scholarly journals The impact of heating, ventilation, and air conditioning design features on the transmission of viruses, including the 2019 novel coronavirus: a systematic review of ultraviolet radiation

Author(s):  
Gail M. Thornton ◽  
Brian A Fleck ◽  
Natalie Fleck ◽  
Emily Kroeker ◽  
Dhyey Dandnayak ◽  
...  

Respiratory viruses are capable of transmitting via an aerosol route. Emerging evidence suggests that SARS-CoV-2 which causes COVID-19 can be spread through airborne transmission, particularly in indoor environments with poor ventilation. Heating, ventilation, and air conditioning (HVAC) systems can play a role in mitigating airborne virus transmission. We conducted a systematic review of the scientific literature examining the effectiveness of HVAC design features in reducing virus transmission; here we report results for ultraviolet (UV) radiation. Following international standards for systematic reviews, we conducted a comprehensive search and synthesized findings from 32 relevant studies published between 1936 and 2020. Research demonstrates that: viruses and bacteriophages are inactivated by UV radiation; increasing UV dose is associated with decreasing survival fraction of viruses and bacteriophages; increasing relative humidity is associated with decreasing susceptibility to UV radiation; UV dose and corresponding survival fraction are affected by airflow pattern, air changes per hour, and UV device location; and UV radiation is associated with decreased transmission in both animal and human studies. This comprehensive synthesis of the scientific evidence examining the impact of UV radiation on virus transmission can be used to guide implementation of systems to mitigate airborne spread and identify priorities for future research.

2021 ◽  
Author(s):  
Gail M. Thornton ◽  
Brian A Fleck ◽  
Dhyey Dandnayak ◽  
Emily Kroeker ◽  
Lexuan Zhong ◽  
...  

The aerosol route has been a pathway for transmission of many viruses. Similarly, recent evidence has determined aerosol transmission for SARS-CoV-2 to be significant. Consequently, public health officials and professionals have sought data regarding the role of Heating, Ventilation, and Air Conditioning (HVAC) features as a means to mitigate transmission of viruses, particularly coronaviruses. Using international standards, a systematic review was conducted to comprehensively identify and synthesize research examining the effect of humidity on transmission of coronaviruses and influenza. The results from 24 relevant studies showed that: increasing from mid (40-60%) to high (>60%) relative humidity (RH) for SARS-CoV-2 was associated with decreased virus survival; although SARS-CoV-2 results appear consistent, coronaviruses do not all behave the same; increasing from low (<40%) to mid RH for influenza was associated with decreased persistence, infectivity, viability, and survival, however effects of increased humidity from mid to high for influenza were not consistent; and medium, temperature, and exposure time were associated with inconsistency in results for both coronaviruses and influenza. Adapting HVAC humidity to mitigate virus transmission is a complex approach due to difficulties of humidity control; humidity is a feature to be considered in conjunction with other HVAC features.


2021 ◽  
Author(s):  
Brian A Fleck ◽  
Gail M. Thornton ◽  
Lexuan Zhong ◽  
Lisa A Hartling ◽  
Dhyey Dandnayak ◽  
...  

Historically, viruses have demonstrated airborne transmission. Emerging evidence suggests the novel coronavirus (SARS-CoV-2) that causes COVID-19 may also spread by airborne transmission. This is more likely in indoor environments, particularly with poor ventilation. In the context of potential airborne transmission, a vital mitigation strategy for the built environment is heating, ventilation, and air conditioning (HVAC) systems. HVAC features could modify virus transmission potential. A systematic review following international standards was conducted to comprehensively identify and synthesize research examining the effectiveness of filters within HVAC systems in reducing virus transmission. Twenty-three relevant studies showed that: filtration was associated with decreased transmission; filters removed viruses from the air; increasing filter efficiency (efficiency of particle removal) was associated with decreased transmission, decreased infection risk, and increased viral filtration efficiency (efficiency of virus removal); increasing filter efficiency above MERV 13 was associated with limited benefit in further reduction of virus concentration and infection risk; and filters with the same efficiency rating from different companies showed variable performance. Increasing filter efficiency may mitigate virus transmission; however, improvement may be limited above MERV 13. Adapting HVAC systems to mitigate virus transmission requires a multi-factorial approach and filtration is one factor offering demonstrated potential for decreased transmission.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 503.1-504
Author(s):  
F. Ingegnoli ◽  
T. Schioppo ◽  
A. Herrick ◽  
A. Sulli ◽  
F. Bartoli ◽  
...  

