi
- Department of Infectious Diseases and HIV Medicine, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Richard Haigh
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Baber Saleem
- Department of Engineering, University of Leicester, Leicester, UK
| | - Joshua Nazareth
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Department of Infectious Diseases and HIV Medicine, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Natalie J Garton
- Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Manish Pareek
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Department of Infectious Diseases and HIV Medicine, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Michael R Barer
- Department of Respiratory Sciences, University of Leicester, Leicester, UK; Department of Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester, UK
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Tan K, Gao B, Yang CH, Johnson EL, Hsu MC, Passalacqua A, Krishnamurthy A, Ganapathysubramanian B. A computational framework for transmission risk assessment of aerosolized particles in classrooms. ENGINEERING WITH COMPUTERS 2023:1-22. [PMID: 36742376 PMCID: PMC9884603 DOI: 10.1007/s00366-022-01773-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 11/28/2022] [Indexed: 06/18/2023]
Abstract
Infectious airborne diseases like the recent COVID-19 pandemic render confined spaces high-risk areas. However, in-person activities like teaching in classroom settings and government services are often expected to continue or restart quickly. It becomes important to evaluate the risk of airborne disease transmission while accounting for the physical presence of humans, furniture, and electronic equipment, as well as ventilation. Here, we present a computational framework and study based on detailed flow physics simulations that allow straightforward evaluation of various seating and operating scenarios to identify risk factors and assess the effectiveness of various mitigation strategies. These scenarios include seating arrangement changes, presence/absence of computer screens, ventilation rate changes, and presence/absence of mask-wearing. This approach democratizes risk assessment by automating a key bottleneck in simulation-based analysis-creating an adequately refined mesh around multiple complex geometries. Not surprisingly, we find that wearing masks (with at least 74% inward protection efficiency) significantly reduced transmission risk against unmasked and infected individuals. While the use of face masks is known to reduce the risk of transmission, we perform a systematic computational study of the transmission risk due to variations in room occupancy, seating layout and air change rates. In addition, our findings on the efficacy of face masks further support use of face masks. The availability of such an analysis approach will allow education administrators, government officials (courthouses, police stations), and hospital administrators to make informed decisions on seating arrangements and operating procedures. Supplementary Information The online version contains supplementary material available at 10.1007/s00366-022-01773-9.
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Affiliation(s)
- Kendrick Tan
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA
- Institute of High Performance Computing, Agency for Science, Technology and Research (A*STAR), Singapore, 138632 Singapore
| | - Boshun Gao
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA
| | - Cheng-Hau Yang
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA
| | - Emily L. Johnson
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556 USA
| | - Ming-Chen Hsu
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA
| | - Alberto Passalacqua
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50011 USA
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Do TV, Manabe T, Vu GV, Nong VM, Fujikura Y, Phan D, Pham TT, Do CD, Doan TT, Nguyen NT, Nguyen TQ, Dong TV, Luong CQ, Manabe H, Kambayashi D, Hoang AV, Vu NV, Trinh GK, Do SN, Kamiya T, Ohara H, Nguyen CV, Dang TQ, Kudo K, Dao CX. Clinical characteristics and mortality risk among critically ill patients with COVID-19 owing to the B.1.617.2 (Delta) variant in Vietnam: A retrospective observational study. PLoS One 2023; 18:e0279713. [PMID: 36662716 PMCID: PMC9858045 DOI: 10.1371/journal.pone.0279713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 12/13/2022] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND SARS-CoV-2 Delta variant caused a large number of COVID-19 cases in many countries, including Vietnam. Understanding mortality risk factors is crucial for the clinical management of severe COVID-19. METHODS We conducted a retrospective study at an intensive care center in Ho Chi Minh City that urgently built by Bach Mai Hospital during the COVID-19 outbreak in Vietnam, when the Delta variant predominated. Participants were laboratory-confirmed patients with SARS-CoV-2 infection, admitted in August 2021. Data on patients' demographic and clinical characteristics, radiographic and laboratory findings, treatment, and clinical time course were compared between survivors and non-survivors. Risk factors to mortality were assessed using logistic regression. RESULTS Among 504 eligible COVID-19 patients, case fatality was 52.2%. Unvaccinated patients accounted for 61.2% of non-survivors and 43.6% of survivors (p < 0.001). The time from onset to hospital admission was 8 days in non-survivors and 7 days in survivors (p = 0.004). Among non-survivors, 90.2% developed acute respiratory distress syndrome (ARDS). Oxygen therapy was administered for all patients, but antiviral agent was given to 51.7% of non-survivors. 54.2% of non-survivors tested positive for the bacterial infection using blood culture. The risk factors for mortality were diabetes mellitus, respiration rate, oxygen saturation, vaccination status, time from onset to admission, and older age. CONCLUSIONS Critical patients with COVID-19 owing to the Delta variant in Vietnam had delayed hospital admission, leading to ARDS and death. Early availability of vaccines and preventing bacterial infections are crucial for reducing mortality of COVID-19, especially in low- and middle-income countries.
