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Zhang WW, Huang YR, Wang YY, Lu ZX, Sun JL, Jing MX. Risk assessment of infection of COVID-19 contacts based on scenario simulation. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2024. [PMID: 39074840 DOI: 10.1111/risa.15103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/31/2024]
Abstract
We constructed a rapid infection risk assessment model for contacts of COVID-19. The improved Wells-Riley model was used to estimate the probability of infection for contacts of COVID-19 in the same place and evaluate their risk grades. We used COVID-19 outbreaks that were documented to validate the accuracy of the model. We analyzed the relationship between controllable factors and infection probability and constructed common scenarios to analyze the infection risk of contacts in different scenarios. The model showed the robustness of the fitting (mean relative error = 5.89%, mean absolute error = 2.03%, root mean squared error = 2.03%, R2 = 0.991). We found that improving ventilation from poorly ventilated to naturally ventilated and wearing masks can reduce the probability of infection by about two times. Contacts in places of light activity, loud talking or singing, and heavy exercise, oral breathing (e.g., gyms, KTV, choirs) were at higher risk of infection. The model constructed in this study can quickly and accurately assess the infection risk grades of COVID-19 contacts. Simply opening doors and windows for ventilation can significantly reduce the risk of infection in certain places. The places of light activity, loud talking or singing, and heavy exercise, oral breathing, should pay more attention to prevent and control transmission of the epidemic.
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Affiliation(s)
- Wei-Wen Zhang
- Department of Preventive Medicine, Shihezi University School of Medicine, Shihezi, China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, The Xinjiang Production and Construction Corps, Xinjiang, China
| | - Yan-Ran Huang
- Department of Preventive Medicine, Shihezi University School of Medicine, Shihezi, China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, The Xinjiang Production and Construction Corps, Xinjiang, China
| | - Yu-Yuan Wang
- Department of Preventive Medicine, Shihezi University School of Medicine, Shihezi, China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, The Xinjiang Production and Construction Corps, Xinjiang, China
| | - Ze-Xi Lu
- Department of Preventive Medicine, Shihezi University School of Medicine, Shihezi, China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, The Xinjiang Production and Construction Corps, Xinjiang, China
| | - Jia-Lin Sun
- Department of Preventive Medicine, Shihezi University School of Medicine, Shihezi, China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, The Xinjiang Production and Construction Corps, Xinjiang, China
| | - Ming-Xia Jing
- Department of Preventive Medicine, Shihezi University School of Medicine, Shihezi, China
- Key Laboratory for Prevention and Control of Emerging Infectious Diseases and Public Health Security, The Xinjiang Production and Construction Corps, Xinjiang, China
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Alqarni Z, Rezgui Y, Petri I, Ghoroghi A. Viral infection transmission and indoor air quality: A systematic review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171308. [PMID: 38432379 DOI: 10.1016/j.scitotenv.2024.171308] [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: 12/14/2023] [Revised: 02/03/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
Respiratory disease transmission in indoor environments presents persistent challenges for health authorities, as exemplified by the recent COVID-19 pandemic. This underscores the urgent necessity to investigate the dynamics of viral infection transmission within indoor environments. This systematic review delves into the methodologies of respiratory infection transmission in indoor settings and explores how the quality of indoor air (IAQ) can be controlled to alleviate this risk while considering the imperative of sustainability. Among the 2722 articles reviewed, 178 were retained based on their focus on respiratory viral infection transmission and IAQ. Fifty eight articles delved into SARS-CoV-2 transmission, 21 papers evaluated IAQ in contexts of other pandemics, 53 papers assessed IAQ during the SARS-CoV-2 pandemic, and 46 papers examined control strategies to mitigate infectious transmission. Furthermore, of the 46 papers investigating control strategies, only nine considered energy consumption. These findings highlight clear gaps in current research, such as analyzing indoor air and surface samples for specific indoor environments, oversight of indoor and outdoor parameters (e.g., temperature, relative humidity (RH), and building orientation), neglect of occupancy schedules, and the absence of considerations for energy consumption while enhancing IAQ. This study distinctly identifies the indoor environmental conditions conducive to the thriving of each respiratory virus, offering IAQ trade-offs to mitigate the risk of dominant viruses at any given time. This study argues that future research should involve digital twins in conjunction with machine learning (ML) techniques. This approach aims to enhance IAQ by analyzing the transmission patterns of various respiratory viruses while considering energy consumption.
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Affiliation(s)
- Zahi Alqarni
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK; School of Computer Science, King Khalid University, Abha 62529, Saudi Arabia.
| | - Yacine Rezgui
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
| | - Ioan Petri
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
| | - Ali Ghoroghi
- School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
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Lozano D, Dohoo C, Elfstrom D, Carswell K, Guthrie JL. COVID-19 outbreak at a residential apartment building in Northern Ontario, Canada. Epidemiol Infect 2024; 152:e53. [PMID: 38433460 PMCID: PMC11022249 DOI: 10.1017/s0950268824000256] [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: 10/06/2023] [Revised: 12/05/2023] [Accepted: 02/02/2024] [Indexed: 03/05/2024] Open
Abstract
In February 2021, a cluster of Beta variant (B.1.351) coronavirus disease 2019 (COVID-19) cases were identified in an apartment building located in Northern Ontario, Canada. Most cases had no known contact with each other. Objectives of this multi-component outbreak investigation were to better understand the social and environmental factors that facilitated the transmission of COVID-19 through this multi-unit residential building (MURB). A case-control study examined building-specific exposures and resident behaviours that may have increased the odds of being a case. A professional engineer assessed the building's heating, ventilation, and air-conditioning (HVAC) systems. Whole-genome sequencing and an in-depth genomic analysis were performed. Forty-five outbreak-confirmed cases were identified. From the case-control study, being on the upper floors (OR: 10.4; 95% CI: 1.63-66.9) and within three adjacent vertical lines (OR: 28.3; 3.57-225) were both significantly associated with being a case of COVID-19, after adjusting for age. There were no significant differences in reported behaviours, use of shared spaces, or precautions taken between cases and controls. An assessment of the building's ventilation found uncontrolled air leakage between apartment units. A single genomic cluster was identified, where most sequences were identical to one another. Findings from the multiple components of this investigation are suggestive of aerosol transmission between units.
