scholarly journals Strategies to minimize SARS-CoV-2 transmission in classroom settings: Combined impacts of ventilation and mask effective filtration efficiency

Author(s):  
David A. Rothamer ◽  
Scott Sanders ◽  
Douglas Reindl ◽  
Timothy H. Bertram

AbstractThe impact of the COVID-19 pandemic continues to be significant and global. As the global community learns more about the novel coronavirus SARS-CoV-2, there is strong evidence that a significant modality of transmission is via the long-range airborne route, referred to here as aerosol transmission. In this paper, we evaluate the efficacy of ventilation, mask effective filtration efficiency, and the combined effect of the two on the reduction of aerosol infection probability for COVID-19 in a classroom setting. The Wells-Riley equation is used to predict the conditional probability of infection for three distinct airborne exposure scenarios: (1) an infectious instructor exposing susceptible students; (2) an infectious student exposing other susceptible students; and (3) an infectious student exposing a susceptible instructor. Field measurements were performed in a classroom using a polydisperse neutralized salt (NaCl) aerosol, generated in a size range consistent with human-generated SARS-CoV-2 containing bioaerosols, as a safe surrogate. Measurements included time-resolved and size-resolved NaCl aerosol concentration distributions and size-resolved effective filtration efficiency of different masks with and without mask fitters. The measurements were used to validate assumptions and inputs for the Wells-Riley model. Aerosol dynamics and distribution measurements confirmed that the majority of the classroom space is uniform in aerosol concentration within a factor of 2 or better for distances > 2 m from the aerosol source. Mask effective filtration efficiency measurements show that most masks fit poorly with estimated leakage rates typically > 50%, resulting in significantly reduced effective filtration efficiency. However, effective filtration efficiencies approaching the mask material filtration efficiency were achievable using simple mask fitters. Wells-Riley model results for the different scenarios suggest that ventilation of the classroom alone is not able to achieve infection probabilities less than 0.01 (1%) for air exchanges rates up to 10 h−1 and an event duration of one hour. The use of moderate to high effective filtration efficiency masks by all individuals present, on the other hand, was able to significantly reduce infection probability and could achieve reductions in infection probability by 5x, 10x, or even >100x dependent on the mask used and use of a mask fitter. This enables conditional infection probabilities < 0.001 (0.1%) or even < 0.0001 (0.01%) to be reached with the use of masks and mask fitters alone. Finally, the results demonstrate that the reductions provided by ventilation and masks are synergistic and multiplicative. The results reinforce the use of properly donned masks to achieve reduced aerosol transmission of SARS-CoV-2 and other infectious diseases transmitted via respiratory aerosol indoors and provide new motivation to further improve the effective filtration efficiency of common face coverings through improved design, and/or the use of mask fitters.

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1198-1201
Author(s):  
Syed Yasir Afaque

In December 2019, a unique coronavirus infection, SARS-CoV-2, was first identified in the province of Wuhan in China. Since then, it spread rapidly all over the world and has been responsible for a large number of morbidity and mortality among humans. According to a latest study, Diabetes mellitus, heart diseases, Hypertension etc. are being considered important risk factors for the development of this infection and is also associated with unfavorable outcomes in these patients. There is little evidence concerning the trail back of these patients possibly because of a small number of participants and people who experienced primary composite outcomes (such as admission in the ICU, usage of machine-driven ventilation or even fatality of these patients). Until now, there are no academic findings that have proven independent prognostic value of diabetes on death in the novel Coronavirus patients. However, there are several conjectures linking Diabetes with the impact as well as progression of COVID-19 in these patients. The aim of this review is to acknowledge about the association amongst Diabetes and the novel Coronavirus and the result of the infection in such patients.


2020 ◽  
Vol 17 (12) ◽  
pp. 1458-1464
Author(s):  
Sweta Kamboj ◽  
Rohit Kamboj ◽  
Shikha Kamboj ◽  
Kumar Guarve ◽  
Rohit Dutt

Background: In the 1960s, the human coronavirus was designated, which is responsible for the upper respiratory tract disease in children. Back in 2003, mainly 5 new coronaviruses were recognized. This study directly pursues to govern knowledge, attitude and practice of viral and droplet infection isolation safeguard among the researchers during the outbreak of the COVID-19. Introduction: Coronavirus is a proteinaceous and infectious pathogen. It is an etiological agent of severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS). Coronavirus, appeared in China from the seafood and poultry market last year, which has spread in various countries, and has caused several deaths. Methods: The literature data has been taken from different search platforms like PubMed, Science Direct, Embase, Web of Science, who.int portal and complied. Results: Corona virology study will be more advanced and outstanding in recent years. COVID-19 epidemic is a threatening reminder not solely for one country but all over the universe. Conclusion: In this review article, we encapsulated the pathogenesis, geographical spread of coronavirus worldwide, also discussed the perspective of diagnosis, effective treatment, and primary recommendations by the World Health Organization, and guidelines of the government to slow down the impact of the virus are also optimistic, efficacious and obliging for the public health. However, it will take a prolonged time in the future to overcome this epidemic.


Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Saima Habeeb ◽  
Manju Chugani

: The novel coronavirus infection (COVID‐19) is a global public health emergency.Since its outbreak in Wuhan, China in December 2019, the infection has spread at an alarming rate across the globe and humans have been locked down to their countries, cities and homes. As of now, the virus has affected over 20million people globally and has inflicted over 7 lac deaths. Nevertheless, the recovery rate is improving with each passing day and over 14 million people have recuperated so far. The statistics indicate that nobody is immune to the disease as the virus continues to spread among all age groups; newborns to the elders, and all compartmentsincluding pregnant women. However, pregnant women may be more susceptible to this infection as they are, in general, highly vulnerable to respiratory infections. There is no evidence for vertical transmission of the COVID-19 virus among pregnant women, but an increased prevalence of preterm deliveries. Besides this, the COVID-19 may alter immune response at the maternal-fetal interface and affect the well-being of mothers as well as infants. Unfortunately, there is limited evidence available in the open literature regarding coronavirus infection during pregnancy and it now appears that certain pregnant women have infected during the present 2019-nCoV pandemic. In this short communication, we study the impact of the COVID-19 infection on vertical transmission and fetal outcome among pregnant women.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 461
Author(s):  
Fu Yang ◽  
Zhengkun Huang ◽  
Jun Huang ◽  
Chongde Wu ◽  
Rongqing Zhou ◽  
...  

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.


Author(s):  
Biyan Nathanael Harapan ◽  
Hyeon Joo Yoo

AbstractSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus, is responsible for the outbreak of coronavirus disease 19 (COVID-19) and was first identified in Wuhan, China in December 2019. It is evident that the COVID-19 pandemic has become a challenging world issue. Although most COVID-19 patients primarily develop respiratory symptoms, an increasing number of neurological symptoms and manifestations associated with COVID-19 have been observed. In this narrative review, we elaborate on proposed neurotropic mechanisms and various neurological symptoms, manifestations, and complications of COVID-19 reported in the present literature. For this purpose, a review of all current published literature (studies, case reports, case series, reviews, editorials, and other articles) was conducted and neurological sequelae of COVID-19 were summarized. Essential and common neurological symptoms including gustatory and olfactory dysfunctions, myalgia, headache, altered mental status, confusion, delirium, and dizziness are presented separately in sections. Moreover, neurological manifestations and complications that are of great concern such as stroke, cerebral (sinus) venous thrombosis, seizures, meningoencephalitis, Guillain–Barré syndrome, Miller Fisher syndrome, acute myelitis, and posterior reversible encephalopathy syndrome (PRES) are also addressed systematically. Future studies that examine the impact of neurological symptoms and manifestations on the course of the disease are needed to further clarify and assess the link between neurological complications and the clinical outcome of patients with COVID-19. To limit long-term consequences, it is crucial that healthcare professionals can early detect possible neurological symptoms and are well versed in the increasingly common neurological manifestations and complications of COVID-19.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 959
Author(s):  
Benjamin Clark ◽  
Ruth DeFries ◽  
Jagdish Krishnaswamy

As part of its nationally determined contributions as well as national forest policy goals, India plans to boost tree cover to 33% of its land area. Land currently under other uses will require tree-plantations or reforestation to achieve this goal. This paper examines the effects of converting cropland to tree or forest cover in the Central India Highlands (CIH). The paper examines the impact of increased forest cover on groundwater infiltration and recharge, which are essential for sustainable Rabi (winter, non-monsoon) season irrigation and agricultural production. Field measurements of saturated hydraulic conductivity (Kfs) linked to hydrological modeling estimate increased forest cover impact on the CIH hydrology. Kfs tests in 118 sites demonstrate a significant land cover effect, with forest cover having a higher Kfs of 20.2 mm hr−1 than croplands (6.7mm hr−1). The spatial processes in hydrology (SPHY) model simulated forest cover from 2% to 75% and showed that each basin reacts differently, depending on the amount of agriculture under paddy. Paddy agriculture can compensate for low infiltration through increased depression storage, allowing for continuous infiltration and groundwater recharge. Expanding forest cover to 33% in the CIH would reduce groundwater recharge by 7.94 mm (−1%) when converting the average cropland and increase it by 15.38 mm (3%) if reforestation is conducted on non-paddy agriculture. Intermediate forest cover shows however shows potential for increase in net benefits.