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Affiliation(s)
- Thanh Van Do
- Center for Tropical Diseases, Bach Mai Hospital, Hanoi, Vietnam
| | - Toshie Manabe
- Nagoya City University Graduate School of Medicine, Nagoya city, Aichi, Japan
- Nagoya City University West Medical Center, Nagoya city, Aichi, Japan
| | - Giap Van Vu
- Hanoi Medical University, Hanoi, Vietnam
- Respiratory Center, Bach Mai Hospital, Hanoi, Vietnam
| | - Vuong Minh Nong
- Center for Tropical Diseases, Bach Mai Hospital, Hanoi, Vietnam
| | - Yuji Fujikura
- Department of Internal Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
- Department of Medical Risk Management and Infection Control, National Defense Medical College Hospital, Tokorozawa, Saitama, Japan
| | - Dung Phan
- Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Thach The Pham
- Intensive Care Center, Bach Mai Hospital, Hanoi, Vietnam
| | - Cuong Duy Do
- Center for Tropical Diseases, Bach Mai Hospital, Hanoi, Vietnam
| | - Tra Thu Doan
- Center for Tropical Diseases, Bach Mai Hospital, Hanoi, Vietnam
| | | | | | - Thanh Van Dong
- Outpatient Department, Bach Mai Hospital, Hanoi, Vietnam
| | - Chinh Quoc Luong
- Center for Emergency Medicine, Bach Mai Hospital, Hanoi, Vietnam
- Department of Emergency and Critical Care Medicine, Hanoi Medical University, Hanoi, Vietnam
- Faculty of Medicine, University of Medicine and Pharmacy, Vietnam National University, Hanoi, Vietnam
| | | | - Dan Kambayashi
- Nagoya City University Graduate School of Medicine, Nagoya city, Aichi, Japan
- Showa Pharmaceutical University, Machidashi, Tokyo, Japan
| | - Anh Viet Hoang
- Training and Direction of Healthcare Activities Center, Bach Mai Hospital, Hanoi, Vietnam
| | - Nhan Van Vu
- Training and Direction of Healthcare Activities Center, Bach Mai Hospital, Hanoi, Vietnam
| | - Giang Kim Trinh
- Training and Direction of Healthcare Activities Center, Bach Mai Hospital, Hanoi, Vietnam
| | - Son Ngoc Do
- Department of Emergency and Critical Care Medicine, Hanoi Medical University, Hanoi, Vietnam
- Faculty of Medicine, University of Medicine and Pharmacy, Vietnam National University, Hanoi, Vietnam
- Center for Critical Care Medicine, Bach Mai Hospital, Hanoi, Vietnam
| | - Takeshi Kamiya
- Nagoya City University Graduate School of Medicine, Nagoya city, Aichi, Japan
| | - Hirotaka Ohara
- Nagoya City University Graduate School of Medicine, Nagoya city, Aichi, Japan
- Nagoya City University West Medical Center, Nagoya city, Aichi, Japan
| | - Chi Van Nguyen
- Center for Emergency Medicine, Bach Mai Hospital, Hanoi, Vietnam
- Department of Emergency and Critical Care Medicine, Hanoi Medical University, Hanoi, Vietnam
| | - Tuan Quoc Dang
- Department of Emergency and Critical Care Medicine, Hanoi Medical University, Hanoi, Vietnam
- Center for Critical Care Medicine, Bach Mai Hospital, Hanoi, Vietnam
| | - Koichiro Kudo
- Yurin Hospital, Tokyo, Japan
- Waseda University, Organization for Regional-Interregional Studies, Tokyo, Japan
| | - Co Xuan Dao
- Department of Emergency and Critical Care Medicine, Hanoi Medical University, Hanoi, Vietnam
- Faculty of Medicine, University of Medicine and Pharmacy, Vietnam National University, Hanoi, Vietnam
- Center for Critical Care Medicine, Bach Mai Hospital, Hanoi, Vietnam
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Cox J, Christensen B, Burton N, Dunn KH, Finnegan M, Ruess A, Estill C. Transmission of SARS-CoV-2 in the workplace: Key findings from a rapid review of the literature. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2023; 57:233-254. [PMID: 37213938 PMCID: PMC10193509 DOI: 10.1080/02786826.2023.2166394] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 12/27/2022] [Indexed: 05/23/2023]
Abstract