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Affiliation(s)
- Dinna Lozano
- North Bay Parry Sound District Health Unit, North Bay, ON, Canada
| | | | | | - Kendra Carswell
- North Bay Parry Sound District Health Unit, North Bay, ON, Canada
| | - Jennifer L. Guthrie
- Department of Microbiology & Immunology, Western University, London, ON, Canada
- Public Health Ontario, Toronto, ON, Canada
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Huang W, Gao CX, Luo D, Wang Y, Zheng X, Liu C, Wang Y, Li Y, Qian H. Risk evaluation of venue types and human behaviors of COVID-19 outbreaks in public indoor environments: A systematic review and meta-analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 341:122970. [PMID: 37979645 DOI: 10.1016/j.envpol.2023.122970] [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: 07/10/2023] [Revised: 10/03/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
Despite increasing vaccination rates, the incidence of breakthrough infections with COVID-19 has increased due to the continued emergence of new variants of the SARS-CoV-2 coronavirus. Therefore, Non-pharmaceutical interventions remain the most effective measures for coping with the ever-changing pandemic. The lifting of compulsory interventions has made individuals primary responsibility for their own health, which highlights the importance of increasing awareness of the infection risk from the environment in which they live and their individual behaviors. We systematically searched PubMed, Web of Science, ScienceDirect, and Scopus on April 17, 2023, for all studies reporting COVID-19 outbreaks in public indoor venues. The study outcome was the attack rate. A total of 42 studies, which included cross-sectional studies, cohort studies, and case studies, reporting data on 1951 confirmed cases in 64 COVID-19 outbreaks satisfied the meta-analysis and were included in the review. A random-effect model was used in the meta-analysis, and subgroup analyses were conducted to investigate factors affecting attack rates. We found a strong level of evidence (p < 0.01) supporting a higher pooled attack rate in recreation-related venues (0.44, 95% CI: 0.30 to 0.60) than in work-related venues (0.21, 95% CI: 0.16 to 0.27). Compared to those outbreaks without that, outbreaks with high-intensity exercise, vocalization, contact behavior, or close body proximity had a higher attack rate of 0.51, 0.55, 0.33, and 0.39, respectively. Further studies suggest that different attack rates across different types of settings may be the result of heterogeneity in exposed people's behaviors. There were significant heterogeneities that may limit the interpretation of connections between influencing factors and outbreak outcomes. The identification of key behaviors that may contribute to transmission risk, and their correlation with venue type, has important implications for the development of future public health interventions and individual prevention strategies for respiratory infectious diseases such as COVID-19.
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Affiliation(s)
- Weiwei Huang
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Caroline X Gao
- Centre for Youth Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia; Orygen, Parkville, VIC 3052, Australia; Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Danting Luo
- School of Energy and Environment, Southeast University, Nanjing, China; Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Yong Wang
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Xiaohong Zheng
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Cong Liu
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Ying Wang
- Hubei Engineering Center for Infectious Disease Prevention, Control and Treatment, Wuhan, China; Department of Infection Management, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yuguo Li
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China; School of Public Health, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Hua Qian
- School of Energy and Environment, Southeast University, Nanjing, China; Hubei Engineering Center for Infectious Disease Prevention, Control and Treatment, Wuhan, China.
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Madhusudanan A, Iddon C, Cevik M, Naismith JH, Fitzgerald S. Non-pharmaceutical interventions for COVID-19: a systematic review on environmental control measures. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20230130. [PMID: 37611631 PMCID: PMC10446906 DOI: 10.1098/rsta.2023.0130] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/06/2023] [Indexed: 08/25/2023]
Abstract
The purpose of this review was to identify the effectiveness of environmental control (EC) non-pharmaceutical interventions (NPIs) in reducing transmission of SARS-CoV-2 through conducting a systematic review. EC NPIs considered in this review are room ventilation, air filtration/cleaning, room occupancy, surface disinfection, barrier devices, [Formula: see text] monitoring and one-way-systems. Systematic searches of databases from Web of Science, Medline, EMBASE, preprint servers MedRxiv and BioRxiv were conducted in order to identify studies reported between 1 January 2020 and 1 December 2022. All articles reporting on the effectiveness of ventilation, air filtration/cleaning, room occupancy, surface disinfection, barrier devices, [Formula: see text] monitoring and one-way systems in reducing transmission of SARS-CoV-2 were retrieved and screened. In total, 13 971 articles were identified for screening. The initial title and abstract screening identified 1328 articles for full text review. Overall, 19 references provided evidence for the effectiveness of NPIs: 12 reported on ventilation, 4 on air cleaning devices, 5 on surface disinfection, 6 on room occupancy and 1 on screens/barriers. No studies were found that considered the effectiveness of [Formula: see text] monitoring or the implementation of one-way systems. Many of these studies were assessed to have critical risk of bias in at least one domain, largely due to confounding factors that could have affected the measured outcomes. As a result, there is low confidence in the findings. Evidence suggests that EC NPIs of ventilation, air cleaning devices and reduction in room-occupancy may have a role in reducing transmission in certain settings. However, the evidence was usually of low or very low quality and certainty, and hence the level of confidence ascribed to this conclusion is low. Based on the evidence found, it was not possible to draw any specific conclusions regarding the effectiveness of surface disinfection and the use of barrier devices. From these results, we further conclude that community agreed standards for well-designed epidemiological studies with low risk of bias are needed. Implementation of such standards would enable more confident assessment in the future of the effectiveness of EC NPIs in reducing transmission of SARS-CoV-2 and other pathogens in real-world settings. This article is part of the theme issue 'The effectiveness of non-pharmaceutical interventions on the COVID-19 pandemic: the evidence'.
