351
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Carbone M, Lednicky J, Xiao SY, Venditti M, Bucci E. Coronavirus 2019 Infectious Disease Epidemic: Where We Are, What Can Be Done and Hope For. J Thorac Oncol 2021; 16:546-571. [PMID: 33422679 PMCID: PMC7832772 DOI: 10.1016/j.jtho.2020.12.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/15/2020] [Accepted: 12/29/2020] [Indexed: 12/18/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads mainly by means of aerosols (microdroplets) in enclosed environments, especially those in which temperature and humidity are regulated by means of air-conditioning. About 30% of individuals infected with SARS-CoV-2 develop coronavirus disease 2019 (COVID-19) disease. Among them, approximately 25% require hospitalization. In medicine, cases are identified as those who become ill. During this pandemic, cases have been identified as those with a positive SARS-CoV-2 polymerase chain reaction test, including approximately 70% who were asymptomatic-this has caused unnecessary anxiety. Individuals more than 65 years old, those affected by obesity, diabetes, asthma, or are immune-depressed owing to cancer and other conditions, are at a higher risk of hospitalization and of dying of COVID-19. Healthy individuals younger than 40 years very rarely die of COVID-19. Estimates of the COVID-19 mortality rate vary because the definition of COVID-19-related deaths varies. Belgium has the highest death rate at 154.9 per 100,000 persons, because it includes anyone who died with symptoms compatible with COVID-19, even those never tested for SARS-CoV-2. The United States includes all patients who died with a positive test, whether they died because of, or with, SARS-CoV-2. Countries that include only patients in which COVID-19 was the main cause of death, rather than a cofactor, have lower death rates. Numerous therapies are being developed, and rapid improvements are anticipated. Because of disinformation, only approximately 50% of the U.S. population plans to receive a COVID-19 vaccine. By sharing accurate information, physicians, health professionals, and scientists play a key role in addressing myths and anxiety, help public health officials enact measures to decrease infections, and provide the best care for those who become sick. In this article, we discuss these issues.
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Affiliation(s)
- Michele Carbone
- Thoracic Oncology, University of Hawaii Cancer Center, Honolulu, Hawaii; Department of Pathology, John A. Burns School of Medicine, Hawaii, Honolulu, Hawaii.
| | - John Lednicky
- Department of Environmental and Global Health, College of Public Health and Health Professions, Emerging Pathogens Institute, University of Florida, Gainesville, Florida
| | - Shu-Yuan Xiao
- Department of Pathology, University of Chicago Medicine, Chicago, llinois
| | - Mario Venditti
- Department of Public Health and Infectious Diseases, Universita` La Sapienza, Roma, Italy
| | - Enrico Bucci
- Sbarro Institute for Cancer Research and Molecular Medicine, College for Science and technology, Temple University, Philadelphia, Pennsylvania; Department of Biology, College for Science and Technology, Temple University, Philadelphia, Pennsylvania
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352
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Planning and Design of a Full-Outer-Air-Intake Natural Air-Conditioning System for Medical Negative Pressure Isolation Wards. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:8872167. [PMID: 33833861 PMCID: PMC8018840 DOI: 10.1155/2021/8872167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/13/2021] [Accepted: 03/17/2021] [Indexed: 11/20/2022]
Abstract
In the beginning of 2020, the coronavirus (COVID-19) pandemic started to spread globally, causing panic to the lives of people around the world; many countries executed lockdown of cities or even total lockdown of the entire countries. The coronavirus disease (COVID-19) is transmitted via air droplets. In medical environments that use traditional hermetic ventilation systems, medical personnel who come in contact with patients are more susceptible to infection compared to regular staff; therefore, the air flow and air quality of hermetic negative pressure isolation wards are highly critical. For this purpose, the study proposes a full-outer-air-intake natural air-conditioning system for negative pressure isolation wards. This innovative system draws in large amounts of fresh external air to greatly improve the air exchange rate in wards; negative pressure environments can be implemented depending on requirements to solve the issue of nosocomial infections in traditional negative pressure isolation wards that draw air from within the hospital. This greatly reduces the probability of nosocomial infection and infection via air droplets; furthermore, the system's intake and exhaust paths are completely isolated, solving the issue of air cross-contamination. Based on the results from the experiment site, this innovative system was designed and implemented based on the guidelines of hospital facilities and achieved air exchange per hour in excess of 12 times/hour, reaching a maximum of 54.5 times/hour. Indoor CO2 concentration was 576 ppm, negative pressure was −14 Pa, indoor temperature was 23.3°C, indoor humidity was 54.1%, and sensible heat exchange efficiency (ηs) was 105.88% which effectively reduced ventilation load. Therefore, this innovative full-outer-air-intake natural air-conditioning system can provide medical staff and patients with a safe and healthy environment that prevents cross-infection.
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353
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Shumsky RA, Debo L, Lebeaux RM, Nguyen QP, Hoen AG. Retail store customer flow and COVID-19 transmission. Proc Natl Acad Sci U S A 2021; 118:e2019225118. [PMID: 33637652 PMCID: PMC7980443 DOI: 10.1073/pnas.2019225118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We examine how operational changes in customer flows in retail stores affect the rate of COVID-19 transmission. We combine a model of customer movement with two models of disease transmission: direct exposure when two customers are in close proximity and wake exposure when one customer is in the airflow behind another customer. We find that the effectiveness of some operational interventions is sensitive to the primary mode of transmission. Restricting customer flow to one-way movement is highly effective if direct exposure is the dominant mode of transmission. In particular, the rate of direct transmission under full compliance with one-way movement is less than one-third the rate under two-way movement. Directing customers to follow one-way flow, however, is not effective if wake exposure dominates. We find that two other interventions-reducing the speed variance of customers and throughput control-can be effective whether direct or wake transmission is dominant. We also examine the trade-off between customer throughput and the risk of infection to customers, and we show how the optimal throughput rate drops rapidly as the population prevalence rises.
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Affiliation(s)
| | - Laurens Debo
- Tuck School of Business, Dartmouth College, Hanover, NH 03755
| | - Rebecca M Lebeaux
- Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755
| | - Quang P Nguyen
- Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755
| | - Anne G Hoen
- Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Hanover, NH 03755
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354
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Kutter JS, de Meulder D, Bestebroer TM, Lexmond P, Mulders A, Richard M, Fouchier RAM, Herfst S. SARS-CoV and SARS-CoV-2 are transmitted through the air between ferrets over more than one meter distance. Nat Commun 2021; 12:1653. [PMID: 33712573 PMCID: PMC7955093 DOI: 10.1038/s41467-021-21918-6] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/19/2021] [Indexed: 02/08/2023] Open
Abstract
SARS-CoV-2 emerged in late 2019 and caused a pandemic, whereas the closely related SARS-CoV was contained rapidly in 2003. Here, an experimental set-up is used to study transmission of SARS-CoV and SARS-CoV-2 through the air between ferrets over more than a meter distance. Both viruses cause a robust productive respiratory tract infection resulting in transmission of SARS-CoV-2 to two of four indirect recipient ferrets and SARS-CoV to all four. A control pandemic A/H1N1 influenza virus also transmits efficiently. Serological assays confirm all virus transmission events. Although the experiments do not discriminate between transmission via small aerosols, large droplets and fomites, these results demonstrate that SARS-CoV and SARS-CoV-2 can remain infectious while traveling through the air. Efficient virus transmission between ferrets is in agreement with frequent SARS-CoV-2 outbreaks in mink farms. Although the evidence for virus transmission via the air between humans under natural conditions is absent or weak for SARS-CoV and SARS-CoV-2, ferrets may represent a sensitive model to study interventions aimed at preventing virus transmission.
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Affiliation(s)
- Jasmin S Kutter
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Dennis de Meulder
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Theo M Bestebroer
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Pascal Lexmond
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ard Mulders
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Mathilde Richard
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ron A M Fouchier
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Sander Herfst
- Department of Viroscience, Erasmus University Medical Center, Rotterdam, The Netherlands.
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355
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Abstract
Engineering controls play an important role in reducing the spread of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).1 Established technologies such as air filtration, and novel approaches such as ultraviolet (UV)-C light or plasma air ionization, have the potential to support the fight against the coronavirus disease 2019 (COVID-19) pandemic.2 We tested the efficacy of an air purification system (APS) combining UV-C light and high-efficiency particulate air (HEPA) filtration in a controlled environment using SARS-CoV-2 as test organism. The APS successfully removed the virus from the air using UV-C light by itself and in combination with HEPA air filtration.
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356
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Feasibility of ultraviolet light-emitting diode irradiation robot for terminal decontamination of coronavirus disease 2019 (COVID-19) patient rooms. Infect Control Hosp Epidemiol 2021; 43:232-237. [PMID: 33685546 PMCID: PMC8160490 DOI: 10.1017/ice.2021.95] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To investigate the feasibility of using an ultraviolet light-emitting diode (UV LED) robot for the terminal decontamination of coronavirus disease 2019 (COVID-19) patient rooms. METHODS We assessed the presence of viral RNA in samples from environmental surfaces before and after UV LED irradiation in COVID-19 patient rooms after patient discharge. RESULTS We analyzed 216 environmental samples from 17 rooms: 2 from airborne infection isolation rooms (AIIRs) in the intensive care unit (ICU) and 15 from isolation rooms in the community treatment center (CTC). Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was detected in 40 (18.5%) of 216 samples after patient discharge: 12 (33.3%) of 36 samples from AIIRs in the ICU, and 28 (15.6%) of 180 samples from isolation rooms in the CTC. In 1 AIIR, all samples were PCR negative after UV LED irradiation. In the CTC rooms, 14 (8.6%) of the 163 samples were PCR positive after UV LED irradiation. However, viable virus was not recovered from the culture of any of the PCR-positive samples. CONCLUSIONS Although no viable virus was recovered, SARS-CoV-2 RNA was detected on various environmental surfaces. The use of a UV LED disinfection robot was effective in spacious areas such as an ICU, but its effects varied in small spaces like CTC rooms. These findings suggest that the UV LED robot may need enough space to disinfect rooms without recontamination by machine wheels or insufficient disinfection by shadowing.
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357
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Kalyan S, Torabi C, Khoo H, Sung HW, Choi SE, Wang W, Treutler B, Kim D, Hur SC. Inertial Microfluidics Enabling Clinical Research. MICROMACHINES 2021; 12:257. [PMID: 33802356 PMCID: PMC7999476 DOI: 10.3390/mi12030257] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/20/2021] [Accepted: 03/01/2021] [Indexed: 02/06/2023]
Abstract
Fast and accurate interrogation of complex samples containing diseased cells or pathogens is important to make informed decisions on clinical and public health issues. Inertial microfluidics has been increasingly employed for such investigations to isolate target bioparticles from liquid samples with size and/or deformability-based manipulation. This phenomenon is especially useful for the clinic, owing to its rapid, label-free nature of target enrichment that enables further downstream assays. Inertial microfluidics leverages the principle of inertial focusing, which relies on the balance of inertial and viscous forces on particles to align them into size-dependent laminar streamlines. Several distinct microfluidic channel geometries (e.g., straight, curved, spiral, contraction-expansion array) have been optimized to achieve inertial focusing for a variety of purposes, including particle purification and enrichment, solution exchange, and particle alignment for on-chip assays. In this review, we will discuss how inertial microfluidics technology has contributed to improving accuracy of various assays to provide clinically relevant information. This comprehensive review expands upon studies examining both endogenous and exogenous targets from real-world samples, highlights notable hybrid devices with dual functions, and comments on the evolving outlook of the field.
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Affiliation(s)
- Srivathsan Kalyan
- Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (S.K.); (C.T.); (H.K.); (S.-E.C.)
| | - Corinna Torabi
- Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (S.K.); (C.T.); (H.K.); (S.-E.C.)
| | - Harrison Khoo
- Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (S.K.); (C.T.); (H.K.); (S.-E.C.)
| | - Hyun Woo Sung
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA;
| | - Sung-Eun Choi
- Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (S.K.); (C.T.); (H.K.); (S.-E.C.)
| | - Wenzhao Wang
- Department of Biomedical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (W.W.); (B.T.)
| | - Benjamin Treutler
- Department of Biomedical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (W.W.); (B.T.)
| | - Dohyun Kim
- Department of Mechanical Engineering, Myongji University, Yongin-si 17508, Korea
| | - Soojung Claire Hur
- Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA; (S.K.); (C.T.); (H.K.); (S.-E.C.)