At the beginning of the COVID-19 pandemic, the primary route of transmission of the SARS-CoV-2 virus was not well understood. Research gathered from other respiratory infectious diseases, including other coronaviruses, was the basis for the initial perceptions for transmission of SARS-CoV-2. To better understand transmission of SARS-CoV-2, a rapid literature review was conducted from literature generated March 19, 2020, through September 23, 2021. 18,616 unique results were identified from literature databases and screened. Of these, 279 key articles were reviewed and abstracted covering critical topics such as environmental/workplace monitoring, sampling and analytical method evaluation, and the ability of the virus to remain intact and infectious during sampling. This paper describes the results of the rapid literature review, which evaluated pathways that contribute to transmission as well as the strengths and limitations of current sampling approaches. This review also evaluates how different factors, including environmental conditions and surface characteristics, could impact the transmission potential of SARS-CoV-2. A continual rapid review in the midst of a pandemic proved particularly useful for quickly understanding the transmission parameters of the virus and enabled us to comprehensively assess literature, respond to workplace questions, and evaluate our understanding as the science evolved. Air and surface sampling with the accompanying analytical methods were not generally effective in recovering SARS-CoV-2 viable virus or RNA in many likely contaminated environments. In light of these findings, the development of validated sampling and analysis methods is critical for determining worker exposure to SARS-CoV-2 and to assess the impact of mitigation efforts.
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Affiliation(s)
- Jennie Cox
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
| | - Brian Christensen
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
| | - Nancy Burton
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
| | - Kevin H. Dunn
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
| | | | - Ana Ruess
- Gryphon Scientific, Takoma Park, MD, USA
| | - Cherie Estill
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
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Aganovic A, Cao G, Kurnitski J, Wargocki P. New dose-response model and SARS-CoV-2 quanta emission rates for calculating the long-range airborne infection risk. BUILDING AND ENVIRONMENT 2023; 228:109924. [PMID: 36531865 PMCID: PMC9747236 DOI: 10.1016/j.buildenv.2022.109924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Predictive models for airborne infection risk have been extensively used during the pandemic, but there is yet still no consensus on a common approach, which may create misinterpretation of results among public health experts and engineers designing building ventilation. In this study we applied the latest data on viral load, aerosol droplet sizes and removal mechanisms to improve the Wells Riley model by introducing the following novelties i) a new model to calculate the total volume of respiratory fluid exhaled per unit time ii) developing a novel viral dose-based generation rate model for dehydrated droplets after expiration iii) deriving a novel quanta-RNA relationship for various strains of SARS-CoV-2 iv) proposing a method to account for the incomplete mixing conditions. These new approaches considerably changed previous estimates and allowed to determine more accurate average quanta emission rates including omicron variant. These quanta values for the original strain of 0.13 and 3.8 quanta/h for breathing and speaking and the virus variant multipliers may be used for simple hand calculations of probability of infection or with developed model operating with six size ranges of aerosol droplets to calculate the effect of ventilation and other removal mechanisms. The model developed is made available as an open-source tool.