Background:Nailfold capillaroscopy (NVC), a non-invasive technique to assess microcirculation, is increasingly being incorporated into rheumatology routine clinical practice. Currently, the degree of description of NVC methods varies amongst research studies, making interpretation and comparison between studies challenging. In this field, an unmet need is the standardization of items to be reported in research studies using NVC.Objectives:To perform a Delphi consensus on minimum reporting standards in methodology for clinical research, based on the items derived from a systematic review focused on this topic.Methods:The systematic review of the literature on NVC methodology relating to rheumatic diseases was performed according to PRISMA guidelines (PROSPERO CRD42018104660) to July 22nd2018 using MEDLINE, Embase, Scopus. Then, a three-step web-based Delphi consensus was performed in between members of the EULAR study group on microcirculation in rheumatic diseases and the Scleroderma Clinical Trials Consortium. Participants were asked to rate each item from 1 (not appropriate) to 9 (completely appropriate).Results:In total, 3491 references were retrieved in the initial search strategy, 2862 were excluded as duplicates or after title/abstract screening. 632 articles were retrieved for full paper review of which 319 fulfilled the inclusion criteria. Regarding patient preparation before the exam, data were scarce: 38% reported acclimatization, 5% to avoid caffeine and smoking, 3% to wash hands and 2% to avoid manicure. Concerning the device description: 90% reported type of instrument, 77% brand/model, 72% magnification, 46% oil use, 40% room temperature and 35% software for image analysis. As regards to examination details: 76% which fingers examined, 75% number of fingers examined, 15% operator experience, 13% reason for finger exclusion, 9% number of images, 8% quality check of the images and 3% time spent for the exam. Then, a three-round Delphi consensus on the selected items was completed by 80 participants internationally, from 31 countries located in Australia, Asia, Europe, North and South America. Some items reached the agreement at the second round (85 participants), and other items were suggested as important to consider in a future research agenda (e.g. temperature for acclimatization, the impact of smoking, allergies at the application of the oil to the nailbed, significance of pericapillary edema, methods of reporting hemorrhages, ramified and giant capillaries). The final agreement results are reported below:Conclusion:On the basis of the available literature the description of NVC methods was highly heterogeneous and individual published studies differed markedly. These practical suggestions developed using a Delphi process among international participants provide a guidance to improve and to standardize the NVC methodology in future clinical research studies.Disclosure of Interests:Francesca Ingegnoli: None declared, Tommaso Schioppo: None declared, Ariane Herrick: None declared, Alberto Sulli Grant/research support from: Laboratori Baldacci, Francesca Bartoli: None declared, Nicola Ughi: None declared, John Pauling: None declared, Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Actelion, Celgene, Consultant of: Bristol-Myers Squibb, Speakers bureau: Sigma-Alpha, Vanessa Smith Grant/research support from: The affiliated company received grants from Research Foundation - Flanders (FWO), Belgian Fund for Scientific Research in Rheumatic diseases (FWRO), Boehringer Ingelheim Pharma GmbH & Co and Janssen-Cilag NV, Consultant of: Boehringer-Ingelheim Pharma GmbH & Co, Speakers bureau: Actelion Pharmaceuticals Ltd, Boehringer-Ingelheim Pharma GmbH & Co and UCB Biopharma Sprl


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Michelle Whaley ◽  
Wendy Dusenbury ◽  
Andrei V Alexandrov ◽  
Georgios Tsivgoulis ◽  
Anne W Alexandrov

