COVID-19-specific adult basic life support guideline strategies for chiropractors and other healthcare providers to maximize the safety and efficacy of resuscitation: a commentary.

BACKGROUND: The emergence of an unprecedented novel severe acute respiratory syndrome coronavirus-2 (SARS-C0V-2), which causes the coronavirus disease 2019 (COVID-19) pandemic, has created new scenarios in basic life support (BLS) management. According to current evidence, SARS-CoV-2 can be transmitted airborne in aerosol particles during resuscitation. Research evidence found an alarming global increase in out-of-hospital cardiac arrests during the COVID-19 pandemic. Healthcare providers are legally obliged to respond to cardiac arrest as soon as possible. Chiropractors will likely encounter potential exercise-related and non-exercise-related cardiac emergencies at some point in their professional lives. They have a duty of care to respond to emergencies such as cardiac arrest. Chiropractors are increasingly involved in providing care, including emergency care, for athletes and spectators at sporting events. Also, exercise-related cardiac arrest in adult patients may occur during exercise testing or rehabilitation with exercise prescriptions in chiropractic and other healthcare settings. Little is known about the COVID-19 BLS guidelines for chiropractors. Knowledge of the current COVID-19-specific adult BLS guidelines is essential to developing an emergency response plan for the on-field and sideline management of exercise-related cardiac arrest and non-athletic, non-exercise-related cardiac arrest. MAIN TEXT: Seven peer-reviewed articles on the COVID-19-specific BLS guidelines, including two updates, were reviewed for this commentary. Responding to the COVID-19 pandemic, the national and international resuscitation organizations recommended interim COVID-19-specific BLS guidelines with precaution, resuscitation, and education strategies. BLS safety is paramount. A precautionary approach with the bare minimum of appropriate personal protective equipment for resuscitation is recommended. There was disagreement among the COVID-19 BLS guidelines on the level of personal protective equipment. All healthcare professionals should also undergo self-directed BLS e-learning and virtual skill e-training. The summarized COVID-19-specific adult BLS guideline strategies and protocols are tabled, respectively. CONCLUSIONS: This commentary provides a practical overview and highlights current evidence-based intervention strategies of the COVID-19-specific adult BLS guidelines that may help chiropractors and other healthcare providers reduce BLS-related exposures to SARS-CoV-2 and the risks of SARS-CoV-2 transmission and maximize the efficacy of resuscitation. This study is relevant to and impacts future COVID-19-related research in areas such as infection prevention and control.

Measurement of Ventilation Rate and Evaluation of Infection Risk in a Classroom

To quantitatively evaluate the effect of increasing ventilation using the immediately practicable method on infection risk, the ventilation rate in a classroom was measured by the concentration decay method using CO2. The measured value was then substituted into the Wells-Riley model to evaluate aerosol infection risk in steady and non-steady states. In the classroom, the air change rate per hour (ACH) ranged from 3.1 to 10.2, and the local mean age of air tended to be larger near the outlet. It was also shown that opening the windows increased the ventilation rate the most, resulting in a more evenly distributed local mean age of air. We also showed that the aerosol infection risk in the classroom could be significantly reduced by increasing ventilation, suppressing vocalization, and wearing a mask, compared to some outbreaks of COVID-19. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

Aerosol transmission in queuing and dining scenarios in canteens and the effectiveness of control measures

This study investigates the aerosol transmission in queuing and dining scenarios in canteens and explores the effectiveness of control measures. An improved Wells-Riley equation is adopted to calculate the infection risk. The dilution of exhaled aerosols is difficult in the crowded queuing scenario, where the replacement of queuing positions increases the cross-infection risk. The highest infection risk is 1.16% and 1.08% for the linear-queue and cross-queue condition, respectively. Shortening the queuing duration, increasing the separation distance, and wearing masks can considerably reduce the infection risk. In the dining scenario, the effect of increasing ACH is limited on reducing the local concentration. An exhaust vent installed close to the top of the partition can effectively remove the local high-concentration aerosols. Intermittent occupation of a seat can considerably reduce the transmission risk between the consecutive dinners taking that seat. These findings should contribute to improved control of infectious transmission in canteens.

Probable Aerosol Transmission of SARS-CoV-2 through Floors and Walls of Quarantine Hotel, Taiwan, 2021.