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Affiliation(s)
- Amar Aganovic
- Department of Automation and Process Engineering, UiT The Arctic University of Norway, Tromsø, Norway
| | - Guangyu Cao
- Department of Energy and Process Engineering, Norwegian University of Science and Technology - NTNU, Trondheim, Norway
| | - Jarek Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn, Estonia
| | - Pawel Wargocki
- Department of Civil Engineering, Technical University of Denmark, Copenhagen, Denmark
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Tan KS, Ang AXY, Tay DJW, Somani J, Ng AJY, Peng LL, Chu JJH, Tambyah PA, Allen DM. Detection of hospital environmental contamination during SARS-CoV-2 Omicron predominance using a highly sensitive air sampling device. Front Public Health 2023; 10:1067575. [PMID: 36703815 PMCID: PMC9873263 DOI: 10.3389/fpubh.2022.1067575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/23/2022] [Indexed: 01/11/2023] Open
Abstract
Background and objectives The high transmissibility of SARS-CoV-2 has exposed weaknesses in our infection control and detection measures, particularly in healthcare settings. Aerial sampling has evolved from passive impact filters to active sampling using negative pressure to expose culture substrate for virus detection. We evaluated the effectiveness of an active air sampling device as a potential surveillance system in detecting hospital pathogens, for augmenting containment measures to prevent nosocomial transmission, using SARS-CoV-2 as a surrogate. Methods We conducted air sampling in a hospital environment using the AerosolSenseTM air sampling device and compared it with surface swabs for their capacity to detect SARS-CoV-2. Results When combined with RT-qPCR detection, we found the device provided consistent SARS-CoV-2 detection, compared to surface sampling, in as little as 2 h of sampling time. The device also showed that it can identify minute quantities of SARS-CoV-2 in designated "clean areas" and through a N95 mask, indicating good surveillance capacity and sensitivity of the device in hospital settings. Conclusion Active air sampling was shown to be a sensitive surveillance system in healthcare settings. Findings from this study can also be applied in an organism agnostic manner for surveillance in the hospital, improving our ability to contain and prevent nosocomial outbreaks.
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Affiliation(s)
- Kai Sen Tan
- Biosafety Level 3 Core Facility, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Infectious Disease Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,*Correspondence: Kai Sen Tan ✉
| | - Alicia Xin Yu Ang
- Department of Medicine, Division of Infectious Diseases, National University Hospital, Singapore, Singapore
| | - Douglas Jie Wen Tay
- Biosafety Level 3 Core Facility, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Infectious Disease Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jyoti Somani
- Department of Medicine, Division of Infectious Diseases, National University Hospital, Singapore, Singapore
| | - Alexander Jet Yue Ng
- Department of Emergency Medicine, National University Hospital, Singapore, Singapore
| | - Li Lee Peng
- Department of Emergency Medicine, National University Hospital, Singapore, Singapore
| | - Justin Jang Hann Chu
- Biosafety Level 3 Core Facility, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Infectious Disease Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Collaborative and Translation Unit for Hand, Foot and Mouth Disease (HFMD), Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | - Paul Anantharajah Tambyah
- Infectious Disease Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Department of Medicine, Division of Infectious Diseases, National University Hospital, Singapore, Singapore
| | - David Michael Allen
- Infectious Disease Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore,Department of Medicine, Division of Infectious Diseases, National University Hospital, Singapore, Singapore,David Michael Allen ✉
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Nishandar SR, He Y, Princevac M, Edwards RD. Fate of Exhaled Droplets From Breathing and Coughing in Supermarket Checkouts and Passenger Cars. ENVIRONMENTAL HEALTH INSIGHTS 2023; 17:11786302221148274. [PMID: 36644342 PMCID: PMC9834932 DOI: 10.1177/11786302221148274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
The global pandemic of COVID-19 has highlighted the importance of understanding the role that exhaled droplets play in virus transmission in community settings. Computational Fluid Dynamics (CFD) enables systematic examination of roles the exhaled droplets play in the spread of SARS-CoV-2 in indoor environments. This analysis uses published exhaled droplet size distributions combined with terminal aerosol droplet size based on measured peak concentrations for SARS-CoV-2 RNA in aerosols to simulate exhaled droplet dispersion, evaporation, and deposition in a supermarket checkout area and rideshare car where close proximity with other individuals is common. Using air inlet velocity of 2 m/s in the passenger car and ASHRAE recommendations for ventilation and comfort in the supermarket, simulations demonstrate that exhaled droplets <20 μm that contain the majority of viral RNA evaporated leaving residual droplet nuclei that remain aerosolized in the air. Subsequently ~ 70% of these droplet nuclei deposited in the supermarket and the car with the reminder vented from the space. The maximum surface deposition of droplet nuclei/m2 for speaking and coughing were 2 and 819, 18 and 1387 for supermarket and car respectively. Approximately 15% of the total exhaled droplets (aerodynamic diameters 20-700 µm) were deposited on surfaces in close proximity to the individual. Due to the non-linear distribution of viral RNA across droplet sizes, however, these larger exhaled droplets that deposit on surfaces have low viral content. Maximum surface deposition of viral RNA was 70 and 1.7 × 103 virions/m2 for speaking and 2.3 × 104 and 9.3 × 104 virions/m2 for coughing in the supermarket and car respectively while the initial airborne concentration of viral RNA was 7 × 106 copies per ml. Integrating the droplet size distributions with viral load distributions, this study helps explain the apparent importance of inhalation exposures compared to surface contact observed in the pandemic.