Background: Recent nursing initiatives encourage early mobilization of neurocritical care patients, but whether this intervention can be safely generalized to acute stroke is debatable. We performed a systematic review of findings from recent studies to provide direction for patient management and future research. Methods: An exhaustive literature search was performed in Medline, SCOPUS and the Cochrane Central Register of Controlled Trials to identify published clinical trial research using a very early mobility intervention (within 24 hours) in acute ischemic stroke patients. The primary efficacy outcome supporting the search was neurologic disability reduction or improved functional outcomes, and the primary safety outcome was neurologic deterioration. Studies were critically reviewed for inclusion by 3 separate investigators, findings were synthesized, and an overall recommendation for very early mobilization use in acute stroke was assigned according to GRADE criteria. Results: We initially identified 12 papers focused on early mobilization in acute stroke; of these, 6 observational studies were excluded, 1 study was excluded due to an ambiguous population, and 3 studies were excluded due to first initial mobilization out of bed occurring greater than 24 hours after admission. Two prospective randomized outcome blinded evaluation (PROBE) studies were retained, consisting of a total 2160 patients; ischemic stroke subtype was not disclosed in either study, limiting an understanding of the impact of very early mobilization on small versus large artery occlusion. Slower mobilization occurring beyond the first 24 hours was associated with higher rates of favorable outcome (mRS 0-2) at 90 days, whereas very early mobilization within the first 24 hours was associated with a number needed to harm of 25. Conclusions: In acute stroke, evidence supports a rested approach to care within the first 24 hours of hospitalization (GRADE: Strong recommendation, high quality of evidence). Similar to acute myocardial infarction, vascular insufficiency experienced in stroke likely warrants a more guarded approach to mobility. Additional studies exploring timing beyond 24 hours and dose of mobility interventions are warranted in discreet populations.


Author(s):  
Rebecca C. Grossman

The imposter phenomenon, or imposter syndrome, is defined as an internal experience of feeling like an intellectual fraud, despite external evidence of an individual's accomplishments, and results in an inability to internalise a sense of success. It is common among high-achieving people, and appears to be more common in women and ethnic minorities. In this chapter, a systematic review of the literature will be presented on imposter syndrome in the medical profession. Topics covered include purported aetiology, implications (including the impact on mental health and career progression), limitations of research, potential coping strategies, and avenues for future research.


2013 ◽  
Vol 7 (2) ◽  
pp. 192-206 ◽  
Author(s):  
Jacqueline Elhage Ramis ◽  
Emmanuel Antonio dos Santos

To evaluate airports' current thermal comfort temperature and humidity were registered in three main Brazilian international airports, other variables were local region climate characteristics and the constructive types of passenger terminal buildings. The Brazilian air transportation demand has considerably grown over the last decade, with some airports reaching their capacity. Thermal discomfort may be a key driver of passenger perceptions of airport service levels, specially under capacity overload situations. Therefore, to achieve airport thermal comfort within this new scenario, and with the imminent and future expansions of the airport system, certainly put extra work on the existing air conditioning systems, consequently increasing energy consumption and its associated costs. Collected temperature and humidity from each study case subsided the data for the psychrometric charts. The evidences showed temperatures below the international standards requirements for thermal comfort levels. These charts also indicated that adequate building types with natural air circulation, provides the best levels of thermal comfort. Results suggest the importance of considering the implementation of a combined system using artificial and natural air conditioning in the planning of future expansions.


2020 ◽  
Vol 11 ◽  
Author(s):  
Dominik Havsteen-Franklin ◽  
Megan Tjasink ◽  
Jacqueline Winter Kottler ◽  
Claire Grant ◽  
Veena Kumari

Crisis events, such as the COVID-19 pandemic, can have a devastating effect on communities and the care professionals within them. Over recent years, arts-based interventions have helped in a wide range of crisis situations, being recommended to support the workforce during and after complex crisis but there has been no systematic review of the role of arts-based crisis interventions and whether there are cogent themes regarding practice elements and outcomes. We, therefore, conducted a systematic review to (i) define the arts-based change process used during and after crisis events, and (ii) explore the perceptions of intermediate and long-term mental health benefits of arts-based interventions for professionals in caring roles. Our search yielded six studies (all qualitative). All data were thematically aggregated and meta-synthesized, revealing seven practice elements (a safe place, focusing on strengths and protective factors, developing psychosocial competencies to support peers, emotional expression and processing, identifying and naming the impact of the crisis, using an integrative creative approach, and cultural and organizational sensitivity) applied across all six studies, as well as a range of intermediate and long-term benefits shared common features (adapting, growing, and recovering; using the community as a healing resource; reducing or preventing symptoms of stress or trauma reactions, psychophysiological homeostasis). The ways in which these studies were designed independently from one another and yet used the same practice elements in their crisis interventions indicates that there is comparability about how and why the arts-based practice elements are being used and to what effect. Our findings provide a sound basis and meaningful parameters for future research incorporating quantitative and qualitative approaches to firmly establish the effectiveness of art-based interventions, and how arts can support cultural sensitivity, acceptability and indicated outcomes, particularly those relating to stress and trauma during or following a crisis.