- Institute for NanoBioTechnology, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
- Department of Oncology, Johns Hopkins University, 600 N Wolfe St, Baltimore, MD 21205, USA
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, 401 N Broadway, Baltimore, MD 21231, USA
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358
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Rahimi NR, Fouladi-Fard R, Aali R, Shahryari A, Rezaali M, Ghafouri Y, Ghalhari MR, Asadi-Ghalhari M, Farzinnia B, Conti Gea O, Fiore M. Bidirectional association between COVID-19 and the environment: A systematic review. ENVIRONMENTAL RESEARCH 2021; 194:110692. [PMID: 33385384 PMCID: PMC7833965 DOI: 10.1016/j.envres.2020.110692] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 11/10/2020] [Accepted: 12/24/2020] [Indexed: 05/17/2023]
Abstract
The global crisis caused by SARS-CoV-2 (COVID-19) affected economics, social affairs, and the environment, not to mention public health. It is estimated that near 82% of the SARS-CoV-2 genome is similar to the severe acute respiratory syndrome. The purpose of the review is to highlight how the virus is impacted by the environment and how the virus has impacted the environment. This review was based on an electronic search of the literature in the Scopus, Science Direct, and PubMed database published from December 2019 to July 2020 using combinations of the following keywords: SARS-CoV-2 transmission, COVID-19 transmission, coronavirus transmission, waterborne, wastewater, airborne, solid waste, fomites, and fecal-oral transmission. Studies suggest the thermal properties of ambient air, as well as relative humidity, may affect the transmissibility and viability of the virus. Samples taken from the wastewater collection network were detected contaminated with the novel coronavirus; consequently, there is a concern of its transmission via an urban sewer system. There are concerns about the efficacy of the wastewater treatment plant disinfection process as the last chance to inactivate the virus. Handling solid waste also requires an utmost caution as it may contain infectious masks, etc. Following the PRISMA approach, among all reviewed studies, more than 36% of them were directly or indirectly related to the indoor and outdoor environment, 16% to meteorological factors, 11% to wastewater, 14% to fomites, 8% to water, 9% to solid waste, and 6% to the secondary environment. The still growing body of literature on COVID-19 and air, suggests the importance of SARS-CoV-2 transmission via air and indoor air quality, especially during lockdown interventions. Environmental conditions are found to be a factor in transmitting the virus beyond geographical borders. Accordingly, countries need to pay extra attention to sustainable development themes and goals.
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Affiliation(s)
- Nayereh Rezaie Rahimi
- Research Center for Environmental Pollutants, Department of Environmental Health Engineering, Faculty of Health, Qom University of Medical Sciences, Qom, Iran; Student Research Committee, Qom University of Medical Sciences, Qom, Iran
| | - Reza Fouladi-Fard
- Research Center for Environmental Pollutants, Department of Environmental Health Engineering, Faculty of Health, Qom University of Medical Sciences, Qom, Iran.
| | - Rahim Aali
- Research Center for Environmental Pollutants, Department of Environmental Health Engineering, Faculty of Health, Qom University of Medical Sciences, Qom, Iran.
| | - Ali Shahryari
- Department of Environmental Health Engineering, Gorgan University of Medical Sciences, Gorgan, Iran
| | | | - Yadollah Ghafouri
- Research Center for Environmental Pollutants, Department of Environmental Health Engineering, Faculty of Health, Qom University of Medical Sciences, Qom, Iran
| | - Mohammad Rezvani Ghalhari
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdi Asadi-Ghalhari
- Research Center for Environmental Pollutants, Department of Environmental Health Engineering, Faculty of Health, Qom University of Medical Sciences, Qom, Iran
| | - Babak Farzinnia
- Research Center for Environmental Pollutants, Department of Environmental Health Engineering, Faculty of Health, Qom University of Medical Sciences, Qom, Iran
| | - Oliveri Conti Gea
- Department of Medical, Surgical and Advanced Technologies "G.F. Ingrassia", University of Catania, Catania, Italy
| | - Maria Fiore
- Department of Medical, Surgical and Advanced Technologies "G.F. Ingrassia", University of Catania, Catania, Italy
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359
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Chaussade S, Ali EA, Hallit R, Belle A, Barret M, Coriat R. Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms. Endosc Int Open 2021; 9:E482-E486. [PMID: 33655053 PMCID: PMC7899790 DOI: 10.1055/a-1336-3280] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/05/2020] [Indexed: 12/30/2022] Open
Abstract
Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO 2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.
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Affiliation(s)
- Stanislas Chaussade
- Department of Gastroenterology and Endoscopy Unit, Cochin Teaching Hospital, AP-HP, and University of Paris, Paris, France,French Society for Digestive Endoscopy (SFED)
| | - Einas Abou Ali
- Department of Gastroenterology and Endoscopy Unit, Cochin Teaching Hospital, AP-HP, and University of Paris, Paris, France,French Society for Digestive Endoscopy (SFED)
| | - Rachel Hallit
- Department of Gastroenterology and Endoscopy Unit, Cochin Teaching Hospital, AP-HP, and University of Paris, Paris, France,French Society for Digestive Endoscopy (SFED)
| | - Arthur Belle
- Department of Gastroenterology and Endoscopy Unit, Cochin Teaching Hospital, AP-HP, and University of Paris, Paris, France,French Society for Digestive Endoscopy (SFED)
| | - Maximilien Barret
- Department of Gastroenterology and Endoscopy Unit, Cochin Teaching Hospital, AP-HP, and University of Paris, Paris, France,French Society for Digestive Endoscopy (SFED)
| | - Romain Coriat
- Department of Gastroenterology and Endoscopy Unit, Cochin Teaching Hospital, AP-HP, and University of Paris, Paris, France
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360
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Cutts T, Kasloff S, Safronetz D, Krishnan J. Decontamination of common healthcare facility surfaces contaminated with SARS-CoV-2 using peracetic acid dry fogging. J Hosp Infect 2021; 109:82-87. [PMID: 33417989 PMCID: PMC7832754 DOI: 10.1016/j.jhin.2020.12.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 12/24/2020] [Accepted: 12/26/2020] [Indexed: 01/12/2023]
Abstract
BACKGROUND The SARS-CoV-2 pandemic has highlighted the urgent need for safe and effective surface decontamination methods, particularly in healthcare settings. AIM To evaluate the effectiveness of peracetic acid (PAA) dry fogging in decontaminating healthcare facility surfaces experimentally contaminated with SARS-CoV-2. METHODS Nine materials (stainless steel, latex painted wood, unsealed hardwood, melamine countertop, vinyl flooring, clear plastic, faux leather, computer keyboard button, and smartphone touch screen) were surface contaminated with >106 median tissue culture infectious dose (TCID50) of SARS-CoV-2, and allowed to dry before exposing to PAA dry fogging. FINDINGS When fumigated with PAA dry fog for 1 h, no infectious SARS-CoV-2 virus was recovered from any of the experimentally inoculated surface types. By contrast, high titres of infectious virus were recovered from corresponding untreated drying controls of the same materials. CONCLUSION Standard surface decontamination processes, including sprays and wipes, are laborious and frequently cannot completely decontaminate sensitive electronic equipment. The ease of use, low cost, and overall effectiveness of a PAA dry fogging suggest that it should be considered for decontaminating healthcare settings, particularly intensive care units where severely ill SARS-CoV-2 patients are cared for.
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Affiliation(s)
- T Cutts
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - S Kasloff
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - D Safronetz
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - J Krishnan
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
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361
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Hadei M, Mohebbi SR, Hopke PK, Shahsavani A, Bazzazpour S, Alipour M, Jafari AJ, Bandpey AM, Zali A, Yarahmadi M, Farhadi M, Rahmatinia M, Hasanzadeh V, Nazari SSH, Asadzadeh-Aghdaei H, Tanhaei M, Zali MR, Kermani M, Vaziri MH, Chobineh H. Presence of SARS-CoV-2 in the air of public places and transportation. ATMOSPHERIC POLLUTION RESEARCH 2021; 12:302-306. [PMID: 33519256 PMCID: PMC7833664 DOI: 10.1016/j.apr.2020.12.016] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/24/2020] [Accepted: 12/25/2020] [Indexed: 05/18/2023]
Abstract
This study investigated the presence of SARS-CoV-2 in air of public places such as shopping centers, a post office, banks, governmental offices, and public transportation facilities including an airport, subways, and buses in Tehran, Iran. A total of 28 air samples were collected from the eight groups of public and transportation locations. The airborne particle samples were collected on PTFE or glass fiber filters using two types of samplers with flow rates of 40 and 3.5 L/min, respectively. The viral samples were leached and concentrated, and RNA was extracted from each. The presence of viral RNA was evaluated using novel coronavirus nucleic acid diagnostic real time PCR kits. In 64% of the samples, SARS-CoV-2 RNA (62% and 67% from the public places and transportation, respectively) was detected. Positive samples were detected in banks (33%), shopping centers (100%), governmental offices (50%), the airport (80%), subway stations (50%), subway trains (100%), and buses (50%). Logistic regression showed that number of people present during the sampling and the sampled air volume were positively associated with presence of SARS-CoV-2; while the percentage of people with masks, air temperature, and sampling site's volume were negatively related to SARS-CoV-2's presence. However, none of these associations were statistically significant. This study showed that most public places and transportation vehicles were contaminated with SARS-CoV-2. Thus, strategies to control the spread of COVID-19 should include reducing the number of people in indoor spaces, more intense disinfection of transport vehicles, and requiring people to wear masks.
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Affiliation(s)
- Mostafa Hadei
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Reza Mohebbi
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Philip K Hopke
- Department of Public Health Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
- Center for Air Resources Engineering and Science, Clarkson University, Potsdam, NY, 13699, USA
| | - Abbas Shahsavani
- Environmental and Occupational Hazards Control Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahriyar Bazzazpour
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Alipour
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ahmad Jonidi Jafari
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
| | - Anooshiravan Mohseni Bandpey
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Alireza Zali
- Department of Neurosurgery, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Yarahmadi
- Environmental and Occupational Health Center, Ministry of Health and Medical Education, Tehran, Iran
| | - Mohsen Farhadi
- Environmental and Occupational Health Center, Ministry of Health and Medical Education, Tehran, Iran
| | - Masoumeh Rahmatinia
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Vajihe Hasanzadeh
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Saeed Hashemi Nazari
- Department of Epidemiology, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Asadzadeh-Aghdaei
- Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Tanhaei
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Zali
- Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Majid Kermani
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
| | - Mohmmad Hossien Vaziri
- Workplace Health Promotion Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Chobineh
- Department of Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran
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362
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Miller SL, Nazaroff WW, Jimenez JL, Boerstra A, Buonanno G, Dancer SJ, Kurnitski J, Marr LC, Morawska L, Noakes C. Transmission of SARS-CoV-2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event. INDOOR AIR 2021; 31:314-323. [PMID: 32979298 DOI: 10.1101/2020.06.15.20132027] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/26/2020] [Accepted: 09/15/2020] [Indexed: 05/22/2023]
Abstract
During the 2020 COVID-19 pandemic, an outbreak occurred following attendance of a symptomatic index case at a weekly rehearsal on 10 March of the Skagit Valley Chorale (SVC). After that rehearsal, 53 members of the SVC among 61 in attendance were confirmed or strongly suspected to have contracted COVID-19 and two died. Transmission by the aerosol route is likely; it appears unlikely that either fomite or ballistic droplet transmission could explain a substantial fraction of the cases. It is vital to identify features of cases such as this to better understand the factors that promote superspreading events. Based on a conditional assumption that transmission during this outbreak was dominated by inhalation of respiratory aerosol generated by one index case, we use the available evidence to infer the emission rate of aerosol infectious quanta. We explore how the risk of infection would vary with several influential factors: ventilation rate, duration of event, and deposition onto surfaces. The results indicate a best-estimate emission rate of 970 ± 390 quanta/h. Infection risk would be reduced by a factor of two by increasing the aerosol loss rate to 5 h-1 and shortening the event duration from 2.5 to 1 h.
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Affiliation(s)
- Shelly L Miller
- Mechanical Engineering, University of Colorado, Boulder, CO, USA
| | - William W Nazaroff
- Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | - Jose L Jimenez
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO, USA
| | - Atze Boerstra
- REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations), BBA Binnenmilieu, Den Haag, The Netherlands
| | - Giorgio Buonanno
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, Italy
| | | | - Jarek Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn, Estonia
| | - Linsey C Marr
- Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Lidia Morawska
- International Laboratory for Air Quality and Heath (ILAQH), WHO Collaborating Centre for Air Quality and Health, School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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363
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Miller SL, Nazaroff WW, Jimenez JL, Boerstra A, Buonanno G, Dancer SJ, Kurnitski J, Marr LC, Morawska L, Noakes C. Transmission of SARS-CoV-2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event. INDOOR AIR 2021; 31:314-323. [PMID: 32979298 PMCID: PMC7537089 DOI: 10.1111/ina.12751] [Citation(s) in RCA: 317] [Impact Index Per Article: 105.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/26/2020] [Accepted: 09/15/2020] [Indexed: 05/02/2023]
Abstract
During the 2020 COVID-19 pandemic, an outbreak occurred following attendance of a symptomatic index case at a weekly rehearsal on 10 March of the Skagit Valley Chorale (SVC). After that rehearsal, 53 members of the SVC among 61 in attendance were confirmed or strongly suspected to have contracted COVID-19 and two died. Transmission by the aerosol route is likely; it appears unlikely that either fomite or ballistic droplet transmission could explain a substantial fraction of the cases. It is vital to identify features of cases such as this to better understand the factors that promote superspreading events. Based on a conditional assumption that transmission during this outbreak was dominated by inhalation of respiratory aerosol generated by one index case, we use the available evidence to infer the emission rate of aerosol infectious quanta. We explore how the risk of infection would vary with several influential factors: ventilation rate, duration of event, and deposition onto surfaces. The results indicate a best-estimate emission rate of 970 ± 390 quanta/h. Infection risk would be reduced by a factor of two by increasing the aerosol loss rate to 5 h-1 and shortening the event duration from 2.5 to 1 h.
