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Choi S, Piri A, Jung J, An S, Hwang J. Determination of airborne influenza virus and coronavirus infectivity using capsid integrity polymerase chain reaction. JOURNAL OF HAZARDOUS MATERIALS 2024; 479:135544. [PMID: 39216245 DOI: 10.1016/j.jhazmat.2024.135544] [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: 02/27/2024] [Revised: 08/12/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024]
Abstract
Accurate airborne virus monitoring is important for preventing the spread of infectious diseases. Although standard reverse transcription-quantitative polymerase chain reaction (RT-qPCR) can efficiently detect viral ribonucleic acid (RNA), it cannot determine whether the RNA is associated with active (infectious) or inactive (non-infectious) viruses. Plaque assay is the gold standard for determining viral infectivity but is laborious and time-consuming. This study explored the viral infectivity of H1N1 influenza virus and human coronavirus (HCoV-229E) using capsid integrity RT-qPCR, where virus samples were pretreated with reagents penetrating viruses with damaged capsids, impeding amplification by binding to their RNA. Therefore, the amplified signals corresponded solely to active viruses with undamaged capsids. Propidium monoazide (PMA) and platinum (IV) chloride (PtCl4) were used to investigate the effects of reagent concentration. Feasibility tests revealed that PtCl4 was more efficient than PMA, with optimal concentrations of 125-250 μM and 250-500 μM for H1N1 influenza virus and HCoV-229E, respectively. The results of percentage of active virus showed that capsid integrity RT-qPCR provided a trend similar to that of plaque assay, indicating an accurate measure of viral infectivity. Virus sampling in the laboratory and field highlighted the precision of this methodology for determining viral infectivity. Therefore, this methodology enables rapid and accurate detection of infectious airborne H1N1 influenza virus and HCoV-229E, allowing swift response to outbreaks.
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Affiliation(s)
- Sangsoo Choi
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Amin Piri
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea; Institute of Engineering Research, Yonsei University, Seoul 03722, Republic of Korea.
| | - Jiwoo Jung
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Sanggwon An
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Jungho Hwang
- Department of Mechanical Engineering, Yonsei University, Seoul 03722, Republic of Korea.
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Xu Z, Zhang H, Zhu M, Ji Y, Xue P, Xie J, Li Y, Zhang N. Human behavior-based COVID-19 transmission in two dining spaces. JOURNAL OF HAZARDOUS MATERIALS 2024; 480:135820. [PMID: 39298960 DOI: 10.1016/j.jhazmat.2024.135820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 08/27/2024] [Accepted: 09/10/2024] [Indexed: 09/22/2024]
Abstract
Since December 2019, the COVID-19 pandemic has rapidly disseminated globally, posing significant threats to the world. The dining spaces are high-risk indoor environments for the transmission of SARS-CoV-2, posing challenges for intervention and control. This study, based on surveillance videos from two COVID-19 outbreak cases in restaurants, obtained real data on human behaviors of close contact and surface touch. A respiratory infectious disease transmission model was developed, incorporating four transmission routes: short-range airborne, long-range airborne, fomite and large droplet. The results indicate that diners and staff spent 21.9 %-28.7 % and 17.5 %-27.8 % of their time on speaking, respectively, while spending 85.9 %-90.7 % and 83.4 %-87.6 % of their time on surface touching. The primary transmission routes were short-range (contributing 5.8 %-70.9 %) and long-range airborne (contributing 28.4 %-93.0 %), with fomite and large droplet routes contributing less than 12.0 %. Staff-only mask wearing reduced infection risk by 12.8 %-31.8 %. It is recommended that mandatory mask wearing for staff is necessary, while diners should wear masks as much as possible, and that the equivalent ventilation rate of clean fresh air is suggested to 30.0 m3/ (h·person). This study provides a scientific support to make non-pharmaceutical interventions in dinning spaces.
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Affiliation(s)
- Zhikang Xu
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Haochen Zhang
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Min Zhu
- 6th Medical Center of General Hospital of PLA, Beijing, China
| | - Ying Ji
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Peng Xue
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Jingchao Xie
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
| | - Yuguo Li
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China
| | - Nan Zhang
- Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China.
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Liu Y, Lin Z, Lin G, Lian W, Tian J, Li G, Qu H. Intelligent Forest Hospital as a New Management System for Hospital-Acquired Infection Control. China CDC Wkly 2024; 6:972-974. [PMID: 39347450 PMCID: PMC11427340 DOI: 10.46234/ccdcw2024.201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 02/27/2024] [Indexed: 10/01/2024] Open
Abstract
Hospital-acquired infection (HAI) is a significant global health concern, elevating the risks of morbidity and imposing a substantial socioeconomic burden. To enhance the management of HAI, particularly in the aftermath of the coronavirus disease 2019 (COVID-19) pandemic, the Guangdong Second Provincial General Hospital (GD2H) has launched a new system called Intelligent Forest Hospital (IFH). Leveraging advancements in artificial intelligence, 5G technology, and cloud networking, the IFH implements customized indoor air quality (IAQ) control strategies tailored to different medical settings. It utilizes various intelligent disinfection devices and air purification systems. The IFH features a dynamic 3D hospital model with real-time monitoring of crucial IAQ parameters and a risk assessment ranking for clinical departments, providing timely risk alerts, communication prompts, and automatic disinfection processes. The IFH aims to effectively mitigate HAI post-COVID-19 and other future pandemics, ensuring a safe and pleasant environment for patients, hospital staff, and visitors.
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Affiliation(s)
- Yingxin Liu
- Center for Clinical Epidemiology and Methodology (CCEM), The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
| | - Zhousheng Lin
- Medical Department, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
| | - Guanwen Lin
- Hospital-Acquired Infection Control Department, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
| | - Wanmin Lian
- Information Department, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
| | - Junzhang Tian
- Institute for Healthcare Artificial Intelligence Application, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
| | - Guowei Li
- Center for Clinical Epidemiology and Methodology (CCEM), The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
- Father Sean O'Sullivan Research Centre, St. Joseph's Healthcare Hamilton, Hamilton, ON, Canada
- Department of Health Research Methods, Evidence, and Impact (HEI), McMaster University, Hamilton, ON, Canada
| | - Hongying Qu
- Center for Clinical Epidemiology and Methodology (CCEM), The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
- Institute for Healthcare Artificial Intelligence Application, The Affiliated Guangdong Second Provincial General Hospital of Jinan University, Guangzhou City, Guangdong Province, China
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Subirana M, Sunyer J, Colom-Cadena A, Bordas A, Casabona J, Gascon M. Monitoring and assessment of CO 2 and NO 2 in schools within the Sentinel Schools Network of Catalonia during the COVID-19 era. CHEMOSPHERE 2024; 362:142575. [PMID: 38852629 DOI: 10.1016/j.chemosphere.2024.142575] [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: 02/22/2024] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 06/11/2024]
Abstract
In response to the global impact of the COVID-19 pandemic, international and national authorities, including those in Catalonia (Spain), recognized the crucial need to ensure proper ventilation in classrooms, emphasizing the importance of safe and healthy indoor environments for face-to-face learning. The present work, conducted within the COVID-19 Sentinel Schools Network of Catalonia (CSSNC) framework, aimed to monitor carbon dioxide (CO2) and nitrogen dioxide (NO2) concentrations in 23 schools, ensuring a comprehensive sample regarding educational levels, daily scholar schedules, and classroom typologies distributed across the four provinces of Catalonia. The research spanned three study periods: March and April 2021, October 2021 to January 2022, and March to June 2022. Briefly, 28%, 25%, and 37% of classrooms surpassed the 700 parts per million (ppm) CO2 limit in each study period, respectively. Generally, CO2 averages were lower in preschool classrooms (mean ± SD = 486 ± 106 ppm), while high school classrooms displayed the highest CO2 concentrations (mean ± SD = 710 ± 253 ppm). Moreover, classrooms in towns (<30000 inhabitants) exhibited higher CO2 levels as compared to classrooms from schools located in cities. As for NO2, the highest averages were obtained in urban areas, particularly in the Barcelona metropolitan area (e.g. mean indoor levels of 24.56 μg m-3 as compared to 11.05 μg m-3 in towns). In addition, the Indoor/Outdoor ratio (I/O ratio) in towns was the lowest (0.60). These results, together with the higher concentration of CO2 indoors, could indicate poorer ventilation in town schools. The results of this study are anticipated to contribute to implementing evidence-based measures to improve indoor air quality (IAQ) in educational settings.
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Affiliation(s)
- Maria Subirana
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
| | - Jordi Sunyer
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain; IMIM (Hospital del Mar Medical Research Insititute), Barcelona, Spain
| | - Andreu Colom-Cadena
- Centre for Epidemiological Studies of Sexually Transmitted Disease and AIDS in Catalonia (CEEISCAT), Badalona, Barcelona, Spain; Germans Trias i Pujol Research Institute (IGTP), Badalona, Barcelona, Spain
| | - Anna Bordas
- Centre for Epidemiological Studies of Sexually Transmitted Disease and AIDS in Catalonia (CEEISCAT), Badalona, Barcelona, Spain; Germans Trias i Pujol Research Institute (IGTP), Badalona, Barcelona, Spain
| | - Jordi Casabona
- CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain; Centre for Epidemiological Studies of Sexually Transmitted Disease and AIDS in Catalonia (CEEISCAT), Badalona, Barcelona, Spain; Germans Trias i Pujol Research Institute (IGTP), Badalona, Barcelona, Spain
| | - Mireia Gascon
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
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Martinot M. Ventilation: why infectious diseases specialists should care. Clin Microbiol Infect 2024; 30:977-979. [PMID: 38729304 DOI: 10.1016/j.cmi.2024.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/19/2024] [Accepted: 05/01/2024] [Indexed: 05/12/2024]
Affiliation(s)
- Martin Martinot
- Department of Infectious Diseases, Hôpitaux Civils de Colmar, Colmar, Alsace, France.
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Greenhalgh T, MacIntyre CR, Baker MG, Bhattacharjee S, Chughtai AA, Fisman D, Kunasekaran M, Kvalsvig A, Lupton D, Oliver M, Tawfiq E, Ungrin M, Vipond J. Masks and respirators for prevention of respiratory infections: a state of the science review. Clin Microbiol Rev 2024; 37:e0012423. [PMID: 38775460 PMCID: PMC11326136 DOI: 10.1128/cmr.00124-23] [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: 06/14/2024] Open
Abstract
SUMMARYThis narrative review and meta-analysis summarizes a broad evidence base on the benefits-and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts-of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.
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Affiliation(s)
- Trisha Greenhalgh
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - C Raina MacIntyre
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Michael G Baker
- Department of Public Health, University of Otago, Wellington, New Zealand
| | - Shovon Bhattacharjee
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
- School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
| | - Abrar A Chughtai
- School of Population Health, University of New South Wales, Sydney, Australia
| | - David Fisman
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Mohana Kunasekaran
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Amanda Kvalsvig
- Department of Public Health, University of Otago, Wellington, New Zealand
| | - Deborah Lupton
- Centre for Social Research in Health and Social Policy Research Centre, Faculty of Arts, Design and Architecture, University of New South Wales, Sydney, Australia
| | - Matt Oliver
- Professional Standards Advocate, Edmonton, Canada
| | - Essa Tawfiq
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Mark Ungrin
- Faculty of Veterinary Medicine; Department of Biomedical Engineering, Schulich School of Engineering; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Joe Vipond
- Department of Emergency Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Ishigaki Y, Yokogawa S. Monitoring the ventilation of living spaces to assess the risk of airborne transmission of infection using a novel Pocket CO2 Logger to track carbon dioxide concentrations in Tokyo. PLoS One 2024; 19:e0303790. [PMID: 38781170 PMCID: PMC11115307 DOI: 10.1371/journal.pone.0303790] [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: 01/18/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024] Open
Abstract
We employed carbon dioxide (CO2) concentration monitoring using mobile devices to identify location-specific risks for airborne infection transmission. We lent a newly developed, portable Pocket CO2 Logger to 10 participants, to be carried at all times, for an average of 8 days. The participants recorded their location at any given time as cinema, gym, hall, home, hospital, other indoors, other outgoings, pub, restaurant, university, store, transportation, or workplace. Generalized linear mixed model was used for statistical analysis, with the objective variable set to the logarithm of CO2 concentration. Analysis was performed by assigning participant identification as the random effect and location as the fixed effect. The data were collected per participant (seven males, four females), resulting in a total of 12,253 records. Statistical analysis identified three relatively poorly ventilated locations (median values > 1,000 ppm) that contributed significantly (p < 0.0001) to CO2 concentrations: homes (1,316 ppm), halls (1,173 ppm), and gyms (1005ppm). In contrast, two locations were identified to contribute significantly (p < 0.0001) to CO2 concentrations but had relatively low average values (<1,000 ppm): workplaces (705 ppm) and stores (620 ppm). The Pocket CO2 Logger can be used to visualize airborne infectious transmission risk by location to help guide recommendation regarding infectious disease policies, such as restrictions on human flow and ventilation measures and guidelines. In the future, large-scale surveys are expected to utilize the global positioning system, Wi-Fi, or Bluetooth of an individual's smartphone to improve ease and accuracy.