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Affiliation(s)
| | - Christopher Iddon
- Department of Civil, Environmental and Geomatic Engineering, University College London, WC1E 6BT, London, UK
| | - Muge Cevik
- Department of Infection and Global Health, School of Medicine, University of St Andrews, KY16 9TF, St Andrews, UK
| | | | - Shaun Fitzgerald
- Department of Engineering, University of Cambridge, CB2 1PZ, Cambridge, UK
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6
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Chauhan A, Patel MK, Nayak MK, Saini SS. Chargeability study of disinfectants and the optimization of design parameters of a handheld electrostatic disinfection device for small scale applications. PLoS One 2023; 18:e0286740. [PMID: 37289733 PMCID: PMC10249885 DOI: 10.1371/journal.pone.0286740] [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: 10/17/2022] [Accepted: 05/23/2023] [Indexed: 06/10/2023] Open
Abstract
Apart from aerosols, contaminated surfaces with SARS-CoV-2 virus are the significant carriers of virus transmission. The disinfection and sanitization of the indoor and outdoor places are one among the powerful and effective strategies to avoid the surface-to-human transmission of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) through frequent touch and physical contact. Electrostatic spraying is one of the effective and efficient methods to apply the liquid-based sprays on surfaces to be disinfected or sanitized. This technique covers the directly exposed and obscured surfaces uniformly and reaches to hidden areas of the target. In this paper, the design and performance parameters of a motorized pressure-nozzle based handheld electrostatic disinfection device were optimized and the chargeability of ethanol (C2H5OH), formaldehyde (CH2O), glutaraldehyde (C5H8O2), hydrogen peroxide (H2O2), phenol (C6H5OH) and sodium hypochlorite (NaClO) has been critically investigated. The chargeability indicator for disinfectants was presented in terms of the charge-to-mass ratio. The significant value of the charge-to-mass ratio of 1.82 mC/kg was achieved at an applied voltage of 2.0 kV, the liquid flow rate and pressure of 28 ml/min and 5 MPa, respectively. The experimental results are well aligned to the proposed theoretical context.
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Affiliation(s)
- Aarti Chauhan
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
- Manufacturing Science and Instrumentation (MSI), CSIR–Central Scientific Instruments Organisation, Chandigarh, Chandigarh, India
| | - Manoj Kumar Patel
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
- Manufacturing Science and Instrumentation (MSI), CSIR–Central Scientific Instruments Organisation, Chandigarh, Chandigarh, India
| | - Manoj Kumar Nayak
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
- Materials Science and Sensor Applications (MSSA), CSIR–Central Scientific Instruments Organisation, Chandigarh, Chandigarh, India
| | - Surender Singh Saini
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India
- Indo Swiss Training Centre (ISTC), CSIR–Central Scientific Instruments Organisation, Chandigarh, Chandigarh, India
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7
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A review on indoor airborne transmission of COVID-19– modelling and mitigation approaches. JOURNAL OF BUILDING ENGINEERING 2023; 64:105599. [PMCID: PMC9699823 DOI: 10.1016/j.jobe.2022.105599] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/11/2022] [Accepted: 11/21/2022] [Indexed: 06/09/2023]
Abstract
In the past few years, significant efforts have been made to investigate the transmission of COVID-19. This paper provides a review of the COVID-19 airborne transmission modeling and mitigation strategies. The simulation models here are classified into airborne transmission infectious risk models and numerical approaches for spatiotemporal airborne transmissions. Mathematical descriptions and assumptions on which these models have been based are discussed. Input data used in previous simulation studies to assess the dispersion of COVID-19 are extracted and reported. Moreover, measurements performed to study the COVID-19 airborne transmission within indoor environments are introduced to support validations for anticipated future modeling studies. Transmission mitigation strategies recommended in recent studies have been classified to include modifying occupancy and ventilation operations, using filters and air purifiers, installing ultraviolet (UV) air disinfection systems, and personal protection compliance, such as wearing masks and social distancing. The application of mitigation strategies to various building types, such as educational, office, public, residential, and hospital, is reviewed. Recommendations for future works are also discussed based on the current apparent knowledge gaps covering both modeling and mitigation approaches. Our findings show that different transmission mitigation measures were recommended for various indoor environments; however, there is no conclusive work reporting their combined effects on the level of mitigation that may be achieved. Moreover, further studies should be conducted to understand better the balance between approaches to mitigating the viral transmissions in buildings and building energy consumption.
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Glenn K, He J, Rochlin R, Teng S, Hecker JG, Novosselov I. Assessment of aerosol persistence in ICUs via low-cost sensor network and zonal models. Sci Rep 2023; 13:3992. [PMID: 36899063 PMCID: PMC10006437 DOI: 10.1038/s41598-023-30778-7] [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: 11/19/2022] [Accepted: 03/01/2023] [Indexed: 03/12/2023] Open
Abstract
The COVID-19 pandemic raised public awareness about airborne particulate matter (PM) due to the spread of infectious diseases via the respiratory route. The persistence of potentially infectious aerosols in public spaces and the spread of nosocomial infections in medical settings deserve careful investigation; however, a systematic approach characterizing the fate of aerosols in clinical environments has not been reported. This paper presents a methodology for mapping aerosol propagation using a low-cost PM sensor network in ICU and adjacent environments and the subsequent development of the data-driven zonal model. Mimicking aerosol generation by a patient, we generated trace NaCl aerosols and monitored their propagation in the environment. In positive (closed door) and neutral-pressure (open door) ICUs, up to 6% or 19%, respectively, of all PM escaped through the door gaps; however, the outside sensors did not register an aerosol spike in negative-pressure ICUs. The K-means clustering analysis of temporospatial aerosol concentration data suggests that ICU can be represented by three distinct zones: (1) near the aerosol source, (2) room periphery, and (3) outside the room. The data suggests two-phase plume behavior: dispersion of the original aerosol spike throughout the room, followed by an evacuation phase where "well-mixed" aerosol concentration decayed uniformly. Decay rates were calculated for positive, neutral, and negative pressure operations, with negative-pressure rooms clearing out nearly twice as fast. These decay trends closely followed the air exchange rates. This research demonstrates the methodology for aerosol monitoring in medical settings. This study is limited by a relatively small data set and is specific to single-occupancy ICU rooms. Future work needs to evaluate medical settings with high risks of infectious disease transmission.
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Affiliation(s)
- K Glenn
- Department of Mechanical Engineering, University of Washington, Seattle, USA
| | - J He
- Department of Mechanical Engineering, University of Washington, Seattle, USA
| | - R Rochlin
- Department of Mechanical Engineering, University of Washington, Seattle, USA
| | - S Teng
- Department of Mechanical Engineering, University of Washington, Seattle, USA
| | - J G Hecker
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, USA
| | - I Novosselov
- Department of Mechanical Engineering, University of Washington, Seattle, USA.
