Factors involved in the aerosol transmission of infection and control of ventilation in healthcare premises

On the Effectiveness of a “Tractor Mounted Road Sanitizing Unit” Designed to Combat COVID-19 Spread

Under the situation of a dreadful spread of COVID-19 throughout the world, it is an absolute necessity to develop proper strategy for its containment. Toward this end, a novel outdoor disinfection system is designed for effective sanitization of long stretches of highways, market places, shopping malls, etc., where there are large traffic and high chances of spreading of the virus. The disinfection system utilizes available tractor powered road tankers of municipal houses, and it has specific features for maximum sanitization coverage. This is achieved through a distributed spraying nozzle mounted around the tank along with two extendable hand sprayers with flexible hoses. The effectiveness of the spray system is studied using an image processing technique. The spray cloud is illuminated by a double-pulsed Nd:YAG laser, and the images are captured using a Nikon D3300 DSLR camera. The average droplet size of the spray coming out from the nozzle is measured, and finally, the area of influence of the spray is obtained from a statistical analysis.

A clinical study measuring dental aerosols with and without a high-volume extraction device

Introduction External high-volume extraction (HVE) devices may offer a way to reduce any aerosol particulate generated.Aims The aim of this study was to measure the particle count during dental aerosol generating procedures and compare the results with when a HVE device is used.Design A comparative clinical study measuring the amount of PM1, PM2.5 and PM10 aerosol particulate with and without the use of an external HVE device was undertaken.Materials and methods In total, ten restorative procedures were monitored with an industrial Trotec PC220 particle counter. The intervention was an external HVE device.Main outcome methods The air sampler was placed at the average working distance of the clinicians involved in the study - 420 mm.Results In the present study, aerosol particulate was recorded at statistically significantly increased levels during dental procedures without an external HVE deviceversus with the device.Discussion The null hypothesis was rejected, in that significant differences were found between the results of the amount of aerosol particle count with and without a HVE device.Conclusion If the results of the present study are repeated in an in vivo setting, an external high-volume suction device may potentially show a lower risk of transmission of viral particulate.

Aerosolisation during tracheal intubation and extubation in an operating theatre setting

Aerosol‐generating procedures such as tracheal intubation and extubation pose a potential risk to healthcare workers because of the possibility of airborne transmission of infection. Detailed characterisation of aerosol quantities, particle size and generating activities has been undertaken in a number of simulations but not in actual clinical practice. The aim of this study was to determine whether the processes of facemask ventilation, tracheal intubation and extubation generate aerosols in clinical practice, and to characterise any aerosols produced. In this observational study, patients scheduled to undergo elective endonasal pituitary surgery without symptoms of COVID‐19 were recruited. Airway management including tracheal intubation and extubation was performed in a standard positive pressure operating room with aerosols detected using laser‐based particle image velocimetry to detect larger particles, and spectrometry with continuous air sampling to detect smaller particles. A total of 482,960 data points were assessed for complete procedures in three patients. Facemask ventilation, tracheal tube insertion and cuff inflation generated small particles 30–300 times above background noise that remained suspended in airflows and spread from the patient’s facial region throughout the confines of the operating theatre. Safe clinical practice of these procedures should reflect these particle profiles. This adds to data that inform decisions regarding the appropriate precautions to take in a real‐world setting.

Covid-19 pandemic and food: Present knowledge, risks, consumers fears and safety

BACKGROUND

COVID-19 is a pandemic disease that has paralyzed social life and the economy around the world since the end of 2019, and which has so far killed nearly 600,000 people. The rapidity of its spread and the lack of detailed research on the course and methods of transmission significantly impede both its eradication and prevention.

SCOPE AND APPROACH

Due to the high transmission rate and fatality resulting from COVID-19 disease, the paper focuses on analyzing the current state of knowledge about SARS-CoV-2 as well as its potential connection with food as a source of pathogen and infection.

KEY FINDINGS AND CONCLUSIONS

There is currently no evidence (scientific publications, WHO, EFSA etc.) that COVID-19 disease can spread directly through food and the human digestive system. However, according to the hypothesis regarding the primary transmission of the virus, the source of which was food of animal origin (meat of wild animals), as well as the fact that food is a basic necessity for humans, it is worth emphasizing that food can, if not directly, be a carrier of the virus. Particular attention should be paid to this indirect pathway when considering the potential for the spread of an epidemic and the development of prevention principles.

Review of ventilation strategies to reduce the risk of disease transmission in high occupancy buildings

An unforeseen pandemic is facing the world caused by a corona virus known as SARS-CoV-2. Numerous measures are being put in place to try and reduce the spread of this deadly disease, with the most effective response to the outbreak being mass quarantines, a public health technique borrowed from the Middle Ages. The widely accepted main transmission mechanism is through droplet borne pathways. However, many researchers and studies are considering that this virus can also spread via the airborne route and remain for up to three hours in the air. This is leading to questions as to whether enough is being done regarding ventilation to reduce the risk of the spread of this or other diseases that may be air borne. Ventilation and air conditioning systems are the main focus when it comes to the transmission of such deadly pathogens and should be appropriately designed and operated. This paper reviews and critically evaluates the current ventilation strategies used in buildings to assess the state of the art and elaborates if there is room for further development, especially for high occupancy buildings, to reduce or eradicate the risk of pathogen transmission and adapt ventilation measures to new threats posed by pandemics.