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Affiliation(s)
- Sanika Ravindra Nishandar
- Department of Mechanical Engineering,
Bourns College of Engineering, University of California, Riverside, CA, USA
| | - Yucheng He
- Department of Mechanical Engineering,
Bourns College of Engineering, University of California, Riverside, CA, USA
| | - Marko Princevac
- Department of Mechanical Engineering,
Bourns College of Engineering, University of California, Riverside, CA, USA
| | - Rufus D Edwards
- Department of Epidemiology, Program in
Public Health, University of California Irvine, CA, USA
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Gutmann D, Scheuch G, Lehmkühler T, Herrlich LS, Landeis A, Hutter M, Stephan C, Vehreschild M, Khodamoradi Y, Gossmann AK, King F, Weis F, Weiss M, Rabenau HF, Graf J, Donath H, Schubert R, Zielen S. Aerosol measurement identifies SARS-CoV 2 PCR positive adults compared with healthy controls. ENVIRONMENTAL RESEARCH 2023; 216:114417. [PMID: 36162469 PMCID: PMC9507996 DOI: 10.1016/j.envres.2022.114417] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/24/2022] [Accepted: 09/20/2022] [Indexed: 05/04/2023]
Abstract
BACKGROUND SARS-CoV-2 is spread primarily through droplets and aerosols. Exhaled aerosols are generated in the upper airways through shear stress and in the lung periphery by 'reopening of collapsed airways'. Aerosol measuring may detect highly contagious individuals ("super spreaders or super-emitters") and discriminate between SARS-CoV-2 infected and non-infected individuals. This is the first study comparing exhaled aerosols in SARS-CoV-2 infected individuals and healthy controls. DESIGN A prospective observational cohort study in 288 adults, comprising 64 patients testing positive by SARS CoV-2 PCR before enrollment, and 224 healthy adults testing negative (matched control sample) at the University Hospital Frankfurt, Germany, from February to June 2021. Study objective was to evaluate the concentration of exhaled aerosols during physiologic breathing in SARS-CoV-2 PCR-positive and -negative subjects. Secondary outcome measures included correlation of aerosol concentration to SARS-CoV-2 PCR results, change in aerosol concentration due to confounders, and correlation between clinical symptoms and aerosol. RESULTS There was a highly significant difference in respiratory aerosol concentrations between SARS-CoV-2 PCR-positive (median 1490.5/L) and -negative subjects (median 252.0/L; p < 0.0001). There were no significant differences due to age, sex, smoking status, or body mass index. ROC analysis showed an AUC of 0.8918. CONCLUSIONS Measurements of respiratory aerosols were significantly elevated in SARS-CoV-2 positive individuals, which helps to understand the spread and course of respiratory viral infections, as well as the detection of highly infectious individuals.