We investigated a cluster of SARS-CoV-2 infections in a quarantine hotel in Taiwan in December 2021. The cluster involved 3 case patients who lived in nonadjacent rooms on different floors. They had no direct contact during their stay. By direct exploration of the space above the room ceilings, we found residual tunnels, wall defects, and truncated pipes between their rooms. We conducted a simplified tracer-gas experiment to assess the interconnection between rooms. Aerosol transmission through structural defects in floors and walls in this poorly ventilated hotel was the most likely route of virus transmission. This event demonstrates the high transmissibility of Omicron variants, even across rooms and floors, through structural defects. Our findings emphasize the importance of ventilation and integrity of building structure in quarantine facilities.

Simulating the impact of ventilation on COVID-19 infection probability from aerosol transmission in enclosed spaces

Most people spend 80-90% of their lives indoors. This makes controlling the airborne transmission of respiratory viruses such as influenza, rhinovirus, SARS, and COVID-19 in indoor environments important for healthy building outcomes. Though direct transmission from droplets and surfaces is usually a more effective means of infection transfer, buildings need to operate assuming aerosol transmission can be a serious risk. This study used simulations to assess the impacts of occupant density and ventilation rates as control measures to reduce the risk of aerosol transmission of COVID-19 in large and small offices. The simulation outputs were selected to correspond with in situ CO2 sensors and control points. The results of the simulation can be used to set targets for CO2 and other parameters that can be measured by low-cost sensors to manage risk of infection due to aerosol transmission. © International Building Performance Simulation Association, 2022

Numerical Study on the Impact of Large Air Purifiers, Physical Distancing, and Mask Wearing in Classrooms

The risk of COVID-19 infection from virulent aerosols is particularly high indoors. This is especially true for classrooms, which often do not have pre-installed ventilation and are occupied by a large number of students at the same time. It has been found that precautionary measures, such as the use of air purifiers (AP), physical distancing, and the wearing of masks, can reduce the risk of infection. To quantify the actual effect of precautions, it is not possible in experimental studies to expose subjects to virulent aerosols. Therefore, in this study, we develop a computational fluid dynamics (CFD) model to evaluate the impact of applying the aforementioned precautions in classrooms on reducing aerosol concentration and potential exposure in the presence of index or infected patients. A CFD-coupled Wells–Riley model is used to quantify the infection probability (IP) in the presence of index patients. Different cases are simulated by varying the occupancy of the room (half/full), the volumetric flow rate of the AP, two different locations of the AP, and the effect of wearing masks. The results suggest that using an AP reduces the spread of virulent aerosols and thereby reduces the risk of infection. However, the risk of the person sitting adjacent to the index patient is only marginally reduced and can be avoided with the half capacity of the class (physical distancing method) or by wearing face masks of high efficiencies.

What Have We Learned About Transmission of Coronavirus Disease-2019: Implications for Pulmonary Function Testing and Pulmonary Procedures.

Because of the potential for high aerosol transmission during pulmonary function testing and pulmonary procedures, performing these tests and procedures must be considered carefully during the coronavirus disease-2019 (COVID-19) pandemic. Much has been learned about the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by aerosols and the potential for such transmission through pulmonary function tests and pulmonary procedures, and subsequently preventative practices have been enhanced and developed to reduce the risk of transmission of virus to patients and personnel. This article reviews what is known about the potential for transmission of SARS-CoV-2 during pulmonary function testing and pulmonary procedures and the recommended mitigation steps to prevent the spread of COVID-19.

Non - pharmaceutical interventions for respiratory virus infection in children and its effect.

With the emergence of new respiratory virus,it is more apparent for the vulnerability of population to respiratory viral infection. Non -pharmaceutical interventions (NPIs) for respiratory virus infection have become the main way to prevent corona virus disease 2019. Some studies had proven its effectiveness. In addition,the NPIs also significantly reduced the incidence and hospitalization rate of other respiratory disease in children. NPIs for respiratory virus infection in children have its particularity and challenge. In daily life,it is important to guide children how to do the NPIs, so as to protect susceptible children and reduce the disease burden in children's health system. Therefore, the aerosol transmission, the specificity of the NPIs in children, and the impact on childhood respiratory diseases are described in this article, to improve the prevention of common respiratory diseases in children.Copyright © 2022 Chinese Medical Journals Publishing House Co.Ltd. All Rights Reserved.