The long-term effects of meteorological parameters on pertussis infections in Chongqing, China, 2004-2018

Evidence on the long-term influence of climatic variables on pertussis is limited. This study aims to explore the long-term quantitative relationship between weather variability and pertussis. Data on the monthly number of pertussis cases and weather parameters in Chongqing in the period of 2004-2018 were collected. Then, we used a negative binomial multivariable regression model and cointegration testing to examine the association of variations in monthly meteorological parameters and pertussis. Descriptive statistics exhibited that the pertussis incidence rose from 0.251 per 100,000 people in 2004 to 3.661 per 100,000 persons in 2018, and pertussis was a seasonal illness, peaked in spring and summer. The results from the regression model that allowed for the long-term trends, seasonality, autoregression, and delayed effects after correcting for overdispersion showed that a 1 hPa increment in the delayed one-month air pressure contributed to a 3.559% (95% CI 0.746-6.293%) reduction in the monthly number of pertussis cases; a 10 mm increment in the monthly aggregate precipitation, a 1 °C increment in the monthly average temperature, and a 1 m/s increment in the monthly average wind velocity resulted in 3.641% (95% CI 0.960-6.330%), 19.496% (95% CI 2.368-39.490%), and 3.812 (95% CI 1.243-11.690)-fold increases in the monthly number of pertussis cases, respectively. The roles of the mentioned weather parameters in the transmission of pertussis were also evidenced by a sensitivity analysis. The cointegration testing suggested a significant value among variables. Climatic factors, particularly monthly temperature, precipitation, air pressure, and wind velocity, play a role in the transmission of pertussis. This finding will be of great help in understanding the epidemic trends of pertussis in the future, and weather variability should be taken into account in the prevention and control of pertussis.

Epidemiology of 2017 influenza outbreaks in nine Australian Aged care facilities

Background

The 2017 A/H3N2 influenza season was the most severe season since the 2009 influenza pandemic. There were over 591 influenza outbreaks in institutions across the state of New South Wales (NSW) in Australia.

Aim

To describe the epidemiology of influenza outbreaks in nine Sydney aged care facilities in 2017.

Methods

Study data were collected from nine Sydney aged care facilities for 2017 influenza season. Descriptive epidemiological analysis was conducted.

Results

From the nine sites included, with a total of 716 residents, four sites reported laboratory‐confirmed influenza outbreaks during the study period, with an attack rate in residents ranging from 6% to 29%. The outbreaks resulted in lockdowns in two facilities and hospitalisation of seven residents. No deaths were reported as a result of influenza infection. Influenza A was the most common influenza type reported across the facilities. The duration of outbreak lasted for 1‐4 weeks varied by site.

Conclusion

The 2017 season was a severe influenza season recorded in Australia. About half of the facilities studied experienced outbreaks of influenza, with a high attack rate among residents. Infection prevention and control measures and outbreak management plans are crucial for aged care facilities, including vaccination of staff and visitors to prevent outbreaks among the vulnerable residents.

Detection of tuberculosis in cynomolgus macaques (Macaca fascicularis) using a supplementary Monkey Interferon Gamma Releasing Assay (mIGRA)

Cynomolgus monkeys (Macaca fascicularis; MF) are commonly used as nonhuman primate models for pharmaceutical product testing. In their habitat range, monkeys have close contact with humans, allowing the possibility of bidirectional transmission of tuberculosis (TB) between the two species. Although the intradermal tuberculin skin test (TST) is used for TB detection in MF, it has limitations. Herein, we established the mIGRA, combining human QuantiFERON-TB Gold-Plus and monkey IFN-γ ELISA^pro systems, and used it to investigate 39 captive MF who were cage-mates or lived in cages located near a monkey who died from the naturally TB infection. During a 12-month period of study, 14 (36%), 10 (26%), and 8 (21%) monkeys showed TB-positive results using the mIGRA, the TST, and TB culture, respectively. Among the 14 mIGRA-positive monkeys, 8 (57.1%) were TST-positive and 7 (50%) were culture-positive, indicating early TB detection in the latent and active TB stages with the mIGRA. Interestingly, 3 (37.5%) of the TST-negative monkeys were culture-positive. Our study showed that the mIGRA offers many advantages, including high sensitivity and high throughput, and it requires only one on-site visit to the animals. The assay may be used as a supplementary tool for TB screening in MF.

A fluid mechanics explanation of the effectiveness of common materials for respiratory masks

OBJECTIVES

Face masks are an important component of personal protection equipment employed in preventing the spread of diseases such as COVID-19. As the supply of mass-produced masks has decreased, the use of homemade masks has become more prevalent. It is important to quantify the effectiveness of different types of materials to provide useful information, which should be considered for homemade masks.

METHODS

Filtration effects of different types of common materials were studied by measuring the aerosol droplet concentrations in the upstream and downstream regions. Flow-field characteristics of surrounding regions of tested materials were investigated using a laser-diagnostics technique, i.e., particle image velocimetry. The pressure difference across the tested materials was measured.

RESULTS

Measured aerosol concentrations indicated a breakup of large-size particles into smaller particles. Tested materials had higher filtration efficiency for large particles. Single-layer materials were less efficient, but they had a low pressure-drop. Multilayer materials could produce greater filtering efficiency with an increased pressure drop, which is an indicator of comfort level and breathability. The obtained flow-fields indicated a flow disruption downstream of the tested materials as the velocity magnitude noticeably decreased.

CONCLUSIONS

The obtained results provide an insight into flow-field characteristics and filtration efficiency of different types of household materials commonly used for homemade masks. This study allows comparison with mass-produced masks under consistent test conditions while employing several well-established techniques.

Infection Risk of COVID-19 in Dentistry Remains Unknown: A Preliminary Systematic Review

COVID-19 is a novel viral respiratory disease caused by a member of the coronavirus family, SARS-CoV-2, and has been declared as a pandemic on March 2020. Dental practitioners are routinely exposed to infectious bodily excretions, for example, saliva, blood, and respiratory excretions. Therefore, they are in the first line of SARS-CoV-2 infection-prone health care providers. The purposes of the current review are to trace documented cases of COVID-19 transmission inside dental settings worldwide and to explore the clinical management of these cases.

Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy

The practice of social distancing and wearing masks has been popular worldwide in combating the contraction of COVID-19. Undeniably, although such practices help control the COVID-19 pandemic to a greater extent, the complete control of virus-laden droplet and aerosol transmission by such practices is poorly understood. This review paper intends to outline the literature concerning the transmission of virus-laden droplets and aerosols in different environmental settings and demonstrates the behavior of droplets and aerosols resulted from a cough-jet of an infected person in various confined spaces. The case studies that have come out in different countries have, with prima facie evidence, manifested that the airborne transmission plays a profound role in contracting susceptible hosts. The infection propensities in confined spaces (airplane, passenger car, and healthcare center) by the transmission of droplets and aerosols under varying ventilation conditions were discussed. Interestingly, the nosocomial transmission by airborne SARS-CoV-2 virus-laden aerosols in healthcare facilities may be plausible. Hence, clearly defined, science-based administrative, clinical, and physical measures are of paramount importance to eradicate the COVID-19 pandemic from the world.