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Affiliation(s)
- Yo Ishigaki
- Research Center for Realizing Sustainable Societies, The University of Electro-Communications, Chofu, Tokyo, Japan
| | - Shinji Yokogawa
- Info-Powered Energy System Research Center (iPERC), The University of Electro-Communications, Chofu, Tokyo, Japan
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Baldelli A, Jerry Wong CY, Oguzlu H, Gholizadeh H, Guo Y, Ong HX, Singh A, Traini D, Pratap-Singh A. Nasal delivery of encapsulated recombinant ACE2 as a prophylactic drug for SARS-CoV-2. Int J Pharm 2024; 655:124009. [PMID: 38493838 DOI: 10.1016/j.ijpharm.2024.124009] [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: 01/26/2024] [Revised: 03/10/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Angiotensin-converting enzyme 2 (ACE2) is responsible for cell fusion with SARS-CoV viruses. ACE2 is contained in different areas of the human body, including the nasal cavity, which is considered the main entrance for different types of airborne viruses. We took advantage of the roles of ACE2 and the nasal cavity in SARS-CoV-2 replication and transmission to develop a nasal dry powder. Recombinant ACE2 (rhACE2), after a proper encapsulation achieved via spray freeze drying, shows a binding efficiency with spike proteins of SARS-CoV-2 higher than 77 % at quantities lower than 5 µg/ml. Once delivered to the nose, encapsulated rhACE2 led to viability and permeability of RPMI 2650 cells of at least 90.20 ± 0.67 % and 47.96 ± 4.46 %, respectively, for concentrations lower than 1 mg/ml. These results were validated using nasal dry powder containing rhACE2 to prevent or treat infections derived from SARS-CoV-2.
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Affiliation(s)
- Alberto Baldelli
- Faculty of Land and Food Systems, The University of British Columbia, Canada; School of Agriculture and Food Sustainability, The University of Queensland, Australia.
| | - Chun Yuen Jerry Wong
- Respiratory Technology, Woolcock Institute of Medical Research, Sydney, Australia
| | - Hale Oguzlu
- Faculty of Dentistry, Department of Oral Biological and Medical Sciences, University of British Columbia, Canada
| | - Hanieh Gholizadeh
- Respiratory Technology, Woolcock Institute of Medical Research, Sydney, Australia
| | - Yigong Guo
- Faculty of Land and Food Systems, The University of British Columbia, Canada
| | - Hui Xin Ong
- Respiratory Technology, Woolcock Institute of Medical Research, Sydney, Australia; Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University Australia Sydney, Australia
| | - Anika Singh
- Natural Health and Food Products Research Group, Centre for Applied Research, and Innovation (CARI), British Columbia Institute of Technology, Canada
| | - Daniela Traini
- Respiratory Technology, Woolcock Institute of Medical Research, Sydney, Australia; Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University Australia Sydney, Australia
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Monteverde G, Bianco F, Papetti P, Komínková D, Spasiano D, Paolella G, Muscetta M, Varjani S, Han N, Esposito G, Race M. Reuse of polymeric waste for the treatment of marine water polluted by diesel. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 356:120529. [PMID: 38490006 DOI: 10.1016/j.jenvman.2024.120529] [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: 08/22/2023] [Revised: 10/23/2023] [Accepted: 02/29/2024] [Indexed: 03/17/2024]
Abstract
Accidental diesel spills can occur in marine environments such as harbors, leading to adverse effects on the environmental compartment and humans. This study proposes the surgical mask as an affordable and sustainable adsorbent for the remediation of diesel-contaminated seawater to cope with the polymeric waste generated monthly in hospital facilities. This approach can also be helpful considering a possible future pandemic, alleviating the pressure on the waste management system by avoiding improper mask incineration and landfilling, as instead occurred during the previous COVID-19. Batch adsorption-desorption experiments revealed a complete diesel removal from seawater after 120 min with the intact laceless mask, which showed an adsorption capacity of up to 3.43 g/g. The adsorption curve was better predicted via Weber and Morris's kinetic (R2 = 0.876) and, in general, with Temkin isotherm (R2 = 0.965-0.996) probably due to the occurrence of chemisorption with intraparticle diffusion as one of the rates-determining steps. A hysteresis index of 0.23-0.36 was obtained from the desorption isotherms, suggesting that diesel adsorption onto surgical masks was faster than the desorption mechanism. Also, the effect of pH, ionic strength and temperature on diesel adsorption was examined. The results from the reusability tests indicated that the surgical mask can be regenerated for 5 consecutive cycles while decreasing the adsorption capacity by only approximately 11%.
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Affiliation(s)
- Gelsomino Monteverde
- Department of Economics and Law, Territorial and Products Analysis Laboratory, University of Cassino and Southern Lazio, Via S. Angelo, Folcara, 03043, Cassino, Italy
| | - Francesco Bianco
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043, Cassino, Italy.
| | - Patrizia Papetti
- Department of Economics and Law, Territorial and Products Analysis Laboratory, University of Cassino and Southern Lazio, Via S. Angelo, Folcara, 03043, Cassino, Italy
| | - Dana Komínková
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Prague-Suchdol, 165 00, Czech Republic
| | - Danilo Spasiano
- Department of Civil, Environmental, Land, Building Engineering and Chemistry, Polytechnic University of Bari, Via E. Orabona 4, 70125, Bari, Italy
| | - Giulia Paolella
- Department of Civil, Architectural and Environmental Engineering, University of Napoli Federico II, Via Claudio 21, 80125, Napoli, Italy
| | - Marica Muscetta
- Department of Chemical, Materials and Production Engineering (DICMaPI), University of Naples Federico II, Piazzale V. Tecchio 80, 80125, Naples, Italy
| | - Sunita Varjani
- School of Engineering, University of Petroleum and Energy Studies, Dehradun 248 007, Uttarakhand, India; Institute of Chartered Waste Managers, Gopalpura Bypass, Jaipur 302019, Rajasthan, India
| | - Ning Han
- Department of Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, 3001, Leuven, Belgium
| | - Giovanni Esposito
- Department of Civil, Architectural and Environmental Engineering, University of Napoli Federico II, Via Claudio 21, 80125, Napoli, Italy
| | - Marco Race
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043, Cassino, Italy
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Wolkoff P. Indoor air humidity revisited: Impact on acute symptoms, work productivity, and risk of influenza and COVID-19 infection. Int J Hyg Environ Health 2024; 256:114313. [PMID: 38154254 DOI: 10.1016/j.ijheh.2023.114313] [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: 09/16/2023] [Revised: 10/30/2023] [Accepted: 12/18/2023] [Indexed: 12/30/2023]
Abstract
Recent epidemiological and experimental findings reconfirm that low indoor air humidity (dry air) increases the prevalence of acute eye and airway symptoms in offices, result in lower mucociliary clearance in the airways, less efficient immune defense, and deteriorate the work productivity. New epidemiological and experimental research also support that the environmental conditions for the risk of infection of influenza and COVID-19 virus is lowest in the Goldilocks zone of 40-60% relative humidity (RH) by decrease of the airways' susceptibility, which can be elevated by particle exposure. Furthermore, low RH increases the generation of infectious virus laden aerosols exhaled from infected people. In general, elevation of the indoor air humidity from dry air increases the health of the airways concomitantly with lower viability of infectious virus. Thus, the negative effects of ventilation with dry outdoor air (low absolute air humidity) should be assessed according to 1) weakened health and functionality of the airways, 2) increased viability and possible increased transmissibility of infectious virus, and 3) evaporation of virus containing droplets to dry out to droplet nuclei (also possible at high room temperature), which increases their floating time in the indoor air. The removal of acid-containing ambient aerosols from the indoor air by filtration increases pH, viability of infectious viruses, and the risk of infection, which synergistically may further increase by particle exposure. Thus, the dilution of indoor air pollutants and virus aerosols by dry outdoor air ventilation should be assessed and compared with the beneficial health effects by control of the center zone of 40-60% RH, an essential factor for optimal functionality of the airways, and with the additional positive impact on acute symptoms, work productivity, and reduced risk of infection.
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Affiliation(s)
- Peder Wolkoff
- National Research Centre for the Working Environment, Denmark.
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Belland K, Garcia D, DeJohn C, Allen GR, Mills WD, Glaudel SP. Safety and Effectiveness Assessment of Ultraviolet-C Disinfection in Aircraft Cabins. Aerosp Med Hum Perform 2024; 95:147-157. [PMID: 38356125 DOI: 10.3357/amhp.6350.2024] [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: 02/16/2024]
Abstract
INTRODUCTION: Aircraft cabins, susceptible to disease transmission, require effective strategies to minimize the spread of airborne diseases. This paper reviews the James Reason Swiss Cheese Theory in mitigating these risks, as implemented by the International Civil Aviation Organization during the COVID-19 pandemic. It also evaluates the use of airborne ultraviolet-C (UV-C) light as an additional protective measure.METHODS: Our approach involved a thorough literature review by experts and a detailed risk-vs.-benefit analysis. The review covered existing research to understand the scientific foundation, while the analysis used established techniques to assess the impact of influenza and COVID-19 in terms of infections, deaths, and economic costs.RESULTS: Integrating UV-C light in aircraft cabins, when applied with appropriate scientific understanding and engineering safeguards, has the potential to reduce in-flight disease transmission. This additional mitigation strategy can work synergistically with existing measures.DISCUSSION: The research and risk-vs.-benefit analysis present strong evidence for the safety and effectiveness of continuous UV-C disinfection in aircraft cabins. It suggests that UV-C light, maintained below exposure limits, can be a valuable addition to existing measures against disease transmission during flights.Belland K, Garcia D, DeJohn C, Allen GR, Mills WD, Glaudel SP. Safety and effectiveness assessment of ultraviolet-C disinfection in aircraft cabins. Aerosp Med Hum Perform. 2024; 95(3):147-157.
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12
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Berlanga FA, Gomez P, Esteban A, Liu L, Nielsen PV. Three dimensional analysis of the exhalation flow in the proximity of the mouth. Heliyon 2024; 10:e26283. [PMID: 38434078 PMCID: PMC10906307 DOI: 10.1016/j.heliyon.2024.e26283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 02/02/2024] [Accepted: 02/09/2024] [Indexed: 03/05/2024] Open
Abstract
The human exhalation flow is characterized in this work from the three-dimensional velocimetry results obtained by using the stereo particle image velocimetry (SPIV) measurement technique on the flow emitted from a realistic airway model. For this purpose, the transient exhalation flow through the mouth of a person performing two different breaths corresponding to two metabolic rates, standing relaxed (SR) and walking active (WA), is emulated and studied. To reproduce the flow realistically, a detailed three-dimensional model obtained from computed tomography measurements on real subjects is used. To cope with the variability of the experimental data, a subsequent analysis of the results is performed using the TR-PIV (time resolved particle image velocimetry) technique. Exhalation produces a transient jet that becomes a puff when flow emission ends. Three-dimensional vector fields of the jet velocity are obtained in five equally spaced transverse planes up to a distance of Image 1 from the mouth at equally spaced time instants Image 2 which will be referred to as phases (φ), from the beginning to the end of exhalation. The time evolution during exhalation of the jet area of influence, the velocity field and the jet air entrainment have been characterized for each of the jet cross sections. The importance of the use of realistic airway models for the study of this type of flow and the influence of the metabolic rate on its development are also analyzed. The results obtained contribute to the characterization of the human exhalation as a pathway of the transmission of pathogens such as SARS-CoV-2 virus.
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Affiliation(s)
- F A Berlanga
- Dept. de Mecánica, ETSII, Universidad Nacional de Educación a Distancia (UNED), E-28040, Madrid, Spain
| | - P Gomez
- Dept. de Mecánica, ETSII, Universidad Nacional de Educación a Distancia (UNED), E-28040, Madrid, Spain
| | - A Esteban
- Dept. de Mecánica, ETSII, Universidad Nacional de Educación a Distancia (UNED), E-28040, Madrid, Spain
| | - L Liu
- Dept. of Building Science and Technology, School of Architecture, Tsinghua University, Haidian District, Beijing, China
| | - P V Nielsen
- Dept. of the Built Environment, Aalborg Universitet, Thomas Manns Vej 23 9220 Aalborg Øst, Denmark
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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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14
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Andrup L, Krogfelt KA, Stephansen L, Hansen KS, Graversen BK, Wolkoff P, Madsen AM. Reduction of acute respiratory infections in day-care by non-pharmaceutical interventions: a narrative review. Front Public Health 2024; 12:1332078. [PMID: 38420031 PMCID: PMC10899481 DOI: 10.3389/fpubh.2024.1332078] [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: 11/02/2023] [Accepted: 02/02/2024] [Indexed: 03/02/2024] Open
Abstract
Objective Children who start in day-care have 2-4 times as many respiratory infections compared to children who are cared for at home, and day-care staff are among the employees with the highest absenteeism. The extensive new knowledge that has been generated in the COVID-19 era should be used in the prevention measures we prioritize. The purpose of this narrative review is to answer the questions: Which respiratory viruses are the most significant in day-care centers and similar indoor environments? What do we know about the transmission route of these viruses? What evidence is there for the effectiveness of different non-pharmaceutical prevention measures? Design Literature searches with different terms related to respiratory infections in humans, mitigation strategies, viral transmission mechanisms, and with special focus on day-care, kindergarten or child nurseries, were conducted in PubMed database and Web of Science. Searches with each of the main viruses in combination with transmission, infectivity, and infectious spread were conducted separately supplemented through the references of articles that were retrieved. Results Five viruses were found to be responsible for ≈95% of respiratory infections: rhinovirus, (RV), influenza virus (IV), respiratory syncytial virus (RSV), coronavirus (CoV), and adenovirus (AdV). Novel research, emerged during the COVID-19 pandemic, suggests that most respiratory viruses are primarily transmitted in an airborne manner carried by aerosols (microdroplets). Conclusion Since airborne transmission is dominant for the most common respiratory viruses, the most important preventive measures consist of better indoor air quality that reduces viral concentrations and viability by appropriate ventilation strategies. Furthermore, control of the relative humidity and temperature, which ensures optimal respiratory functionality and, together with low resident density (or mask use) and increased time outdoors, can reduce the occurrence of respiratory infections.