Author(s):  
Ding Ding ◽  
Chong Guan ◽  
Calvin M. L. Chan ◽  
Wenting Liu

Abstract As the 2019 novel coronavirus disease (COVID-19) pandemic rages globally, its impact has been felt in the stock markets around the world. Amidst the gloomy economic outlook, certain sectors seem to have survived better than others. This paper aims to investigate the sectors that have performed better even as market sentiment is affected by the pandemic. The daily closing stock prices of a total usable sample of 1,567 firms from 37 sectors are first analyzed using a combination of hierarchical clustering and shape-based distance (SBD) measures. Market sentiment is modeled from Google Trends on the COVID-19 pandemic. This is then analyzed against the time series of daily closing stock prices using augmented vector autoregression (VAR). The empirical results indicate that market sentiment towards the pandemic has significant effects on the stock prices of the sectors. Particularly, the stock price performance across sectors is differentiated by the level of the digital transformation of sectors, with those that are most digitally transformed, showing resilience towards negative market sentiment on the pandemic. This study contributes to the existing literature by incorporating search trends to analyze market sentiment, and by showing that digital transformation moderated the stock market resilience of firms against concern over the COVID-19 outbreak.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Heidi Luise Schulte ◽  
José Diego Brito-Sousa ◽  
Marcus Vinicius Guimarães Lacerda ◽  
Luciana Ansaneli Naves ◽  
Eliana Teles de Gois ◽  
...  

Abstract Background Since the novel coronavirus disease outbreak, over 179.7 million people have been infected by SARS-CoV-2 worldwide, including the population living in dengue-endemic regions, particularly Latin America and Southeast Asia, raising concern about the impact of possible co-infections. Methods Thirteen SARS-CoV-2/DENV co-infection cases reported in Midwestern Brazil between April and September of 2020 are described. Information was gathered from hospital medical records regarding the most relevant clinical and laboratory findings, diagnostic process, therapeutic interventions, together with clinician-assessed outcomes and follow-up. Results Of the 13 cases, seven patients presented Acute Undifferentiated Febrile Syndrome and six had pre-existing co-morbidities, such as diabetes, hypertension and hypopituitarism. Two patients were pregnant. The most common symptoms and clinical signs reported at first evaluation were myalgia, fever and dyspnea. In six cases, the initial diagnosis was dengue fever, which delayed the diagnosis of concomitant infections. The most frequently applied therapeutic interventions were antibiotics and analgesics. In total, four patients were hospitalized. None of them were transferred to the intensive care unit or died. Clinical improvement was verified in all patients after a maximum of 21 days. Conclusions The cases reported here highlight the challenges in differential diagnosis and the importance of considering concomitant infections, especially to improve clinical management and possible prevention measures. Failure to consider a SARS-CoV-2/DENV co-infection may impact both individual and community levels, especially in endemic areas.


2020 ◽  
Vol 93 (6) ◽  
pp. 343-350
Author(s):  
Molly O. Regelmann ◽  
Rushika Conroy ◽  
Evgenia Gourgari ◽  
Anshu Gupta ◽  
Ines Guttmann-Bauman ◽  
...  

<b><i>Background:</i></b> Pediatric endocrine practices had to rapidly transition to telemedicine care at the onset of the novel coronavirus disease 2019 (COVID-19) pandemic. For many, it was an abrupt introduction to providing virtual healthcare, with concerns related to quality of patient care, patient privacy, productivity, and compensation, as workflows had to change. <b><i>Summary:</i></b> The review summarizes the common adaptations for telemedicine during the pandemic with respect to the practice of pediatric endocrinology and discusses the benefits and potential barriers to telemedicine. <b><i>Key Messages:</i></b> With adjustments to practice, telemedicine has allowed providers to deliver care to their patients during the COVID-19 pandemic. The broader implementation of telemedicine in pediatric endocrinology practice has the potential for expanding patient access. Research assessing the impact of telemedicine on patient care outcomes in those with pediatric endocrinology conditions will be necessary to justify its continued use beyond the COVID-19 pandemic.


Thesis Eleven ◽  
2021 ◽  
pp. 072551362110331
Author(s):  
Jon Stratton

Panic buying of toilet rolls in Australia began in early March 2020. This was related to the realisation that the novel coronavirus was spreading across the country. To the general population the impact of the virus was unknown. Gradually the federal government started closing the country’s borders. The panic buying of toilet rolls was not unique to Australia. It happened across all societies that used toilet paper rather than water to clean after defecation and urination. However, research suggests that the panic buying was most extreme in Australia. This article argues that the panic buying was closely linked to everyday notions of Western civilisation. Pedestal toilets and toilet paper are key aspects of civilisation and the fear of the loss of toilet paper is connected to anxiety about social breakdown, the loss of civilisation. This is the fear manifested in the perceived threat posed by the virus.


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