Simple Face Shield for Public as a Crucial Factor to Slow Aerosol Transmission During Unlock Phase of COVID Pandemic

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Till now, the total number of affected patients are 9,073,969 with 471,199 deaths and 3,747,128 currently infected active cases. Major concern is due to the droplets and aerosols of SARS CoV 2 causing the rapid spread and transmission. Since last 3 months we are using the indigenous face shields for our health care workers which costs only 0.13 USD per shield. Now we propose the use of this same shield for the general public to reduce the transmission of SARS CoV2.

Advances in Antiviral Material Development

The rise in human pandemics demands prudent approaches in antiviral material development for disease prevention and treatment via effective protective equipment and therapeutic strategy. However, the current state of the antiviral materials research is predominantly aligned towards drug development and its related areas, catering to the field of pharmaceutical technology. This review distinguishes the research advances in terms of innovative materials exhibiting antiviral activities that take advantage of fast-developing nanotechnology and biopolymer technology. Essential concepts of antiviral principles and underlying mechanisms are illustrated, followed with detailed descriptions of novel antiviral materials including inorganic nanomaterials, organic nanomaterials and biopolymers. The biomedical applications of the antiviral materials are also elaborated based on the specific categorization. Challenges and future prospects are discussed to facilitate the research and development of protective solutions and curative treatments.

Of Mice and Men: The Coronavirus MHV and Mouse Models as a Translational Approach to Understand SARS-CoV-2

The fatal acute respiratory coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since COVID-19 was declared a pandemic by the World Health Organization in March 2020, infection and mortality rates have been rising steadily worldwide. The lack of a vaccine, as well as preventive and therapeutic strategies, emphasize the need to develop new strategies to mitigate SARS-CoV-2 transmission and pathogenesis. Since mouse hepatitis virus (MHV), severe acute respiratory syndrome coronavirus (SARS-CoV), and SARS-CoV-2 share a common genus, lessons learnt from MHV and SARS-CoV could offer mechanistic insights into SARS-CoV-2. This review provides a comprehensive review of MHV in mice and SARS-CoV-2 in humans, thereby highlighting further translational avenues in the development of innovative strategies in controlling the detrimental course of SARS-CoV-2. Specifically, we have focused on various aspects, including host species, organotropism, transmission, clinical disease, pathogenesis, control and therapy, MHV as a model for SARS-CoV and SARS-CoV-2 as well as mouse models for infection with SARS-CoV and SARS-CoV-2. While MHV in mice and SARS-CoV-2 in humans share various similarities, there are also differences that need to be addressed when studying murine models. Translational approaches, such as humanized mouse models are pivotal in studying the clinical course and pathology observed in COVID-19 patients. Lessons from prior murine studies on coronavirus, coupled with novel murine models could offer new promising avenues for treatment of COVID-19.

The Differential Vertical Distribution of the Airborne Biological Particles Reveals an Atmospheric Reservoir of Microbial Pathogens and Aeroallergens

The most abundant biological particles present in the air are bacteria, fungal propagules and pollen grains. Many of them are proved allergens or even responsible for airborne infectious diseases, which supports the increase of studies in recent years on their composition, diversity, and factors involved in their variability. However, most studies in urban areas are conducted close to ground level and a factor such as height is rarely taken into account. Thus, the information about how the composition of biological particles changes with this variable is scarce. Here, we examined the differential distribution of bacteria, fungi, and plants at four altitudes (up to ∼ 250 m) in a metropolitan area using high-throughput DNA sequencing. Most taxa were present at all levels (common taxa). However, a transitional layer between 80 and 150 m seemed to affect the scattering of these bioaerosols. Taxa not present at all altitudes (non-common) showed an upward tendency of diversity for bacteria and plants with height, while the opposite trend was observed for fungi. Certain patterns were observed for fungi and specific plant genera, while bacterial taxa showed a more arbitrary distribution and no patterns were found. We detected a wide variety of aeroallergens and potential pathogens at all heights, which summed a substantial portion of the total abundance for fungi and plants. We also identified potential connections between the biological particles based on their abundances across the vertical section.

Personal Protective Equipment and COVID-19: A Review for Surgeons

: There is a long history of personal protective equipment (PPE) used by the surgeon to minimize the transmission of various pathogens. In the context of the present coronavirus disease 2019 pandemic there is significant controversy as to what forms of PPE are appropriate or adequate. This review aims to describe the pathogenic mechanism and route of spread of the causative virus, severe acute respiratory syndrome coronavirus, as it pertains to accumulated published data from experienced centers globally. The various forms of PPE that are both available and appropriate are addressed. There are options in the form of eyewear, gloves, masks, respirators, and gowns. The logical and practical utilization of these should be data driven and evolve based on both experience and data. Last, situations specific to surgical populations are addressed. We aim to provide granular collective data that has thus far been published and that can be used as a reference for optimal PPE choices in the perioperative setting for surgical teams.

Demystifying the mist: Sources of microbial bioload in dental aerosols

The risk of transmitting airborne pathogens is an important consideration in dentistry and has acquired special significance in the context of recent respiratory disease epidemics. The purpose of this review, therefore, is to examine (1) what is currently known regarding the physics of aerosol creation, (2) the types of environmental contaminants generated by dental procedures, (3) the nature, quantity, and sources of microbiota in these contaminants and (4) the risk of disease transmission from patients to dental healthcare workers. Most dental procedures that use ultrasonics, handpieces, air‐water syringes, and lasers generate sprays, a fraction of which are aerosolized. The vast heterogeneity in the types of airborne samples collected (spatter, settled aerosol, or harvested air), the presence and type of at‐source aerosol reduction methods (high‐volume evacuators, low volume suction, or none), the methods of microbial sampling (petri dishes with solid media, filter paper discs, air harvesters, and liquid transport media) and assessment of microbial bioload (growth conditions, time of growth, specificity of microbial characterization) are barriers to drawing robust conclusions. For example, although several studies have reported the presence of microorganisms in aerosols generated by ultrasonic scalers and high‐speed turbines, the specific types of organisms or their source is not as well studied. This paucity of data does not allow for definitive conclusions to be drawn regarding saliva as a major source of airborne microorganisms during aerosol generating dental procedures. Well‐controlled, large‐scale, multi center studies using atraumatic air harvesters, open‐ended methods for microbial characterization and integrated data modeling are urgently needed to characterize the microbial constituents of aerosols created during dental procedures and to estimate time and extent of spread of these infectious agents.

