Shining (Invisible) Light On Viral Pathogens: Virucidal Contamination Control Strategies Using UV-C Light

Respiratory droplets are coronaviruses primary transmission mode and thus the majority of coronavirus risk mitigation strategies focus on the control of air. However, surface contact remains an alternative infection route. Hence, it remains a concern that the SARS CoV-2 virus can remain viable on surfaces for several hours.

Shining (Invisible) Light On Viral Pathogens: Virucidal Contamination Control Strategies Using UV-C Light

Respiratory droplets are coronaviruses primary transmission mode and thus the majority of coronavirus risk mitigation strategies focus on the control of air. However, surface contact remains an alternative infection route. Hence, it remains a concern that the SARS CoV-2 virus can remain viable on surfaces for several hours.

A Review on Current Situation of Coronavirus (COVID-19)

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus. Most people infected with COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment. Older people and those with underlying medical problem like cardiovascular disease, Diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness. The best way to prevent and solve down transmission is to be well informed it causes and how it spread. Protect yourself and other from infection by washing your hands or using alcohol base rub frequently and not touching your face. The COVID-19 virus spread primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes, so it’s important that you also practice respiratory etiquette (for ex. by coughing into a flexed elbow).The COVID-19 is a respiratory illness and the primary transmission of C0VID-19 route is through person to person contact and through when a contact infected person coughs or sneezes with respiratory droplets. No evidence of viruses that causes respiratory illness being transmitted via food or packaging. Corona viruses multiply in animal or human host, they cannot multiply in food.

Experimental characterization of speech aerosol dispersion dynamics

Contact and inhalation of virions-carrying human aerosols represent the primary transmission pathway for airborne diseases including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Relative to sneezing and coughing, non-symptomatic aerosol-producing activities such as speaking are highly understudied. The dispersions of aerosols from vocalization by a human subject are hereby quantified using high-speed particle image velocimetry. Syllables of different aerosol production rates were tested and compared to coughing. Results indicate aerosol productions and penetrations are not correlated. E.g. ‘ti’ and ‘ma’ have similar production rates but only ‘ti’ penetrated as far as coughs. All cases exhibited a rapidly penetrating “jet phase” followed by a slow “puff phase.” Immediate dilution of aerosols was prevented by vortex ring flow structures that concentrated particles toward the plume-front. A high-fidelity assessment of risks to exposure must account for aerosol production rate, penetration, plume direction and the prevailing air current.

Face coverings and respiratory tract droplet dispersion

Respiratory droplets are the primary transmission route for SARS-CoV-2, a principle which drives social distancing guidelines. Evidence suggests that virus transmission can be reduced by face coverings, but robust evidence for how mask usage might affect safe distancing parameters is lacking. Accordingly, we set out to quantify the effects of face coverings on respiratory tract droplet deposition. We tested an anatomically realistic manikin head which ejected fluorescent droplets of water and human volunteers, in speaking and coughing conditions without a face covering, or with a surgical mask or a single-layer cotton face covering. We quantified the number of droplets in flight using laser sheet illumination and UV-light for those that had landed at table height at up to 2 m. For human volunteers, expiratory droplets were caught on a microscope slide 5 cm from the mouth. Whether manikin or human, wearing a face covering decreased the number of projected droplets by less than 1000-fold. We estimated that a person standing 2 m from someone coughing without a mask is exposed to over 10 000 times more respiratory droplets than from someone standing 0.5 m away wearing a basic single-layer mask. Our results indicate that face coverings show consistent efficacy at blocking respiratory droplets and thus provide an opportunity to moderate social distancing policies. However, the methodologies we employed mostly detect larger (non-aerosol) sized droplets. If the aerosol transmission is later determined to be a significant driver of infection, then our findings may overestimate the effectiveness of face coverings.