Designing Out the Risk of Infections via Aerosols by Updating Restrictions on Indoor Environments Depending on Local Incidence Rates and the Dominant SARS-Co V -2 Strain

The paper contributes to existing research on transmission of infectious diseases in indoor environments, with a focus on the SARS-Co V -2 virus, considered in an environment with a potentially high infectious risk, i.e. a university building. A multi-functional zone with variable occupancy schedules involving both students and staff is used as a case study. A computational fluid dynamics (CFD) model is developed to simulate and analyze three scenarios involving mixed, mechanical, and natural ventilation. Based on the physical and operational configuration of the selected zone, initial results show that mechanical ventilation involves areas of stagnant air (i.e. air velocity is less than 0.1m/s), while reliance on natural ventilation leads to increase in C02 levels. Hence, a mixed mode (natural and mechanical) ventilation is suggested. Then, based on the probability of the presence of (an) infected individual(s), considering the local COVID-19 incidence rate, initial estimates suggest that the Delta variant requires the air change rate (ACH) to be increased more than 1000 times, when compared to the original strain. The paper thus establishes a correlation between the prevalence of a given SARS-Co V -2 variant with the required air change rate, emphasizing the need to factor in not only the presence of infected individual(s), based on the local incidence rate, but also the viral charge of the dominant SARS-Co V -2 variant. The paper argues the need for a better controlled and optimized ventilation to ensure safer indoor environments. © 2022 IEEE.

EVALUATION ON INDOOR ENVIRONMENT AND ALTERNATIVE VENTILATION METHODS IN A SCHOOL CLASSROOM IN A COLD REGION UNDER COVID-19 PANDEMIC

COVID-19 caused a global pandemic. The possibility of aerosol transmission has been pointed out as a possible route of infection, and there are reports that conventional infection control measures are insufficient to counteract aerosol transmission. Therefore, this report presents the results of an actual survey at a high school, including measurement of CO2 concentration and a questionnaire survey, and the results of an experiment to evaluate the attenuation of particle concentration by an air cleaner based on this survey.

Efficacy of Grignard Pure to Inactivate Airborne Phage MS2, a Common SARS-CoV-2 Surrogate.

Grignard Pure (GP) is a unique and proprietary blend of triethylene glycol (TEG) and inert ingredients designed for continuous antimicrobial treatment of air. TEG has been designated as a ″Safer Chemical" by the US EPA. GP has already received approval from the US EPA under its Section 18 Public Health Emergency Exemption program for use in seven states. This study characterizes the efficacy of GP for inactivating MS2 bacteriophage─a nonenveloped virus widely used as a surrogate for SARS-CoV-2. Experiments measured the decrease in airborne viable MS2 concentration in the presence of different concentrations of GP from 60 to 90 min, accounting for both natural die-off and settling of MS2. Experiments were conducted both by introducing GP aerosol into air containing MS2 and by introducing airborne MS2 into air containing GP aerosol. GP is consistently able to rapidly reduce viable MS2 bacteriophage concentration by 2-3 logs at GP concentrations of 0.04-0.5 mg/m3 (corresponding to TEG concentrations of 0.025 to 0.287 mg/m3). Related GP efficacy experiments by the US EPA, as well as GP (TEG) safety and toxicology, are also discussed.

Informing Building Strategies to Reduce Infectious Aerosol Transmission Risk by Integrating DNA Aerosol Tracers with Quantitative Microbial Risk Assessment.

Using aerosol-based tracers to estimate risk of infectious aerosol transmission aids in the design of buildings with adequate protection against aerosol transmissible pathogens, such as SARS-CoV-2 and influenza. We propose a method for scaling a SARS-CoV-2 bulk aerosol quantitative microbial risk assessment (QMRA) model for impulse emissions, coughing or sneezing, with aerosolized synthetic DNA tracer concentration measurements. With point-of-emission ratios describing relationships between tracer and respiratory aerosol emission characteristics (i.e., volume and RNA or DNA concentrations) and accounting for aerosolized pathogen loss of infectivity over time, we scale the inhaled pathogen dose and risk of infection with time-integrated tracer concentrations measured with a filter sampler. This tracer-scaled QMRA model is evaluated through scenario testing, comparing the impact of ventilation, occupancy, masking, and layering interventions on infection risk. We apply the tracer-scaled QMRA model to measurement data from an ambulatory care room to estimate the risk reduction resulting from HEPA air cleaner operation. Using DNA tracer measurements to scale a bulk aerosol QMRA model is a relatively simple method of estimating risk in buildings and can be applied to understand the impact of risk mitigation efforts.