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Mikszewski A, Stabile L, Buonanno G, Morawska L. The airborne contagiousness of respiratory viruses: A comparative analysis and implications for mitigation. GEOSCIENCE FRONTIERS 2022; 13:101285. [PMID: 38620948 PMCID: PMC8378671 DOI: 10.1016/j.gsf.2021.101285] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/22/2021] [Accepted: 08/06/2021] [Indexed: 05/07/2023]
Abstract
The infectious emission rate is a fundamental input parameter for airborne transmission risk assessment, but data are limited due to reliance on estimates from chance superspreading events. This study assesses the strength of a predictive estimation approach developed by the authors for SARS-CoV-2 and uses novel estimates to compare the contagiousness of respiratory pathogens. We applied the approach to SARS-CoV-1, SARS-CoV-2, MERS, measles virus, adenovirus, rhinovirus, coxsackievirus, seasonal influenza virus and Mycobacterium tuberculosis (TB) and compared quanta emission rate (ERq) estimates to literature values. We calculated infection risk in a prototypical classroom and barracks to assess the relative ability of ventilation to mitigate airborne transmission. Our median standing and speaking ERq estimate for SARS-CoV-2 (2.7 quanta h-1) is similar to active, untreated TB (3.1 quanta h-1), higher than seasonal influenza (0.17 quanta h-1), and lower than measles virus (15 quanta h-1). We calculated event reproduction numbers above 1 for SARS-CoV-2, measles virus, and untreated TB in both the classroom and barracks for an activity level of standing and speaking at low, medium and high ventilation rates of 2.3, 6.6 and 14 L per second per person (L s-1 p-1), respectively. Our predictive ERq estimates are consistent with the range of values reported over decades of research. In congregate settings, current ventilation standards are unlikely to control the spread of viruses with upper quartile ERq values above 10 quanta h-1, such as SARS-CoV-2, indicating the need for additional control measures.
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Affiliation(s)
- Alex Mikszewski
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia
- CIUS Building Performance Lab, The City University of New York, New York, NY, USA
| | - Luca Stabile
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR, Italy
| | - Giorgio Buonanno
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR, Italy
| | - Lidia Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland, Australia
- Global Centre for Clean Air Research (GCARE), Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
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Schimmoller BJ, Trovão NS, Isbell M, Goel C, Heck BF, Archer TC, Cardinal KD, Naik NB, Dutta S, Rohr Daniel A, Beheshti A. COVID-19 Exposure Assessment Tool (CEAT): Exposure quantification based on ventilation, infection prevalence, group characteristics, and behavior. SCIENCE ADVANCES 2022; 8:eabq0593. [PMID: 36179034 PMCID: PMC9524836 DOI: 10.1126/sciadv.abq0593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 08/17/2022] [Indexed: 06/16/2023]
Abstract
The coronavirus disease 2019 (COVID-19) Exposure Assessment Tool (CEAT) allows users to compare respiratory relative risk to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for various scenarios, providing understanding of how combinations of protective measures affect risk. CEAT incorporates mechanistic, stochastic, and epidemiological factors including the (i) emission rate of virus, (ii) viral aerosol degradation and removal, (iii) duration of activity/exposure, (iv) inhalation rates, (v) ventilation rates (indoors/outdoors), (vi) volume of indoor space, (vii) filtration, (viii) mask use and effectiveness, (ix) distance between people (taking into account both near-field and far-field effects of proximity), (x) group size, (xi) current infection rates by variant, (xii) prevalence of infection and immunity in the community, (xiii) vaccination rates, and (xiv) implementation of COVID-19 testing procedures. CEAT applied to published studies of COVID-19 transmission events demonstrates the model's accuracy. We also show how health and safety professionals at NASA Ames Research Center used CEAT to manage potential risks posed by SARS-CoV-2 exposures.
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Affiliation(s)
- Brian J. Schimmoller
- Signature Science LLC, Austin, TX 78759, USA
- COVID-19 International Research Team, Medford, MA 02155, USA
| | - Nídia S. Trovão
- COVID-19 International Research Team, Medford, MA 02155, USA
- Fogarty International Center, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Chirag Goel
- COVID-19 International Research Team, Medford, MA 02155, USA
- Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Benjamin F. Heck
- Bastion Technologies, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Tenley C. Archer
- COVID-19 International Research Team, Medford, MA 02155, USA
- Biomea Fusion Inc., Redwood City, CA 94063, USA
| | - Klint D. Cardinal
- Leidos Inc., NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Neil B. Naik
- Leidos Inc., NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Som Dutta
- COVID-19 International Research Team, Medford, MA 02155, USA
- Mechanical and Aerospace Engineering, Utah State University, Logan, UT 84332, USA
| | - Ahleah Rohr Daniel
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - Afshin Beheshti
- COVID-19 International Research Team, Medford, MA 02155, USA
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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11
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Goraya H, Meena N, Jagana R. Personal Protective Equipment Efficiency in Healthcare Emergencies: A Single-Center Experience. Cureus 2022; 14:e27823. [PMID: 35971399 PMCID: PMC9371593 DOI: 10.7759/cureus.27823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2022] [Indexed: 12/04/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19) has dramatically shifted the healthcare landscape since 2020. Measures against it includes universal masking in the healthcare areas and the community, viral testing before aerosolizing procedures, and ambulatory elective surgical procedures. Some hospitals have had mandated viral testing policies even before admission to the hospital. Healthcare workers (HCWs) have been cautiously modifying all pertinent practices to avoid the transmission of the virus. Personal protective equipment (PPE), including gowns, gloves, eye protection, and properly fitted N95 respirator or powered air-purifying respirators (PAPR) while treating the suspected and confirmed COVID-19 patients were made mandatory. Similarly, we changed our aerosol-generating procedures (AGPs) protocols based on available limited data. We amended our approach to in-hospital cardiopulmonary resuscitation (basic life support (BLS)/advanced cardiovascular life support (ACLS)), given the risk of aerosol generation and transmission during the process. This article shares our experience and outcomes of PPE use in healthcare emergencies at our tertiary care academic center.