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Affiliation(s)
- Lars Andrup
- The National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Karen A Krogfelt
- Department of Science and Environment, Molecular and Medical Biology, PandemiX Center, Roskilde University, Roskilde, Denmark
| | - Lene Stephansen
- Gladsaxe Municipality, Social and Health Department, Gladsaxe, Denmark
| | | | | | - Peder Wolkoff
- The National Research Centre for the Working Environment, Copenhagen, Denmark
| | - Anne Mette Madsen
- The National Research Centre for the Working Environment, Copenhagen, Denmark
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15
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He J, Li J, Chen B, Yang W, Yu X, Zhang F, Li Y, Shu H, Zhu X. Study of aerosol dispersion and control in dental practice. Clin Oral Investig 2024; 28:120. [PMID: 38280059 DOI: 10.1007/s00784-024-05524-6] [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: 10/23/2023] [Accepted: 01/19/2024] [Indexed: 01/29/2024]
Abstract
OBJECTIVES In this study, we investigated the dispersion patterns of aerosols and droplets in dental clinics and developed a suction device to evaluate its effectiveness in reducing aerosols during dental procedures. MATERIALS AND METHODS Firstly, the continuous images of oral aerosols and droplets were photographed with a high-speed camera, and the trajectories of these particles were recognized and processed by Image J to determine key parameters affecting particle dispersion: diffusion velocity, distance, and angle. Secondly, based on the parameter data, the flow field of aerosol particles around the oral cavity was simulated using computational fluid dynamics (CFD), and the flow field under adsorption conditions was simulated to demonstrate the aerodynamic characteristics and capture efficiencies of the single-channel and three-channel adsorption ports at different pressures. Finally, according to the simulated data, a three-channel suction device was developed, and the capture efficiency of the device was tested by the fluorescein tracer method. RESULTS The dispersion experimental data showed that aerosol particles' maximum diffusion velocity, distance, and angle were 6.2 m/s, 0.55 m, and 130°, respectively. The simulated aerosol flow-field distribution was consistent with the aerosol dispersion patterns. The adsorption simulation results showed that the outlet flow rate of single-channel adsorption was 184.5 L/s at - 350 Pa, and the aerosol capture efficiency could reach 79.4%. At - 350 Pa and - 150 Pa, the outlet flow rate of three-channel adsorption was 228.9 L/s, and the capture efficiency was 99.23%. The adsorption experimental data showed that the capture efficiency of three-channel suction device was 97.71%. CONCLUSIONS A three-channel suction device was designed by simulations and experiments, which can capture most aerosols in the dental clinic and prevent them from spreading. CLINICAL RELEVANCE Using three-channel suction devices during oral treatment effectively reduces the spread of oral aerosols, which is essential to prevent the spread of epidemics and ensure the health and safety of patients and dental staff.
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Affiliation(s)
- Junjie He
- School of Mechanical Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Jiachun Li
- School of Mechanical Engineering, Guizhou University, Guiyang, Guizhou, China.
| | - Bo Chen
- School of Mechanical Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Wei Yang
- School of Medicine, Guizhou University, Guiyang, Guizhou, China
| | - Xiaoyan Yu
- Guiyang Stomatological Hospital, Guiyang, Guizhou, China
| | - Fan Zhang
- School of Mechanical Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Yugang Li
- School of Mechanical Engineering, Guizhou University, Guiyang, Guizhou, China
| | - Haiyin Shu
- School of Medicine, Guizhou University, Guiyang, Guizhou, China
| | - Xiankun Zhu
- Guiyang Stomatological Hospital, Guiyang, Guizhou, China
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16
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Coleman H, Saylor Perez J, Schwartz DK, Kaar J, Garcea RL, Randolph TW. Effect of mechanical stresses on viral capsid disruption during droplet formation and drying. Colloids Surf B Biointerfaces 2024; 233:113661. [PMID: 38006709 PMCID: PMC10986848 DOI: 10.1016/j.colsurfb.2023.113661] [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: 05/09/2023] [Revised: 11/10/2023] [Accepted: 11/19/2023] [Indexed: 11/27/2023]
Abstract
Identification of the mechanisms by which viruses lose activity during droplet formation and drying is of great importance to understanding the spread of infectious diseases by virus-containing respiratory droplets and to developing thermally stable spray dried live or inactivated viral vaccines. In this study, we exposed suspensions of baculovirus, an enveloped virus, to isolated mechanical stresses similar to those experienced during respiratory droplet formation and spray drying: fluid shear forces, osmotic pressure forces, and surface tension forces at interfaces. DNA released from mechanically stressed virions was measured by SYBR Gold staining to quantify viral capsid disruption. Theoretical estimates of the force exerted by fluid shear, osmotic pressures and interfacial tension forces during respiratory droplet formation and spray drying suggest that osmotic and interfacial stresses have greater potential to mechanically destabilize viral capsids than forces associated with shear stresses. Experimental results confirmed that rapid changes in osmotic pressure, such as those associated with drying of virus-containing droplets, caused significant viral capsid disruption, whereas the effect of fluid shear forces was negligible. Surface tension forces were sufficient to provoke DNA release from virions adsorbed at air-water interfaces, but the extent of this disruption was limited by the time required for virions to diffuse to interfaces. These results demonstrate the effect of isolated mechanical stresses on virus particles during droplet formation and drying.
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Affiliation(s)
- Holly Coleman
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80303, United States
| | - J Saylor Perez
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80303, United States
| | - Daniel K Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80303, United States
| | - Joel Kaar
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80303, United States
| | - Robert L Garcea
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, CO 80303, United States
| | - Theodore W Randolph
- Department of Chemical and Biological Engineering, University of Colorado Boulder, CO 80303, United States.
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17
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Lordly K, Kober L, Jadidi M, Antoun S, Dworkin SB, Karataş AE. Understanding lifetime and dispersion of cough-emitted droplets in air. INDOOR + BUILT ENVIRONMENT : THE JOURNAL OF THE INTERNATIONAL SOCIETY OF THE BUILT ENVIRONMENT 2023; 32:1929-1948. [PMID: 38023440 PMCID: PMC10657780 DOI: 10.1177/1420326x221098753] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 04/19/2022] [Indexed: 12/01/2023]
Abstract
To understand the exact transmission routes of SARS-CoV-2 and to explore effects of time, space and indoor environment on the dynamics of droplets and aerosols, rigorous testing and observation must be conducted. In the current work, the spatial and temporal dispersions of aerosol droplets from a simulated cough were comprehensively examined over a long duration (70 min). An artificial cough generator was constructed to generate reliably repeatable respiratory ejecta. The measurements were performed at different locations in front (along the axial direction and off-axis) and behind the source in a sealed experimental enclosure. Aerosols of 0.3-10 µm (around 20% of the maximum nuclei count) were shown to persist for a very long time in a still environment, and this has a substantial implication for airborne disease transmission. The experiments demonstrated that a ventilation system could reduce the total aerosol volume and the droplet lifetime significantly. To explain the experimental observations in more detail and to understand the droplet in-air behaviour at various ambient temperatures and relative humidity, numerical simulations were performed using the Eulerian-Lagrangian approach. The simulations show that many of the small droplets remain suspended in the air over time instead of falling to the ground.
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Affiliation(s)
- Kai Lordly
- Department of Aerospace Engineering, Toronto Metropolitan University, Toronto, ON, Canada
| | - Leya Kober
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada
| | - Mehdi Jadidi
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada
| | - Sylvie Antoun
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada
| | - Seth B Dworkin
- Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada
| | - Ahmet E Karataş
- Department of Aerospace Engineering, Toronto Metropolitan University, Toronto, ON, Canada
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18
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Li YG, Li JC, Yu XY, Hu J, Li Z, Cao JC. Quantitative assessment of aerosol contamination generated during tooth grinding with a speed-increasing handpiece. J Dent 2023; 139:104631. [PMID: 37495202 DOI: 10.1016/j.jdent.2023.104631] [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: 03/20/2023] [Revised: 06/29/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023] Open
Abstract
OBJECTIVES Tooth grinding produces a significant amount of aerosol particles. The aim of this study was to quantitatively assess particle contamination produced from tooth grinding with a speed-increasing handpiece across a real-world clinical setting. METHODS All molar crowns were pretreated into cylinders with a uniform size. A novel computer-assisted numerical control system was used to parametrically study the bur speed: from 20,000 (20 K) to 200 K rpm at 20 K rpm intervals. 5-minute tooth grinding was performed in triplicate at each speed setting. Three online real-time particle counters (ORPC; TR-8301, TongrenCo.) were placed at 3 positions (0.5, 1, and 1.5 m) to evaluate particle production. All experimental instruments were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Scheirer-Ray-Hare and Kruskal-Wallis/ Dunn-Bonferroni tests, p < 0.05). RESULTS The concentration level of aerosol particles production during the grinding experiment was elevated above the control group for all conditions, and increased with bur speed at any location (the maximum peak, reaching 5.59 × 107 particles/m3, at 200 K and 1 m), with differences between conditions. The effect of speed on the increment of particles across different channels compared to the control group was statistically significant among locations (p < 0.001). CONCLUSIONS Statistically significant particle contamination was produced using a speed-increasing handpiece, but the contamination level for each experimental condition was reduced to baseline within 30 min, and most particles with a diameter greater than 1üm produced at low speeds (80 K or lower) tended to settle within 1 m. CLINICAL RELEVANCE Our study suggested that the use of a speed-increasing handpiece below 80 K and 30 min of fallow time may lead to an adequate reduction in the health effects of particle contamination.
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Affiliation(s)
- Yu-Gang Li
- School of Mechanical Engineering, Guizhou University, Guiyang, China; Guizhou Equipment Manufacturing Polytechnic, Guiyang, China
| | - Jia-Chun Li
- School of Mechanical Engineering, Guizhou University, Guiyang, China.
| | - Xiao-Yan Yu
- Guiyang Hospital of Stomatology, Guiyang, China
| | - Jie Hu
- School of Mechanical Engineering, Guizhou University, Guiyang, China
| | - Zhe Li
- School of Life Sciences, Guizhou Normal University, Guiyang, China
| | - Ji-Chao Cao
- College of Mechanical and Vehicle Engineering, Hunan University, Changsha, China
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19
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Agrawal A, Keerthipati S, Sreerama S, Singla D, Acharya S, Mehta D, Kumar S, Paiwal K. Effect of herbal mouthrinsein dental ultrasonic scalers among Indians. Bioinformation 2023; 19:1104-1110. [PMID: 38046514 PMCID: PMC10692984 DOI: 10.6026/973206300191104] [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: 11/01/2023] [Revised: 11/30/2023] [Accepted: 11/30/2023] [Indexed: 12/05/2023] Open
Abstract
The use of herbal mouthrinse is gaining momentum in recent years. Therefore, it is of interest to evaluate the effect of 2 herbal mouthrinse (curcumin, cinnamon) in comparison with2 conventional mouthrinse (povidone iodine, chlorhexidine) when used as coolant in dental ultrasonic scalers. Hence, 200 participants were included in this study. Analysis of gingival index, periodontal index at baseline and one month follow up was completed. The inhibitory effects of both conventional and herbal mouth rinse in gingival health are similar. However, cinnamon and curcumin owing to its minimal adverse effects and low cost is useful as an alternative to chlorhexidine for reducing bacterial load in dental aerosols produced due to ultrasonic scalers.
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Affiliation(s)
- Ankita Agrawal
- Department of Conservative and Endodontics, Buddha Institute of Dental Sciences and Hospital, Patna, Bihar, India
| | - Shilpa Keerthipati
- Department of Orthodontics, Gitam Dental College and Hospital, Visakhapatnam, India
| | | | - Deepika Singla
- Department of Conservative Dentistry & Endodontics, Desh Bhagat Dental College & Hospital, Mandi Gobindgarh, Punjab, India
| | - Sonu Acharya
- Department of Pediatric and Preventive Dentistry, Institute of Dental Sciences, Siksha Anusandhan (Deemed to be) University, Bhubaneswar, India
| | - DhavalNiranjan Mehta
- Department of Oral Medicine and Radiology, Narsinbhai Patel Dental College and Hospital, Sankalchand PatelUniversity, Visnagar, Gujarat, India
| | - Santosh Kumar
- Department of Periodontology, Karnavati School of Dentistry, Karnavati University, Gandhinagar, Gujarat, India
| | - Kapil Paiwal
- Department of Oral & Maxillofacial Pathology, Daswani Dental College & Research Center, Kota, India
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20
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Ratliff KM, Oudejans L, Archer J, Calfee W, Gilberry JU, Hook DA, Schoppman WE, Yaga RW, Brooks L, Ryan S. Impact of test methodology on the efficacy of triethylene glycol (Grignard Pure) against bacteriophage MS2. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2023; 57:1178-1185. [PMID: 38268721 PMCID: PMC10805242 DOI: 10.1080/02786826.2023.2262004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 09/15/2023] [Indexed: 01/26/2024]
Abstract
The COVID-19 pandemic has raised interest in using chemical air treatments as part of a strategy to reduce the risk of disease transmission, but more information is needed to characterize their efficacy at scales translatable to applied settings and to develop standardized test methods for characterizing the performance of these products. Grignard Pure, a triethylene glycol (TEG) active ingredient air treatment, was evaluated using two different test protocols in a large bioaerosol test chamber and observed to inactivate bacteriophage MS2 in air (up to 99.9% at 90 min) and on surfaces (up to 99% at 90 min) at a concentration of approximately 1.2 - 1.5 mg/m3. Introducing bioaerosol into a TEG-charged chamber led to overall greater reductions compared to when TEG was introduced into a bioaerosol-charged chamber, although the differences in efficacy against airborne MS2 were only significant in the first 15 min. Time-matched control conditions (no TEG present) and replicate tests for each condition were essential for characterizing treatment efficacy. These findings suggest that chemical air treatments could be effective in reducing the air and surface concentrations of infectious pathogens in occupied spaces, although standard methods are needed for evaluating their efficacy and comparing results across studies. The potential health impacts of chronic exposure to chemicals should also be considered, but those were not evaluated here.
