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Identifying Airborne Transmission as the Dominant Route for the Spread of COVID-19
Published in William C. Cockerham, Geoffrey B. Cockerham, The COVID-19 Reader, 2020
Renyi Zhang, Yixin Li, Annie L. Zhang, Yuan Wang, Mario J. Molina
Several parameters likely influence the microorganism survival and delivery in air, including temperature, humidity, microbial resistance to external physical and biological stresses, and solar ultraviolet (UV) radiation (7). Transmission and infectivity of airborne viruses are also dependent on the size and number concentration of inhaled aerosols, which regulate the amount (dose) and pattern for respiratory deposition. With typical nasal breathing (i.e., at a velocity of –1 m·s−1) (4), inhalation of airborne viruses leads to direct and continuous deposition into the human respiratory tract. In particular, fine aerosols (i.e., particulate matter smaller than 2.5 μm, or PM2.5) penetrate deeply into the respiratory tract and even reach other vital organs (14, 15). In addition, viral shedding is dependent on the stages of infection and varies between symptomatic and asymptomatic carriers. A recent finding (16) showed that the highest viral load in the upper respiratory tract occurs at the symptom onset, suggesting the peak of infectiousness on or before the symptom onset and substantial asymptomatic transmission for SARS-CoV-2.
And Now, as Promised
Published in Rae-Ellen W. Kavey, Allison B. Kavey, Viral Pandemics, 2020
Rae-Ellen W. Kavey, Allison B. Kavey
There are three essential requirements for a global pandemic to occur: emergence of a new agent that infects humans; little or no population immunity to that agent; and easy pathogen transmission from one person to another: SARS-CoV-2 has them all. The speed of transmissibility and the strength of infectivity exemplify the power of this newly emerged pathogen. Still, it is hard to believe the rapidity with which this epidemic has evolved – the first rumors about a new coronavirus outbreak emerged just 9 weeks ago. The current numbers are staggering, but because the outbreak is evolving in real time, we can’t yet see the total picture of those infected. This means calculation of things like the fatality rate is impossible – although we probably have a reasonable handle on the number of people who have died, we still do not know the number with mild or no symptoms who no one knows are infected. An enormous hidden population like this sounds alarming, but a multitude of survivors who had minimal or no symptoms means a multitude of individuals with immunity, and herd immunity like this could theoretically mean a dwindling population of susceptible people and even, ultimately, the end of the outbreak.
Ecology
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
Generally, it was evident that viruses could be adsorbed onto solid surfaces and keep their infectivity for a long time. Moreover, it was quite true that the virus adsorption onto solid surfaces remained one of the major factors controlling their transport and survival in a water environment. Thus, the adsorbed phages ranged from 12%−30% of the total coliphages in the raw sewage, and over 97% of the coliphages in the activated sludge were associated with suspended solids, most of which were the FRNA phages (Ketratanakul and Ohgaki 1989). It was not surprising therefore that the stormwater treatment systems, where wetlands and ponds ensured physical sedimentation of particles of sand, silt, and clay to which pollutants adsorb, demonstrated high efficiency to remove the FRNA phages (Yousefi et al. 2001; Davies et al. 2003; Meuleman et al. 2003).
An effective deep residual network based class attention layer with bidirectional LSTM for diagnosis and classification of COVID-19
Published in Journal of Applied Statistics, 2023
Denis A. Pustokhin, Irina V. Pustokhina, Phuoc Nguyen Dinh, Son Van Phan, Gia Nhu Nguyen, Gyanendra Prasad Joshi, Shankar K.
Symptoms of infectivity have dyspnea (i.e. shortness of breath), fever, cough, and respiratory sign. In other severe victims, the infectivity leads to pneumonia, organ failure, septic shock, severe acute respiratory syndrome, as well as mortality. It has been computed that males are highly infectious than females and that the kids under the age group of (0–9) kids also have a certain probability of infection. The person already suffering respiratory issues are easily infected by COVID-19 pneumonia compared to healthier humans. Although in several countries, the health infrastructure has moved towards failing because of rising requisition for Intensive Care Units (ICU) at. ICU is fully occupied by the COVID-19 cases that are in serious stage along with pneumonia. The allotment of this patient observed globally among the times of 16th February and 21st March 2020.
Quantification methods for viruses and virus-like particles applied in biopharmaceutical production processes
Published in Expert Review of Vaccines, 2022
Keven Lothert, Friederike Eilts, Michael W. Wolff
As indicated in the individual chapters, process automation is an important approach to enable a robust and reliable data acquisition, as well as to reduce hands-on time. Thus, automation is implemented throughout sample preparation as well as analysis. Generally, pipetting robots have the potential to reduce the effort for classical titration and immunoassays that are applied in a multiwell-plate format [168]. Automation is also used to shorten the analysis time, in order to ensure an optimal process monitoring, which is essential during process development and control. In the case of infectivity assays, automated image analysis algorithms facilitate the identification of virus colonies, and were described, e.g. for the Zika virus [169], filoviruses [170], or the Ebola virus [171]. Especially assays, that are limited by the incubation time prior to a possible read-out, are at focus in this research. Infectivity assays are confined by the infection kinetics and the assays’ sensitivity toward the target viral components to be analyzed. These limitations will be addressed even more in the future by means of mathematical models, based on process-specific databases. The necessary models have been the focus of research for some time [172–177].
Rise of the SARS-CoV-2 Variants: can proteomics be the silver bullet?
Published in Expert Review of Proteomics, 2022
Arup Acharjee, Joshua Stephen Kingsly, Madhura Kamat, Vishakha Kurlawala, Aparajita Chakraborty, Priyanka Vyas, Radhika Vaishnav, Sanjeeva Srivastava
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a novel coronavirus, the causative agent behind the current Coronavirus Disease 2019 (COVID-19) pandemic, has been a public health challenge over the past two years. SARS-CoV-2 has affected well over 436 million individuals and claimed the lives of around 6 million individuals as of 28 February 2022 [1]. However, we may never truly know the actual extent of loss as it is widely thought that these official figures are significantly underestimated [2]. The monstrosity of the pandemic fueled active research, and proteomics technologies have generated essential findings since the initial wave of COVID-19. However, the unfortunate emergence of variants precludes the end of the pandemic. Therefore, intense, relentless, multidimensional, and coordinated counterattacks against this pestilence seem to be the order of the day, and proteomics shall play a definitive role in this strategy. Historically, coronaviruses are predisposed to lead to epidemics [3]. SARS-CoV-2 is the ninth coronavirus to infect humans and the seventh in the previous two decades [4,5]. Coronaviruses, in general, infect various mammals and birds. Moreover, the mutations that accumulate over repeated cross-species infections [3] can transmit viruses with greater infectivity and altered pathology. SARS-CoV-2 not only affects the respiratory system but can affect multiple human organs and physiological systems [6].