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Affiliation(s)
| | - William W Nazaroff
- Civil and Environmental EngineeringUniversity of CaliforniaBerkeleyCAUSA
| | - Jose L. Jimenez
- Department of Chemistry and CIRESUniversity of ColoradoBoulderCOUSA
| | - Atze Boerstra
- REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations)BBA BinnenmilieuDen HaagThe Netherlands
| | - Giorgio Buonanno
- Department of Civil and Mechanical EngineeringUniversity of Cassino and Southern LazioCassinoItaly
| | | | - Jarek Kurnitski
- REHVA Technology and Research CommitteeTallinn University of TechnologyTallinnEstonia
| | - Linsey C. Marr
- Civil and Environmental EngineeringVirginia TechBlacksburgVAUSA
| | - Lidia Morawska
- International Laboratory for Air Quality and Heath (ILAQH)WHO Collaborating Centre for Air Quality and HealthSchool of Earth and Atmospheric SciencesQueensland University of TechnologyBrisbaneQueenslandAustralia
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364
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Komperda J, Peyvan A, Li D, Kashir B, Yarin AL, Megaridis CM, Mirbod P, Paprotny I, Cooper LF, Rowan S, Stanford C, Mashayek F. Computer simulation of the SARS-CoV-2 contamination risk in a large dental clinic. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2021; 33:033328. [PMID: 33897241 PMCID: PMC8060974 DOI: 10.1063/5.0043934] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/16/2021] [Indexed: 05/18/2023]
Abstract
COVID-19, caused by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) virus, has been rapidly spreading worldwide since December 2019, causing a public health crisis. Recent studies showed SARS-CoV-2's ability to infect humans via airborne routes. These motivated the study of aerosol and airborne droplet transmission in a variety of settings. This study performs a large-scale numerical simulation of a real-world dentistry clinic that contains aerosol-generating procedures. The simulation tracks the dispersion of evaporating droplets emitted during ultrasonic dental scaling procedures. The simulation considers 25 patient treatment cubicles in an open plan dentistry clinic. The droplets are modeled as having a volatile (evaporating) and nonvolatile fraction composed of virions, saliva, and impurities from the irrigant water supply. The simulated clinic's boundary and flow conditions are validated against experimental measurements of the real clinic. The results evaluate the behavior of large droplets and aerosols. We investigate droplet residence time and travel distance for different droplet diameters, surface contamination due to droplet settling and deposition, airborne aerosol mass concentration, and the quantity of droplets that escape through ventilation. The simulation results raise concerns due to the aerosols' long residence times (averaging up to 7.31 min) and travel distances (averaging up to 24.45 m) that exceed social distancing guidelines. Finally, the results show that contamination extends beyond the immediate patient treatment areas, requiring additional surface disinfection in the clinic. The results presented in this research may be used to establish safer dental clinic operating procedures, especially if paired with future supplementary material concerning the aerosol viral load generated by ultrasonic scaling and the viral load thresholds required to infect humans.
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Affiliation(s)
- Jonathan Komperda
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Ahmad Peyvan
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Dongru Li
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Babak Kashir
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Alexander L. Yarin
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Constantine M. Megaridis
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Parisa Mirbod
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Igor Paprotny
- Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Lyndon F. Cooper
- College of Dentistry, University of Illinois at Chicago, Chicago, Illinois 60612, USA
| | - Susan Rowan
- College of Dentistry, University of Illinois at Chicago, Chicago, Illinois 60612, USA
| | - Clark Stanford
- College of Dentistry, University of Illinois at Chicago, Chicago, Illinois 60612, USA
| | - Farzad Mashayek
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, USA
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365
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Stern RA, Koutrakis P, Martins MAG, Lemos B, Dowd SE, Sunderland EM, Garshick E. Characterization of hospital airborne SARS-CoV-2. Respir Res 2021; 22:73. [PMID: 33637076 PMCID: PMC7909372 DOI: 10.1186/s12931-021-01637-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/24/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The mechanism for spread of SARS-CoV-2 has been attributed to large particles produced by coughing and sneezing. There is controversy whether smaller airborne particles may transport SARS-CoV-2. Smaller particles, particularly fine particulate matter (≤ 2.5 µm in diameter), can remain airborne for longer periods than larger particles and after inhalation will penetrate deeply into the lungs. Little is known about the size distribution and location of airborne SARS-CoV-2 RNA. METHODS As a measure of hospital-related exposure, air samples of three particle sizes (> 10.0 µm, 10.0-2.5 µm, and ≤ 2.5 µm) were collected in a Boston, Massachusetts (USA) hospital from April to May 2020 (N = 90 size-fractionated samples). Locations included outside negative-pressure COVID-19 wards, a hospital ward not directly involved in COVID-19 patient care, and the emergency department. RESULTS SARS-CoV-2 RNA was present in 9% of samples and in all size fractions at concentrations of 5 to 51 copies m-3. Locations outside COVID-19 wards had the fewest positive samples. A non-COVID-19 ward had the highest number of positive samples, likely reflecting staff congregation. The probability of a positive sample was positively associated (r = 0.95, p < 0.01) with the number of COVID-19 patients in the hospital. The number of COVID-19 patients in the hospital was positively associated (r = 0.99, p < 0.01) with the number of new daily cases in Massachusetts. CONCLUSIONS More frequent detection of positive samples in non-COVID-19 than COVID-19 hospital areas indicates effectiveness of COVID-ward hospital controls in controlling air concentrations and suggests the potential for disease spread in areas without the strictest precautions. The positive associations regarding the probability of a positive sample, COVID-19 cases in the hospital, and cases in Massachusetts suggests that hospital air sample positivity was related to community burden. SARS-CoV-2 RNA with fine particulate matter supports the possibility of airborne transmission over distances greater than six feet. The findings support guidelines that limit exposure to airborne particles including fine particles capable of longer distance transport and greater lung penetration.
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Affiliation(s)
- Rebecca A Stern
- Harvard John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
| | - Petros Koutrakis
- Department of Environmental Health, Harvard T.H. Chan School of Public Heath, Boston, MA, USA
| | - Marco A G Martins
- Department of Environmental Health, Harvard T.H. Chan School of Public Heath, Boston, MA, USA
| | - Bernardo Lemos
- Department of Environmental Health and Molecular and Integrative Physiological Sciences Program, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Scot E Dowd
- Molecular Research LP (MR DNA), Shallowater, TX, USA
| | - Elsie M Sunderland
- Harvard John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, MA, USA
- Department of Environmental Health, Harvard T.H. Chan School of Public Heath, Boston, MA, USA
| | - Eric Garshick
- Pulmonary, Allergy, Sleep, and Critical Care Medicine Section, VA Boston Healthcare System, 1400 VFW Pkwy, West Roxbury, Boston, MA, 02132, USA.
- Channing Division of Network Medicine, Brigham and Women's Hospital, Boston, MA, USA.
- Harvard Medical School, Boston, MA, USA.
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366
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Oberst M, Heinrich A. [Effect of a mobile room air filter on the aerosol burden in surgical examination rooms against the background of the COVID-19 pandemic]. Unfallchirurg 2021; 124:362-365. [PMID: 33638014 PMCID: PMC7909946 DOI: 10.1007/s00113-021-00975-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2021] [Indexed: 11/24/2022]
Abstract
Due to the airborne transmission of the coronavirus disease 2019 (COVID 19) via aerosols or microdroplets, this study investigated the effect of a mobile air filter system in a surgical examination room. The use of the air filter system led to a significant reduction of aerosols in the room. Therefore the use of a high efficiency air filtration device, in examination rooms with poor ventilation, e.g. lack of windows or local exhaust, is mandatory.
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Affiliation(s)
- Michael Oberst
- Klinik für Orthopädie, Unfall- und Wirbelsäulenchirurgie, Ostalb-Klinikum, Im Kälblesrain 1, 73430, Aalen, Deutschland.
| | - Andreas Heinrich
- Zentrum für Optische Technologien (ZOT), Hochschule Aalen, Beethovenstr. 1, 73430, Aalen, Deutschland
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367
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Lednicky JA, Cherabuddi K, Tagliamonte MS, Elbadry MA, Subramaniam K, Waltzek TB, Morris JG. In-Frame 12-Nucleotide Deletion within Open Reading Frame 3a in a SARS-CoV-2 Strain Isolated from a Patient Hospitalized with COVID-19. Microbiol Resour Announc 2021; 10:e00137-21. [PMID: 33632859 PMCID: PMC7909084 DOI: 10.1128/mra.00137-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 02/05/2021] [Indexed: 11/24/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain UF-8, with an in-frame 12-nucleotide deletion within open reading frame 3a (ORF3a), was isolated from a 78-year-old COVID-19 patient in March 2020.
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Affiliation(s)
- John A Lednicky
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
| | - Kartikeya Cherabuddi
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Massimiliano S Tagliamonte
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Maha A Elbadry
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, Florida, USA
| | - Kuttichantran Subramaniam
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - Thomas B Waltzek
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - J Glenn Morris
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA
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368
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Suggestions for global coagulation assays for the assessment of COVID-19 associated hypercoagulability. Thromb Res 2021; 201:84-89. [PMID: 33662799 PMCID: PMC7903905 DOI: 10.1016/j.thromres.2021.02.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/26/2021] [Accepted: 02/16/2021] [Indexed: 12/15/2022]
Abstract
Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection is associated with a clear prothrombotic phenotype. Although the exact pathophysiological mechanisms are not yet fully understood, thrombosis is clearly a highly important in the prognosis and outcome of COVID-19. As such, there is a need for diagnostic analysis and quantification of the coagulation potential in these patients, both at diagnosis and follow-up. Global coagulation assays like thrombin generation (TG) and rotational thromboelastometry (ROTEM) might be suitable in estimating COVID-19 associated coagulopathy and thrombosis risk. Therefore, we aimed at validating both assays for samples with high levels of fibrinogen and in the presence of anticoagulant heparins, such as commonly observed for COVID-19 ICU patients. Materials and methods Calibrated Automated Thrombography (CAT) was optimized to assess plasma thrombin generation in the presence of heparins. The final conditions with either 10 μg/mL Ellagic acid (EA) or PPP Reagent HIGH (high tissue factor; HPPH) were validated according to the EP5 protocol for within-run and between-run variability. Overall variability was well below 10%. To estimate the influences of heparins and high fibrinogen levels, CAT was performed on spiked plasma aliquots from 13 healthy volunteers. Comparable to the CAT method, tPA-ROTEM was used to validate the effect of high fibrinogen and heparins on clotting time, clot firmness and clot lysis parameters. Results Our adjusted COVID-19 assay showed a heparin dose dependent decrease in peak height and endogenous thrombin potential (ETP) for both EA and HPPH triggered variants. High fibrinogen did not alter the inhibitory effect of either LMWH or UFH, nor did it influence the peak height or ETP in any of the conditions. The tPA-ROTEM showed a significant prolongation in clotting time with the additions of heparin, which normalized with the addition of high fibrinogen. MCF was markedly increased in all hyperfibrinogenemic conditions. A trend towards increased lysis time and, thus, decreased fibrinolysis was observed. Conclusion Thrombin generation and tPA-ROTEM protocols for measurements in the COVID-19 populations were adjusted and validated. The adjusted thrombin generation assay shows good sensitivity for measurements in heparin spiked plasma. High levels of fibrinogen did not alter the assay or the effectiveness of heparins as measured in this assay. t-PA ROTEM was effective in measurement of both high fibrinogen and heparins spiked samples and was sensitive to the expected relevant coagulant changes by these conditions. No clear fibrinolytic effect was observed in different conditions.
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369
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Azimi P, Keshavarz Z, Cedeno Laurent JG, Stephens B, Allen JG. Mechanistic transmission modeling of COVID-19 on the Diamond Princess cruise ship demonstrates the importance of aerosol transmission. Proc Natl Acad Sci U S A 2021; 118:e2015482118. [PMID: 33536312 PMCID: PMC7923347 DOI: 10.1073/pnas.2015482118] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Several lines of existing evidence support the possibility of airborne transmission of coronavirus disease 2019 (COVID-19). However, quantitative information on the relative importance of transmission pathways of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains limited. To evaluate the relative importance of multiple transmission routes for SARS-CoV-2, we developed a modeling framework and leveraged detailed information available from the Diamond Princess cruise ship outbreak that occurred in early 2020. We modeled 21,600 scenarios to generate a matrix of solutions across a full range of assumptions for eight unknown or uncertain epidemic and mechanistic transmission factors. A total of 132 model iterations met acceptability criteria (R2 > 0.95 for modeled vs. reported cumulative daily cases and R2 > 0 for daily cases). Analyzing only these successful model iterations quantifies the likely contributions of each defined mode of transmission. Mean estimates of the contributions of short-range, long-range, and fomite transmission modes to infected cases across the entire simulation period were 35%, 35%, and 30%, respectively. Mean estimates of the contributions of larger respiratory droplets and smaller respiratory aerosols were 41% and 59%, respectively. Our results demonstrate that aerosol inhalation was likely the dominant contributor to COVID-19 transmission among the passengers, even considering a conservative assumption of high ventilation rates and no air recirculation conditions for the cruise ship. Moreover, close-range and long-range transmission likely contributed similarly to disease progression aboard the ship, with fomite transmission playing a smaller role. The passenger quarantine also affected the importance of each mode, demonstrating the impacts of the interventions.