Real-Time Estimation and Monitoring of COVID-19 Aerosol Transmission Risk in Office Buildings.

A healthy and safe indoor environment is an important part of containing the coronavirus disease 2019 (COVID-19) pandemic. Therefore, this work presents a real-time Internet of things (IoT) software architecture to automatically calculate and visualize a COVID-19 aerosol transmission risk estimation. This risk estimation is based on indoor climate sensor data, such as carbon dioxide (CO2) and temperature, which is fed into Streaming MASSIF, a semantic stream processing platform, to perform the computations. The results are visualized on a dynamic dashboard that automatically suggests appropriate visualizations based on the semantics of the data. To evaluate the complete architecture, the indoor climate during the student examination periods of January 2020 (pre-COVID) and January 2021 (mid-COVID) was analyzed. When compared to each other, we observe that the COVID-19 measures in 2021 resulted in a safer indoor environment.

SARS-CoV-2 Omicron variant shedding during respiratory activities.

OBJECTIVES: As the world transitions to COVID-19 endemicity, studies focusing on aerosol shedding of highly transmissible SARS-CoV-2 variants of concern (VOCs) are vital for the calibration of infection control measures against VOCs that are likely to circulate seasonally. This follow-up Gesundheit-II aerosol sampling study aims to compare the aerosol shedding patterns of Omicron VOC samples with pre-Omicron variants analyzed in our previous study. DESIGN: Coarse and fine aerosol samples from 47 patients infected with SARS-CoV-2 were collected during various respiratory activities (passive breathing, talking, and singing) and analyzed using reverse transcription-quantitative polymerase chain reaction and virus culture. RESULTS: Compared with patients infected with pre-Omicron variants, comparable SARS-CoV-2 RNA copy numbers were detectable in aerosol samples of patients infected with Omicron despite being fully vaccinated. Patients infected with Omicron also showed a slight increase in viral aerosol shedding during breathing activities and were more likely to have persistent aerosol shedding beyond 7 days after disease onset. CONCLUSION: This follow-up study reaffirms the aerosol shedding properties of Omicron and should guide continued layering of public health interventions even in highly vaccinated populations.

A multicenter study to investigate the positive rate of SARS-CoV-2 in middle ear and mastoid specimens from otologic surgery patients.

OBJECTIVE: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus, causes coronavirus disease 2019 (COVID-19). Otologic surgeries with drilling by powered instruments induce significant aerosols, which may induce SARS-CoV-2 transmission to medical staff if SARS-CoV-2 exists in the middle ear and mastoid cavity. During a COVID-19 pandemic, therefore, confirming a negative COVID-19 test prior to otologic surgery is recommended. However, previous coronavirus studies demonstrated that coronavirus was detected in the middle ear in some patients even though the polymerase chain reaction (PCR) test using their nasopharyngeal swab was negative. This study aimed to elucidate the probability of a positive SARS-CoV-2 PCR test in the middle ear or mastoid specimens from otologic surgery patients in whom SARS-CoV-2 was not detected by preoperative PCR test using a nasopharyngeal swab. METHODS: We conducted a prospective, multicenter clinical study. Between April 2020 and December 2021, during the COVID-19 pandemic, 251 ears of the 228 participants who underwent otologic surgery were included in this study. All participants had no symptoms suggesting COVID-19 or close contact with a confirmed COVID-19 patient two weeks prior to the surgery. They were also negative in the SARS-CoV-2 PCR tests using a nasopharyngeal swab before surgery. We collected mucosa, granulation, bone dust with mucosa or fluid from the middle ear or mastoid for the SARS-CoV-2 PCR tests during each otologic surgery. RESULTS: The median age of the participants at surgery was 31.5 years old. Mastoidectomy using a powered instrument was conducted in 180 of 251 otologic surgeries (71.8%). According to intraoperative findings, active inflammation in the middle ear or mastoid cavities was evident in 20 otologic surgeries (8.0%), while minor inflammation was observed in 77 (30.7%). All SARS-CoV-2 PCR tests of otologic specimens showed a negative result. No patient suffered from COVID-19 within two months after otologic surgery. Furthermore, no hospital-acquired infections associated with otologic surgery occurred in our institutions CONCLUSIONS: Our results showed that PCR testing did not detect SARS-CoV-2 in middle ear and mastoid specimens, suggesting that the risk of transmission of SARS-CoV-2 is not high in otologic surgeries even using powered instruments when both clinical and laboratory tests are confirmed to be negative for COVID-19.