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Affiliation(s)
- Katherine M. Ratliff
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Lukas Oudejans
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - John Archer
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Worth Calfee
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | | | - David Adam Hook
- Jacobs Technology Inc, Research Triangle Park, North Carolina, USA
| | | | - Robert W. Yaga
- Jacobs Technology Inc, Research Triangle Park, North Carolina, USA
| | - Lance Brooks
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Shawn Ryan
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
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21
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Hanna F, Alameddine I, Zaraket H, Alkalamouni H, El-Fadel M. Airborne influenza virus shedding by patients in health care units: Removal mechanisms affecting virus transmission. PLoS One 2023; 18:e0290124. [PMID: 37878553 PMCID: PMC10599543 DOI: 10.1371/journal.pone.0290124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/01/2023] [Indexed: 10/27/2023] Open
Abstract
In this study, we characterize the distribution of airborne viruses (influenza A/B) in hospital rooms of patients with confirmed infections. Concurrently, we monitored fine particulate matter (PM2.5 & PM10) and several physical parameters including the room air exchange rate, temperature, and relative humidity to identify corresponding correlations with virus transport and removal determinants. The results continue to raise concerns about indoor air quality (IAQ) in healthcare facilities and the potential exposure of patients, staff and visitors to aerosolized viruses as well as elevated indoor PM levels caused by outdoor sources and/or re-suspension of settled particles by indoor activities. The influenza A virus was detected in 42% of 33 monitored rooms, with viruses detectible up to 1.5 m away from the infected patient. Active coughing was a statistically significant variable that contributed to a higher positive rate of virus detection in the collected air samples. Viral load across patient rooms ranged between 222 and 5,760 copies/m3, with a mean of 820 copies/m3. Measured PM2.5 and PM10 levels exceeded IAQ daily exposure guidelines in most monitored rooms. Statistical and numerical analyses showed that dispersion was the dominant viral removal pathway followed by settling. Changes in the relative humidity and the room's temperature were had a significant impact on the viral load removal. In closure, we highlight the need for an integrated approach to control determinants of IAQ in patients' rooms.
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Affiliation(s)
- Francis Hanna
- Department of Civil Infrastructure & Environmental Engineering, College of Engineering, Khalifa University, United Arab Emirates
- Department of Civil & Environmental Engineering, Faculty of Engineering & Architecture, American University of Beirut, Lebanon
| | - Ibrahim Alameddine
- Department of Civil & Environmental Engineering, Faculty of Engineering & Architecture, American University of Beirut, Lebanon
| | - Hassan Zaraket
- Department of Experimental Pathology, Immunology & Microbiology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Habib Alkalamouni
- Department of Experimental Pathology, Immunology & Microbiology, Faculty of Medicine, American University of Beirut, Lebanon
| | - Mutasem El-Fadel
- Department of Civil Infrastructure & Environmental Engineering, College of Engineering, Khalifa University, United Arab Emirates
- Department of Civil & Environmental Engineering, Faculty of Engineering & Architecture, American University of Beirut, Lebanon
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22
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Naik R, Avula S, Palleti SK, Gummadi J, Ramachandran R, Chandramohan D, Dhillon G, Gill AS, Paiwal K, Shaik B, Balachandran M, Patel B, Gurugubelli S, Mariswamy Arun Kumar AK, Nanjundappa A, Bellamkonda M, Rathi K, Sakhamuri PL, Nassar M, Bali A. From Emergence to Endemicity: A Comprehensive Review of COVID-19. Cureus 2023; 15:e48046. [PMID: 37916248 PMCID: PMC10617653 DOI: 10.7759/cureus.48046] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2023] [Indexed: 11/03/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later renamed coronavirus disease 2019 (COVID-19), was first identified in Wuhan, China, in early December 2019. Initially, the China office of the World Health Organization was informed of numerous cases of pneumonia of unidentified etiology in Wuhan, Hubei Province at the end of 2019. This would subsequently result in a global pandemic with millions of confirmed cases of COVID-19 and millions of deaths reported to the WHO. We have analyzed most of the data published since the beginning of the pandemic to compile this comprehensive review of SARS-CoV-2. We looked at the core ideas, such as the etiology, epidemiology, pathogenesis, clinical symptoms, diagnostics, histopathologic findings, consequences, therapies, and vaccines. We have also included the long-term effects and myths associated with some therapeutics of COVID-19. This study presents a comprehensive assessment of the SARS-CoV-2 virology, vaccines, medicines, and significant variants identified during the course of the pandemic. Our review article is intended to provide medical practitioners with a better understanding of the fundamental sciences, clinical treatment, and prevention of COVID-19. As of May 2023, this paper contains the most recent data made accessible.
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Affiliation(s)
- Roopa Naik
- Medicine, Geisinger Commonwealth School of Medicine, Scranton, USA
- Internal Medicine/Hospital Medicine, Geisinger Health System, Wilkes Barre, USA
| | - Sreekant Avula
- Diabetes, Endocrinology, and Metabolism, University of Minnesota, Minneapolis, USA
| | - Sujith K Palleti
- Nephrology, Louisiana State University Health Sciences Center, Shreveport, USA
| | - Jyotsna Gummadi
- Internal Medicine, MedStar Franklin Square Medical Center, Baltimore, USA
| | | | | | - Gagandeep Dhillon
- Physician Executive MBA, University of Tennessee, Knoxville, USA
- Internal Medicine, University of Maryland Baltimore Washington Medical Center, Glen Burnie, USA
| | | | - Kapil Paiwal
- Oral & Maxillofacial Pathology, Daswani Dental College & Research Center, Kota, IND
| | - Bushra Shaik
- Internal Medicine, Onslow Memorial Hospital, Jacksonville, USA
| | | | - Bhumika Patel
- Oral Medicine and Radiology, Howard University, Washington, D.C., USA
| | | | | | | | - Mahita Bellamkonda
- Hospital Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Kanika Rathi
- Internal Medicine, University of Florida, Gainesville, USA
| | | | - Mahmoud Nassar
- Endocrinology, Diabetes, and Metabolism, Jacobs School of Medicine and Biomedical Sciences, Buffalo, USA
| | - Atul Bali
- Internal Medicine/Nephrology, Geisinger Medical Center, Danville, USA
- Internal Medicine/Nephrology, Geisinger Health System, Wilkes-Barre, USA
- Medicine, Geisinger Commonwealth School of Medicine, Scranton, USA
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23
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Humphreys H, Vos M, Presterl E, Hell M. Greater attention to flexible hospital designs and ventilated clinical facilities are a pre-requisite for coping with the next airborne pandemic. Clin Microbiol Infect 2023; 29:1229-1231. [PMID: 37182640 DOI: 10.1016/j.cmi.2023.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/21/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023]
Affiliation(s)
- Hilary Humphreys
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland University of Medicine and Health Sciences, Dublin, Ireland; ESCMID Study Group for Nosocomial Infections (ESGNI), Switzerland.
| | - Margreet Vos
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Centre, Rotterdam, the Netherlands; ESCMID Study Group for Nosocomial Infections (ESGNI), Switzerland
| | - Elisabeth Presterl
- Department of Hospital Epidemiology and Infection Control, Vienna General Hospital, Medical University of Vienna, Vienna, Austria; ESCMID Study Group for Nosocomial Infections (ESGNI), Switzerland
| | - Markus Hell
- Department of Clinical Microbiology and Hygiene, Medilab, Academic Teaching Laboratories of the Paracelsus Medical University, Salzburg, Austria; ESCMID Study Group for Nosocomial Infections (ESGNI), Switzerland
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24
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Acharya A, Surbaugh K, Thurman M, Wickramaratne C, Myers P, Mittal R, Pandey K, Klug E, Stein SJ, Ravnholdt AR, Herrera VL, Rivera DN, Williams P, Santarpia JL, Kaushik A, Dhau JS, Byrareddy SN. Efficient trapping and destruction of SARS-CoV-2 using PECO-assisted Molekule air purifiers in the laboratory and real-world settings. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 264:115487. [PMID: 37729804 DOI: 10.1016/j.ecoenv.2023.115487] [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: 01/28/2023] [Revised: 09/04/2023] [Accepted: 09/13/2023] [Indexed: 09/22/2023]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted human-to-human via aerosols and air-borne droplets. Therefore, capturing and destroying viruses from indoor premises are essential to reduce the probability of human exposure and virus transmission. While the heating, ventilation, and air conditioning (HVAC) systems help in reducing the indoor viral load, a targeted approach is required to effectively remove SARS-CoV-2 from indoor air to address human exposure concerns. The present study demonstrates efficient trapping and destruction of SARS-CoV-2 via nano-enabled filter technology using the UV-A-stimulated photoelectrochemical oxidation (PECO) process. Aerosols containing SARS-CoV-2 were generated by nebulization inside an air-controlled test chamber where an air purifier (Air Mini+) was placed. The study demonstrated the efficient removal of SARS-CoV-2 (99.98 %) from the test chamber in less than two minutes and PECO-assisted destruction (over 99%) on the filtration media in 1 h. Furthermore, in a real-world scenario, the Molekule Air-Pro air purifier removed SARS-CoV-2 (a negative RT-qPCR result post-running the filter device) from the circulating air in a COVID-19 testing facility. Overall, the ability of two FDA-approved class II medical devices, Molekule Air-Mini+ and Air-Pro air purifiers, to remove and destroy SARS-CoV-2 in indoor settings was successfully demonstrated. The study indicates that as the "tripledemic" of COVID-19, influenza, and respiratory syncytial virus (RSV) overwhelm the healthcare facilities in the USA, the use of a portable air filtration device will help contain the spread of the viruses in close door facilities, such as in schools and daycare facilities.
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Affiliation(s)
- Arpan Acharya
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68131, USA
| | - Kerri Surbaugh
- Research and Development, Molekule, Inc., 3802 Spectrum Blvd, Tampa, FL 33612, USA
| | - Michellie Thurman
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68131, USA
| | | | - Philip Myers
- Research and Development, Molekule, Inc., 3802 Spectrum Blvd, Tampa, FL 33612, USA
| | - Rajat Mittal
- Clean Energy Research Center, University of South Florida, Tampa, FL 33612, USA
| | - Kabita Pandey
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68131, USA
| | - Elizabeth Klug
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68131, USA
| | - Sarah J Stein
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ashley R Ravnholdt
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Vicki L Herrera
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Danielle N Rivera
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Paul Williams
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Joshua L Santarpia
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Ajeet Kaushik
- Department of Environmental Engineering, Florida Polytechnic University, 4700 Research Way, Lakeland, FL 33805, USA; Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68131, USA
| | - Jaspreet S Dhau
- Research and Development, Molekule, Inc., 3802 Spectrum Blvd, Tampa, FL 33612, USA.
| | - Siddappa N Byrareddy
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68131, USA; Department of Environmental Engineering, Florida Polytechnic University, 4700 Research Way, Lakeland, FL 33805, USA; Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68131, USA; Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68131, USA.
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25
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Kusama T, Takeuchi K, Tamada Y, Kiuchi S, Osaka K, Tabuchi T. Compliance Trajectory and Patterns of COVID-19 Preventive Measures, Japan, 2020-2022. Emerg Infect Dis 2023; 29:1747-1756. [PMID: 37487165 PMCID: PMC10461672 DOI: 10.3201/eid2909.221754] [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: 07/26/2023] Open
Abstract
COVID-19 remains a global health threat. Compliance with nonpharmaceutical interventions is essential because of limited effectiveness of COVID-19 vaccines, emergence of highly contagious variants, and declining COVID-19 antibody titers over time. We evaluated compliance with 14 nonpharmaceutical intervention-related COVID-19 preventive behaviors, including mask wearing, ventilation, and surface sanitation, in a longitudinal study in Japan using 4 waves of Internet survey data obtained during 2020-2022. Compliance with most preventive behaviors increased or remained stable during the 2-year period, except for surface sanitation and going out behaviors; compliance with ventilation behavior substantially decreased in winter. Compliance patterns identified from latent class analysis showed that the number of persons in the low compliance class decreased, whereas those in the personal hygiene class increased. Our findings reflect the relaxation of mobility restriction policy in Japan, where the COVID-19 pandemic continues. Policymakers should consider behavioral changes caused by new policies to improve COVID-19 prevention strategies.