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Affiliation(s)
- Parham Azimi
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA 02115;
| | - Zahra Keshavarz
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA 02115
| | | | - Brent Stephens
- Department of Civil, Architectural, and Environmental Engineering, Illinois Institute of Technology, Chicago, IL 60616
| | - Joseph G Allen
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA 02115;
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370
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Azimi P, Keshavarz Z, Cedeno Laurent JG, Stephens B, Allen JG. Mechanistic transmission modeling of COVID-19 on the Diamond Princess cruise ship demonstrates the importance of aerosol transmission. Proc Natl Acad Sci U S A 2021. [PMID: 33536312 DOI: 10.1101/2020.07.13.20153049] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
Several lines of existing evidence support the possibility of airborne transmission of coronavirus disease 2019 (COVID-19). However, quantitative information on the relative importance of transmission pathways of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains limited. To evaluate the relative importance of multiple transmission routes for SARS-CoV-2, we developed a modeling framework and leveraged detailed information available from the Diamond Princess cruise ship outbreak that occurred in early 2020. We modeled 21,600 scenarios to generate a matrix of solutions across a full range of assumptions for eight unknown or uncertain epidemic and mechanistic transmission factors. A total of 132 model iterations met acceptability criteria (R2 > 0.95 for modeled vs. reported cumulative daily cases and R2 > 0 for daily cases). Analyzing only these successful model iterations quantifies the likely contributions of each defined mode of transmission. Mean estimates of the contributions of short-range, long-range, and fomite transmission modes to infected cases across the entire simulation period were 35%, 35%, and 30%, respectively. Mean estimates of the contributions of larger respiratory droplets and smaller respiratory aerosols were 41% and 59%, respectively. Our results demonstrate that aerosol inhalation was likely the dominant contributor to COVID-19 transmission among the passengers, even considering a conservative assumption of high ventilation rates and no air recirculation conditions for the cruise ship. Moreover, close-range and long-range transmission likely contributed similarly to disease progression aboard the ship, with fomite transmission playing a smaller role. The passenger quarantine also affected the importance of each mode, demonstrating the impacts of the interventions.
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Affiliation(s)
- Parham Azimi
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA 02115;
| | - Zahra Keshavarz
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA 02115
| | | | - Brent Stephens
- Department of Civil, Architectural, and Environmental Engineering, Illinois Institute of Technology, Chicago, IL 60616
| | - Joseph G Allen
- Environmental Health Department, Harvard T.H. Chan School of Public Health, Boston, MA 02115;
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371
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372
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Zhou L, Yao M, Zhang X, Hu B, Li X, Chen H, Zhang L, Liu Y, Du M, Sun B, Jiang Y, Zhou K, Hong J, Yu N, Ding Z, Xu Y, Hu M, Morawska L, Grinshpun SA, Biswas P, Flagan RC, Zhu B, Liu W, Zhang Y. Breath-, air- and surface-borne SARS-CoV-2 in hospitals. JOURNAL OF AEROSOL SCIENCE 2021; 152:105693. [PMID: 33078030 PMCID: PMC7557302 DOI: 10.1016/j.jaerosci.2020.105693] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 05/09/2023]
Abstract
The COVID-19 pandemic has brought an unprecedented crisis to the global health sector. When discharging COVID-19 patients in accordance with throat or nasal swab protocols using RT-PCR, the potential risk of reintroducing the infection source to humans and the environment must be resolved. Here, 14 patients including 10 COVID-19 subjects were recruited; exhaled breath condensate (EBC), air samples and surface swabs were collected and analyzed for SARS-CoV-2 using reverse transcription-polymerase chain reaction (RT-PCR) in four hospitals with applied natural ventilation and disinfection practices in Wuhan. Here we discovered that 22.2% of COVID-19 patients (n = 9), who were ready for hospital discharge based on current guidelines, had SARS-CoV-2 in their exhaled breath (~105 RNA copies/m3). Although fewer surface swabs (3.1%, n = 318) tested positive, medical equipment such as face shield frequently contacted/used by healthcare workers and the work shift floor were contaminated by SARS-CoV-2 (3-8 viruses/cm2). Three of the air samples (n = 44) including those collected using a robot-assisted sampler were detected positive by a digital PCR with a concentration level of 9-219 viruses/m3. RT-PCR diagnosis using throat swab specimens had a failure rate of more than 22% in safely discharging COVID-19 patients who were otherwise still exhaling the SARS-CoV-2 by a rate of estimated ~1400 RNA copies per minute into the air. Direct surface contact might not represent a major transmission route, and lower positive rate of air sample (6.8%) was likely due to natural ventilation (1.6-3.3 m/s) and regular disinfection practices. While there is a critical need for strengthening hospital discharge standards in preventing re-emergence of COVID-19 spread, use of breath sample as a supplement specimen could further guard the hospital discharge to ensure the safety of the public and minimize the pandemic re-emergence risk.
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Affiliation(s)
- Lian Zhou
- Department of Environment and Health, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Maosheng Yao
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Xiang Zhang
- The First Affiliated Hospital of Nanjing Medical University (Jiangsu Province Hospital), Nanjing, 210009, China
| | - Bicheng Hu
- The Clinical Laboratory, Wuhan No.1 Hospital, Wuhan, 430022, China
| | - Xinyue Li
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Haoxuan Chen
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Lu Zhang
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Yun Liu
- The First Affiliated Hospital of Nanjing Medical University (Jiangsu Province Hospital), Nanjing, 210009, China
| | - Meng Du
- Zhenjiang Center for Disease Control and Prevention, Zhenjiang, 212003, China
| | - Bochao Sun
- Yancheng Center for Disease Control and Prevention, Yancheng, 224002, China
| | - Yunyu Jiang
- Taizhou Center for Disease Control and Prevention, Taizhou, 225306, China
| | - Kai Zhou
- Suzhou Center for Disease Control and Prevention, Suzhou, 215004, China
| | - Jie Hong
- Department of Environment and Health, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Na Yu
- The First Hospital of China Medical University, Shenyang, 110001, China
| | - Zhen Ding
- Department of Environment and Health, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Yan Xu
- Department of Environment and Health, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
| | - Min Hu
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Lidia Morawska
- International Laboratory for Air Quality and Heath (ILAQH), WHO Collaborating Centre for Air Quality and Health, School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Queensland, QLD 4001, Australia
| | - Sergey A Grinshpun
- Center for Health-Related Aerosol Studies, Department of Environmental & Public Health Sciences, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Pratim Biswas
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Richard C Flagan
- Department of Environmental Science and Engineering and Department of Chemical Engineering, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Baoli Zhu
- Department of Environment and Health, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, China
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, 211166, China
| | - Wenqing Liu
- Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei City, Anhui Province, 230031, China
| | - Yuanhang Zhang
- College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
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373
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Liu H, He S, Shen L, Hong J. Simulation-based study of COVID-19 outbreak associated with air-conditioning in a restaurant. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2021; 33:023301. [PMID: 33746488 PMCID: PMC7976041 DOI: 10.1063/5.0040188] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 12/29/2020] [Indexed: 05/03/2023]
Abstract
COVID-19 has shown a high potential of transmission via virus-carrying aerosols as supported by growing evidence. However, detailed investigations that draw direct links between aerosol transport and virus infection are still lacking. To fill in the gap, we conducted a systematic computational fluid dynamics (CFD)-based investigation of indoor airflow and the associated aerosol transport in a restaurant setting, where likely cases of airflow-induced infection of COVID-19 caused by asymptomatic individuals were widely reported by the media. We employed an advanced in-house large eddy simulation solver and other cutting-edge numerical methods to resolve complex indoor processes simultaneously, including turbulence, flow-aerosol interplay, thermal effect, and the filtration effect by air conditioners. Using the aerosol exposure index derived from the simulation, we are able to provide a spatial map of the airborne infection risk under different settings. Our results have shown a remarkable direct linkage between regions of high aerosol exposure index and the reported infection patterns in the restaurant, providing strong support to the airborne transmission occurring in this widely reported incident. Using flow structure analysis and reverse-time tracing of aerosol trajectories, we are able to further pinpoint the influence of environmental parameters on the infection risks and highlight the need for more effective preventive measures, e.g., placement of shielding according to the local flow patterns. Our research, thus, has demonstrated the capability and value of high-fidelity CFD tools for airborne infection risk assessment and the development of effective preventive measures.
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Affiliation(s)
- Han Liu
- Department of Mechanical Engineering and St. Anthony Falls Laboratory,
University of Minnesota, Minneapolis, Minnesota 55455,
USA
| | - Sida He
- Department of Mechanical Engineering and St. Anthony Falls Laboratory,
University of Minnesota, Minneapolis, Minnesota 55455,
USA
| | - Lian Shen
- Department of Mechanical Engineering and St. Anthony Falls Laboratory,
University of Minnesota, Minneapolis, Minnesota 55455,
USA
| | - Jiarong Hong
- Department of Mechanical Engineering and St. Anthony Falls Laboratory,
University of Minnesota, Minneapolis, Minnesota 55455,
USA
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374
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Scaggs Huang F, Schaffzin JK. Rewriting the playbook: infection prevention practices to mitigate nosocomial severe acute respiratory syndrome coronavirus 2 transmission. Curr Opin Pediatr 2021; 33:136-143. [PMID: 33315687 DOI: 10.1097/mop.0000000000000973] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW Given the limited evidence and experience with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), this novel pathogen has challenged the field of infection prevention. Despite uncertainty, infection prevention principles and experience with similar diseases have helped guide how to best protect providers and patients against disease acquisition. RECENT FINDINGS Guidance to date has relied on data from SARS-CoV-1 and MERS-CoV to guide practices on patient isolation and personal protective equipment (PPE) use. Although a face mask and eye protection are likely adequate for most clinical scenarios, published guidelines for PPE can be confusing and conflicting. Consensus for what constitutes a high-risk aerosol-generating procedure (AGP) is lacking, but most agree providers performing procedures such as bronchoscopy, intubation, and cardiopulmonary resuscitation would likely benefit from the use of an N95 respirator and eye protection. SUMMARY Needed research to elucidate the predominant SARS-CoV-2 mode of transmission is not likely to be completed in the immediate future. Recommendations for PPE to mitigate procedure-associated risk remain controversial. Nonetheless, implementation of existing measures based on basic infection prevention principles is likely to prevent transmission significantly.
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Affiliation(s)
- Felicia Scaggs Huang
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
| | - Joshua K Schaffzin
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, USA
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375
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Abstract
Healthcare workers (HCWs) in Ontario, Canada have faced unprecedented risks during the COVID-19 pandemic. They have been infected at an elevated rate compared to the general public. HCWs have argued for better protections with minimal success. A worldwide shortage of N95s and comparable respirators appears to have influenced guidelines for protection, which stand at odds with increasing scientific evidence. In-depth interviews were conducted with ten frontline HCWs about their concerns. They reported that the risk of contracting COVID-19 and infecting family members has created intense anxiety. This, in conjunction with understaffing and an increased workload, has resulted in exhaustion and burnout. HCWs feel abandoned by their governments, which failed to prepare for an inevitable epidemic, despite recommendations. The knowledge that they are at increased risk of infection due to lack of protection has resulted in anger, frustration, fear, and a sense of violation that may have long-lasting implications.Sacrifié: Le personnel de la santé ontarien à l'époque de la COVID-19RésuméEn Ontario, au Canada, le personnel de la santé a eu à faire face à des risques sans précédent durant la pandémie de COVID-19. On y a constaté un taux d'infection plus élevé chez les travailleuses et travailleurs de la santé (TTS) qu'au sein de la population en général. Les TTS ont revendiqué des moyens de protection améliorés, sans grand succès. Une pénurie mondiale de masques respirateurs de type N95 ou similaires semble avoir joué sur les directives en matière de protection, qui ne cadrent pas avec une accumulation de preuves scientifiques. Lors d'entretiens en profondeur, dix TTS de première ligne ont été invités à donner leur avis sur la situation. à les entendre, le risque de contracter la COVID-19 et d'infecter les membres de leur famille leur cause beaucoup d'anxiété. Associée à un manque de personnel et à une charge de travail accrue, cette anxiété se traduit par un épuisement physique et professionnel. Les TTS se sentent abandonnés par leurs gouvernements, qui ont manqué de se préparer à l'inévitabilité d'une épidémie, malgré ce qui leur avait été recommandé. Leur réalisation d'être exposés à un plus grand risque d'infection par manque d'équipement de protection s'est muée en colère, frustration et peur, et en un sentiment de violation de leurs droits dont on peut craindre qu'il subsiste fort longtemps.