Approach to childhood asthma in the era of COVID-19: The official statement endorsed by the Saudi Pediatric Pulmonology Association (SPPA)

Coronaviruses are a large family of viruses that infect humans, which may result in mild symptoms similar to those of the common cold. COVID-19 is most recent subtype similar or even worse than the two previous pandemic strains which were the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV). The first cases of COVID-19 emerged in December 2019. Since then, the virus causing the disease has infected more than four million people around the globe and led to hundreds of thousands deaths. We think addressing the management of asthma in the era of this pandemic is important for several reasons: high prevalence of asthma in Saudi Arabia, further, majorities were uncontrolled disease. The statement will provide special instructions and answers to common questions of physicians dealing with asthmatic children during this pandemic.

Coronavirus (COVID-19) outbreak: what the department of endoscopy should know

Italy recorded its first case of confirmed acute respiratory illness because of coronavirus on February 18, 2020, soon after the initial reports in China. Since that time, Italy and nations throughout the world have adopted very stringent and severe measures to protect populations from spread of infection. Despite these measures, the number of infected people is growing exponentially, with a significant number of patients developing acute respiratory insufficiency. Endoscopy departments face significant risk for diffusion of respiratory diseases that can be spread via an airborne route, including aspiration of oral and fecal material via endoscopes. The purpose of this article is to discuss the measures, with specific focus on personal protection equipment and dress code modalities, implemented in our hospital to prevent further dissemination of COVID-19 infection.

Anesthetic Management of Endovascular Treatment of Acute Ischemic Stroke During COVID-19 Pandemic: Consensus Statement From Society for Neuroscience in Anesthesiology & Critical Care (SNACC): Endorsed by Society of Vascular & Interventional Neurology (SVIN), Society of NeuroInterventional Surgery (SNIS), Neurocritical Care Society (NCS), European Society of Minimally Invasive Neurological Therapy (ESMINT) and American Association of Neurological Surgeons (AANS) and Congress of Neurological Surgeons (CNS) Cerebrovascular Section

The pandemic of coronavirus disease 2019 (COVID-19) has unique implications for the anesthetic management of endovascular therapy for acute ischemic stroke. The Society for Neuroscience in Anesthesiology and Critical Care appointed a task force to provide timely, consensus-based expert recommendations using available evidence for the safe and effective anesthetic management of endovascular therapy for acute ischemic stroke during the COVID-19 pandemic. The goal of this consensus statement is to provide recommendations for anesthetic management considering the following (and they are): (1) optimal neurological outcomes for patients; (2) minimizing the risk for health care professionals, and (3) facilitating judicious use of resources while accounting for existing variability in care. It provides a framework for selecting the optimal anesthetic technique (general anesthesia or monitored anesthesia care) for a given patient and offers suggestions for best practices for anesthesia care during the pandemic. Institutions and health care providers are encouraged to adapt these recommendations to best suit local needs, considering existing practice standards and resource availability to ensure safety of patients and providers.

The impact of COVID-19 pandemic on IBD endoscopic procedures in a high-volume IBD Center

Background and study aims  The COVID-19 pandemic is having a major clinical and also organizational impact on national health care systems, particularly in high-volume hospitals that are utilized for several essential clinical needs. We aimed to analyze the short-term impact of the SARS-CoV-2 pandemic on management of endoscopic procedures in patients with inflammatory bowel disease (IBD). Patients and methods  This was an observational prospective study exploring major clinical and organizational changes in endoscopic management at the IBD Center - CEMAD of the Fondazione Policlinico Gemelli IRCCS, Rome, Italy since the beginning of SARS-CoV-2 pandemic. Results  Our IBD Unit, with up to 1,500 IBD patients receiving biotechnological or experimental therapy, represents a high-volume Italian and European IBD center. Since the beginning of the outbreak, our hospital has been extremely impacted by care related to COVID-19 cases, with a consequent need to dramatically reorganize management of endoscopic procedures for IBD. Conclusions  Outbreak restrictions have significantly impacted the volume of endoscopic activities for IBD. Specific strategies have been designed to guarantee a high level of safety for both patients with IBD and healthcare personnel dedicated to their treatment.

Reducing visible aerosol generation during phacoemulsification in the era of Covid-19

Objective

To assess potential methods of reducing visible aerosol generation during clear corneal phacoemulsification surgery in the era of Covid-19.

Methods

Aerosol generation during phacoemulsification was assessed using a model comprising a human cadaveric corneoscleral rim mounted on an artificial anterior chamber. Typical phacoemulsification settings were used and visible aerosol production was recorded using high-speed 4K camera. Aerosolisation was evaluated under various experimental settings: Two different phacoemulsification tip sizes (2.2, 2.75 mm), varying levels of corneal moisture, the use of suction and blowing air in the surgical field, the use of hydroxypropyl methylcellulose (HPMC) coating of the cornea with a static and moving tip.

Results

This model demonstrates visible aerosol generation during phacoemulsification with a 2.75-mm phacoemulsification tip. No visible aerosol was noted with a 2.2-mm tip. The presence of visible aerosol was unrelated to corneal wetting. Suction in close proximity to the aerosol plume did not impact on its dispersion. Blowing air redirected the aerosol plume toward the ocular surface. Visible aerosol production was abolished when HPMC was used to coat the cornea. This effect lasted for an average of 67 ± 8 s in the static model. Visible aerosol generation was discerned during movement of the 2.2-mm tip toward the corneal wound.

Conclusions

We demonstrate visible aerosol production in the setting of a model of clear corneal phacoemulsification. Visible aerosol can be reduced using a 2.2-mm phacoemulsification tip and reapplying HPMC every minute during phacoemulsification.