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Affiliation(s)
- Desireé Gutmann
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany.
| | - Gerhard Scheuch
- GS Bio-Inhalation GmbH, Headquarters & Logistics, Gemuenden, Germany
| | - Timon Lehmkühler
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Laura-Sabine Herrlich
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Anton Landeis
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Martin Hutter
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Christoph Stephan
- Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Maria Vehreschild
- Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Yascha Khodamoradi
- Department of Internal Medicine, Infectious Diseases, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Ann-Kathrin Gossmann
- Palas GmbH, Partikel- und Lasermesstechnik, Greschbachstrasse 3b; 76229, Karlsruhe, Germany
| | - Florian King
- Palas GmbH, Partikel- und Lasermesstechnik, Greschbachstrasse 3b; 76229, Karlsruhe, Germany
| | - Frederik Weis
- Palas GmbH, Partikel- und Lasermesstechnik, Greschbachstrasse 3b; 76229, Karlsruhe, Germany
| | - Maximilian Weiss
- Palas GmbH, Partikel- und Lasermesstechnik, Greschbachstrasse 3b; 76229, Karlsruhe, Germany
| | - Holger F Rabenau
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Juergen Graf
- Medical Director, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Helena Donath
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Ralf Schubert
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
| | - Stefan Zielen
- Department for Children and Adolescents, Division of Allergology, Pulmonology and Cystic Fibrosis, University Hospital Frankfurt, Goethe University, 60590, Frankfurt, Germany
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Schuchmann P, Scheuch G, Naumann R, Keute M, Lücke T, Zielen S, Brinkmann F. Exhaled aerosols among PCR-confirmed SARS-CoV-2-infected children. Front Pediatr 2023; 11:1156366. [PMID: 37152322 PMCID: PMC10160682 DOI: 10.3389/fped.2023.1156366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
Background Available data on aerosol emissions among children and adolescents during spontaneous breathing are limited. Our aim was to gain insight into the role of children in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and whether aerosol measurements among children can be used to help detect so-called superspreaders-infected individuals with extremely high numbers of exhaled aerosol particles. Methods In this prospective study, the aerosol concentrations of SARS-CoV-2 PCR-positive and SARS-CoV-2 PCR-negative children and adolescents (2-17 years) were investigated. All subjects were asked about their current health status and medical history. The exhaled aerosol particle counts of PCR-negative and PCR-positive subjects were measured using the Resp-Aer-Meter (Palas GmbH, Karlsruhe, Germany) and compared using linear regression. Results A total of 250 children and adolescents were included in this study, 105 of whom were SARS-CoV-2 positive and 145 of whom were SARS-CoV-2 negative. The median age in both groups was 9 years (IQR 7-11 years). A total of 124 (49.6%) participants were female, and 126 (50.4%) participants were male. A total of 81.9% of the SARS-CoV-2-positive group had symptoms of viral infection. The median particle count of all individuals was 79.55 particles/liter (IQR 44.55-141.15). There was a tendency for older children to exhale more particles (1-5 years: 79.54 p/L; 6-11 years: 77.96 p/L; 12-17 years: 98.63 p/L). SARS-CoV-2 PCR status was not a bivariate predictor (t = 0.82, p = 0.415) of exhaled aerosol particle count; however, SARS-CoV-2 status was shown to be a significant predictor in a multiple regression model together with age, body mass index (BMI), COVID-19 vaccination, and past SARS-CoV-2 infection (t = 2.81, p = 0.005). COVID-19 vaccination status was a highly significant predictor of exhaled aerosol particles (p < .001). Conclusion During SARS-CoV-2 infection, children and adolescents did not have elevated aerosol levels. In addition, no superspreaders were found.