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Affiliation(s)
- James T. Brophy
- University of Windsor, ON, Canada
- University of Stirling, Scotland
- Athabasca University, AB, Canada
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376
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Lane MA, Brownsword EA, Babiker A, Ingersoll JM, Waggoner J, Ayers M, Klopman M, Uyeki TM, Lindsley WG, Kraft CS. Bioaerosol sampling for SARS-CoV-2 in a referral center with critically ill COVID-19 patients March-May 2020. Clin Infect Dis 2021; 73:e1790-e1794. [PMID: 33506256 PMCID: PMC7953966 DOI: 10.1093/cid/ciaa1880] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Indexed: 12/23/2022] Open
Abstract
Background Previous research has shown that rooms of patients with coronavirus disease 2019 (COVID-19) present the potential for healthcare-associated transmission through aerosols containing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, data on the presence of these aerosols outside of patient rooms are limited. We investigated whether virus-containing aerosols were present in nursing stations and patient room hallways in a referral center with critically ill COVID-19 patients. Methods Eight National Institute for Occupational Safety and Health BC 251 2-stage cyclone samplers were set up throughout 6 units, including nursing stations and visitor corridors in intensive care units and general medical units, for 6 h each sampling period. Samplers were placed on tripods which held 2 samplers positioned 102 cm and 152 cm above the floor. Units were sampled for 3 days. Extracted samples underwent reverse transcription polymerase chain reaction for selected gene regions of the SARS-CoV-2 virus nucleocapsid and the housekeeping gene human RNase P as an internal control. Results The units sampled varied in the number of laboratory-confirmed COVID-19 patients present on the days of sampling. Some of the units included patient rooms under negative pressure, while most were maintained at a neutral pressure. Of 528 aerosol samples collected, none were positive for SARS-CoV-2 RNA by the estimated limit of detection of 8 viral copies/m3 of air. Conclusions Aerosolized SARS-CoV-2 outside of patient rooms was undetectable. While healthcare personnel should avoid unmasked close contact with each other, these findings may provide reassurance for the use of alternatives to tight-fitting respirators in areas outside of patient rooms during the current pandemic.
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Affiliation(s)
- Morgan A Lane
- Division of Infectious Diseases, Department of Medicine Emory University, Atlanta, GA, USA
| | - Erik A Brownsword
- Division of Infectious Diseases, Department of Medicine Emory University, Atlanta, GA, USA
| | - Ahmed Babiker
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Jessica M Ingersoll
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Jesse Waggoner
- Division of Infectious Diseases, Department of Medicine Emory University, Atlanta, GA, USA.,Emory Healthcare, Atlanta, GA
| | | | - Matthew Klopman
- Emory Healthcare, Atlanta, GA.,Department of Anesthesiology, Emory University, Atlanta, GA, USA
| | - Timothy M Uyeki
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA
| | | | - Colleen S Kraft
- Division of Infectious Diseases, Department of Medicine Emory University, Atlanta, GA, USA.,Emory Healthcare, Atlanta, GA.,Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
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377
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Percivalle E, Clerici M, Cassaniti I, Vecchio Nepita E, Marchese P, Olivati D, Catelli C, Berri A, Baldanti F, Marone P, Bruno R, Triarico A, Lago P. SARS-CoV-2 viability on different surfaces after gaseous ozone treatment: a preliminary evaluation. J Hosp Infect 2021; 110:33-36. [PMID: 33516798 PMCID: PMC7842195 DOI: 10.1016/j.jhin.2021.01.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022]
Abstract
COVID-19 is a global health threat with a huge number of confirmed cases and deaths all over the world. Human-to-human transmission via respiratory droplets and contact with aerosol-infected surfaces are the major routes of virus spread. Because SARS-CoV-2 can remain in the air and on surfaces from several hours to several days, disinfection of frequently touched surfaces and critical rooms, in addition to observing individual hygiene tips, is required to reduce the virus spreading. Here we report on an investigation into the use of gaseous ozone as a potentially effective sanitizing method against the new coronavirus.
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Affiliation(s)
- E Percivalle
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - M Clerici
- P.C. di Pompeo Catelli SRL, Uggiate Trevano, Como, Italy.
| | - I Cassaniti
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - E Vecchio Nepita
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - P Marchese
- Safety Bio Life SRL, Albuzzano, Pavia, Italy
| | - D Olivati
- Safety Bio Life SRL, Albuzzano, Pavia, Italy
| | - C Catelli
- P.C. di Pompeo Catelli SRL, Uggiate Trevano, Como, Italy
| | - A Berri
- Safety Bio Life SRL, Albuzzano, Pavia, Italy
| | - F Baldanti
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - P Marone
- Molecular Virology Unit, Microbiology and Virology Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - R Bruno
- Infection Diseases Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - A Triarico
- Medical Direction, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, Italy
| | - P Lago
- Clinical Engineering Department, Fondazione I.R.C.C.S. Policlinico San Matteo, Pavia, ITALY; Industrial and Information Engineering Department, University of Pavia, Pavia, ITALY
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378
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Lack of viable severe acute respiratory coronavirus virus 2 (SARS-CoV-2) among PCR-positive air samples from hospital rooms and community isolation facilities. Infect Control Hosp Epidemiol 2021; 42:1327-1332. [PMID: 33487210 PMCID: PMC7870907 DOI: 10.1017/ice.2021.8] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Understanding the extent of aerosol-based transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important for tailoring interventions for control of the coronavirus disease 2019 (COVID-19) pandemic. Multiple studies have reported the detection of SARS-CoV-2 nucleic acid in air samples, but only one study has successfully recovered viable virus, although it is limited by its small sample size. OBJECTIVE We aimed to determine the extent of shedding of viable SARS-CoV-2 in respiratory aerosols from COVID-19 patients. METHODS In this observational air sampling study, air samples from airborne-infection isolation rooms (AIIRs) and a community isolation facility (CIF) housing COVID-19 patients were collected using a water vapor condensation method into liquid collection media. Samples were tested for presence of SARS-CoV-2 nucleic acid using quantitative real-time polymerase chain reaction (qRT-PCR), and qRT-PCR-positive samples were tested for viability using viral culture. RESULTS Samples from 6 (50%) of the 12 sampling cycles in hospital rooms were positive for SARS-CoV-2 RNA, including aerosols ranging from <1 µm to >4 µm in diameter. Of 9 samples from the CIF, 1 was positive via qRT-PCR. Viral RNA concentrations ranged from 179 to 2,738 ORF1ab gene copies per cubic meter of air. Virus cultures were negative after 4 blind passages. CONCLUSION Although SARS-CoV-2 is readily captured in aerosols, virus culture remains challenging despite optimized sampling methodologies to preserve virus viability. Further studies on aerosol-based transmission and control of SARS-CoV-2 are needed.
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379
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Tang JW, Bahnfleth WP, Bluyssen PM, Buonanno G, Jimenez JL, Kurnitski J, Li Y, Miller S, Sekhar C, Morawska L, Marr LC, Melikov AK, Nazaroff WW, Nielsen PV, Tellier R, Wargocki P, Dancer SJ. Dismantling myths on the airborne transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). J Hosp Infect 2021; 110:89-96. [PMID: 33453351 PMCID: PMC7805396 DOI: 10.1016/j.jhin.2020.12.022] [Citation(s) in RCA: 185] [Impact Index Per Article: 61.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 12/20/2022]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has caused untold disruption throughout the world. Understanding the mechanisms for transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is key to preventing further spread, but there is confusion over the meaning of ‘airborne’ whenever transmission is discussed. Scientific ambivalence originates from evidence published many years ago which has generated mythological beliefs that obscure current thinking. This article collates and explores some of the most commonly held dogmas on airborne transmission in order to stimulate revision of the science in the light of current evidence. Six ‘myths’ are presented, explained and ultimately refuted on the basis of recently published papers and expert opinion from previous work related to similar viruses. There is little doubt that SARS-CoV-2 is transmitted via a range of airborne particle sizes subject to all the usual ventilation parameters and human behaviour. Experts from specialties encompassing aerosol studies, ventilation, engineering, physics, virology and clinical medicine have joined together to produce this review to consolidate the evidence for airborne transmission mechanisms, and offer justification for modern strategies for prevention and control of COVID-19 in health care and the community.
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Affiliation(s)
- J W Tang
- Respiratory Sciences, University of Leicester, Leicester, UK
| | - W P Bahnfleth
- Department of Architectural Engineering, The Pennsylvania State University, State College, PA, USA
| | - P M Bluyssen
- Faculty of Architecture and the Built Environment, Delft University of Technology, Delft, The Netherlands
| | - G Buonanno
- Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, Italy
| | - J L Jimenez
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO, USA
| | - J Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn, Estonia
| | - Y Li
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - S Miller
- Mechanical Engineering, University of Colorado, Boulder, CO, USA
| | - C Sekhar
- Department of Building, National University of Singapore, Singapore
| | - L Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD, Australia
| | - L C Marr
- Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - A K Melikov
- International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - W W Nazaroff
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | - P V Nielsen
- Faculty of Engineering and Science, Department of Civil Engineering, Aalborg University, Aalborg, Denmark
| | - R Tellier
- Department of Medicine, McGill University, Montreal, QC, Canada
| | - P Wargocki
- International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - S J Dancer
- Department of Microbiology, NHS Lanarkshire, Glasgow, UK; School of Applied Sciences, Edinburgh Napier University, Edinburgh, UK.
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380
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Earliest detection to date of SARS-CoV-2 in Florida: Identification together with influenza virus on the main entry door of a university building, February 2020. PLoS One 2021; 16:e0245352. [PMID: 33439885 PMCID: PMC7806172 DOI: 10.1371/journal.pone.0245352] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/29/2020] [Indexed: 01/16/2023] Open
Abstract
In February and March, 2020, environmental surface swab samples were collected from the handle of the main entry door of a major university building in Florida, as part of a pilot surveillance project screening for influenza. Samples were taken at the end of regular classroom hours, between the dates of February 1–5 and February 19-March 4, 2020. Influenza A(H1N1)pdm09 virus was isolated from the door handle on four of the 19 days sampled. Both SARS-CoV-2 and A(H1N1)pdm09 virus were detected in a sample collected on February 21, 2020. Based on sequence analysis, the Florida SARS-CoV-2 strain (designated UF-11) was identical to strains being identified in Washington state during the same time period, while the earliest similar sequences were sampled in China/Hubei between Dec 30th 2019 and Jan 5th 2020. The first human case of COVID-19 was not officially reported in Florida until March 1st. In an analysis of sequences from COVID-19 patients in this region of Florida, there was only limited evidence of subsequent dissemination of the UF-11 strain. Identical or highly similar strains, possibly related through a common transmission chain, were detected with increasing frequency in Washington state between end of February and beginning of March. Our data provide further documentation of the rapid early spread of SARS-CoV-2 and underscore the likelihood that closely related strains were cryptically circulating in multiple U.S. communities before the first “official” cases were recognized.
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381
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Delikhoon M, Guzman MI, Nabizadeh R, Norouzian Baghani A. Modes of Transmission of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) and Factors Influencing on the Airborne Transmission: A Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:E395. [PMID: 33419142 PMCID: PMC7825517 DOI: 10.3390/ijerph18020395] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/28/2020] [Accepted: 12/31/2020] [Indexed: 12/11/2022]
Abstract
The multiple modes of SARS-CoV-2 transmission including airborne, droplet, contact, and fecal-oral transmissions that cause coronavirus disease 2019 (COVID-19) contribute to a public threat to the lives of people worldwide. Herein, different databases are reviewed to evaluate modes of transmission of SARS-CoV-2 and study the effects of negative pressure ventilation, air conditioning system, and related protection approaches of this virus. Droplet transmission was commonly reported to occur in particles with diameter >5 µm that can quickly settle gravitationally on surfaces (1-2 m). Instead, fine and ultrafine particles (airborne transmission) can stay suspended for an extended period of time (≥2 h) and be transported further, e.g., up to 8 m through simple diffusion and convection mechanisms. Droplet and airborne transmission of SARS-CoV-2 can be limited indoors with adequate ventilation of rooms, by routine disinfection of toilets, using negative pressure rooms, using face masks, and maintaining social distancing. Other preventive measures recommended include increasing the number of screening tests of suspected carriers of SARS-CoV-2, reducing the number of persons in a room to minimize sharing indoor air, and monitoring people's temperature before accessing a building. The work reviews a body of literature supporting the transmission of SARS-CoV-2 through air, causing COVID-19 disease, which requires coordinated worldwide strategies.