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12
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Zhang L, Guo Y, Chang X, Yao Z, Wei X, Feng Z, Zhang D, Zhou Q, Wang X, Luo H. In-duct grating-like dielectric barrier discharge system for air disinfection. JOURNAL OF HAZARDOUS MATERIALS 2022; 435:129075. [PMID: 35650753 PMCID: PMC9072810 DOI: 10.1016/j.jhazmat.2022.129075] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/01/2022] [Accepted: 05/02/2022] [Indexed: 05/04/2023]
Abstract
In the context of spreading Coronavirus disease 2019 (COVID-19), the combination of heating, ventilation, and air-conditioning (HVAC) system with air disinfection device is an effective way to reduce transmissible infections. Atmospheric-pressure non-equilibrium plasma is an emerging technique for fast pathogen aerosol abatement. In this work, in-duct disinfectors based on grating-like dielectric barrier discharge (DBD) plasmas with varied electrode arrangements were established and evaluated. The highest airborne bacterial inactivation efficiency was achieved by 'vertical' structure, namely when aerosol was in direct contact with the discharge region, at a given discharge power. For all reactors, the efficiency was linearly correlated to the discharge power (R2 =0.929-0.994). The effects of environmental factors were examined. Decreased airflow rates boosted the efficiency, which reached 99.8% at the velocity of 0.5 m/s with an aerosol residence time of ~3.6 ms. Increasing humidity (relative humidity (RH)=20-60%) contributed to inactivation efficacy, while high humidity (RH=70%-90%) led to a saturated efficiency, possibly due to the disruption of discharge uniformity. As suggested by the plasma effluent treatment and scavenger experiments, gaseous short-lived chemical species or charged particles were concluded as the major agents accounting for bacterial inactivation. This research provides new hints for air disinfection by DBD plasmas.
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Affiliation(s)
- Liyang Zhang
- Department of Electrical Engineering, Tsinghua University, Beijing, China
| | - Yuntao Guo
- Department of Electrical Engineering, Tsinghua University, Beijing, China.
| | - Xuanyu Chang
- Marine Design and Research Institute of China (MARIC), Shanghai, China
| | - Zenghui Yao
- School of Electrical and Electronic Engineering, North China Electric Power University, Beijing, China
| | - Xiaodong Wei
- Marine Design and Research Institute of China (MARIC), Shanghai, China
| | - Zihao Feng
- Department of Electrical Engineering, Tsinghua University, Beijing, China
| | - Dongheyu Zhang
- Department of Electrical Engineering, Tsinghua University, Beijing, China
| | - Qun Zhou
- Department of Chemistry, Tsinghua University, Beijing, China
| | - Xinxin Wang
- Department of Electrical Engineering, Tsinghua University, Beijing, China
| | - Haiyun Luo
- Department of Electrical Engineering, Tsinghua University, Beijing, China.
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13
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Lunati I, Mucignat C. Infection risk in cable cars and other enclosed spaces. INDOOR AIR 2022; 32:e13094. [PMID: 36040286 PMCID: PMC9539082 DOI: 10.1111/ina.13094] [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: 01/09/2022] [Revised: 06/10/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
As virus-laden aerosols can accumulate and remain suspended for hours in insufficiently ventilated enclosed spaces, indoor environments can heavily contribute to the spreading of airborne infections. In the COVID-19 pandemics, the role possibly played by cable cars has attracted media attention following several outbreaks in ski resort. To assess the real risk of infection, we experimentally characterize the natural ventilation in cable cars and develop a general stochastic model of infection in an arbitrary indoor space that accounts for the epidemiological situation, the virological parameters, and the indoor characteristics (ventilation rate and occupant number density). As a results of the high air exchange rate (we measured up to 180 air changes per hour) and the relatively short duration of the journey, the infection probability in cable cars traveling with open windows is remarkably lower than in other enclosed spaces such as aircraft cabins, train cars, offices, classrooms, and dining rooms. Accounting for the typical duration of the stay, the probability of infection during a cable-car ride is lower by two to three orders of magnitude than in the other examples considered (the highest risk being estimated in case of a private gathering in a poorly ventilated room). For most practical purposes, the infection probability can be approximated by the inhaled viral dose, which provides an upper bound and allows a simple comparison between different indoor situations once the air exchange rate and the occupant number density are known. Our approach and findings are applicable to any indoor space in which the viral transmission is predominately airborne and the air is well mixed.
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Affiliation(s)
- Ivan Lunati
- Laboratory of Multiscale Studies in Building Physics, EmpaDübendorfSwitzerland
| | - Claudio Mucignat
- Laboratory of Multiscale Studies in Building Physics, EmpaDübendorfSwitzerland
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14
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Duval D, Palmer JC, Tudge I, Pearce-Smith N, O'Connell E, Bennett A, Clark R. Long distance airborne transmission of SARS-CoV-2: rapid systematic review. BMJ 2022; 377:e068743. [PMID: 35768139 PMCID: PMC9240778 DOI: 10.1136/bmj-2021-068743] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/04/2022] [Indexed: 12/22/2022]
Abstract
OBJECTIVES To evaluate the potential for long distance airborne transmission of SARS-CoV-2 in indoor community settings and to investigate factors that might influence transmission. DESIGN Rapid systematic review and narrative synthesis. DATA SOURCES Medline, Embase, medRxiv, Arxiv, and WHO COVID-19 Research Database for studies published from 27 July 2020 to 19 January 2022; existing relevant rapid systematic review for studies published from 1 January 2020 to 27 July 2020; and citation analysis in Web of Science and Cocites. ELIGIBILITY CRITERIA FOR STUDY SELECTION Observational studies reporting on transmission events in indoor community (non-healthcare) settings in which long distance airborne transmission of SARS-CoV-2 was the most likely route. Studies such as those of household transmission where the main transmission route was likely to be close contact or fomite transmission were excluded. DATA EXTRACTION AND SYNTHESIS Data extraction was done by one reviewer and independently checked by a second reviewer. Primary outcomes were SARS-CoV-2 infections through long distance airborne transmission (>2 m) and any modifying factors. Methodological quality of included studies was rated using the quality criteria checklist, and certainty of primary outcomes was determined using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. Narrative synthesis was themed by setting. RESULTS 22 reports relating to 18 studies were identified (methodological quality was high in three, medium in five, and low in 10); all the studies were outbreak investigations. Long distance airborne transmission was likely to have occurred for some or all transmission events in 16 studies and was unclear in two studies (GRADE: very low certainty). In the 16 studies, one or more factors plausibly increased the likelihood of long distance airborne transmission, particularly insufficient air replacement (very low certainty), directional air flow (very low certainty), and activities associated with increased emission of aerosols, such as singing or speaking loudly (very low certainty). In 13 studies, the primary cases were reported as being asymptomatic, presymptomatic, or around symptom onset at the time of transmission. Although some of the included studies were well conducted outbreak investigations, they remain at risk of bias owing to study design and do not always provide the level of detail needed to fully assess transmission routes. CONCLUSION This rapid systematic review found evidence suggesting that long distance airborne transmission of SARS-CoV-2 might occur in indoor settings such as restaurants, workplaces, and venues for choirs, and identified factors such as insufficient air replacement that probably contributed to transmission. These results strengthen the need for mitigation measures in indoor settings, particularly the use of adequate ventilation. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42021236762.