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26
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Upadrasta A, Daniels S, Thompson TP, Gilmore B, Humphreys H. In situ generation of cold atmospheric plasma-activated mist and its biocidal activity against surrogate viruses for COVID-19. J Appl Microbiol 2023; 134:lxad181. [PMID: 37580171 DOI: 10.1093/jambio/lxad181] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/17/2023] [Accepted: 08/12/2023] [Indexed: 08/16/2023]
Abstract
AIMS To provide an alternative to ultra violet light and vapourized hydrogen peroxide to enhance decontamination of surfaces as part of the response to the COVID-19 pandemic. METHODS AND RESULTS We developed an indirect method for in situ delivery of cold plasma and evaluated the anti-viral activity of plasma-activated mist (PAM) using bacteriophages phi6, MS2, and phiX174, surrogates for SARS-CoV-2. Exposure to ambient air atmospheric pressure derived PAM caused a 1.71 log10 PFU ml-1 reduction in phi6 titer within 5 min and a 7.4 log10 PFU ml-1 reduction after 10 min when the the PAM source was at 5 and 10 cm. With MS2 and phiX174, a 3.1 and 1.26 log10 PFU ml-1 reduction was achieved, respectively, after 30 min. The rate of killing was increased with longer exposure times but decreased when the PAM source was further away. Trace amounts of reactive species, hydrogen peroxide and nitrite were produced in the PAM, and the anti-viral activity was probably attributable to these and their secondary reactive species. CONCLUSIONS PAM exhibits virucidal activity against surrogate viruses for COVID-19, which is time and distance from the plasma source dependent.
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Affiliation(s)
- Aditya Upadrasta
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D09 YD60, Ireland
| | - Stephen Daniels
- School of Electronic Engineering, Dublin City University, Dublin, D09 V209, Ireland
| | | | - Brendan Gilmore
- School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland
| | - Hilary Humphreys
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, D09 YD60, Ireland
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27
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Lu Y, Okpani AI, McLeod CB, Grant JM, Yassi A. Masking strategy to protect healthcare workers from COVID-19: An umbrella meta-analysis. Infect Dis Health 2023; 28:226-238. [PMID: 36863978 PMCID: PMC9932689 DOI: 10.1016/j.idh.2023.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 02/18/2023]
Abstract
BACKGROUND The burden of severe disease and death due to SARS-CoV-2 (COVID-19) pandemic among healthcare workers (HCWs) worldwide has been substantial. Masking is a critical control measure to effectively protect HCWs from respiratory infectious diseases, yet for COVID-19, masking policies have varied considerably across jurisdictions. As Omicron variants began to be predominant, the value of switching from a permissive approach based on a point of care risk assessment (PCRA) to a rigid masking policy needed to be assessed. METHODS A literature search was conducted in MEDLINE (Ovid platform), Cochrane Library, Web of Science (Ovid platform), and PubMed to June 2022. An umbrella review of meta-analyses investigating protective effects of N95 or equivalent respirators and medical masks was then conducted. Data extraction, evidence synthesis and appraisal were duplicated. RESULTS While the results of Forest plots slightly favoured N95 or equivalent respirators over medical masks, eight of the ten meta-analyses included in the umbrella review were appraised as having very low certainty and the other two as having low certainty. CONCLUSION The literature appraisal, in conjunction with risk assessment of the Omicron variant, side-effects and acceptability to HCWs, along with the precautionary principle, supported maintaining the current policy guided by PCRA rather than adopting a more rigid approach. Well-designed prospective multi-centre trials, with systematic attention to the diversity of healthcare settings, risk levels and equity concerns are needed to support future masking policies.
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Affiliation(s)
- Yijun Lu
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia (BC), V6T 1Z3, Canada; Workplace Health & Safety, Interior Health, Kelowna, BC, V1Y OC5, Canada.
| | - Arnold Ikedichi Okpani
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia (BC), V6T 1Z3, Canada
| | - Christopher B McLeod
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia (BC), V6T 1Z3, Canada
| | - Jennifer M Grant
- Divisons of Infectious Diseases and Medical Microbiology University of British Columbia, Vancouver, BC, V6T 1Z3, Canada; Divisions of Medical Microbiology and Infectious Diseases Vancouver Coastal Health, BC, Canada
| | - Annalee Yassi
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia (BC), V6T 1Z3, Canada; Medical Practitioners Occupational Safety and Health, Vancouver Coastal Health, BC, Canada
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28
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Zheng M, Fan Y, Li X, Lester D, Chen X, Li Y, Cole I. Aerosol exchange between pressure-equilibrium rooms induced by door motion and human movement. BUILDING AND ENVIRONMENT 2023; 241:110486. [PMID: 37287526 PMCID: PMC10232724 DOI: 10.1016/j.buildenv.2023.110486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/11/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023]
Abstract
It is now widely recognised that aerosol transport is major vector for transmission of diseases such as COVID-19, and quantification of aerosol transport in the built environment is critical to risk analysis and management. Understanding the effects of door motion and human movement on the dispersion of virus-laden aerosols under pressure-equilibrium conditions is of great significance to the evaluation of infection risks and development of mitigation strategies. This study uses novel numerical simulation techniques to quantify the impact of these motions upon aerosol transport and provides valuable insights into the wake dynamics of swinging doors and human movement. The results show that the wake flow of an opening swinging door delays aerosol escape, while that of a person walking out entrains aerosol out of the room. Aerosol escape caused by door motion mainly happens during the closing sequence which pushes the aerosols out. Parametric studies show that while an increased door swinging speed or human movement speed can enhance air exchange across the doorway, the cumulative aerosol exchange across the doorway is not clearly affected by the speeds.
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Affiliation(s)
- Minfeng Zheng
- Fujian Eco-materials Engineering Research Center, Fujian University of Technology, Fuzhou, 350118, PR China
- College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, 350118, PR China
| | - Yaming Fan
- Fujian Eco-materials Engineering Research Center, Fujian University of Technology, Fuzhou, 350118, PR China
- College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, 350118, PR China
| | - Xiangdong Li
- School of Engineering, RMIT University, Melbourne, VIC, 3000, Australia
| | - Daniel Lester
- School of Engineering, RMIT University, Melbourne, VIC, 3000, Australia
| | - Xin Chen
- College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, PR China
| | - Yiyu Li
- Fujian Eco-materials Engineering Research Center, Fujian University of Technology, Fuzhou, 350118, PR China
- College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou, 350118, PR China
| | - Ivan Cole
- School of Engineering, RMIT University, Melbourne, VIC, 3000, Australia
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29
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Palmowski J, Kohnhorst S, Bauer P, Puta C, Haunhorst S, Gebhardt K, Reichel T, Keller C, Huber M, Raifer H, Krüger K. T-cell-derived TNF-α and a cluster of immunological parameters from plasma allow a separation between SARS-CoV-2 convalescent versus vaccinated elite athletes. Front Physiol 2023; 14:1203983. [PMID: 37427401 PMCID: PMC10324374 DOI: 10.3389/fphys.2023.1203983] [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: 04/11/2023] [Accepted: 06/09/2023] [Indexed: 07/11/2023] Open
Abstract
Guidelines for medical clearing after SARS-CoV-2 infection in elite athletes do not include T-cell immunity aspects despite its relevance in the course of COVID-19 disease. Therefore, we aimed to analyze T-cell-related cytokines before and after in-vitro activation of CD4+ T-cells. We sampled professional indoor sports athletes at medical clearing after SARS-CoV-2 infection obtaining clinical, fitness data, and serological data including CD4+ T-cell cytokines. All data were analyzed by principal component analysis and 2 × 2 repeated measures ANOVA. CD4+ T-cells were sampled for cell culture activation with anti-CD3/anti-CD28 tetramers. At medical clearing, CD4+ T-cells from convalescent athletes secreted increased levels of TNF-α 72 h after in-vitro activation compared to vaccinated athletes. IL-18 levels in plasma were elevated and a cluster of parameters differentiated convalescent from vaccinated athletes by 13 parameters at the timepoint of medical clearing. All clinical data indicate infection is resolved, while increased TNF-α may reflect altered proportions of peripheral T-cells as a hangover of infection.
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Affiliation(s)
- Jana Palmowski
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, Justus Liebig University Giessen, Giessen, Germany
| | - Sarah Kohnhorst
- Center for Tumor and Immunology, Institute for Systems Immunology, Marburg, Germany
| | - Pascal Bauer
- Department of Cardiology and Angiology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Christian Puta
- Department of Sports Medicine and Health Promotion, Friedrich Schiller University Jena, Jena, Germany
- Center for Sepsis Control and Care (CSCC), Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
- Center for Interdisciplinary Prevention of Diseases Related to Professional Activities, Jena, Germany
| | - Simon Haunhorst
- Department of Sports Medicine and Health Promotion, Friedrich Schiller University Jena, Jena, Germany
| | - Kristina Gebhardt
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, Justus Liebig University Giessen, Giessen, Germany
| | - Thomas Reichel
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, Justus Liebig University Giessen, Giessen, Germany
| | - Christian Keller
- Institute of Virology, Philipps University Marburg, Marburg, Germany
| | - Magdalena Huber
- Center for Tumor and Immunology, Institute for Systems Immunology, Marburg, Germany
| | - Hartmann Raifer
- Center for Tumor and Immunology, Institute for Systems Immunology, Marburg, Germany
| | - Karsten Krüger
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, Justus Liebig University Giessen, Giessen, Germany
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30
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Yang X, Liu R, Zhu J, Luo T, Zhan Y, Li C, Li Y, Yu H. Evaluating the microbial aerosol generated by dental instruments: addressing new challenges for oral healthcare in the hospital infection. BMC Oral Health 2023; 23:409. [PMID: 37344797 DOI: 10.1186/s12903-023-03109-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/06/2023] [Indexed: 06/23/2023] Open
Abstract
BACKGROUND Using a rotary instrument or ultrasonic instrument for tooth preparation is a basic operation in the dental clinic that can produce a significant number of droplets and aerosols. The dental droplet and aerosol can lead to the transfer of harmful germs. The goal of this study was to analyze the properties of microbiological aerosol created by droplets and aerosol generated by three common tooth-preparation instruments. METHODS Streptococcus mutans UA159 was used as the biological tracer to visualize the droplets and aerosols. The passive sampling method was used to map the three-dimensional spatial distribution and the six-stage Andersen microbial sampler (AMS) was used as the active sampling method to catch aerosol particles at a specific time. RESULTS The aerosol concentration is related to instruments, three-dimensional spatial distribution, and dissipation time. Most aerosols were generated by air turbines. More microorganisms are concentrated at the 1.5 m plane. The majority of the post dental procedure contamination was detected within the 0-10-min period and it decreased rapidly within 30 min. CONCLUSION This study is conducive to the proposal and improvement of relevant infection control measures in dental procedures and provides a basis for the assessment of measures, reducing the risk of nosocomial infection.
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Affiliation(s)
- Xin Yang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, No. 14, 3Rd Section of Ren Min Nan Rd, Chengdu, 610041, Sichuan Province, China
| | - Ruolan Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, No. 14, 3Rd Section of Ren Min Nan Rd, Chengdu, 610041, Sichuan Province, China
| | - Jiakang Zhu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, No. 14, 3Rd Section of Ren Min Nan Rd, Chengdu, 610041, Sichuan Province, China
| | - Tian Luo
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, No. 14, 3Rd Section of Ren Min Nan Rd, Chengdu, 610041, Sichuan Province, China
| | - Yu Zhan
- Department of Environmental Science and Engineering, Sichuan University, Chengdu, 610065, Sichuan, China
| | - Chunyuan Li
- Department of Environmental Science and Engineering, Sichuan University, Chengdu, 610065, Sichuan, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| | - Haiyang Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
- Department of Prosthodontics, West China Hospital of Stomatology, Sichuan University, No. 14, 3Rd Section of Ren Min Nan Rd, Chengdu, 610041, Sichuan Province, China.
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31
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González RI, Moya PS, Bringa EM, Bacigalupe G, Ramírez-Santana M, Kiwi M. Model based on COVID-19 evidence to predict and improve pandemic control. PLoS One 2023; 18:e0286747. [PMID: 37319168 PMCID: PMC10270358 DOI: 10.1371/journal.pone.0286747] [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: 08/17/2022] [Accepted: 05/22/2023] [Indexed: 06/17/2023] Open
Abstract
Based on the extensive data accumulated during the COVID-19 pandemic, we put forward simple to implement indicators, that should alert authorities and provide early warnings of an impending sanitary crisis. In fact, Testing, Tracing, and Isolation (TTI) in conjunction with disciplined social distancing and vaccination were expected to achieve negligible COVID-19 contagion levels; however, they proved to be insufficient, and their implementation has led to controversial social, economic and ethical challenges. This paper focuses on the development of simple indicators, based on the experience gained by COVID-19 data, which provide a sort of yellow light as to when an epidemic might expand, despite some short term decrements. We show that if case growth is not stopped during the 7 to 14 days after onset, the growth risk increases considerably, and warrants immediate attention. Our model examines not only the COVID contagion propagation speed, but also how it accelerates as a function of time. We identify trends that emerge under the various policies that were applied, as well as their differences among countries. The data for all countries was obtained from ourworldindata.org. Our main conclusion is that if the reduction spread is lost during one, or at most two weeks, urgent measures should be implemented to avoid scenarios in which the epidemic gains strong impetus.