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Affiliation(s)
- Mahdieh Delikhoon
- Department of Occupational Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran;
| | - Marcelo I. Guzman
- Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA;
| | - Ramin Nabizadeh
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;
| | - Abbas Norouzian Baghani
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;
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382
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Dumont-Leblond N, Veillette M, Mubareka S, Yip L, Longtin Y, Jouvet P, Paquet Bolduc B, Godbout S, Kobinger G, McGeer A, Mikszewski A, Duchaine C. Low incidence of airborne SARS-CoV-2 in acute care hospital rooms with optimized ventilation. Emerg Microbes Infect 2021; 9:2597-2605. [PMID: 33206022 PMCID: PMC7734095 DOI: 10.1080/22221751.2020.1850184] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The worldwide repercussions of COVID-19 sparked important research efforts, yet the detailed contribution of aerosols in the transmission of SARS-CoV-2 has not been elucidated. In an attempt to quantify viral aerosols in the environment of infected patients, we collected 100 air samples in acute care hospital rooms hosting 22 patients over the course of nearly two months using three different air sampling protocols. Quantification by RT-qPCR (ORF1b) led to 11 positive samples from 6 patient rooms (Ct < 40). Viral cultures were negative. No correlation was observed between particular symptoms, length of hospital stay, clinical parameters, and time since symptom onset and the detection of airborne viral RNA. Low detection rates in the hospital rooms may be attributable to the appropriate application of mitigation methods according to the risk control hierarchy, such as increased ventilation to 4.85 air changes per hour to create negative pressure rooms. Our work estimates the mean emission rate of patients and potential airborne concentration in the absence of ventilation. Additional research is needed understand aerosolization events occur, contributing factors, and how best to prevent them.
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Affiliation(s)
- Nathan Dumont-Leblond
- Centre de recherche de l'institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Canada
| | - Marc Veillette
- Centre de recherche de l'institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Canada
| | - Samira Mubareka
- Sunnybrook Research Institute, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Lily Yip
- Sunnybrook Research Institute, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Yves Longtin
- Jewish General Hospital, Montreal, Canada.,Lady Davis Research Institute, Montreal, Canada
| | - Philippe Jouvet
- Department of Pediatrics, Université de Montréal, St. Justine Hospital, Montreal, Canada
| | - Bianka Paquet Bolduc
- Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Canada
| | - Stéphane Godbout
- Institut de Recherche & Development Agroenvironmental, Quebec City, Canada
| | - Gary Kobinger
- Département de microbiologie-infectiologie et d'immunologie, Université Laval, Quebec City, Canada
| | - Allison McGeer
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, USA.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Alex Mikszewski
- The City University of New York, CIUS Building Performance Lab, New York, NY, USA
| | - Caroline Duchaine
- Centre de recherche de l'institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, Canada.,Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Quebec City, Canada.,Canada Research Chair on Bioaerosols, Quebec City, Canada
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383
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Barbosa BPP, de Carvalho Lobo Brum N. Ventilation mode performance against airborne respiratory infections in small office spaces: limits and rational improvements for Covid-19. JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING 2021; 43:316. [PMCID: PMC8155653 DOI: 10.1007/s40430-021-03029-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 05/11/2021] [Indexed: 05/29/2023]
Abstract
The Coronavirus disease (Covid-19), caused by the SARS-CoV-2 virus, has produced significant social and economic disruptions in different countries. Current evidence suggests a strong correlation between the infection and the cohabitation of indoor spaces. International organizations and experts consider that the airborne transmission through aerosols can occur in specific conditions and that inadequate ventilation increases the risk of infection. As a result, the increase in ventilation rates and air filtration efficiencies are recommended for public buildings in the context of Covid-19, with significant impacts on energy consumption, and a paradigm shift in the design of ventilation systems is necessary for this new context. Therefore, this study has assessed the comparative performance of the displacement ventilation and the mixed ventilation mode on reducing the risk of long-range airborne infection for the Covid-19 in a small office application. A coupled multizone-CFD (Computational Fluid Dynamics) software developed by the National Institute of Standards and Technology was used in this study to assess the relative performance of several design solutions related to different ventilation modes, filter efficiencies, and outdoor air flow rates. The results demonstrate that the displacement ventilation technique produces a better overall performance in reducing the SARS-CoV-2 airborne infection risk than the conventional mixed ventilation for all the studied cases.
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Affiliation(s)
- Bruno Perazzo Pedroso Barbosa
- Department of Architecture and Engineering-DAE, FIOCRUZ, Av. Brasil, 4365, Rio de Janeiro, RJ 21040-900 Brazil
- LTTC-Laboratory of Heat Transfer and Technology, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2.030, Centro de Tecnologia, Bloco I-2000, sala 132 – Cidade Universitaria, Rio de Janeiro, RJ 21941-914 Brazil
| | - Nisio de Carvalho Lobo Brum
- Department of Mechanical Engineering, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2.030, Centro de Tecnologia, Bloco G, sala 204 – Cidade Universitaria, Rio de Janeiro, RJ 21941-914 Brazil
- LTTC-Laboratory of Heat Transfer and Technology, Federal University of Rio de Janeiro, Av. Horacio Macedo, 2.030, Centro de Tecnologia, Bloco I-2000, sala 132 – Cidade Universitaria, Rio de Janeiro, RJ 21941-914 Brazil
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384
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Abstract
Human respiratory virus infections lead to a spectrum of respiratory symptoms and disease severity, contributing to substantial morbidity, mortality and economic losses worldwide, as seen in the COVID-19 pandemic. Belonging to diverse families, respiratory viruses differ in how easy they spread (transmissibility) and the mechanism (modes) of transmission. Transmissibility as estimated by the basic reproduction number (R0) or secondary attack rate is heterogeneous for the same virus. Respiratory viruses can be transmitted via four major modes of transmission: direct (physical) contact, indirect contact (fomite), (large) droplets and (fine) aerosols. We know little about the relative contribution of each mode to the transmission of a particular virus in different settings, and how its variation affects transmissibility and transmission dynamics. Discussion on the particle size threshold between droplets and aerosols and the importance of aerosol transmission for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza virus is ongoing. Mechanistic evidence supports the efficacies of non-pharmaceutical interventions with regard to virus reduction; however, more data are needed on their effectiveness in reducing transmission. Understanding the relative contribution of different modes to transmission is crucial to inform the effectiveness of non-pharmaceutical interventions in the population. Intervening against multiple modes of transmission should be more effective than acting on a single mode.
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Affiliation(s)
- Nancy H. L. Leung
- grid.194645.b0000000121742757WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
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385
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Jung J, Lee J, Jo S, Bae S, Kim JY, Cha HH, Lim YJ, Kwak SH, Hong MJ, Kim EO, Bae JY, Kang C, Sung M, Park MS, Kim SH. Nosocomial Outbreak of COVID-19 in a Hematologic Ward. Infect Chemother 2021; 53:332-341. [PMID: 34216126 PMCID: PMC8258301 DOI: 10.3947/ic.2021.0046] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
Background Coronavirus disease 2019 (COVID-19) outbreaks occur in hospitals in many parts of the world. In hospital settings, the possibility of airborne transmission needs to be investigated thoroughly. Materials and Methods There was a nosocomial outbreak of COVID-19 in a hematologic ward in a tertiary hospital, Seoul, Korea. We found 11 patients and guardians with COVID-19 through vigorous contact tracing and closed-circuit television monitoring. We found one patient who probably had acquired COVID-19 through airborne-transmission. We performed airflow investigation with simulation software, whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results Of the nine individuals with COVID-19 who had been in the hematologic ward, six stayed in one multi-patient room (Room 36), and other three stayed in different rooms (Room 1, 34, 35). Guardian in room 35 was close contact to cases in room 36, and patient in room 34 used the shared bathroom for teeth brushing 40 minutes after index used. Airflow simulation revealed that air was spread from the bathroom to the adjacent room 1 while patient in room 1 did not used the shared bathroom. Airflow was associated with poor ventilation in shared bathroom due to dysfunctioning air-exhaust, grill on the door of shared bathroom and the unintended negative pressure of adjacent room. Conclusion Transmission of SARS-CoV-2 in the hematologic ward occurred rapidly in the multi-patient room and shared bathroom settings. In addition, there was a case of possible airborne transmission due to unexpected airflow.
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Affiliation(s)
- Jiwon Jung
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.,Office for Infection Control, Asan Medical Center, Seoul, Korea
| | - Jungmin Lee
- Department of Microbiology, Institute for Viral Diseases, Biosafety Center, College of Medicine, Korea University, Seoul, Korea
| | - Seongmin Jo
- Department of Architectural Engineering, Sejong University, Seoul, Korea
| | - Seongman Bae
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Ji Yeun Kim
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Hye Hee Cha
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Young Ju Lim
- Office for Infection Control, Asan Medical Center, Seoul, Korea
| | - Sun Hee Kwak
- Office for Infection Control, Asan Medical Center, Seoul, Korea
| | - Min Jee Hong
- Office for Infection Control, Asan Medical Center, Seoul, Korea
| | - Eun Ok Kim
- Office for Infection Control, Asan Medical Center, Seoul, Korea
| | - Joon Yong Bae
- Department of Microbiology, Institute for Viral Diseases, Biosafety Center, College of Medicine, Korea University, Seoul, Korea
| | - Changmin Kang
- Department of Microbiology, Institute for Viral Diseases, Biosafety Center, College of Medicine, Korea University, Seoul, Korea
| | - Minki Sung
- Department of Architectural Engineering, Sejong University, Seoul, Korea.
| | - Man Seong Park
- Department of Microbiology, Institute for Viral Diseases, Biosafety Center, College of Medicine, Korea University, Seoul, Korea.
| | - Sung Han Kim
- Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.,Office for Infection Control, Asan Medical Center, Seoul, Korea.
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386
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Mousazadeh M, Naghdali Z, Rahimian N, Hashemi M, Paital B, Al-Qodah Z, Mukhtar A, Karri RR, Mahmoud AED, Sillanpää M, Dehghani MH, Emamjomeh MM. Management of environmental health to prevent an outbreak of COVID-19. ENVIRONMENTAL AND HEALTH MANAGEMENT OF NOVEL CORONAVIRUS DISEASE (COVID-19 ) 2021. [PMCID: PMC8237497 DOI: 10.1016/b978-0-323-85780-2.00007-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The World Health Organization (WHO) has recently pronounced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a serious pandemic. It is, therefore, mandatory for public health authorities to have an environmental health management plan against COVID-19. This chapter summarizes articles and official reports related to environmental health management and prevention policies against COVID-19. Because medical sectors require comprehensive guidelines to follow in such pandemic situations, this chapter highlights the significant factors of COVID-19 transmission in our environment (e.g., air), waste management for COVID-19, and protection and disinfection policies against COVID-19. At present, scientists are still discovering more about COVID-19 and its effect on the environment and the health sector. As such, further research is required to increase knowledge about the structural and pathogenic features of COVID-19 and to find effective treatments to dominate this epidemic.
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387
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Ren YF, Huang Q, Marzouk T, Richard R, Pembroke K, Martone P, Venner T, Malmstrom H, Eliav E. Effects of mechanical ventilation and portable air cleaner on aerosol removal from dental treatment rooms. J Dent 2020; 105:103576. [PMID: 33388387 PMCID: PMC7834919 DOI: 10.1016/j.jdent.2020.103576] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/23/2020] [Accepted: 12/26/2020] [Indexed: 01/10/2023] Open
Abstract
Objectives To evaluate the mechanical ventilation rates of dental treatment rooms and assess the effectiveness of aerosol removal by mechanical ventilation and a portable air cleaner (PAC) with a high-efficiency particulate air (HEPA) filter. Methods Volumetric airflow were measured to assess air change rate per hour by ventilation (ACHvent). Equivalent ventilation provided by the PAC (ACHpac) was calculated based on its clean air delivery rate. Concentrations of 0.3, 0.5 and 1.0 μm aerosol particles were measured in 10 dental treatment rooms with various ventilation rates at baseline, after 5-min of incense burn, and after 30-min of observation with and without the PAC or ventilation system in operation. Velocities of aerosol removal were assessed by concentration decay constants for the 0.3 μm particles with ventilation alone (Kn) and with ventilation and PAC (Kn+pac), and by times needed to reach 95 % and 100 % removal of accumulated aerosol particles. Results ACHvent varied from 3 to 45. Kn and Kn+pac were correlated with ACHvent (r = 0.90) and combined ACHtotal (r = 0.81), respectively. Accumulated aerosol particles could not be removed by ventilation alone within 30-min in rooms with ACHvent<15. PAC reduced aerosol accumulation and accelerated aerosol removal, and accumulated aerosols could be completely removed in 4 to 12-min by ventilation combined with PAC. Effectiveness of the PAC was especially prominent in rooms with poor ventilation. Added benefit of PAC in aerosol removal was inversely correlated with ACHvent. Conclusions Aerosol accumulation may occur in dental treatment rooms with poor ventilation. Addition of PAC with a HEPA filter significantly reduced aerosol accumulation and accelerated aerosol removal. Clinical significance Addition of PAC with a HEPA filter improves aerosol removal in rooms with low ventilation rates.