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Affiliation(s)
- Pia Schuchmann
- Department of Children and Adolescents, University Children’s Hospital, Ruhr University of Bochum, Bochum, Germany
- Pediatric Practice (Dr. Voigt, Dr. Heier), Stadtbergen, Germany
- Correspondence: Pia Schuchmann
| | - Gerhard Scheuch
- GS Bio-Inhalation GmbH, Headquarters & Logistics, Gemuenden, Germany
| | | | - Marius Keute
- Independent Statistical Consultant, Warendorf, Germany
| | - Thomas Lücke
- Department of Children and Adolescents, University Children’s Hospital, Ruhr University of Bochum, Bochum, Germany
| | - Stefan Zielen
- Department for Children and Adolescents, Allergology, Pulmonology and Cystic Fibrosis, University Hospital, Goethe University, Frankfurt, Germany
| | - Folke Brinkmann
- Department of Pediatric Pneumology, University Children's Hospital, Ruhr University of Bochum, Bochum, Germany
- Department of Pediatric Pneumology and Allergology, University Children’s Hospital Schleswig-Holstein, Lübeck, Germany
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Kitagawa H, Nomura T, Kaiki Y, Kakimoto M, Nazmul T, Omori K, Shigemoto N, Sakaguchi T, Ohge H. Viable SARS-CoV-2 detected in the air of hospital rooms of patients with COVID-19 with an early infection. Int J Infect Dis 2023; 126:73-78. [PMID: 36356797 PMCID: PMC9640214 DOI: 10.1016/j.ijid.2022.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 10/31/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVES This study assessed the concentration of SARS-CoV-2 in the air of hospital rooms occupied by patients with COVID-19 who had viable SARS-CoV-2 in nasopharyngeal (NP) samples in early infection. METHODS Between July and October 2021, NP swabs were collected from 20 patients with early SARS-CoV-2 infection admitted to a tertiary hospital in Japan. Air samples were collected from their rooms, tested for SARS-CoV-2 RNA, and cultured to determine potential infectivity. RESULTS The NP swab samples of 18 patients were positive for viable SARS-CoV-2 (median concentration: 4.0 × 105 tissue culture infectious dose 50/ml). In the air samples, viral RNA (median concentration: 1.1 × 105 copies/m3) was detected in 12/18 (67%) patients, and viable virus (median concentration: 8.9 × 102 tissue culture infectious dose 50/m3) was detected in 5/18 (28%) patients. The median time between illness onset and sampling was 3 days. The RNA concentration was significantly higher in samples wherein viable SARS-CoV-2 was detected than in samples in which viable virus was not detected (P-value = 0.027). CONCLUSION Viable SARS-CoV-2 can be detected in the air surrounding patients with early SARS-CoV-2 infection. Health care workers should pay attention to infection control when caring for patients with early SARS-CoV-2 infection.
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Affiliation(s)
- Hiroki Kitagawa
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan,Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan,Corresponding author: Hiroki Kitagawa, Department of Infectious Diseases, Hiroshima University Hospital, Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Toshihito Nomura
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan,Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yuki Kaiki
- Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masaki Kakimoto
- Department of General Internal Medicine, Hiroshima University Hospital, Hiroshima, Japan
| | - Tanuza Nazmul
- Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Keitaro Omori
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
| | - Norifumi Shigemoto
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan,Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan,Translational Research Center, Hiroshima University, Hiroshima, Japan
| | - Takemasa Sakaguchi
- Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hiroki Ohge
- Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan
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Dommer A, Casalino L, Kearns F, Rosenfeld M, Wauer N, Ahn SH, Russo J, Oliveira S, Morris C, Bogetti A, Trifan A, Brace A, Sztain T, Clyde A, Ma H, Chennubhotla C, Lee H, Turilli M, Khalid S, Tamayo-Mendoza T, Welborn M, Christensen A, Smith DG, Qiao Z, Sirumalla SK, O'Connor M, Manby F, Anandkumar A, Hardy D, Phillips J, Stern A, Romero J, Clark D, Dorrell M, Maiden T, Huang L, McCalpin J, Woods C, Gray A, Williams M, Barker B, Rajapaksha H, Pitts R, Gibbs T, Stone J, Zuckerman DM, Mulholland AJ, Miller T, Jha S, Ramanathan A, Chong L, Amaro RE. #COVIDisAirborne: AI-enabled multiscale computational microscopy of delta SARS-CoV-2 in a respiratory aerosol. THE INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS 2023; 37:28-44. [PMID: 36647365 PMCID: PMC9527558 DOI: 10.1177/10943420221128233] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We seek to completely revise current models of airborne transmission of respiratory viruses by providing never-before-seen atomic-level views of the SARS-CoV-2 virus within a respiratory aerosol. Our work dramatically extends the capabilities of multiscale computational microscopy to address the significant gaps that exist in current experimental methods, which are limited in their ability to interrogate aerosols at the atomic/molecular level and thus obscure our understanding of airborne transmission. We demonstrate how our integrated data-driven platform provides a new way of exploring the composition, structure, and dynamics of aerosols and aerosolized viruses, while driving simulation method development along several important axes. We present a series of initial scientific discoveries for the SARS-CoV-2 Delta variant, noting that the full scientific impact of this work has yet to be realized.