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Affiliation(s)
- Daphne Duval
- COVID-19 Rapid Evidence Service, UK Health Security Agency, London, UK
| | - Jennifer C Palmer
- COVID-19 Rapid Evidence Service, UK Health Security Agency, London, UK
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol, UK
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, UK
| | - Isobel Tudge
- COVID-19 Rapid Evidence Service, UK Health Security Agency, London, UK
| | | | - Emer O'Connell
- COVID-19 Advice and Guidance, UK Health Security Agency, London, UK
| | - Allan Bennett
- Biosafety, Air, and Water Microbiology Group, Research and Evaluation, UK Health Security Agency, Porton, UK
| | - Rachel Clark
- COVID-19 Rapid Evidence Service, UK Health Security Agency, London, UK
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15
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Guo W, Fu Y, Jia R, Guo Z, Su C, Li J, Zhao X, Jin Y, Li P, Fan J, Zhang C, Qu P, Cui H, Gao S, Cheng H, Li J, Li X, Lu B, Xu X, Wang Z. Visualization of the infection risk assessment of SARS-CoV-2 through aerosol and surface transmission in a negative-pressure ward. ENVIRONMENT INTERNATIONAL 2022; 162:107153. [PMID: 35202929 PMCID: PMC8858715 DOI: 10.1016/j.envint.2022.107153] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/22/2022] [Accepted: 02/16/2022] [Indexed: 06/10/2023]
Abstract
Since December 2019, coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a great challenge to the world's public health system. Nosocomial infections have occurred frequently in medical institutions worldwide during this pandemic. Thus, there is an urgent need to construct an effective surveillance and early warning system for pathogen exposure and infection to prevent nosocomial infections in negative-pressure wards. In this study, visualization and construction of an infection risk assessment of SARS-CoV-2 through aerosol and surface transmission in a negative-pressure ward were performed to describe the distribution regularity and infection risk of SARS-CoV-2, the critical factors of infection, the air changes per hour (ACHs) and the viral variation that affect infection risk. The SARS-CoV-2 distribution data from this model were verified by field test data from the Wuhan Huoshenshan Hospital ICU ward. ACHs have a great impact on the infection risk from airborne exposure, while they have little effect on the infection risk from surface exposure. The variant strains demonstrated significantly increased viral loads and risks of infection. The level of protection for nurses and surgeons should be increased when treating patients infected with variant strains, and new disinfection methods, electrostatic adsorption and other air purification methods should be used in all human environments. The results of this study may provide a theoretical reference and technical support for reducing the occurrence of nosocomial infections.
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Affiliation(s)
- Weiqi Guo
- Academy of Military Sciences, Beijing, China
| | - Yingying Fu
- Academy of Military Sciences, Beijing, China
| | - Rui Jia
- China Biotechnology Co. LTD, Beijing, China
| | | | - Chen Su
- Academy of Military Sciences, Beijing, China
| | - Jiaming Li
- Academy of Military Sciences, Beijing, China
| | - Xiuguo Zhao
- Academy of Military Sciences, Beijing, China
| | - Yifei Jin
- Academy of Military Sciences, Beijing, China
| | - Penghui Li
- Academy of Military Sciences, Beijing, China
| | - Jinbo Fan
- Academy of Military Sciences, Beijing, China
| | - Cheng Zhang
- Academy of Military Sciences, Beijing, China
| | - Pengtao Qu
- Academy of Military Sciences, Beijing, China
| | - Huan Cui
- Academy of Military Sciences, Beijing, China
| | - Sheng Gao
- Academy of Military Sciences, Beijing, China
| | | | - Jingjing Li
- Academy of Military Sciences, Beijing, China
| | - Xiang Li
- Academy of Military Sciences, Beijing, China
| | - Bing Lu
- Academy of Military Sciences, Beijing, China.
| | - Xinxi Xu
- Academy of Military Sciences, Beijing, China.
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16
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Schimmoller BJ, Trovão NS, Isbell M, Goel C, Heck BF, Archer TC, Cardinal KD, Naik NB, Dutta S, Daniel AR, Beheshti A. Covid-19 Exposure Assessment Tool (CEAT): Easy-to-use tool to quantify exposure based on airflow, group behavior, and infection prevalence in the community. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2022:2022.03.02.22271806. [PMID: 35291295 PMCID: PMC8923112 DOI: 10.1101/2022.03.02.22271806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The COVID-19 Exposure Assessment Tool (CEAT) allows users to compare respiratory relative risk to SARS-CoV-2 for various scenarios, providing understanding of how combinations of protective measures affect exposure, dose, and risk. CEAT incorporates mechanistic, stochastic and epidemiological factors including the: 1) emission rate of virus, 2) viral aerosol degradation and removal, 3) duration of activity/exposure, 4) inhalation rates, 5) ventilation rates (indoors/outdoors), 6) volume of indoor space, 7) filtration, 8) mask use and effectiveness, 9) distance between people, 10) group size, 11) current infection rates by variant, 12) prevalence of infection and immunity in the community, 13) vaccination rates of the community, and 14) implementation of COVID-19 testing procedures. Demonstration of CEAT, from published studies of COVID-19 transmission events, shows the model accurately predicts transmission. We also show how health and safety professionals at NASA Ames Research Center used CEAT to manage potential risks posed by SARS-CoV-2 exposures. Given its accuracy and flexibility, the wide use of CEAT will have a long lasting beneficial impact in managing both the current COVID-19 pandemic as well as a variety of other scenarios.