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Affiliation(s)
- Rafael I. González
- Centro de Nanotecnología Aplicada, Universidad Mayor, Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Santiago, Chile
| | - Pablo S. Moya
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Eduardo M. Bringa
- Centro de Nanotecnología Aplicada, Universidad Mayor, Santiago, Chile
- CONICET, Facultad de Ingeniería, Universidad de Mendoza, Mendoza, Argentina
| | - Gonzalo Bacigalupe
- School of Education and Human Development, University of Massachusetts Boston, Boston, MA, United States of America
- CreaSur, Universidad de Concepción, Concepción, Chile
| | - Muriel Ramírez-Santana
- Departamento de Salud Pública, Facultad de Medicina, Universidad Católica del Norte, Coquimbo, Chile
| | - Miguel Kiwi
- Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Santiago, Chile
- Departamento de Física, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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32
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Cheong KL, Chen S, Teng B, Veeraperumal S, Zhong S, Tan K. Oligosaccharides as Potential Regulators of Gut Microbiota and Intestinal Health in Post-COVID-19 Management. Pharmaceuticals (Basel) 2023; 16:860. [PMID: 37375807 DOI: 10.3390/ph16060860] [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: 04/30/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
The COVID-19 pandemic has had a profound impact worldwide, resulting in long-term health effects for many individuals. Recently, as more and more people recover from COVID-19, there is an increasing need to identify effective management strategies for post-COVID-19 syndrome, which may include diarrhea, fatigue, and chronic inflammation. Oligosaccharides derived from natural resources have been shown to have prebiotic effects, and emerging evidence suggests that they may also have immunomodulatory and anti-inflammatory effects, which could be particularly relevant in mitigating the long-term effects of COVID-19. In this review, we explore the potential of oligosaccharides as regulators of gut microbiota and intestinal health in post-COVID-19 management. We discuss the complex interactions between the gut microbiota, their functional metabolites, such as short-chain fatty acids, and the immune system, highlighting the potential of oligosaccharides to improve gut health and manage post-COVID-19 syndrome. Furthermore, we review evidence of gut microbiota with angiotensin-converting enzyme 2 expression for alleviating post-COVID-19 syndrome. Therefore, oligosaccharides offer a safe, natural, and effective approach to potentially improving gut microbiota, intestinal health, and overall health outcomes in post-COVID-19 management.
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Affiliation(s)
- Kit-Leong Cheong
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Province Engineering Laboratory for Marine Biological Products, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Provincial Science and Technology Innovation Center for Subtropical Fruit and Vegetable Processing, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China
| | - Shutong Chen
- Department of Biology, College of Science, Shantou University, Shantou 515063, China
| | - Bo Teng
- Department of Biology, College of Science, Shantou University, Shantou 515063, China
| | - Suresh Veeraperumal
- Department of Biology, College of Science, Shantou University, Shantou 515063, China
| | - Saiyi Zhong
- Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Province Engineering Laboratory for Marine Biological Products, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Provincial Science and Technology Innovation Center for Subtropical Fruit and Vegetable Processing, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China
| | - Karsoon Tan
- Guangxi Key Laboratory of Beibu Gulf Biodiversity Conservation, Beibu Gulf University, Qinzhou 535000, China
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Vita G, Woolf D, Avery-Hickmott T, Rowsell R. A CFD-based framework to assess airborne infection risk in buildings. BUILDING AND ENVIRONMENT 2023; 233:110099. [PMID: 36815961 PMCID: PMC9925846 DOI: 10.1016/j.buildenv.2023.110099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/31/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
The COVID-19 pandemic has prompted huge efforts to further the scientific knowledge of indoor ventilation and its relationship to airborne infection risk. Exhaled infectious aerosols are spread and inhaled as a result of room airflow characteristics. Many calculation methods and assertions on risk assume 'well-mixed' flow conditions. However, ventilation in buildings is complex and often not showing well-mixed conditions. Ventilation guidance is typically based on the provision of generic minimum ventilation flow rates for a given space, irrespective of the effectiveness in the delivery of the supply air. Furthermore, the airflow might be heavily affected by the season, the HVAC ventilation, or the opening of windows, which would potentially generate draughts and non-uniform conditions. As a result, fresh air concentration would be variable depending upon a susceptible receptor's position in a room and, therefore, associated airborne infection risk. A computational fluid dynamics (CFD) and dynamic thermal modelling (DTM) framework is proposed to assess the influence of internal airflow characteristics on airborne infection risk. A simple metric is proposed, the hourly airborne infection rate (HAI) which can easily help designers to stress-test the ventilation within a building under several conditions. A case study is presented, and the results clearly demonstrate the importance of understanding detailed indoor airflow characteristics and associated concentration patterns in order to provide detailed design guidance, e.g. occupancy, supply air diffusers and furniture layouts, to reduce airborne infection risk.
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Affiliation(s)
- Giulio Vita
- Wirth Research Ltd, Charlotte Avenue, Bicester, OX27 8BL, United Kingdom
- University of Birmingham School of Engineering Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Darren Woolf
- Wirth Research Ltd, Charlotte Avenue, Bicester, OX27 8BL, United Kingdom
| | | | - Rob Rowsell
- Wirth Research Ltd, Charlotte Avenue, Bicester, OX27 8BL, United Kingdom
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Pratt A, Eckermann N, Venugopalan SR, Uribe LM, Barlow L, Nonnenmann M. Evaluation of aerosols in a simulated orthodontic debanding procedure. Sci Rep 2023; 13:4826. [PMID: 36964164 PMCID: PMC10036970 DOI: 10.1038/s41598-023-32082-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 03/22/2023] [Indexed: 03/26/2023] Open
Abstract
Dental practitioners may be at risk for exposure to severe acute respiratory syndrome corona virus 2 when performing aerosol generating procedures. Though recent evidence suggests that coronavirus may be transmitted through aerosol generating procedures, it is unknown whether common procedures performed in dental clinics generate aerosol. The aim of this study was to simultaneously quantify airborne concentrations of the bacteriophage MS2 near the oral cavity of a dental mannequin and behind personal protective equipment (i.e., face shield) of the practitioner during a simulated orthodontic debanding procedure. A deband was performed eight times on a dental mannequin. Optical particle counters and SKC Biosamplers were used to measure particle concentration and to collect virus aerosol generated during the procedure, both near the oral cavity and behind the orthodontists face shield. A plaque assay was used to determine the viable virus airborne concentration. When comparing the two measuring locations, near the oral cavity and behind the clinician's face shield, there was no statistically significant difference of virus concentrations or particle size distribution. This study suggests that debanding under these conditions generates live virus aerosol and a face shield does not provide increased protection from virus aerosol, but does provide some protection against splatter during the procedure.
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Affiliation(s)
- Alessandra Pratt
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA, USA.
- Center for Access and Delivery Research and Evaluation, Iowa City VA Medical Center, Iowa City, IA, USA.
| | - Nile Eckermann
- Department of Orthodontics, University of Iowa, Iowa City, IA, USA
| | | | | | - Lauren Barlow
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA, USA
| | - Matthew Nonnenmann
- Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE, USA
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35
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Yang YF, Lin YJ, You SH, Lu TH, Chen CY, Wang WM, Liao CM. Control measure implications of COVID-19 infection in healthcare facilities reconsidered from human physiological and engineering aspects. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:36228-36243. [PMID: 36547825 PMCID: PMC9772602 DOI: 10.1007/s11356-022-24815-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
The Wells-Riley model invokes human physiological and engineering parameters to successfully treat airborne transmission of infectious diseases. Applications of this model would have high potentiality on evaluating policy actions and interventions intended to improve public safety efforts on preventing the spread of COVID-19 in an enclosed space. Here, we constructed the interaction relationships among basic reproduction number (R0) - exposure time - indoor population number by using the Wells-Riley model to provide a robust means to assist in planning containment efforts. We quantified SARS-CoV-2 changes in a case study of two Wuhan (Fangcang and Renmin) hospitals. We conducted similar approach to develop control measures in various hospital functional units by taking all accountable factors. We showed that inhalation rates of individuals proved crucial for influencing the transmissibility of SARS-CoV-2, followed by air supply rate and exposure time. We suggest a minimum air change per hour (ACH) of 7 h-1 would be at least appropriate with current room volume requirements in healthcare buildings when indoor population number is < 10 and exposure time is < 1 h with one infector and low activity levels being considered. However, higher ACH (> 16 h-1) with optimal arranged-exposure time/people and high-efficiency air filters would be suggested if more infectors or higher activity levels are presented. Our models lay out a practical metric for evaluating the efficacy of control measures on COVID-19 infection in built environments. Our case studies further indicate that the Wells-Riley model provides a predictive and mechanistic basis for empirical COVID-19 impact reduction planning and gives a framework to treat highly transmissible but mechanically heterogeneous airborne SARS-CoV-2.
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Affiliation(s)
- Ying-Fei Yang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Yi-Jun Lin
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chia Tung University, Taipei, 11221, Taiwan
| | - Shu-Han You
- Institute of Food Safety and Risk Management, National Taiwan Ocean University, Keelung City, 20224, Taiwan
| | - Tien-Hsuan Lu
- Department of Environmental Engineering, Da-Yeh University, Changhua, 515006, Taiwan
| | - Chi-Yun Chen
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Wei-Min Wang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Chung-Min Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan.
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36
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Konatzii R, Schmidt-Ott F, Palazis L, Stagianos P, Foka M, Richter J, Christodoulou C, Sciare J, Pikridas M. Exposure to airborne SARS-CoV-2 in four hospital wards and ICUs of Cyprus. A detailed study accounting for day-to-day operations and aerosol generating procedures. Heliyon 2023; 9:e13669. [PMID: 36819229 PMCID: PMC9918438 DOI: 10.1016/j.heliyon.2023.e13669] [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: 02/16/2022] [Revised: 01/27/2023] [Accepted: 02/07/2023] [Indexed: 02/13/2023] Open
Abstract
In any infectious disease, understanding the modes of transmission is key to selecting effective public health measures. In the case of COVID-19 spread, the strictness of the imposed measures outlined the lack of understanding on how SARS-CoV-2 transmits, particularly via airborne pathways. With the aim to characterize the transmission dynamics of airborne SARS-CoV-2, 165 and 62 air and environmental samples, respectively, were collected in four COVID-19 wards and ICUs in Cyprus and analyzed by RT-PCR. An alternative method for SARS-CoV-2 detection in air that provides comparable results but is less cumbersome and time demanding, is also proposed. Considering that all clinics employed 14 regenerations per hour of full fresh air inside patient rooms, it was hypothesized that the viral levels and the frequency of positive samples would be minimum outside of the rooms. However, it is shown that leaving the door opened in patient rooms hinders the efficiency of the ventilation system applied, allowing the virus to escape. As a result, the highest observed viral levels (135 copies m-3) were observed in the corridor of a ward and the frequency of positive samples in the same area was comparable to that inside a two-bed cohort. SARS-CoV-2 in that corridor was found primarily to lie in the coarse mode, at sizes between 1.8 and 10 μm. Similar to previous studies, the frequency of positive samples and viral levels were the lowest inside intensive care units. However, if a patient with sufficient viral load (Ct-value 31) underwent aerosol generating procedures, positive samples with viral levels below 45 copies m-3 were acquired within a 2 m distance of the patient. Our results suggest that a robust ventilation system can prevent unnecessary exposure to SARS-CoV-2 but with limitations related to foot traffic or the operations taking place at the time.
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Affiliation(s)
- Rafail Konatzii
- Climate and Atmosphere Research Centre, The Cyprus Institute, Nicosia, 2121, Cyprus
| | - Fabian Schmidt-Ott
- Climate and Atmosphere Research Centre, The Cyprus Institute, Nicosia, 2121, Cyprus,Department of Physics, University of Helsinki, Helsinki, 00014, Finland
| | - Lakis Palazis
- Department of Intensive Care Unit, Nicosia General Hospital, Ministry of Health, Nicosia, 2029, Cyprus
| | - Panagiotis Stagianos
- Climate and Atmosphere Research Centre, The Cyprus Institute, Nicosia, 2121, Cyprus
| | - Maria Foka
- Department of Intensive Care Unit, Nicosia General Hospital, Ministry of Health, Nicosia, 2029, Cyprus
| | - Jan Richter
- Department of Molecular Virology, The Cyprus Institute of Neurology and Genetics, Nicosia, 1683, Cyprus
| | - Christina Christodoulou
- Department of Molecular Virology, The Cyprus Institute of Neurology and Genetics, Nicosia, 1683, Cyprus
| | - Jean Sciare
- Climate and Atmosphere Research Centre, The Cyprus Institute, Nicosia, 2121, Cyprus
| | - Michael Pikridas
- Climate and Atmosphere Research Centre, The Cyprus Institute, Nicosia, 2121, Cyprus,Corresponding author
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37
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Zhang S, Yan Z, Zhang Y, Wu X, Liu L, Yang A, Duan M. Protocol of a randomised controlled trial to assess medical staff's inhalation exposure to infectious particles exhaled by patients during oesophagogastroduodenoscopy and the efficacy of surgical masks in this context. BMJ Open 2023; 13:e068291. [PMID: 36854596 PMCID: PMC9980315 DOI: 10.1136/bmjopen-2022-068291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
BACKGROUND Aerosol-generating procedures such as oesophagogastroduodenoscopy (OGD) result in infectious particles being exhaled by patients. This substantially increases the medical staff's risk of occupational exposure to pathogenic particles via airway inhalation and facial mucosal deposition. Infectious particles are regarded as a key route of transmission of SARS-CoV-2 and, thus, represents a major risk factor for medical staff during the ongoing COVID-19 pandemic. There is a need for quantitative evidence on medical staff's risk of multiroute exposure to infectious particles exhaled by patients during OGD to enable the development of practical, feasible and economical methods of risk-reduction for use in OGD and related procedures. This randomised controlled trial (RCT)-Personal protective EquiPment intervention TrIal for oesophagogastroDuodEnoscopy (PEPTIDE)-aims to establish a state-of-the-art protocol for quantifying the multiroute exposure of medical staff to infectious particles exhaled by patients during real OGD procedures. METHOD AND ANALYSIS PEPTIDE will be a prospective, two-arm, RCT using quantitative methods and will be conducted at a tertiary hospital in China. It will enrol 130 participants (65 per group) aged over 18. The intervention will be an anthropomorphic model with realistic respiratory-related morphology and respiratory function that simulates a medical staff member. This model will be used either without or with a surgical mask, depending on the group allocation of a participant, and will be placed beside the participants as they undergo an OGD procedure. The primary outcome will be the anthropomorphic model's airway dosage of the participants' exhaled infectious particles with or without a surgical mask, and the secondary outcome will be the anthropomorphic model's non-surgical mask-covered facial mucosa dosage of the participants' exhaled infectious particles. Analyses will be performed in accordance with the type of data collected (categorical or quantitative data) using SPSS (V.26.0) and RStudio (V.1.3.959). ETHICS AND DISSEMINATION Ethical approval for this RCT was obtained from the Ethics Committee of Peking Union Medical College Hospital (ZS-3377). All of the potential participants who agree to participate will provide their written informed consent before they are enrolled. The results will be disseminated through presentations at national and international conferences and publications in peer-reviewed journals. TRIAL REGISTRATION NUMBER NCT05321056.