COVID-19 in Smokeless Tobacco Habitués: Increased Susceptibility and Transmission

As the coronavirus disease (COVID-19) pandemic continues to sweep across the globe, the world is responding by implementing public awareness campaigns, social distancing measures, and other preventive strategies to arrest the spread of this lethal disease. Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exacts a heavy toll on patients with existing comorbidities. Smokeless tobacco (SLT) consumption is of particular concern in countries in South Asia with high population densities, as it facilitates exposure to SARS-CoV-2 within or between communities by the act of public spitting. Salivary droplets generated in this act are a potential threat because they can transmit this airborne infection. Moreover, large gatherings at tobacco retail outlets, frequent hand-to-mouth contact, and sharing of apparatus by SLT habitués could also aid in increasing the spread of SARS-CoV-2. SLT-induced higher expression of angiotensin-converting enzyme 2 receptors along with the presence of furin in the oral mucosa and dysfunctional immune responses among SLT habitués increase viral dissemination and an individual's susceptibility to COVID-19. Issuing rigorous regulations to restrict the use of various forms of SLT products and the obnoxious act of spitting in public can assist in arresting the spread of COVID-19. Widespread education campaigns enlightening the community regarding the adverse effects of SLT consumption and its relationship with COVID-19, along with providing effective assistance to quit for those who are addicted, would decrease the spread of COVID-19.

Assessing visible aerosol generation during vitrectomy in the era of Covid-19

Objective

To assess visible aerosol generation during simulated vitrectomy surgery.

Methods

A model comprising a human cadaveric corneoscleral rim mounted on an artificial anterior chamber was used. Three-port 25 gauge vitrectomy simulated surgery was performed with any visible aerosol production recorded using high-speed 4K camera. The following were assessed: (1) vitrector at maximum cut rate in static and dynamic conditions inside the model, (2) vitrector at air–fluid interface in a physical model, (3) passive fluid–air exchange with a backflush hand piece, (4) valved cannulas under air, and (5) a defective valved cannula under air.

Results

No visible aerosol or droplets were identified when the vitrector was used within the model. In the physical model, no visible aerosol or droplets were seen when the vitrector was engaged at the air–fluid interface. Droplets were produced from the opening of backflush hand piece during passive fluid–air exchange. No visible aerosol was produced from the intact valved cannulas under air pressure, but droplets were seen at the beginning of fluid–air exchange when the valved cannula was defective.

Conclusions

We found no evidence of visible aerosol generation during simulated vitrectomy surgery with competent valved cannulas. In the physical model, no visible aerosol was generated by the high-speed vitrector despite cutting at the air–fluid interface.

[Management of diagnostic procedures and treatment of sleep related breathing disorders in the context of the coronavirus pandemic]

Bei der Erbringung schlafmedizinischer Leistungen im Zusammenhang mit der Corona-Pandemie sind besondere Aspekte zu berücksichtigen. Trotz aller vorbeugender Maßnahmen muss aufgrund der hohen Dunkelziffer mit SARS-CoV2-Kontakten im Schlaflabor gerechnet und entsprechende Vorkehrungen getroffen werden. Die Fortführung bzw. Wiederaufnahme schlafmedizinischer Leistungen unter den gebotenen Hygienemaßnahmen ist dennoch dringend anzustreben zur Vermeidung medizinischer und psychosozialer Komplikationen. Es gibt keine gesicherten Hinweise für eine Verschlechterung der COVID-19 durch eine CPAP-Therapie. Grundsätzlich kann die Anwendung einer Überdrucktherapie über verschiedene Maskensysteme mit der Bildung einer infektiösen Aerosolwolke einhergehen. Bei bestätigter Infektion mit SARS-CoV-2 sollte im ambulanten Umfeld eine vorbestehende Maskentherapie unter Einhaltung der Vorgaben des RKI zur häuslichen Isolierung fortgeführt werden, da eine Therapiebeendigung mit einer zusätzlichen kardiopulmonalen Belastung durch die unbehandelte schlafbezogene Atmungsstörung einhergeht. Mit geeigneter persönlicher Schutzausrüstung (Augenschutz, FFP2/FFP3-Maske, Kittel) kann eine PAP-Therapie nach jetzigem Kenntnisstand vom Personal ohne erhöhtes Infektionsrisiko durchgeführt werden.

Dieses gemeinsame Positionspapier der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin (DGP) und der Deutschen Gesellschaft für Schlafmedizin (DGSM) beinhaltet konkrete Empfehlungen zur Durchführung schlafmedizinischer Diagnostik und Therapie im Umfeld der Corona-Pandemie.

Air Contamination in Different Departments of a Tertiary Hospital. Assessment of Microbial Load and of Antimicrobial Susceptibility

Air contamination in the hospital setting can be a reason for the spread of nosocomial infection among susceptible patients. The aim of this study was to identify bacterial species, and their load and drug resistance, in the air of a tertiary hospital. Air samples were collected on a monthly basis for 12 consecutive months in four different departments of the hospital (Intensive Care Unit (ICU), Internal Medicine Ward (IMW), Surgical Ward (SW), and Neonatal Unit (NU)). In total, 101 samples were collected, out of which 158 Gram-positive (GP) and 44 Gram-negative (GN) strains were isolated. The majority of GP isolates were Staphylococcus spp. (n = 100). The highest total microbial load was reported in the IMW (p = 0.005), while the highest Staphylococcus load was observed in the ICU (p = 0.018). GP bacterial load was higher in autumn, while GN load was higher in spring. Regarding drug resistance, four multi-drug-resistant (MDR) strains and one extensively drug-resistant (XDR) strain were isolated in the ICU, two MDR strains and one XDR strain in the SW, one MDR strain in the IMW and one MDR strain in the NU samples. Air in hospital settings is contaminated with various microbes; some of them are MDR, consisting a potential cause of hospital-acquired infection.

Asymptomatic carriage and transmission of SARS-CoV-2: What do we know?

Purpose

Risk to healthcare workers treating asymptomatic patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the operating room depends on multiple factors. This review examines the evidence for asymptomatic or pre-symptomatic carriage of SARS-CoV-2, the risk of transmission from asymptomatic patients, and the specific risks associated with aerosol-generating procedures. Protective measures, such as minimization of aerosols and use of personal protective equipment in the setting of treating asymptomatic patients, are also reviewed.