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Affiliation(s)
| | | | | | | | | | | | - John Russo
- Oregon Health & Science University, Portland, OR, USA
| | | | | | | | - Anda Trifan
- Argonne National Laboratory, Lemont, IL, USA
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Alexander Brace
- Argonne National Laboratory, Lemont, IL, USA
- University of Chicago, Chicago, IL, USA
| | - Terra Sztain
- UC San Diego, La Jolla, CA, USA
- Freie Universitat Berlin
| | - Austin Clyde
- Argonne National Laboratory, Lemont, IL, USA
- University of Chicago, Chicago, IL, USA
| | - Heng Ma
- Argonne National Laboratory, Lemont, IL, USA
| | | | - Hyungro Lee
- Brookhaven National Lab and Rutgers University
| | | | | | | | | | | | | | - Zhuoran Qiao
- California Institute of Technology, Pasadena, CA, USA
| | | | | | | | - Anima Anandkumar
- California Institute of Technology, Pasadena, CA, USA
- NVIDIA Corp, Santa Clara, CA, USA
| | - David Hardy
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - James Phillips
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | | | | | | | - Tom Maiden
- Pittsburgh Supercomputing Center, Pittsburgh, PA, USA
| | - Lei Huang
- Texas Advanced Computing Center, Austin, TX, USA
| | | | | | | | | | | | | | | | | | - John Stone
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
- NVIDIA Corp, Santa Clara, CA, USA
| | | | | | - Thomas Miller
- Entos, Inc., San Diego, CA, USA
- California Institute of Technology, Pasadena, CA, USA
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Aganovic A, Cao G, Kurnitski J, Melikov A, Wargocki P. Zonal modeling of air distribution impact on the long-range airborne transmission risk of SARS-CoV-2. APPLIED MATHEMATICAL MODELLING 2022; 112:800-821. [PMID: 36060304 PMCID: PMC9420246 DOI: 10.1016/j.apm.2022.08.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 08/15/2022] [Accepted: 08/25/2022] [Indexed: 05/10/2023]
Abstract
A widely used analytical model to quantitatively assess airborne infection risk is the Wells-Riley model which is limited to complete air mixing in a single zone. However, this assumption tends not to be feasible (or reality) for many situations. This study aimed to extend the Wells-Riley model so that the infection risk can be calculated in spaces where complete mixing is not present. Some more advanced ventilation concepts create either two horizontally divided air zones in spaces as displacement ventilation or the space may be divided into two vertical zones by downward plane jet as in protective-zone ventilation systems. This is done by evaluating the time-dependent distribution of infectious quanta in each zone and by solving the coupled system of differential equations based on the zonal quanta concentrations. This model introduces a novel approach by estimating the interzonal mixing factor based on previous experimental data for three types of ventilation systems: incomplete mixing ventilation, displacement ventilation, and protective zone ventilation. The modeling approach is applied to a room with one infected and one susceptible person present. The results show that using the Wells-Riley model based on the assumption of completely air mixing may considerably overestimate or underestimate the long-range airborne infection risk in rooms where air distribution is different than complete mixing, such as displacement ventilation, protected zone ventilation, warm air supplied from the ceiling, etc. Therefore, in spaces with non-uniform air distribution, a zonal modeling approach should be preferred in analytical models compared to the conventional single-zone Wells-Riley models when assessing long-range airborne transmission risk of infectious respiratory diseases.
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Affiliation(s)
- Amar Aganovic
- Department of Automation and Process Engineering, UiT The Arctic University of Norway, Postboks 6050 Langnes, Tromsø 9037, Norway
| | - Guangyu Cao
- Department of Energy and Process Engineering, Norwegian University of Science and Technology - NTNU, Trondheim, Norway
| | - Jarek Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn, Estonia
| | - Arsen Melikov
- Department of Civil Engineering, Technical University of Denmark, Copenhagen, Denmark
| | - Pawel Wargocki
- Department of Civil Engineering, Technical University of Denmark, Copenhagen, Denmark
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