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Affiliation(s)
- Brian J. Schimmoller
- Signature Science LLC, Austin, TX, 78759, USA
- COVID-19 International Research Team
- Lead Contacts
| | - Nídia S. Trovão
- COVID-19 International Research Team
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Chirag Goel
- COVID-19 International Research Team
- Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Benjamin F. Heck
- Bastion Technologies, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Tenley C. Archer
- COVID-19 International Research Team
- Biomea Fusion, Inc. Redwood City, CA, 94063, USA
| | - Klint D. Cardinal
- Leidos, Inc., NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Neil B. Naik
- Leidos, Inc., NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Som Dutta
- COVID-19 International Research Team
- Mechanical & Aerospace Engineering, Utah State University, Logan, UT 84332, USA
| | - Ahleah Rohr Daniel
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Afshin Beheshti
- COVID-19 International Research Team
- KBR, Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Lead Contacts
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17
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Lau Z, Griffiths IM, English A, Kaouri K. Predicting the spatio-temporal infection risk in indoor spaces using an efficient airborne transmission model. Proc Math Phys Eng Sci 2022; 478:20210383. [PMID: 35310953 PMCID: PMC8924953 DOI: 10.1098/rspa.2021.0383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 02/14/2022] [Indexed: 12/19/2022] Open
Abstract
We develop a spatially dependent generalization to the Wells-Riley model, which determines the infection risk due to airborne transmission of viruses. We assume that the infectious aerosol concentration is governed by an advection-diffusion-reaction equation with the aerosols advected by airflow, diffused due to turbulence, emitted by infected people, and removed due to ventilation, inactivation of the virus and gravitational settling. We consider one asymptomatic or presymptomatic infectious person breathing or talking, with or without a mask, and model a quasi-three-dimensional set-up that incorporates a recirculating air-conditioning flow. We derive a semi-analytic solution that enables fast simulations and compare our predictions to three real-life case studies-a courtroom, a restaurant, and a hospital ward-demonstrating good agreement. We then generate predictions for the concentration and the infection risk in a classroom, for four different ventilation settings. We quantify the significant reduction in the concentration and the infection risk as ventilation improves, and derive appropriate power laws. The model can be easily updated for different parameter values and can be used to make predictions on the expected time taken to become infected, for any location, emission rate, and ventilation level. The results have direct applicability in mitigating the spread of the COVID-19 pandemic.
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Affiliation(s)
- Zechariah Lau
- School of Mathematics, Cardiff University, CF24 4AG Cardiff, UK
- Mathematical Institute, University of Oxford, OX1 6GG Oxford, UK
| | - Ian M. Griffiths
- Mathematical Institute, University of Oxford, OX1 6GG Oxford, UK
| | - Aaron English
- School of Mathematics, Cardiff University, CF24 4AG Cardiff, UK
- Department of Mechanical, Aerospace and Civil Engineering, University of Manchester, M13 9PL Manchester, UK
| | - Katerina Kaouri
- School of Mathematics, Cardiff University, CF24 4AG Cardiff, UK
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18
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Angel DM, Gao D, DeLay K, Lin EZ, Eldred J, Arnold W, Santiago R, Redlich C, Martinello RA, Sherman JD, Peccia J, Godri Pollitt KJ. Development and Application of a Polydimethylsiloxane-Based Passive Air Sampler to Assess Personal Exposure to SARS-CoV-2. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2022; 9:153-159. [PMID: 37566382 PMCID: PMC8768000 DOI: 10.1021/acs.estlett.1c00877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/23/2021] [Accepted: 12/28/2021] [Indexed: 05/12/2023]
Abstract
Exhaled respiratory droplets and aerosols can carry infectious viruses and are an important mode of transmission for COVID-19. Recent studies have been successful in detecting airborne SARS-CoV-2 RNA in indoor settings using active sampling methods. The cost, size, and maintenance of these samplers, however, limit their long-term monitoring ability in high-risk transmission areas. As an alternative, passive samplers can be small, lightweight, and inexpensive and do not require electrical power or maintenance for continual operation. Integration of passive samplers into wearable designs can be used to better understand personal exposure to the respiratory virus. This study evaluated the use of a polydimethylsiloxane (PDMS)-based passive sampler to assess personal exposure to aerosol and droplet SARS-CoV-2. The rate of uptake of virus-laden aerosol on PDMS was determined in lab-based rotating drum experiments to estimate time-weighted averaged airborne viral concentrations from passive sampler viral loading. The passive sampler was then embedded in a wearable clip design and distributed to community members across Connecticut to surveil personal SARS-CoV-2 exposure. The virus was detected on clips worn by five of the 62 participants (8%) with personal exposure ranging from 4 to 112 copies of SARS-CoV-2 RNA/m3, predominantly in indoor restaurant settings. Our findings demonstrate that PDMS-based passive samplers may serve as a useful exposure assessment tool for airborne viral exposure in real-world high-risk settings and provide avenues for early detection of potential cases and guidance on site-specific infection control protocols that preempt community transmission.
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Affiliation(s)
- Darryl M. Angel
- Department of Chemical and Environmental Engineering,
Yale School of Engineering and Applied Science, Yale
University, New Haven, Connecticut 06520, United
States
| | - Dong Gao
- Department of Environmental Health Sciences,
Yale School of Public Health, New Haven, Connecticut 06520,
United States
| | - Kayley DeLay
- Department of Chemical and Environmental Engineering,
Yale School of Engineering and Applied Science, Yale
University, New Haven, Connecticut 06520, United
States
- Department of Environmental Health Sciences,
Yale School of Public Health, New Haven, Connecticut 06520,
United States
| | - Elizabeth Z. Lin
- Department of Environmental Health Sciences,
Yale School of Public Health, New Haven, Connecticut 06520,
United States
| | - Jacob Eldred
- Department of Mechanical Engineering and Materials
Science, Yale School of Engineering and Applied Science, Yale
University, New Haven, Connecticut 06511, United
States
| | - Wyatt Arnold
- Department of Chemical and Environmental Engineering,
Yale School of Engineering and Applied Science, Yale
University, New Haven, Connecticut 06520, United
States
| | - Romero Santiago
- Department of Internal Medicine, Yale
School of Medicine, New Haven, Connecticut 06510, United
States
| | - Carrie Redlich
- Department of Internal Medicine, Yale
School of Medicine, New Haven, Connecticut 06510, United
States
| | - Richard A. Martinello
- Department of Internal Medicine, Yale
School of Medicine, New Haven, Connecticut 06510, United
States
- Department of Infection Prevention, Yale
New Haven Health System, New Haven, Connecticut 06510, United
States
- Department of Pediatrics, Yale School of
Medicine, New Haven, Connecticut 06510, United
States
| | - Jodi D. Sherman
- Department of Environmental Health Sciences,
Yale School of Public Health, New Haven, Connecticut 06520,
United States
- Department of Anesthesiology, Yale School of
Medicine, New Haven, Connecticut 06510, United
States
| | - Jordan Peccia
- Department of Chemical and Environmental Engineering,
Yale School of Engineering and Applied Science, Yale
University, New Haven, Connecticut 06520, United
States
| | - Krystal J. Godri Pollitt
- Department of Chemical and Environmental Engineering,
Yale School of Engineering and Applied Science, Yale
University, New Haven, Connecticut 06520, United
States
- Department of Environmental Health Sciences,
Yale School of Public Health, New Haven, Connecticut 06520,
United States
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19
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Castellini JE, Faulkner CA, Zuo W, Lorenzetti DM, Sohn MD. Assessing the use of portable air cleaners for reducing exposure to airborne diseases in a conference room with thermal stratification. BUILDING AND ENVIRONMENT 2022; 207:108441. [PMID: 34720357 PMCID: PMC8548847 DOI: 10.1016/j.buildenv.2021.108441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/24/2021] [Accepted: 10/11/2021] [Indexed: 05/29/2023]
Abstract
The COVID-19 pandemic has highlighted the need for strategies that mitigate the risk of aerosol disease transmission in indoor environments with different ventilation strategies. It is necessary for building operators to be able to estimate and compare the relative impacts of different mitigation strategies to determine suitable strategies for a particular situation. Using a validated CFD model, this study simulates the dispersion of exhaled contaminants in a thermally stratified conference room with overhead heating. The impacts of portable air-cleaners (PACs) on the room airflow and contaminant distribution were evaluated for different PAC locations and flow rates, as well as for different room setups (socially distanced or fully occupied). To obtain a holistic view of a strategy's impacts under different release scenarios, we simultaneously model the steady-state distribution of aerosolized virus contaminants from eight distinct sources in 18 cases for a total of 144 release scenarios. The simulations show that the location of the source, the PAC settings, and the room set-up can impact the average exposure and PAC effectiveness. For this studied case, the PACs reduced the room average exposure by 31%-66% relative to the baseline case. Some occupant locations were shown to have a higher-than-average exposure, particularly those seated near the airflow outlet, and occupants closest to sources tended to see the highest exposure from said source. We found that these PACs were effective at reducing the stratification caused by overhead heating, and also identified at least one sub-optimal location for placing a PAC in this space.