Heart ◽  
2020 ◽  
Vol 106 (15) ◽  
pp. 1142-1147 ◽  
Author(s):  
Xintao Li ◽  
Bo Guan ◽  
Tong Su ◽  
Wei Liu ◽  
Mengyao Chen ◽  
...  

BackgroundCoronavirus disease 2019 (COVID-19) has produced a significant health burden worldwide, especially in patients with cardiovascular comorbidities. The aim of this systematic review and meta-analysis was to assess the impact of underlying cardiovascular comorbidities and acute cardiac injury on in-hospital mortality risk.MethodsPubMed, Embase and Web of Science were searched for publications that reported the relationship of underlying cardiovascular disease (CVD), hypertension and myocardial injury with in-hospital fatal outcomes in patients with COVID-19. The ORs were extracted and pooled. Subgroup and sensitivity analyses were performed to explore the potential sources of heterogeneity.ResultsA total of 10 studies were enrolled in this meta-analysis, including eight studies for CVD, seven for hypertension and eight for acute cardiac injury. The presence of CVD and hypertension was associated with higher odds of in-hospital mortality (unadjusted OR 4.85, 95% CI 3.07 to 7.70; I2=29%; unadjusted OR 3.67, 95% CI 2.31 to 5.83; I2=57%, respectively). Acute cardiac injury was also associated with a higher unadjusted odds of 21.15 (95% CI 10.19 to 43.94; I2=71%).ConclusionCOVID-19 patients with underlying cardiovascular comorbidities, including CVD and hypertension, may face a greater risk of fatal outcomes. Acute cardiac injury may act as a marker of mortality risk. Given the unadjusted results of our meta-analysis, future research are warranted.


Author(s):  
Justine Rockwood ◽  
Dan Nathan-Roberts

Effective communication is critical to team performance but can be impacted by the distribution of team members. Distribution is increasingly found in high-risk environments where task complexity necessitates geographic and/or temporal separation of team members. Understanding the impact of distribution on communication is critical to ensuring effective team performance. We review the research examining communication in distributed teams in high-risk environments to provide an overview of the literature to date. Articles examining communication in distributed teams were analyzed in a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Themes relevant to the research question were extracted from the studies using thematic analysis. Five themes were identified: updating shared mental models, effects of transmission lags, content of communication, communication protocols, and technological advances. The five themes identify directions for future research.


2019 ◽  
Vol 35 (7) ◽  
pp. 1125-1140 ◽  
Author(s):  
Birce Dobrucalı

Purpose This paper aims to provide a comprehensive and systematic review of the extant empirical body of knowledge regarding the impact of Guanxi on international Business-to-Business (B-to-B) relationships. Design/methodology/approach After the collection and refinement of studies that appeared in marketing, business and management literature during 1995-2018 period, a systematic review was conducted to discover the current situation and future research directions on the subject. Findings Theoretically, vast majority of the reviewed studies lacked a theoretical foundation, with the remainder anchored primarily on the resource-based view, social network theory and social exchange theory. Methodologically, Ganqing, Xinren and Mianzi are the most frequently investigated dimensions, whereas Renqing is the least investigated dimension. Data are mostly obtained from both Chinese and Western counterparts through survey and analyzed through univariate and multivariate data analysis techniques. Empirically, extant research focused on many diverse outcomes including trust, financial performance, cooperation, satisfaction, time orientation, opportunism and liability of foreignness, while under-examining the drives of Guanxi. Research limitations/implications This study provides a synthesis of extant line of research on the subject that are published in peer-reviewed international journals, which publish research in English. A meta-analysis may be conducted for providing a further detailed framework. Originality/value This study contributes to international marketing literature by providing an in-depth and synthesized inventory of knowledge to scholars; deriving a comprehensive analysis of theoretical foundations, methodological approaches and findings addressed by scholars in the field; noticing theoretical, methodological and empirical gaps to be examined; and providing future research directions.


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