Source

We examined the published literature as well as Societal guidelines.

Principal findings

There is evidence that a proportion of those infected with SARS-CoV-2 have detectable viral loads prior to exhibiting symptoms, or without ever developing symptoms. The degree of risk of transmission from asymptomatic patients to healthcare providers will depend on the prevalence of disease in the population, which is difficult to assess without widespread population screening. Aerosol-generating procedures increase the odds of viral transmission from infected symptomatic patients to healthcare providers, but transmission from asymptomatic patients has not been reported. Techniques to minimize aerosolization and appropriate personal protective equipment may help reduce the risk to healthcare workers in the operating room. Some societal guidelines recommend the use of airborne precautions during aerosol-generating procedures on asymptomatic patients during the coronavirus disease pandemic, although evidence supporting this practice is limited.

Conclusion

Viral transmission from patients exhibiting no symptoms in the operating room is plausible and efforts to reduce risk to healthcare providers include reducing aerosolization and wearing appropriate personal protective equipment, the feasibility of which will vary based on geographic risk and equipment availability.

ESGE and ESGENA Position Statement on gastrointestinal endoscopy and the COVID-19 pandemic

We are currently living in the throes of the COVID-19 pandemic that imposes a significant stress on health care providers and facilities. Europe is severely affected with an exponential increase in incident infections and deaths. The clinical manifestations of COVID-19 can be subtle, encompassing a broad spectrum from asymptomatic mild disease to severe respiratory illness. Health care professionals in endoscopy units are at increased risk of infection from COVID-19. Infection prevention and control has been shown to be dramatically effective in assuring the safety of both health care professionals and patients. The European Society of Gastrointestinal Endoscopy (www.esge.com) and the European Society of Gastroenterology and Endoscopy Nurses and Associates (www.esgena.org) are joining forces to provide guidance during this pandemic to help assure the highest level of endoscopy care and protection against COVID-19 for both patients and endoscopy unit personnel. This guidance is based upon the best available evidence regarding assessment of risk during the current status of the pandemic and a consensus on which procedures to perform and the priorities on resumption. We appreciate the gaps in knowledge and evidence, especially on the proper strategy(ies) for the resumption of normal endoscopy practice during the upcoming phases and end of the pandemic and therefore a list of potential research questions is presented. New evidence may result in an updated statement.

Endoscopy during the Covid-19 outbreak: experience and recommendations from a single center in a high-incidence scenario

A dramatic SARS-Cov-2 outbreak is hitting Italy hard. To face the new scenario all the hospitals have been re-organised in order to reduce all the outpatient services and to devote almost all their personnel and resources to the management of Covid-19 patients. As a matter of fact, all the services have undergone a deep re-organization guided by: the necessity to reduce exams, to create an environment that helps reduce the virus spread, and to preserve the medical personnel from infection. In these days a re-organization of the endoscopic unit, sited in a high-incidence area, has been adopted, with changes to logistics, work organization and patients selection. With the present manuscript, we want to support gastroenterologists and endoscopists in the organization of a "new" endoscopy unit that responds to the "new" scenario, while remaining fully aware that resources, availability and local circumstances may extremely vary from unit to unit.

Visualizing the effectiveness of face masks in obstructing respiratory jets

The use of face masks in public settings has been widely recommended by public health officials during the current COVID-19 pandemic. The masks help mitigate the risk of cross-infection via respiratory droplets; however, there are no specific guidelines on mask materials and designs that are most effective in minimizing droplet dispersal. While there have been prior studies on the performance of medical-grade masks, there are insufficient data on cloth-based coverings, which are being used by a vast majority of the general public. We use qualitative visualizations of emulated coughs and sneezes to examine how material- and design-choices impact the extent to which droplet-laden respiratory jets are blocked. Loosely folded face masks and bandana-style coverings provide minimal stopping-capability for the smallest aerosolized respiratory droplets. Well-fitted homemade masks with multiple layers of quilting fabric, and off-the-shelf cone style masks, proved to be the most effective in reducing droplet dispersal. These masks were able to curtail the speed and range of the respiratory jets significantly, albeit with some leakage through the mask material and from small gaps along the edges. Importantly, uncovered emulated coughs were able to travel notably farther than the currently recommended 6-ft distancing guideline. We outline the procedure for setting up simple visualization experiments using easily available materials, which may help healthcare professionals, medical researchers, and manufacturers in assessing the effectiveness of face masks and other personal protective equipment qualitatively.

Personal Protective Equipment for Healthcare Workers during the COVID-19 Pandemic

The coronavirus disease (COVID-19) pandemic has posed a challenge for healthcare systems, and healthcare workers (HCWs) are at high risk of exposure. Protecting HCWs is of paramount importance to maintain continuous patient care and keep healthcare systems functioning. Used alongside administrative and engineering control measures, personal protective equipment (PPE) is the last line of defense and the core component of protection. Current data suggest that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is mainly transmitted through respiratory droplets and close contact. Airborne transmission may occur during aerosol-generating procedures. However, the modes of transmission still remain uncertain, especially regarding the possibility of airborne transmission when aerosol-generating procedures are not performed. Thus, there are some inconsistencies in the respiratory protective equipment recommended by international and national organizations. In Korea, there have been several modifications to PPE recommendations offering options in choosing PPE for respiratory and body protection, which confuses HCWs; they are often unsure what to wear and when to wear it. The choice of PPE is based on the risk of exposure and possible modes of transmission. The level of protection provided by PPE differs based on standards and test methods. Thus, understanding them is the key in selecting the proper PPE. This article reviews evidence on the mode of SARS-CoV-2 transmission, compares the current PPE recommendations of the World Health Organization with those in Korea, and discusses standard requirements and the proper selection of PPE.