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Affiliation(s)
- Shengyu Zhang
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Zhiyu Yan
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- 4+4 M.D. Program, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yuheng Zhang
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xi Wu
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Li Liu
- Department of Building Science, Tsinghua University, Beijing, China
- Laboratory of Eco-Planning & Green Building, Ministry of Education, Tsinghua University, Beijing, China
| | - Aiming Yang
- Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Mengjie Duan
- Department of Building Science, Tsinghua University, Beijing, China
- Laboratory of Eco-Planning & Green Building, Ministry of Education, Tsinghua University, Beijing, China
- Vanke School of Public Health, Tsinghua University, Beijing, China
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38
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de Crane D’Heysselaer S, Parisi G, Lisson M, Bruyère O, Donneau AF, Fontaine S, Gillet L, Bureau F, Darcis G, Thiry E, Ducatez M, Snoeck CJ, Zientara S, Haddad N, Humblet MF, Ludwig-Begall LF, Daube G, Thiry D, Misset B, Lambermont B, Tandjaoui-Lambiotte Y, Zahar JR, Sartor K, Noël C, Saegerman C, Haubruge E. Systematic Review of the Key Factors Influencing the Indoor Airborne Spread of SARS-CoV-2. Pathogens 2023; 12:382. [PMID: 36986304 PMCID: PMC10053454 DOI: 10.3390/pathogens12030382] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [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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Affiliation(s)
| | - Gianni Parisi
- Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiege), FARAH Research Centre, Faculty of Veterinary Medicine, University of Liege, 4000 Liege, Belgium
| | - Maxime Lisson
- TERRA Research Centre, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
| | - Olivier Bruyère
- Division of Public Health, Epidemiology and Health Economics, Faculty of Medicine, University of Liège, 4000 Liège, Belgium
| | | | - Sebastien Fontaine
- Institute for Research in Social Sciences (IRSS), Faculty of Social Sciences, University of Liege, 4000 Liège, Belgium
| | - Laurent Gillet
- Immunology-Vaccinology Laboratory, FARAH Research Center, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Fabrice Bureau
- Laboratory of Cellular and Molecular Immunology, GIGA Institute, University of Liege, 4000 Liège, Belgium
| | - Gilles Darcis
- Infectious Diseases Department, Centre Hospitalier Universitaire de Liège, 4000 Liège, Belgium
| | - Etienne Thiry
- Veterinary Virology and Animal Viral Diseases, FARAH Research Centre, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Mariette Ducatez
- IHAP, Université de Toulouse, INRAE, ENVT, 31000 Toulouse, France
| | - Chantal J. Snoeck
- Clinical and Applied Virology Group, Department of Infection and Immunity, Luxembourg Institute of Health, 4354 Esch-sur-Alzette, Luxembourg
| | - Stéphan Zientara
- UMR1161 Virologie, INRAE, Ecole Nationale Vétérinaire d’Alfort, Anses, Université Paris-Est, F-94700 Maisons-Alfort, France
| | - Nadia Haddad
- UMR BIPAR 956, Anses, INRAE, Ecole Nationale Vétérinaire d’Alfort, Université Paris-Est, 94700 Maisons-Alfort, France
| | - Marie-France Humblet
- Department of Occupational Safety and Health, University of Liege, 4000 Liege, Belgium
| | - Louisa F. Ludwig-Begall
- Veterinary Virology and Animal Viral Diseases, FARAH Research Centre, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Georges Daube
- Laboratoire de Microbiologie des Denrées Alimentaires, FARAH Research Center, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Damien Thiry
- Bacteriology, FARAH Research Center, Faculty of Veterinary Medicine, University of Liege, 4000 Liège, Belgium
| | - Benoît Misset
- Service des Soins Intensifs, CHU Sart Tilman, Department des Sciences Cliniques, University of Liège, 4000 Liege, Belgium
| | - Bernard Lambermont
- Service des Soins Intensifs, CHU Sart Tilman, Department des Sciences Cliniques, University of Liège, 4000 Liege, Belgium
| | - Yacine Tandjaoui-Lambiotte
- Laboratoire Hypoxie and Poumon INSERM U1272, Service de Réanimation Médico-Chirurgicale, CHU Avicenne, Assistance Publique-Hôpitaux de Paris, 93000 Bobigny, France
| | | | - Kevin Sartor
- Planification: Energie—Environnement, Département d’Aérospatiale et Mécanique, Systèmes Énergétiques, University of Liège, 4000 Liège, Belgium
| | - Catherine Noël
- Department of Occupational Safety and Health, University of Liege, 4000 Liege, Belgium
| | - Claude Saegerman
- Research Unit in Epidemiology and Risk Analysis Applied to Veterinary Sciences (UREAR-ULiege), FARAH Research Centre, Faculty of Veterinary Medicine, University of Liege, 4000 Liege, Belgium
| | - Eric Haubruge
- TERRA Research Centre, Gembloux Agro-Bio Tech, University of Liège, 5030 Gembloux, Belgium
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De Santi C, Cavalleri GL, Kerrigan SW, Fitzpatrick F, McGrogan K, Gilroy J, Baxter R, Quadu V, Ryan K, Humphreys H. Screening medical students for SARS-CoV-2 to facilitate face-to-face clinical teaching and prevent onward spread to patients. J Hosp Infect 2023; 135:1-3. [PMID: 36775068 PMCID: PMC9916130 DOI: 10.1016/j.jhin.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/13/2023] [Accepted: 02/04/2023] [Indexed: 02/12/2023]
Affiliation(s)
- C De Santi
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland (RCSI) University of Medicine and Health Sciences, Dublin, Ireland
| | - G L Cavalleri
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland (RCSI) University of Medicine and Health Sciences, Dublin, Ireland; Science Foundation Ireland FutureNeuro Research Centre, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - S W Kerrigan
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland (RCSI) University of Medicine and Health Sciences, Dublin, Ireland
| | - F Fitzpatrick
- Department of Clinical Microbiology, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland; Department of Microbiology, Beaumont Hospital, Dublin, Ireland
| | - K McGrogan
- Mercer's Medical Centre, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland
| | - J Gilroy
- Student Academic and Regulatory Affairs, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland
| | - R Baxter
- Estate and Support Services, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland
| | - V Quadu
- Mercer's Medical Centre, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland
| | - K Ryan
- Department of Surgical Affairs, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland
| | - H Humphreys
- Department of Clinical Microbiology, RCSI University of Medicine and Healthcare Sciences, Dublin, Ireland.
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40
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Otter JA, Zhou J, Price JR, Reeves L, Zhu N, Randell P, Sriskandan S, Barclay WS, Holmes AH. SARS-CoV-2 surface and air contamination in an acute healthcare setting during the first and second pandemic waves. J Hosp Infect 2023; 132:36-45. [PMID: 36435307 PMCID: PMC9683853 DOI: 10.1016/j.jhin.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 11/10/2022] [Accepted: 11/13/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Surfaces and air in healthcare facilities can be contaminated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Previously, the authors identified SARS-CoV-2 RNA on surfaces and air in their hospital during the first wave of the coronavirus disease 2019 pandemic (April 2020). AIM To explore whether the profile of SARS-CoV-2 surface and air contamination had changed between April 2020 and January 2021. METHODS This was a prospective, cross-sectional, observational study in a multi-site London hospital. In January 2021, surface and air samples were collected from comparable areas to those sampled in April 2020, comprising six clinical areas and a public area. SARS-CoV-2 was detected using reverse transcription polymerase chain reaction and viral culture. Sampling was also undertaken in two wards with natural ventilation alone. The ability of the prevalent variants at the time of the study to survive on dry surfaces was evaluated. FINDINGS No viable virus was recovered from surfaces or air. Five percent (N=14) of 270 surface samples and 4% (N=1) of 27 air samples were positive for SARS-CoV-2, which was significantly lower than in April 2020 [52% (N=114) of 218 surface samples and 48% (N=13) of 27 air samples (P<0.001, Fisher's exact test)]. There was no clear difference in the proportion of surface and air samples positive for SARS-CoV-2 RNA based on the type of ventilation in the ward. All variants tested survived on dry surfaces for >72 h, with a <3-log10 reduction in viable count. CONCLUSION This study suggests that enhanced infection prevention measures have reduced the burden of SARS-CoV-2 RNA on surfaces and air in healthcare facilities.
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Affiliation(s)
- J A Otter
- National Institute for Healthcare Research Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London & Public Health England, Hammersmith Hospital, London, UK; Guy's and St. Thomas' NHS Foundation Trust, London, UK.
| | - J Zhou
- Department of Infectious Disease, Imperial College London, London, UK
| | - J R Price
- National Institute for Healthcare Research Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London & Public Health England, Hammersmith Hospital, London, UK; Imperial College Healthcare NHS Trust, St. Mary's Hospital, London, UK
| | - L Reeves
- National Institute for Healthcare Research Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London & Public Health England, Hammersmith Hospital, London, UK
| | - N Zhu
- National Institute for Healthcare Research Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London & Public Health England, Hammersmith Hospital, London, UK
| | - P Randell
- Imperial College Healthcare NHS Trust, St. Mary's Hospital, London, UK
| | - S Sriskandan
- National Institute for Healthcare Research Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London & Public Health England, Hammersmith Hospital, London, UK; Imperial College Healthcare NHS Trust, St. Mary's Hospital, London, UK
| | - W S Barclay
- Department of Infectious Disease, Imperial College London, London, UK
| | - A H Holmes
- National Institute for Healthcare Research Health Protection Research Unit in Healthcare-associated Infection and Antimicrobial Resistance, Imperial College London & Public Health England, Hammersmith Hospital, London, UK; Imperial College Healthcare NHS Trust, St. Mary's Hospital, London, UK
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41
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Mondal M, Chakrabarti S, Gao YQ, Bhattacharyya D, Chakrabarti J. Microscopic model on indoor propagation of respiratory droplets. Comput Biol Chem 2023; 102:107806. [PMID: 36608615 DOI: 10.1016/j.compbiolchem.2022.107806] [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: 08/19/2022] [Revised: 12/06/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
Indoor propagation of airborne diseases is yet poorly understood. Here, we theoretically study a microscopic model based on the motions of virus particles in a respiratory microdroplet, responsible for airborne transmission of diseases, to understand their indoor propagation. The virus particles are driven by a driving force that mimics force due to gushing of air by devices like indoor air conditioning along with the gravity. A viral particle within the droplet experiences viscous drag due to the droplet medium, force due to interfacial tension at the droplet boundary, the thermal forces and mutual interaction forces with the other viral particles. We use Brownian Dynamics (BD) simulations and scaling arguments to study the motion of the droplet, given by that of the center of mass of the viral assembly. The BD simulations show that in presence of the gravity force alone, the time the droplet takes to reach the ground level, defined by the gravitational potential energy being zero, from a vertical height H,tf∼γ-0.1 dependence, where γ is the interfacial tension. In presence of the driving force of magnitude F0 and duration τ0, the horizontal propagation length, Ymax from the source increase linearly with τ0, where the slope is steeper for larger F0. Our scaling analysis explains qualitatively well the simulation observations and show long-distance transmission of airborne respiratory droplets in the indoor conditions due to F0 ∼ nano-dyne.
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Affiliation(s)
- Manas Mondal
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518107, China.
| | - Srabani Chakrabarti
- Department of Physics, Lady Brabourne College, P-1/2, Suhrawardy Avenue, Kolkata 700017, West Bengal, India.
| | - Yi Qin Gao
- Institute of Systems and Physical Biology, Shenzhen Bay Laboratory, Shenzhen 518107, China; Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Biomedical Pioneering Innovation Center, Beijing Advanced Innovation Center for Genomics, Peking University, Beijing 100871, China.
| | - Dhananjay Bhattacharyya
- Computational Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India.
| | - Jaydeb Chakrabarti
- Department of Chemical, Biological and Macro-Molecular Sciences, Thematic unit of Excellence on Computational Materials Science and Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Sector-III, Salt Lake, Kolkata 700098, India.