Ventilation Methods against Indoor Aerosol Infection of COVID-19 in Japan

The importance of effective ventilation as one of the measures against COVID-19 is widely recognized worldwide. In Japan, at the early stage of the pandemic, in March 2020, an official announcement was made about basic ventilation measures against COVID-19. WHO also used the term "long-range aerosol or long-range airborne transmission” for the first time in December 2021. Based on the aerosol infection control measures before 2021 by the Japanese government, we conducted experiments on methods related to partition placement as an element of effective ventilation methods. In July 2022, the governmental subcommittee on Novel Coronavirus Disease Control provided an emergent proposal about effective ventilation methods to prevent two types of aerosol infection;infection by large aerosol on the air current and infection by small floating aerosol diffusion in a room. They also showed the way of setting droplet prevention partitions, which do not block off ventilation based on this investigation's results. © 2023 by the authors.

EVALUATION ON INDOOR ENVIRONMENT AND ALTERNATIVE VENTILATION METHODS IN A SCHOOL CLASSROOM IN A COLD REGION UNDER COVID-19 PANDEMIC

COVID-19 caused a global pandemic. The possibility of aerosol transmission has been pointed out as a possible route of infection, and there are reports that conventional infection control measures are insufficient to counteract aerosol transmission. Therefore, this report presents the results of an actual survey at a high school, including measurement of CO2 concentration and a questionnaire survey, and the results of an experiment to evaluate the attenuation of particle concentration by an air cleaner based on this survey. © 2023 Architectural Institute of Japan. All rights reserved.

Research on the relationship between architectural features in northeast China and vertical aerosol transmission of COVID-19.

During the COVID-19 pandemic, many buildings in northeast China have had clusters of infected cases in the vertical layout. There is speculation that vertical aerosol transmission occurs. The houses in northeast China are airtight, and range hoods may be used for a long period of time when cooking. The pathway and factors influencing vertical aerosol transmission are worth studying. To elucidate a viral aerosol transmission pathway, we selected a multistory apartment and a high-rise building in Changchun city, Jilin province, China, to conduct an in-depth investigation and on-site simulation experiments. According to epidemiological investigation information on infected cases, building structures, drainage, ventilation, etc., we used fluorescent microspheres to simulate the behaviors of infected people, such as breathing and flushing the toilet after defecation, to discharge simulated viruses and track and monitor them. The field simulation experiment confirmed the transmission of fluorescent microsphere aerosols to other rooms in two types of buildings using a vertical aerosol transmission pathway of toilet flush-sewage pipe-floor drain without a water seal. Our study showed that, in the absence of a U-shaped trap or floor drain water seal whether in a multistory apartment or high-rise residential building, there is a transmission pathway of "excretion of virus through feces-toilet flushing-sewage pipe-floor drain without water seal," which will cause the vertical transmission of viral aerosol across floors during the COVID-19 pandemic. Moreover, the negative pressure generated by turning on the range hood when closing doors and windows increase aerosol transmission. Based on this negative pressure, prevention and control measures for residential buildings in northeast China during the COVID-19 pandemic were proposed.

Neglected Aspects of SARS-CoV-2 Aerosol Transmission in Bathrooms of Multistory and High-Rise Buildings - Beijing Municipality, China, October 2022.

What is already known about this topic?: There is a toilet flush-soil stack-floor drain pathway of aerosol transmission in multistory and high-rise buildings, but the influencing factors are not completely clear. What is added by this report?: The poor airtightness of the connecting parts of the floor drain, as well as pressure fluctuations in the sewage pipe during toilet flushing caused by blockage of the soil stack vent, may lead to the cross-floor transmission of viral aerosols through the soil stack and floor drains. What are the implications for public health practice?: In multistory and high-rise buildings, the bathroom floor drains should be kept sealed, and floor drain connecting parts should be airtight. Furthermore, the soil stack vent should not be blocked. In this way, the cross-floor transmission of viral aerosols can be effectively reduced.