Pediatric Endoscopy in the Era of Coronavirus Disease 2019: A North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position Paper

The delivery of endoscopic care is changing rapidly in the era of Coronavirus Disease 2019 (COVID-19). The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) Endoscopy and Procedures Committee has formulated this statement to offer practical guidance to help standardize endoscopy services for pediatric patients with the aim of minimizing COVID-19 transmission to staff, patients, and caregivers and to conserve personal protective equipment (PPE) during this critical time. Appropriate use of PPE is essential to minimize transmission and preserve supply. Pediatric endoscopic procedures are considered at high risk for COVID-19 transmission. We recommend that all pediatric endoscopic procedures are done in a negative pressure room with all staff using proper airborne, contact, and droplet precautions regardless of patient risk stratification. This includes appropriate use of a filtering face-piece respirator (N95, N99, FFP2/3, or PAPR), double gloves, facial protection (full visor and/or face shield), full body water-resistant disposable gown, shoe covers and a hairnet. In deciding which endoscopic procedures should proceed, it is important to weigh the risks and benefits to optimize healthcare delivery and minimize risk. To inform these decisions, we propose a framework for stratifying procedures as emergent (procedures that need to PROCEEED), urgent (PAUSE, weigh the benefits and risks in deciding whether to proceed) and elective (POSTPONE procedures). This statement was based on emerging evidence and is meant as a guide. It is important that all endoscopy facilities where pediatric procedures are performed follow current recommendations from public health agencies within their jurisdiction regarding infection prevention and control of COVID-19.

Reducing aerosol dispersion by High Flow Therapy in COVID-19: High Resolution Computational Fluid Dynamics Simulations of Particle Behavior during High Velocity Nasal Insufflation with a Simple Surgical Mask

Objective

All respiratory care represents some risk of becoming an aerosol‐generating procedure (AGP) during COVID‐19 patient management. Personal protective equipment (PPE) and environmental control/engineering is advised. High velocity nasal insufflation (HVNI) and high flow nasal cannula (HFNC) deliver high flow oxygen (HFO) therapy, established as a competent means of supporting oxygenation for acute respiratory distress patients, including that precipitated by COVID‐19. Although unlikely to present a disproportionate particle dispersal risk, AGP from HFO continues to be a concern. Previously, we published a preliminary model. Here, we present a subsequent highresolution simulation (higher complexity/reliability) to provide a more accurate and precise particle characterization on the effect of surgical masks on patients during HVNI, low‐flow oxygen therapy (LFO2), and tidal breathing.

Methods

This in silico modeling study of HVNI, LFO2, and tidal breathing presents ANSYS fluent computational fluid dynamics simulations that evaluate the effect of Type I surgical mask use over patient face on particle/droplet behavior.

Results

This in silico modeling simulation study of HVNI (40 L min⁻¹) with a simulated surgical mask suggests 88.8% capture of exhaled particulate mass in the mask, compared to 77.4% in LFO2 (6 L min⁻¹) capture, with particle distribution escaping to the room (> 1 m from face) lower for HVNI+Mask versus LFO2+Mask (8.23% vs 17.2%). The overwhelming proportion of particulate escape was associated with mask‐fit designed model gaps. Particle dispersion was associated with lower velocity.

Conclusions

These simulations suggest employing a surgical mask over the HVNI interface may be useful in reduction of particulate mass distribution associated with AGPs.

Airborne Aerosol Generation During Endonasal Procedures in the Era of COVID-19: Risks and Recommendations

OBJECTIVE

In the era of SARS-CoV-2, the risk of infectious airborne aerosol generation during otolaryngologic procedures has been an area of increasing concern. The objective of this investigation was to quantify airborne aerosol production under clinical and surgical conditions and examine efficacy of mask mitigation strategies.

STUDY DESIGN

Prospective quantification of airborne aerosol generation during surgical and clinical simulation.

SETTING

Cadaver laboratory and clinical examination room.

SUBJECTS AND METHODS

Airborne aerosol quantification with an optical particle sizer was performed in real time during cadaveric simulated endoscopic surgical conditions, including hand instrumentation, microdebrider use, high-speed drilling, and cautery. Aerosol sampling was additionally performed in simulated clinical and diagnostic settings. All clinical and surgical procedures were evaluated for propensity for significant airborne aerosol generation.

RESULTS

Hand instrumentation and microdebridement did not produce detectable airborne aerosols in the range of 1 to 10 μm. Suction drilling at 12,000 rpm, high-speed drilling (4-mm diamond or cutting burs) at 70,000 rpm, and transnasal cautery generated significant airborne aerosols (P < .001). In clinical simulations, nasal endoscopy (P < .05), speech (P < .01), and sneezing (P < .01) generated 1- to 10-μm airborne aerosols. Significant aerosol escape was seen even with utilization of a standard surgical mask (P < .05). Intact and VENT-modified (valved endoscopy of the nose and throat) N95 respirator use prevented significant airborne aerosol spread.

CONCLUSION

Transnasal drill and cautery use is associated with significant airborne particulate matter production in the range of 1 to 10 μm under surgical conditions. During simulated clinical activity, airborne aerosol generation was seen during nasal endoscopy, speech, and sneezing. Intact or VENT-modified N95 respirators mitigated airborne aerosol transmission, while standard surgical masks did not.

Infection control measures of a Taiwanese hospital to confront the COVID-19 pandemic

The World Health Organization announced the coronavirus disease 2019 (COVID-19) outbreak a pandemic on 12 March 2020. Although being in proximity to China, the original epicenter of the COVID-19 outbreak, Taiwan has maintained a low number of COVID-19 cases despite its close social ties and heavy traffic between Taiwan and China. Containment strategies executed by the Taiwanese government have attracted global attention. Similarly, in-hospital settings, high alertness and swift responses to the changing outbreak situation are necessary to ensure hospital staff members' safety so they can continue to save patients' lives. Herein, we present infection control measures that can be adopted in hospital settings that were executed in a Taiwanese hospital to confront the COVID-19 pandemic, including emergency preparedness and responses from the hospital administration, education, surveillance, patient flow arrangement, the partition of hospital zones, and the prevention of a systemic shutdown by using the "divided cabin, divided flow" strategy. The measures implemented by a Taiwan hospital during the COVID-19 pandemic may not be universally applicable in every hospital. Nonetheless, the presented infection control methods have been practically executed and can be referenced or modified to fit each hospital's unique condition.