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Affiliation(s)
- Yan-Fang Ren
- Eastman Institute for Oral Health, University of Rochester Medical Center, Rochester, New York, USA.
| | - Qirong Huang
- Eastman Institute for Oral Health, University of Rochester Medical Center, Rochester, New York, USA
| | - Tamer Marzouk
- Eastman Institute for Oral Health, University of Rochester Medical Center, Rochester, New York, USA
| | - Ray Richard
- Facility Operations, University of Rochester Medical Center, Rochester, New York, USA
| | - Karen Pembroke
- Facility Operations, University of Rochester Medical Center, Rochester, New York, USA
| | - Pat Martone
- Facility Operations, University of Rochester Medical Center, Rochester, New York, USA
| | - Tom Venner
- Eastman Institute for Oral Health, University of Rochester Medical Center, Rochester, New York, USA
| | - Hans Malmstrom
- Eastman Institute for Oral Health, University of Rochester Medical Center, Rochester, New York, USA
| | - Eli Eliav
- Eastman Institute for Oral Health, University of Rochester Medical Center, Rochester, New York, USA
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388
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Port JR, Yinda CK, Owusu IO, Holbrook M, Fischer R, Bushmaker T, Avanzato VA, Schulz JE, van Doremalen N, Clancy CS, Munster VJ. SARS-CoV-2 disease severity and transmission efficiency is increased for airborne but not fomite exposure in Syrian hamsters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.12.28.424565. [PMID: 33398267 PMCID: PMC7781302 DOI: 10.1101/2020.12.28.424565] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Transmission of SARS-CoV-2 is driven by contact, fomite, and airborne transmission. The relative contribution of different transmission routes remains subject to debate. Here, we show Syrian hamsters are susceptible to SARS-CoV-2 infection through intranasal, aerosol and fomite exposure. Different routes of exposure presented with distinct disease manifestations. Intranasal and aerosol inoculation caused more severe respiratory pathology, higher virus loads and increased weight loss. Fomite exposure led to milder disease manifestation characterized by an anti-inflammatory immune state and delayed shedding pattern. Whereas the overall magnitude of respiratory virus shedding was not linked to disease severity, the onset of shedding was. Early shedding was linked to an increase in disease severity. Airborne transmission was more efficient than fomite transmission and dependent on the direction of the airflow. Carefully characterized of SARS-CoV-2 transmission models will be crucial to assess potential changes in transmission and pathogenic potential in the light of the ongoing SARS-CoV-2 evolution.
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Affiliation(s)
- Julia R. Port
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Claude Kwe Yinda
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Irene Offei Owusu
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Myndi Holbrook
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Robert Fischer
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Trenton Bushmaker
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
- Montana State University, Bozeman, Montana, USA
| | - Victoria A. Avanzato
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Jonathan E. Schulz
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Neeltje van Doremalen
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Chad S. Clancy
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
| | - Vincent J. Munster
- Laboratory of Virology, Division of Intramural Research, National Institutes of Health, Hamilton, MT, USA
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389
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Novelli G, Biancolella M, Mehrian-Shai R, Erickson C, Godri Pollitt KJ, Vasiliou V, Watt J, Reichardt JKV. COVID-19 update: the first 6 months of the pandemic. Hum Genomics 2020; 14:48. [PMID: 33357238 PMCID: PMC7757844 DOI: 10.1186/s40246-020-00298-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
The COVID-19 pandemic is sweeping the world and will feature prominently in all our lives for months and most likely for years to come. We review here the current state 6 months into the declared pandemic. Specifically, we examine the role of the pathogen, the host and the environment along with the possible role of diabetes. We also firmly believe that the pandemic has shown an extraordinary light on national and international politicians whom we should hold to account as performance has been uneven. We also call explicitly on competent leadership of international organizations, specifically the WHO, UN and EU, informed by science. Finally, we also condense successful strategies for dealing with the current COVID-19 pandemic in democratic countries into a developing pandemic playbook and chart a way forward into the future. This is useful in the current COVID-19 pandemic and, we hope, in a very distant future again when another pandemic might arise.
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Affiliation(s)
- Giuseppe Novelli
- Department of Biomedicine and Prevention, "Tor Vergata" University of Rome, 00133, Rome, Italy.
- IRCCS Neuromed, Pozzilli, IS, Italy.
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, NV, 89557, USA.
| | | | - Ruty Mehrian-Shai
- Pediatric Hemato-Oncology, Sheba Medical Center, Tel Hashomer, Israel
| | | | - Krystal J Godri Pollitt
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, 06510, USA
| | - Vasilis Vasiliou
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, 06510, USA
| | - Jessica Watt
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD, Australia
| | - Juergen K V Reichardt
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, 4878, Australia
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390
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MacIntyre CR, Ananda-Rajah MR. Scientific evidence supports aerosol transmission of SARS-COV-2. Antimicrob Resist Infect Control 2020; 9:202. [PMID: 33339522 PMCID: PMC7747188 DOI: 10.1186/s13756-020-00868-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 12/11/2020] [Indexed: 01/06/2023] Open
Affiliation(s)
- C Raina MacIntyre
- Biosecurity Research Program, Kirby Institute, UNSW Medicine, Sydney, Australia.
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391
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Zhang XS, Duchaine C. SARS-CoV-2 and Health Care Worker Protection in Low-Risk Settings: a Review of Modes of Transmission and a Novel Airborne Model Involving Inhalable Particles. Clin Microbiol Rev 2020; 34:e00184-20. [PMID: 33115724 PMCID: PMC7605309 DOI: 10.1128/cmr.00184-20] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Since the beginning of the COVID-19 pandemic, there has been intense debate over SARS-CoV-2's mode of transmission and appropriate personal protective equipment for health care workers in low-risk settings. The objective of this review is to identify and appraise the available evidence (clinical trials and laboratory studies on masks and respirators, epidemiological studies, and air sampling studies), clarify key concepts and necessary conditions for airborne transmission, and shed light on knowledge gaps in the field. We find that, except for aerosol-generating procedures, the overall data in support of airborne transmission-taken in its traditional definition (long-distance and respirable aerosols)-are weak, based predominantly on indirect and experimental rather than clinical or epidemiological evidence. Consequently, we propose a revised and broader definition of "airborne," going beyond the current droplet and aerosol dichotomy and involving short-range inhalable particles, supported by data targeting the nose as the main viral receptor site. This new model better explains clinical observations, especially in the context of close and prolonged contacts between health care workers and patients, and reconciles seemingly contradictory data in the SARS-CoV-2 literature. The model also carries important implications for personal protective equipment and environmental controls, such as ventilation, in health care settings. However, further studies, especially clinical trials, are needed to complete the picture.
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Affiliation(s)
- X Sophie Zhang
- Department of General Medicine, CIUSSS Centre-Sud-de-l'Île-de-Montréal, Montreal, Canada
- CHSLD Bruchési and CHSLD Jean De La Lande, Montreal, Canada
- GMF-U Faubourgs, Montreal, Canada
- Centre de Recherche et d'Aide aux Narcomanes, Montreal, Canada
| | - Caroline Duchaine
- Department of Biochemistry, Microbiology, and Bioinformatics, Université Laval, Quebec City, Canada
- Quebec Heart and Lung Institute-Université Laval (CRIUCPQ), Quebec City, Canada
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392
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Mansilla Domínguez JM, Font Jiménez I, Belzunegui Eraso A, Peña Otero D, Díaz Pérez D, Recio Vivas AM. Risk Perception of COVID-19 Community Transmission among the Spanish Population. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E8967. [PMID: 33276532 PMCID: PMC7731328 DOI: 10.3390/ijerph17238967] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 02/07/2023]
Abstract
On 11 March 2020 the SARS-CoV-2 virus was officially declared a pandemic and measures were set up in various countries to avoid its spread among the population. This paper aims to analyse the perception of risk of COVID-19 infection in the Spanish population. A cross-sectional, descriptive observational study was conducted with a total of 16,372 Spanish participants. An online survey was used to gather data for 5 consecutive days over the compulsory lockdown period which was established after the state of emergency was declared. There is an association between socio-demographic variables and risk perception, and a very strong relationship between this perception and contact and direct experience with the virus in a family, social or professional setting. We also found that compared to working from home, working outside the home increased the perception of risk of infection and the perception of worsening health. Understanding the public perception of the risk of COVID-19 infection is fundamental for establishing effective prevention measures.
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Affiliation(s)
- José Miguel Mansilla Domínguez
- Department of Nursing, Faculty of Biomedical and Health Science, Universidad Europea de Madrid, 28670 Madrid, Spain; (J.M.M.D.); (A.M.R.V.)
| | - Isabel Font Jiménez
- Department of Nursing, Faculty of Biomedical and Health Science, Universidad Europea de Madrid, 28670 Madrid, Spain; (J.M.M.D.); (A.M.R.V.)
| | - Angel Belzunegui Eraso
- Medical Anthropology Research Center, Faculty of Nursing, Rovira i Virgili University, 43002 Tarragona, Spain;
| | - David Peña Otero
- Hospital de Sierrallana, Advisor, Sub-Directorate of Primary Care, Cantabrian Health Service, 39011 Cantabria, Spain;
- Nursing Area, IiSGM Research Institutes Gregorio Marañón, 29007 Madrid, Spain
- Nursing Area, IDIVAL Research Institutes Valdecilla, 39011 Cantabria, Spain
- Respiratory Nursing Department at Sociedad Española de Neumología y Cirugía Torácica (SEPAR), 08029 Barcelona, Spain;
| | - David Díaz Pérez
- Respiratory Nursing Department at Sociedad Española de Neumología y Cirugía Torácica (SEPAR), 08029 Barcelona, Spain;
- Pneumology and Thoracic Surgery Service of the Hospital Universitario Nuestra Señora de Candelaria, 38010 Tenerife, Spain
- Coordinator of the Respiratory Nursing Department at SEPAR, 08029 Barcelona, Spain
| | - Ana María Recio Vivas
- Department of Nursing, Faculty of Biomedical and Health Science, Universidad Europea de Madrid, 28670 Madrid, Spain; (J.M.M.D.); (A.M.R.V.)
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393
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Birgand G, Peiffer-Smadja N, Fournier S, Kerneis S, Lescure FX, Lucet JC. Assessment of Air Contamination by SARS-CoV-2 in Hospital Settings. JAMA Netw Open 2020. [PMID: 33355679 DOI: 10.1001/jamaetworkopen.2020.33232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
IMPORTANCE Controversy remains regarding the transmission routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OBJECTIVE To review current evidence on air contamination with SARS-CoV-2 in hospital settings and the factors associated with contamination, including viral load and particle size. EVIDENCE REVIEW The MEDLINE, Embase, and Web of Science databases were systematically queried for original English-language articles detailing SARS-CoV-2 air contamination in hospital settings between January 1 and October 27, 2020. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The positivity rate of SARS-CoV-2 viral RNA and culture were described and compared according to the setting, clinical context, air ventilation system, and distance from patients. The SARS-CoV-2 RNA concentrations in copies per meter cubed of air were pooled, and their distribution was described by hospital areas. Particle sizes and SARS-CoV-2 RNA concentrations in copies or median tissue culture infectious dose (TCID50) per meter cubed were analyzed after categorization as less than 1 μm, from 1 to 4 μm, and greater than 4 μm. FINDINGS Among 2284 records identified, 24 cross-sectional observational studies were included in the review. Overall, 82 of 471 air samples (17.4%) from close patient environments were positive for SARS-CoV-2 RNA, with a significantly higher positivity rate in intensive care unit settings (intensive care unit, 27 of 107 [25.2%] vs non-intensive care unit, 39 of 364 [10.7%]; P < .001). There was no difference according to the distance from patients (≤1 m, 3 of 118 [2.5%] vs >1-5 m, 13 of 236 [5.5%]; P = .22). The positivity rate was 5 of 21 air samples (23.8%) in toilets, 20 of 242 (8.3%) in clinical areas, 15 of 122 (12.3%) in staff areas, and 14 of 42 (33.3%) in public areas. A total of 81 viral cultures were performed across 5 studies, and 7 (8.6%) from 2 studies were positive, all from close patient environments. The median (interquartile range) SARS-CoV-2 RNA concentrations varied from 1.0 × 103 copies/m3 (0.4 × 103 to 3.1 × 103 copies/m3) in clinical areas to 9.7 × 103 copies/m3 (5.1 × 103 to 14.3 × 103 copies/m3) in the air of toilets or bathrooms. Protective equipment removal and patient rooms had high concentrations per titer of SARS-CoV-2 (varying from 0.9 × 103 to 40 × 103 copies/m3 and 3.8 × 103 to 7.2 × 103 TCID50/m3), with aerosol size distributions that showed peaks in the region of particle size less than 1 μm; staff offices had peaks in the region of particle size greater than 4 μm. CONCLUSIONS AND RELEVANCE In this systematic review, the air close to and distant from patients with coronavirus disease 2019 was frequently contaminated with SARS-CoV-2 RNA; however, few of these samples contained viable viruses. High viral loads found in toilets and bathrooms, staff areas, and public hallways suggest that these areas should be carefully considered.