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Affiliation(s)
- John E Castellini
- Department of Mechanical Engineering, University of Colorado Boulder, UCB 427, Boulder, 80309, CO, USA
| | - Cary A Faulkner
- Department of Mechanical Engineering, University of Colorado Boulder, UCB 427, Boulder, 80309, CO, USA
| | - Wangda Zuo
- Department of Mechanical Engineering, University of Colorado Boulder, UCB 427, Boulder, 80309, CO, USA
- Department of Civil, Environmental and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, 80309, CO, USA
- National Renewable Energy National Laboratory, Golden, 80401, CO, USA
| | - David M Lorenzetti
- Energy Analysis and Environmental Impacts Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, 94720, CA, USA
| | - Michael D Sohn
- Energy Analysis and Environmental Impacts Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, 94720, CA, USA
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20
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Nazaroff WW. Indoor aerosol science aspects of SARS-CoV-2 transmission. INDOOR AIR 2022; 32:e12970. [PMID: 34873752 DOI: 10.1111/ina.12970] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 11/17/2021] [Accepted: 11/26/2021] [Indexed: 05/04/2023]
Abstract
Knowledge about person-to-person transmission of SARS-CoV-2 is reviewed, emphasizing three components: emission of virus-containing particles and drops from infectious persons; transport and fate of such emissions indoors; and inhalation of viral particles by susceptible persons. Emissions are usefully clustered into three groups: small particles (diameter 0.1-5 µm), large particles (5-100 µm), and ballistic drops (>100 µm). Speaking generates particles and drops across the size spectrum. Small particles are removed from indoor air at room scale by ventilation, filtration, and deposition; large particles mainly deposit onto indoor surfaces. Proximate exposure enhancements are associated with large particles with contributions from ballistic drops. Masking and social distancing are effective in mitigating transmission from proximate exposures. At room scale, masking, ventilation, and filtration can contribute to limit exposures. Important information gaps prevent a quantitative reconciliation of the high overall global spread of COVID-19 with known transmission pathways. Available information supports several findings with moderate-to-high confidence: transmission occurs predominantly indoors; inhalation of airborne particles (up to 50 µm in diameter) contributes substantially to viral spread; transmission occurs in near proximity and at room scale; speaking is a major source of airborne SARS-CoV-2 virus; and emissions can occur without strong illness symptoms.
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Affiliation(s)
- William W Nazaroff
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, USA
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21
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Kriegel M, Hartmann A, Buchholz U, Seifried J, Baumgarte S, Gastmeier P. SARS-CoV-2 Aerosol Transmission Indoors: A Closer Look at Viral Load, Infectivity, the Effectiveness of Preventive Measures and a Simple Approach for Practical Recommendations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:220. [PMID: 35010484 PMCID: PMC8750733 DOI: 10.3390/ijerph19010220] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/12/2022]
Abstract
There is uncertainty about the viral loads of infectious individuals required to transmit COVID-19 via aerosol. In addition, there is a lack of both quantification of the influencing parameters on airborne transmission and simple-to-use models for assessing the risk of infection in practice, which furthermore quantify the influence of non-medical preventive measures. In this study, a dose-response model was adopted to analyze 25 documented outbreaks at infection rates of 4-100%. We show that infection was only possible if the viral load was higher than 108 viral copies/mL. Based on mathematical simplifications of our approach to predict the probable situational attack rate (PARs) of a group of persons in a room, and valid assumptions, we provide simplified equations to calculate, among others, the maximum possible number of persons and the person-related virus-free air supply flow necessary to keep the number of newly infected persons to less than one. A comparison of different preventive measures revealed that testing contributes the most to the joint protective effect, besides wearing masks and increasing ventilation. In addition, we conclude that absolute volume flow rate or person-related volume flow rate are more intuitive parameters for evaluating ventilation for infection prevention than air exchange rate.
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Affiliation(s)
- Martin Kriegel
- Hermann-Rietschel-Institut, Technical University of Berlin, 10623 Berlin, Germany;
| | - Anne Hartmann
- Hermann-Rietschel-Institut, Technical University of Berlin, 10623 Berlin, Germany;
| | - Udo Buchholz
- Department for Infectious Disease Epidemiology, Robert Koch Institute, 13353 Berlin, Germany; (U.B.); (J.S.)
| | - Janna Seifried
- Department for Infectious Disease Epidemiology, Robert Koch Institute, 13353 Berlin, Germany; (U.B.); (J.S.)
| | | | - Petra Gastmeier
- Institute for Hygiene and Environmental Medicine, Charité-University Medicine Berlin, 12203 Berlin, Germany;
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