Consideration of the Aerosol Transmission for COVID-19 and Public Health

This article analyzes the available evidence to address airborne, aerosol transmission of the SARS-CoV-2. We review and present three lines of evidence: case reports of transmission for asymptomatic individuals in association with studies that show that normal breathing and talking produce predominantly small droplets of the size that are subject to aerosol transport; limited empirical data that have recorded aerosolized SARS-CoV-2 particles that remain suspended in the air for hours and are subject to transport over distances including outside of rooms and intrabuilding, and the broader literature that further supports the importance of aerosol transmission of infectious diseases. The weight of the available evidence warrants immediate attention to address the significance of aerosols and implications for public health protection.

ISDE guidance statement: management of upper gastrointestinal endoscopy and surgery in COVID-19 outbreak

This is an official guidance statement of The International Society of the Diseases of the Esophagus (ISDE) to address all the operators involved in management of patients affected by upper gastrointestinal diseases during COVID-19 pandemic. This guidance is based on the best available evidence to date and will be updated as new evidence becomes available.

Saliva: potential diagnostic value and transmission of 2019-nCoV

2019-nCoV epidemic was firstly reported at late December of 2019 and has caused a global outbreak of COVID-19 now. Saliva, a biofluid largely generated from salivary glands in oral cavity, has been reported 2019-nCoV nucleic acid positive. Besides lungs, salivary glands and tongue are possibly another hosts of 2019-nCoV due to expression of ACE2. Close contact or short-range transmission of infectious saliva droplets is a primary mode for 2019-nCoV to disseminate as claimed by WHO, while long-distance saliva aerosol transmission is highly environment dependent within indoor space with aerosol-generating procedures such as dental practice. So far, no direct evidence has been found that 2019-nCoV is vital in air flow for long time. Therefore, to prevent formation of infectious saliva droplets, to thoroughly disinfect indoor air and to block acquisition of saliva droplets could slow down 2019-nCoV dissemination. This review summarizes diagnostic value of saliva for 2019-nCoV, possibly direct invasion into oral tissues, and close contact transmission of 2019-nCoV by saliva droplets, expecting to contribute to 2019-nCoV epidemic control.

Ventilation and laboratory confirmed acute respiratory infection (ARI) rates in college residence halls in College Park, Maryland

Strategies to protect building occupants from the risk of acute respiratory infection (ARI) need to consider ventilation for its ability to dilute and remove indoor bioaerosols. Prior studies have described an association of increased self-reported colds and influenza-like symptoms with low ventilation but have not combined rigorous characterization of ventilation with assessment of laboratory confirmed infections. We report a study designed to fill this gap. We followed laboratory confirmed ARI rates and measured CO₂ concentrations for four months during the winter-spring of 2018 in two campus residence halls: (1) a high ventilation building (HVB) with a dedicated outdoor air system that supplies 100% of outside air to each dormitory room, and (2) a low ventilation building (LVB) that relies on infiltration as ventilation. We enrolled 11 volunteers for a total of 522 person-days in the HVB and 109 volunteers for 6069 person-days in the LVB, and tested upper-respiratory swabs from symptomatic cases and their close contacts for the presence of 44 pathogens using a molecular assay. We observed one ARI case in the HVB (0.70/person-year) and 47 in the LVB (2.83/person-year). Simultaneously, 154 CO₂ sensors distributed primarily in the dormitory rooms collected 668,390 useful data points from over 1 million recorded data points. Average and standard deviation of CO₂ concentrations were 1230 ppm and 408 ppm in the HVB, and 1492 ppm and 837 ppm in the LVB, respectively. Importantly, this study developed and calibrated multi-zone models for the HVB with 229 zones and 983 airflow paths, and for the LVB with 529 zones and 1836 airflow paths by using a subset of CO₂ data for model calibration. The models were used to calculate ventilation rates in the two buildings and potential for viral aerosol migration between rooms in the LVB. With doors and windows closed, the average ventilation rate was 12 L/s in the HVB dormitory rooms and 4 L/s in the LVB dormitory rooms. As a result, residents had on average 6.6 L/(s person) of outside air in the HVB and 2.3 L/(s person) in the LVB. LVB rooms located at the leeward side of the building had smaller average ventilation rates, as well as a somewhat higher ARI incidence rate and average CO₂ concentrations when compared to those values in the rooms located at the windward side of the building. Average ventilation rates in twenty LVB dormitory rooms increased from 2.3 L/s to 7.5 L/s by opening windows, 3.6 L/s by opening doors, and 8.8 L/s by opening both windows and doors. Therefore, opening both windows and doors in the LVB dormitory rooms can increase ventilation rates to the levels comparable to those in the HVB. But it can also have a negative effect on thermal comfort due to low outdoor temperatures. Simulation results identified an aerobiologic pathway from a room occupied by an index case of influenza A to a room occupied by a possible secondary case.

Coronavirus Disease 2019 (COVID-19) Complicated by Acute Respiratory Distress Syndrome: An Internist's Perspective

A pandemic outbreak of a novel coronavirus disease (COVID-19) that began in Wuhan, China, in December 2019 has spread rapidly to multiple countries. In the United States, the first confirmed case was reported on January 20, 2020, and since then, the number of cases is rising exponentially on a daily basis. We report a case of COVID-19 infection that presented with symptoms suggestive of pneumonia. Due to the major backlog with an immense number of pending tests, it took 48 hours for the result to come back positive, while the patient went into acute respiratory distress syndrome. We provide an internist's perspective of the difficulties encountered in terms of the available management options, as the patient progressively deteriorated on the regular medical floor prompting transfer to the intensive care unit.

Hepatic and gastrointestinal involvement in coronavirus disease 2019 (COVID-19): What do we know till now?

Since December 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen of coronavirus disease 2019 (COVID-19), has posed a serious threat to global health and is currently causing a major pandemic. While patients typically present with fever and a respiratory illness, mounting evidence indicates that patients might also report extra-pulmonary manifestations, including those affecting the liver and gastrointestinal tract. This involvement may have important implications to the disease management, transmission, and prognosis, especially in patients with pre-existing hepatic or digestive co-morbidities. In this review, the characteristics and possible explanations of hepatic and gastrointestinal involvement caused by SARS-CoV-2 infection are summarized, adding to our knowledge of the spectrum of COVID-19. In addition, preventive measures implemented in endoscopy departments to prevent further dissemination of SARS-CoV-2 infection are proposed.