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Affiliation(s)
- Gabriel Birgand
- National Institute of Health Research Health Protection Research Unit in Healthcare Associated Infection and Antimicrobial Resistance, Imperial College London, London, United Kingdom
- Centre Hospitalo-Universitaire de Nantes, Nantes, France
| | - Nathan Peiffer-Smadja
- National Institute of Health Research Health Protection Research Unit in Healthcare Associated Infection and Antimicrobial Resistance, Imperial College London, London, United Kingdom
- INSERM, IAME, UMR 1137, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Bichat-Claude Bernard, Infectious Diseases Unit, Paris, Paris, France
- Equipe Operationnelle d'Hygiène, Siège Assistance Publique-Hôpitaux de Paris, Paris, France
- Universitaire Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Sandra Fournier
- Central Infection Control Team, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Solen Kerneis
- Equipe Mobile d'Infectiologie, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France
- Equipe de Prévention du Risque Infectieux, Hôpital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - François-Xavier Lescure
- INSERM, IAME, UMR 1137, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Bichat-Claude Bernard, Infectious Diseases Unit, Paris, Paris, France
- Equipe Operationnelle d'Hygiène, Siège Assistance Publique-Hôpitaux de Paris, Paris, France
- Universitaire Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Jean-Christophe Lucet
- INSERM, IAME, UMR 1137, Paris, France
- Equipe Operationnelle d'Hygiène, Siège Assistance Publique-Hôpitaux de Paris, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Bichat-Claude Bernard, Infection Control Unit, Paris, France
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394
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Cowling BJ, Leung GM. Face masks and COVID-19: don't let perfect be the enemy of good. Euro Surveill 2020; 25:2001998. [PMID: 33303063 PMCID: PMC7730488 DOI: 10.2807/1560-7917.es.2020.25.49.2001998] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/09/2020] [Indexed: 01/31/2023] Open
Affiliation(s)
- Benjamin J Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
- Laboratory of Data Discovery for Health, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
| | - Gabriel M Leung
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
- Laboratory of Data Discovery for Health, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
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395
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Birgand G, Peiffer-Smadja N, Fournier S, Kerneis S, Lescure FX, Lucet JC. Assessment of Air Contamination by SARS-CoV-2 in Hospital Settings. JAMA Netw Open 2020; 3:e2033232. [PMID: 33355679 PMCID: PMC7758808 DOI: 10.1001/jamanetworkopen.2020.33232] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
IMPORTANCE Controversy remains regarding the transmission routes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). OBJECTIVE To review current evidence on air contamination with SARS-CoV-2 in hospital settings and the factors associated with contamination, including viral load and particle size. EVIDENCE REVIEW The MEDLINE, Embase, and Web of Science databases were systematically queried for original English-language articles detailing SARS-CoV-2 air contamination in hospital settings between January 1 and October 27, 2020. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The positivity rate of SARS-CoV-2 viral RNA and culture were described and compared according to the setting, clinical context, air ventilation system, and distance from patients. The SARS-CoV-2 RNA concentrations in copies per meter cubed of air were pooled, and their distribution was described by hospital areas. Particle sizes and SARS-CoV-2 RNA concentrations in copies or median tissue culture infectious dose (TCID50) per meter cubed were analyzed after categorization as less than 1 μm, from 1 to 4 μm, and greater than 4 μm. FINDINGS Among 2284 records identified, 24 cross-sectional observational studies were included in the review. Overall, 82 of 471 air samples (17.4%) from close patient environments were positive for SARS-CoV-2 RNA, with a significantly higher positivity rate in intensive care unit settings (intensive care unit, 27 of 107 [25.2%] vs non-intensive care unit, 39 of 364 [10.7%]; P < .001). There was no difference according to the distance from patients (≤1 m, 3 of 118 [2.5%] vs >1-5 m, 13 of 236 [5.5%]; P = .22). The positivity rate was 5 of 21 air samples (23.8%) in toilets, 20 of 242 (8.3%) in clinical areas, 15 of 122 (12.3%) in staff areas, and 14 of 42 (33.3%) in public areas. A total of 81 viral cultures were performed across 5 studies, and 7 (8.6%) from 2 studies were positive, all from close patient environments. The median (interquartile range) SARS-CoV-2 RNA concentrations varied from 1.0 × 103 copies/m3 (0.4 × 103 to 3.1 × 103 copies/m3) in clinical areas to 9.7 × 103 copies/m3 (5.1 × 103 to 14.3 × 103 copies/m3) in the air of toilets or bathrooms. Protective equipment removal and patient rooms had high concentrations per titer of SARS-CoV-2 (varying from 0.9 × 103 to 40 × 103 copies/m3 and 3.8 × 103 to 7.2 × 103 TCID50/m3), with aerosol size distributions that showed peaks in the region of particle size less than 1 μm; staff offices had peaks in the region of particle size greater than 4 μm. CONCLUSIONS AND RELEVANCE In this systematic review, the air close to and distant from patients with coronavirus disease 2019 was frequently contaminated with SARS-CoV-2 RNA; however, few of these samples contained viable viruses. High viral loads found in toilets and bathrooms, staff areas, and public hallways suggest that these areas should be carefully considered.
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Affiliation(s)
- Gabriel Birgand
- National Institute of Health Research Health Protection Research Unit in Healthcare Associated Infection and Antimicrobial Resistance, Imperial College London, London, United Kingdom
- Centre Hospitalo-Universitaire de Nantes, Nantes, France
| | - Nathan Peiffer-Smadja
- National Institute of Health Research Health Protection Research Unit in Healthcare Associated Infection and Antimicrobial Resistance, Imperial College London, London, United Kingdom
- INSERM, IAME, UMR 1137, Paris, France
- Assistance Publique–Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Infectious Diseases Unit, Paris, Paris, France
- Equipe Operationnelle d'Hygiène, Siège Assistance Publique–Hôpitaux de Paris, Paris, France
- Universitaire Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Sandra Fournier
- Central Infection Control Team, Assistance Publique–Hôpitaux de Paris, Paris, France
| | - Solen Kerneis
- Equipe Mobile d’Infectiologie, Hôpital Cochin, Assistance Publique–Hôpitaux de Paris, Paris, France
- Equipe de Prévention du Risque Infectieux, Hôpital Bichat, Assistance Publique–Hôpitaux de Paris, Paris, France
| | - François-Xavier Lescure
- INSERM, IAME, UMR 1137, Paris, France
- Assistance Publique–Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Infectious Diseases Unit, Paris, Paris, France
- Equipe Operationnelle d'Hygiène, Siège Assistance Publique–Hôpitaux de Paris, Paris, France
- Universitaire Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Jean-Christophe Lucet
- INSERM, IAME, UMR 1137, Paris, France
- Equipe Operationnelle d'Hygiène, Siège Assistance Publique–Hôpitaux de Paris, Paris, France
- Assistance Publique–Hôpitaux de Paris, Hôpital Bichat–Claude Bernard, Infection Control Unit, Paris, France
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396
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Murphy B, Cahill R, McCaul C, Buggy D. Optical gas imaging of carbon dioxide at tracheal extubation: a novel technique for visualising exhaled breath. Br J Anaesth 2020; 126:e77-e78. [PMID: 33358042 PMCID: PMC7687366 DOI: 10.1016/j.bja.2020.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 11/03/2022] Open
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397
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Perella P, Tabarra M, Hataysal E, Pournasr A, Renfrew I. Minimising exposure to droplet and aerosolised pathogens: a computational fluid dynamics study. Br J Anaesth 2020; 126:544-549. [PMID: 33213833 DOI: 10.1016/j.bja.2020.09.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/19/2020] [Accepted: 09/19/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Hazardous pathogens are spread in either droplets or aerosols produced during aerosol-generating procedures (AGP). Adjuncts minimising exposure of healthcare workers to hazardous pathogens released during AGP may be beneficial. We used state-of-the-art computational fluid dynamics (CFD) modelling to optimise the performance of a custom-designed shield. METHODS We modelled airflow patterns and trajectories of particles (size range 1-500 μm) emitted during a typical cough using CFD (ANSYS Fluent software, Canonsburg, PA, USA), in the presence and absence of a protective shield enclosing the head of a patient. We modelled the effect of different shield designs, suction tube position, and suction flow rate on particle escape from the shield. RESULTS Use of the shield prevented escape of 99.1-100% of particles, which were either trapped on the shield walls (16-21%) or extracted via suction (79-82%). At most, 0.9% particles remained floating inside the shield. Suction flow rates (40-160 L min-1) had no effect on the final location of particles in a closed system. Particle removal from within the shield was optimal when a suction catheter was placed vertically next to the head of the patient. Addition of multiple openings in the shield reduced the purging performance from 99% at 160 L min-1 to 67% at 40 L min-1. CONCLUSION CFD modelling provides information to guide optimisation of the efficient removal of hazardous pathogens released during AGP from a custom-designed shield. These data are essential to establish before clinical use, pragmatic clinical trials, or both.
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Affiliation(s)
- Paolo Perella
- Department of Anaesthesia & Perioperative Medicine, Royal London Hospital, Barts Health NHS Trust, London, UK.
| | | | | | | | - Ian Renfrew
- Department of Interventional Radiology, Royal London Hospital, Barts Health NHS Trust, London, UK
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398
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Wolff M. On build-up of epidemiologic models-Development of a SEI 3RSD model for the spread of SARS-CoV-2. ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK 2020; 100:e202000230. [PMID: 33173245 PMCID: PMC7646042 DOI: 10.1002/zamm.202000230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/25/2020] [Indexed: 05/09/2023]
Abstract
The present study investigates essential steps in build-up of models for description of the spread of infectious diseases. Combining these modules, a SEI3RSD model will be developed, which can take into account a possible passive immunisation by vaccination as well as different durations of latent and incubation periods. Besides, infectious persons with and without symptoms can be distinguished. Due to the current world-wide SARS-CoV-2 pandemic (COVID-19 pandemic) models for description of the spread of infectious diseases and their application for forecasts have become into the focus of the scientific community as well as of broad public more than usual. Currently, many papers and studies have appeared and appear dealing with the virus SARS-CoV-2 and the COVID-19 disease caused by it. This occurs under medical, virological, economic, sociological and further aspects as well as under mathematical points of view. Concerning the last-mentioned point, the main focus lies on the application of existing models and their adaptation to data about the course of infection available at the current time. Clearly, the aim is to predict the possible further development, for instance in Germany. It is of particular interest to investigate how will be the influence of political and administrative measures like contact restrictions, closing or rather re-opening of schools, restaurants, hotels etc. on the course of infection. The steps considered here for building up suitable models are well-known for long time. However, understandably they will not be dealt with in an extended way in current application-oriented works. Therefore, it is the aim of this study to present some existing steps of modelling without any pretension of completeness. Thus, on the one hand we give assistance and, on the other hand, we develop a model capable to take already known properties of COVID-19 as well as a later possible passive immunisation by vaccination and a possible loss of immunity of recovered persons into account.
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Affiliation(s)
- Michael Wolff
- Center for Industrial MathematicsUniversity of BremenBremenGemany
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399
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Lee BU. Minimum Sizes of Respiratory Particles Carrying SARS-CoV-2 and the Possibility of Aerosol Generation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17196960. [PMID: 32977575 PMCID: PMC7579175 DOI: 10.3390/ijerph17196960] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
This study calculates and elucidates the minimum size of respiratory particles that are potential carriers of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); furthermore, it evaluates the aerosol generation potential of SARS-CoV-2. The calculations are based on experimental results and theoretical models. In the case of maximum viral-loading derived from experimental data of COVID-19 patients, 8.97 × 10−5% of a respiratory fluid particle from a COVID-19 patient is occupied by SARS-CoV-2. Hence, the minimum size of a respiratory particle that can contain SARS-CoV-2 is calculated to be approximately 9.3 μm. The minimum size of the particles can decrease due to the evaporation of water on the particle surfaces. There are limitations to this analysis: (a) assumption that the viruses are homogeneously distributed in respiratory fluid particles and (b) considering a gene copy as a single virion in unit conversions. However, the study shows that high viral loads can decrease the minimum size of respiratory particles containing SARS-CoV-2, thereby increasing the probability of aerosol generation of the viruses. The aerosol generation theory created in this study for COVID-19 has the potential to be applied to other contagious diseases that are caused by respiratory infectious microorganisms.
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Affiliation(s)
- Byung Uk Lee
- Aerosol and Bioengineering Laboratory, College of Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
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400
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Recent Advances in Occupational Exposure Assessment of Aerosols. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17186820. [PMID: 32962023 PMCID: PMC7559367 DOI: 10.3390/ijerph17186820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/27/2020] [Accepted: 08/31/2020] [Indexed: 01/15/2023]
Abstract
Exposure science is underpinned by characterization (measurement) of exposures. In this article, six recent advances in exposure characterization by sampling and analysis are reviewed as tools in the occupational exposure assessment of aerosols. Three advances discussed in detail are (1) recognition and inclusion of sampler wall deposits; (2) development of a new sampling and analytical procedure for respirable crystalline silica that allows non-destructive field analysis at the end of the sampling period; and (3) development of a new sampler to collect the portion of sub-300 nm aerodynamic diameter particles that would deposit in human airways. Three additional developments are described briefly: (4) a size-selective aerosol sampler that allows the collection of multiple physiologically-relevant size fractions; (5) a miniaturized pump and versatile sampling head to meet multiple size-selective sampling criteria; and (6) a novel method of sampling bioaerosols including viruses while maintaining viability. These recent developments are placed in the context of the historical evolution in sampling and analytical developments from 1900 to the present day. While these are not the only advances in exposure characterization, or exposure assessment techniques, they provide an illustration of how technological advances are adding more tools to our toolkit. The review concludes with a number of recommended areas for future research, including expansion of real-time and end-of-shift on-site measurement, development of samplers that operate at higher flow-rates to ensure measurement at lowered limit values, and development of procedures that accurately distinguish aerosol and vapor phases of semi-volatile substances.
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