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González-Parra G, Arenas AJ. Mathematical Modeling of SARS-CoV-2 Omicron Wave under Vaccination Effects. COMPUTATION (BASEL, SWITZERLAND) 2023; 11:36. [PMID: 38957648 PMCID: PMC11218807 DOI: 10.3390/computation11020036] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Over the course of the COVID-19 pandemic millions of deaths and hospitalizations have been reported. Different SARS-CoV-2 variants of concern have been recognized during this pandemic and some of these variants of concern have caused uncertainty and changes in the dynamics. The Omicron variant has caused a large amount of infected cases in the US and worldwide. The average number of deaths during the Omicron wave toll increased in comparison with previous SARS-CoV-2 waves. We studied the Omicron wave by using a highly nonlinear mathematical model for the COVID-19 pandemic. The novel model includes individuals who are vaccinated and asymptomatic, which influences the dynamics of SARS-CoV-2. Moreover, the model considers the waning of the immunity and efficacy of the vaccine against the Omicron strain. This study uses the facts that the Omicron strain has a higher transmissibility than the previous circulating SARS-CoV-2 strain but is less deadly. Preliminary studies have found that Omicron has a lower case fatality rate compared to previous circulating SARS-CoV-2 strains. The simulation results show that even if the Omicron strain is less deadly it might cause more deaths, hospitalizations and infections. We provide a variety of scenarios that help to obtain insight about the Omicron wave and its consequences. The proposed mathematical model, in conjunction with the simulations, provides an explanation for a large Omicron wave under various conditions related to vaccines and transmissibility. These results provide an awareness that new SARS-CoV-2 variants can cause more deaths even if their fatality rate is lower.
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Affiliation(s)
- Gilberto González-Parra
- Department of Mathematics, New Mexico Tech, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA
| | - Abraham J. Arenas
- Departamento de Matematicas y Estadistica, Universidad de Cordoba, Monteria 230002, Colombia
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43
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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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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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45
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López LR, Dessì P, Cabrera-Codony A, Rocha-Melogno L, Kraakman B, Naddeo V, Balaguer MD, Puig S. CO 2 in indoor environments: From environmental and health risk to potential renewable carbon source. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159088. [PMID: 36181799 DOI: 10.1016/j.scitotenv.2022.159088] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/10/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
In the developed world, individuals spend most of their time indoors. Poor Indoor Air Quality (IAQ) has a wide range of effects on human health. The burden of disease associated with indoor air accounts for millions of premature deaths related to exposure to Indoor Air Pollutants (IAPs). Among them, CO2 is the most common one, and is commonly used as a metric of IAQ. Indoor CO2 concentrations can be significantly higher than outdoors due to human metabolism and activities. Even in presence of ventilation, controlling the CO2 concentration below the Indoor Air Guideline Values (IAGVs) is a challenge, and many indoor environments including schools, offices and transportation exceed the recommended value of 1000 ppmv. This is often accompanied by high concentration of other pollutants, including bio-effluents such as viruses, and the importance of mitigating the transmission of airborne diseases has been highlighted by the COVID-19 pandemic. On the other hand, the relatively high CO2 concentration of indoor environments presents a thermodynamic advantage for direct air capture (DAC) in comparison to atmospheric CO2 concentration. This review aims to describe the issues associated with poor IAQ, and to demonstrate the potential of indoor CO2 DAC to purify indoor air while generating a renewable carbon stream that can replace conventional carbon sources as a building block for chemical production, contributing to the circular economy.
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Affiliation(s)
- L R López
- LEQUiA, Institute of Environment, University of Girona, Campus Montilivi, carrer Maria Aurelia Capmany 69, Girona, Spain.
| | - P Dessì
- LEQUiA, Institute of Environment, University of Girona, Campus Montilivi, carrer Maria Aurelia Capmany 69, Girona, Spain
| | - A Cabrera-Codony
- LEQUiA, Institute of Environment, University of Girona, Campus Montilivi, carrer Maria Aurelia Capmany 69, Girona, Spain
| | - L Rocha-Melogno
- ICF, 2635 Meridian Parkway Suite 200, Durham, NC 27713, United States
| | - B Kraakman
- Jacobs Engineering, Templey Quay 1, Bristol BAS1 6DG, UK; Institute of Sustainable Processes, University of Valladolid, Dr. Mergelina s/n., 47011 Valladolid, Spain
| | - V Naddeo
- Sanitary Environmental Engineering Division, Department of Civil Engineering, University of Salerno, 84084 Fisciano, SA, Italy
| | - M D Balaguer
- LEQUiA, Institute of Environment, University of Girona, Campus Montilivi, carrer Maria Aurelia Capmany 69, Girona, Spain
| | - S Puig
- LEQUiA, Institute of Environment, University of Girona, Campus Montilivi, carrer Maria Aurelia Capmany 69, Girona, Spain
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46
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Ratliff KM, Oudejans L, Archer J, Calfee W, Gilberry JU, Hook DA, Schoppman WE, Yaga RW, Brooks L, Ryan S. Large-scale evaluation of microorganism inactivation by bipolar ionization and photocatalytic devices. BUILDING AND ENVIRONMENT 2023; 227:109804. [PMID: 36407013 PMCID: PMC9652099 DOI: 10.1016/j.buildenv.2022.109804] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/20/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
The COVID-19 pandemic has raised awareness in the spread of disease via airborne transmission. As a result, there has been increasing interest in technologies that claim to reduce concentrations of airborne pathogens in indoor environments. The efficacy of many of these emerging technologies is not fully understood, and the testing that has been done is often conducted at a small scale and not representative of applied settings. There is currently no standard test method for evaluating air treatment technologies, making it difficult to compare results across studies or technology types. Here, a consistent testing approach in an operational-scale test chamber with a mock recirculating heating, ventilation, and air conditioning (HVAC) system was used to evaluate the efficacy of bipolar ionization and photocatalytic devices against the non-enveloped bacteriophage MS2 in the air and on surfaces. Statistically significant differences between replicate sets of technology tests and control tests (without technologies active) are apparent after 1 h, ranging to a maximum of 0.88 log10 reduction for the bipolar ionization tests and 1.8 log10 reduction for the photocatalytic device tests. It should be noted that ozone concentrations were elevated above background concentrations in the test chamber during the photocatalytic device testing. No significant differences were observed between control and technology tests in terms of the amount of MS2 deposited or inactivated on surfaces during testing. A standardized, large-scale testing approach, with replicate testing and time-matched control conditions, is necessary for contextualizing laboratory efficacy results, translating them to real-world conditions, and for facilitating technology comparisons.
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Affiliation(s)
- Katherine M Ratliff
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Lukas Oudejans
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - John Archer
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Worth Calfee
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | | | | | | | - Robert W Yaga
- Jacobs Technology Inc., Research Triangle Park, NC, USA
| | - Lance Brooks
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Shawn Ryan
- Center for Environmental Solutions and Emergency Response, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
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Fischetti M, Fischetti M, Stoustrup J. Safe distancing in the time of COVID-19. EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2023; 304:139-149. [PMID: 34316090 PMCID: PMC8272071 DOI: 10.1016/j.ejor.2021.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 07/02/2021] [Indexed: 05/25/2023]
Abstract
The spread of viruses such as SARS-CoV-2 brought new challenges to our society, including a stronger focus on safety across all businesses. Many countries have imposed a minimum social distance among people in order to ensure their safety. This brings new challenges to many customer-related businesses, such as restaurants, offices, theaters, etc., on how to locate their facilities (tables, seats etc.) under distancing constraints. We propose a parallel between this problem and that of locating wind turbines in an offshore area. The discovery of this parallel allows us to apply Mathematical Optimization algorithms originally designed for wind farms, to produce optimized facility layouts that minimize the overall risk of infection among customers. In this way we can investigate the structure of the safest layouts, with some surprising outcomes. A lesson learned is that, in the safest layouts, the facilities are not equally distanced (as it is typically believed) but tend to concentrate on the border of the available area-a policy that significantly reduces the overall risk of contagion.
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Affiliation(s)
| | - Matteo Fischetti
- Department of Information Engineering, University of Padua, via Gradenigo 6/A, Padova 35100, Italy
| | - Jakob Stoustrup
- Automation & Control, Department of Electronic Systems, Aalborg University, Fredrik Bajers Vej 7C, Aalborg 9220, Denmark
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Sheraz M, Mir KA, Anus A, Le VCT, Kim S, Nguyen VQ, Lee WR. SARS-CoV-2 airborne transmission: a review of risk factors and possible preventative measures using air purifiers. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:2191-2216. [PMID: 36278886 DOI: 10.1039/d2em00333c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the resulting worldwide death toll have prompted worries regarding its transmission mechanisms. Direct, indirect, and droplet modes are the basic mechanisms of transmission. SARS-CoV-2 spreads by respiratory droplets (size range >10 μm size ranges), aerosols (5 μm), airborne, and particulate matter. The rapid transmission of SARS-CoV-2 is due to the involvement of tiny indoor air particulate matter (PM2.5), which functions as a vector. SARS-CoV-2 is more contagious in the indoor environment where particulate matter floats for a longer period and greater distances. Extended residence time in the environment raises the risk of SARS-CoV-2 entering the lower respiratory tract, which may cause serious infection and possibly death. To decrease viral transmission in the indoor environment, it is essential to catch and kill the SARS-CoV-2 virus and maintain virus-free air, which will significantly reduce viral exposure concerns. Therefore, effective air filters with anti-viral, anti-bacterial, and anti-air-pollutant characteristics are gaining popularity recently. It is essential to develop cost-effective materials based on nanoparticles and metal-organic frameworks in order to lower the risk of airborne transmission in developing countries. A diverse range of materials play an important role in the manufacturing of effective air filters. We have summarized in this review article the basic concepts of the transmission routes of SARS-CoV-2 virus and precautionary measures using air purifiers with efficient materials-based air filters for the indoor environment. The performance of air-filter materials, challenges and alternative approaches, and future perspectives are also presented. We believe that air purifiers fabricated with highly efficient materials can control various air pollutants and prevent upcoming pandemics.
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Affiliation(s)
- Mahshab Sheraz
- Research Centre for Climate Change and Energy, Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon-si, 24252, Republic of Korea
- Nano-Innotek Corporation, 123, Digital-ro 26 Gil, Guro-gu, Seoul, South Korea
| | - Kaleem Anwar Mir
- Research Centre for Climate Change and Energy, Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon-si, 24252, Republic of Korea
- Global Change Impact Studies Centre, Ministry of Climate Change, Government of Pakistan, Islamabad, 44000, Pakistan
| | - Ali Anus
- Research Centre for Climate Change and Energy, Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon-si, 24252, Republic of Korea
- Nano-Innotek Corporation, 123, Digital-ro 26 Gil, Guro-gu, Seoul, South Korea
| | - Van Cam Thi Le
- Research Centre for Climate Change and Energy, Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon-si, 24252, Republic of Korea
- Nano-Innotek Corporation, 123, Digital-ro 26 Gil, Guro-gu, Seoul, South Korea
- School of Chemical, Biological, and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Seungdo Kim
- Research Centre for Climate Change and Energy, Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon-si, 24252, Republic of Korea
- Nano-Innotek Corporation, 123, Digital-ro 26 Gil, Guro-gu, Seoul, South Korea
- Environment Strategy Development Institute, Hallym University, Chuncheon-si 24252, South Korea
| | - Van Quyet Nguyen
- Nano-Innotek Corporation, 123, Digital-ro 26 Gil, Guro-gu, Seoul, South Korea
| | - Woo Ram Lee
- Department of Chemistry, School of Future Convergence, Hallym University, Engineering Building# 1348, 1 Hallymdaehak-gil, Chuncheon-si 24252, Gangwon-do, South Korea.
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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: 6] [Impact Index Per Article: 3.0] [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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50
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Andrés M, García MC, Fajardo A, Grau L, Pagespetit L, Plasencia V, Martínez I, Abadía C, Sanahuja A, Bella F. Nosocomial outbreak of COVID-19 in an internal medicine ward: Probable airborne transmission. Rev Clin Esp 2022; 222:578-583. [PMID: 35798645 PMCID: PMC9239913 DOI: 10.1016/j.rceng.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/09/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVES Despite the increasing evidence supporting the importance of airborne transmission in SARS-CoV-2 infection, it has not been considered relevant in the vast majority of reported nosocomial outbreaks of COVID-19. The aim of this study is to describe a nosocomial outbreak of SARS-CoV-2 infection whose features suggest that aerosol transmission had an important role. METHODS This is a descriptive analysis of a nosocomial outbreak of SARS-CoV-2 infection in an internal medicine ward that occurred in December 2020. All cases were confirmed by a positive PCR test for SARS-CoV-2. RESULTS From December 5 to December 17, 21 patients and 44 healthcare workers (HCWs) developed a nosocomial SARS-CoV-2 infection. Fifty-one of the 65 cases (78.5%) were diagnosed between December 6 and 9. The attack rate in patients was 80.8%. Among HCWs, the attack rate was higher in those who had worked at least one full working day in the ward (56.3%) than in those who had occasionally been in the ward (25.8%; p = 0.005). Three days before the first positive case was detected, two extractor fans were found to be defective, affecting the ventilation of three rooms. Sixteen cases were asymptomatic, 48 cases had non-severe symptoms, and 2 cases required admission to the intensive care unit. All patients eventually recovered. CONCLUSION The high attack rate, the explosive nature of the outbreak, and the coincidence in time with the breakdown in air extractors in some rooms of the ward suggest that airborne transmission played a key role in the development of the outbreak.
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Affiliation(s)
- M Andrés
- Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain.
| | - M-C García
- Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - A Fajardo
- Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - L Grau
- Equipo de Control de Infecciones, Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - L Pagespetit
- Equipo de Control de Infecciones, Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - V Plasencia
- Laboratorio de Microbiología, CATLAB, Viladecavalls (Barcelona), Spain
| | - I Martínez
- Servicio de Prevención de Riesgos Laborales, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - C Abadía
- Servicio de Salud Laboral, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - A Sanahuja
- Departamento de Recursos Físicos, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
| | - F Bella
- Unidad de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital de Terrassa (Consorci Sanitari de Terrassa), Terrassa (Barcelona), Spain
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