Face Coverings and Respiratory Tract Droplet Dispersion

Respiratory droplets are the primary transmission route for SARS-CoV-2. Evidence suggests that virus transmission can be reduced by face coverings, but robust evidence for how mask usage might affect safe distancing parameters is lacking. Accordingly, we investigate the effectiveness of surgical masks and single-layer cotton masks on mitigating dispersion of large respiratory droplets (i.e. non aerosol). We tested a manikin ejecting fluorescent droplets and human volunteers in speaking and coughing conditions. We quantified the number of droplets in flight using laser sheet illumination and UV-light for those that had landed at table height at up to 2m. For human volunteers, expiratory droplets were caught on a microscope slide 5cm from the mouth. Whether manikin or human, wearing a face covering decreased the number of projected droplets by >1000-fold. We estimated that a person standing 2m from someone coughing without a mask is exposed to over 1000 times more respiratory droplets than from someone standing 5 cm away wearing a basic single layer mask. Our results indicate that face coverings show consistent efficacy at blocking respiratory droplets. If aerosol transmission is later determined to be a significant driver of infection, then our findings may overestimate the effectiveness of face coverings.

Insights on Epidemiology, Pathogenesis, Diagnosis and Possible Treatment of COVID-19 infection

COVID-19, SARS-CoV-2 virus of the coronavirus family, created worldwide infectious outbreak affecting millions of people across the globe showing mild to severe symptoms of pneumonia and acute respiratory distress. Absence of precise information on primary transmission, diagnosis, prognosis, and therapeutics for patients with COVID-19 makes prevention and control tough. Treatment of millions of COVID19 patients without any specific drug is one of the biggest challenge, many existing antiviral drugs are in use as an alternative treatment and hunting is still on the way to develop COVID19 specific drug and vaccine. Being the world second largest populated country, fluctuating climatic condition at every 4 months, India is also at the high risk for spread of COVID19 infection. This review article has been intended to discuss biology of COVID-19, mechanism of COVID-19 infection in humans, epidemiology, possible effect of COVID19 infection on pregnancy, nervous system, individuals diabetes and cardiovascular disease, drug repurposing strategy as an alternative line of treatment and clinical practices recommended by World Health Organization (WHO) and other government agencies followed by situation and measures taken by Indian government to minimize the spread of COVID19 in India.

Predictive factors for unfavourable treatment in MDR-TB and XDR-TB patients in Rio de Janeiro State, Brazil, 2000-2016

SettingThe State of Rio de Janeiro stands out as having the second highest incidence and the highest mortality rate due to TB in Brazil. This study aims at identifying the factors associated with the unfavourable treatment of MDR/XDR-TB patients in that State.MethodData on 2269 MDR-TB cases reported in 2000-2016 in Rio de Janeiro State were collected from the Tuberculosis Surveillance System. Bivariate and multivariate logistic regressions were run to estimate the factors associated with unfavourable outcomes (failure, default, and death) and, specifically, default and death.ResultsThe proportion of unfavourable outcomes was 41.9% among MDR-TB and 81.5% among XDR-TB. Having less than 8 years of schooling, and being an Afro-Brazilian, under 40 years old and drug user were associated with unfavourable outcome and default. Bilateral disease, HIV positive, and comorbidities were associated with death. XDR-TB cases had a 4.7-fold higher odds of an unfavourable outcome, with 29.3% of such cases being in the first treatment for multidrug resistance.ConclusionAbout 30% of XDR-TB cases may have occurred by primary transmission. The high rates of failure and death in this category reflect the limitation of treatment options. This highlights the urgency to incorporate new drugs in the treatment.

Bandwidth Allocation of Cognitive Relay Networks with Energy Harvesting for Smart Grid

In this paper, we investigate an energy harvesting scheme in a smart grid based on the cognitive relay protocol, where a primary transmitter scavenges energy from the nature sources and then employs the harvested energy to forward the primary signal. Depending on the intensity of the energy harvesting from nature, a secondary user dynamically acts as a relay node to assist the primary transmission or does not. When the energy is not enough powerful to support the direct transmission between two primary users, the secondary users share the spectrum by assisting the primary transmission. For the relaying scheme, both amplify-and-forward (AF) and decode-and-forward (DF) protocols are investigated. We analytically obtain the exact transmission rates for both primary and secondary networks and derive the exact expressions of the system outage probabilities for both primary and secondary users in the smart grid. Moreover, we develop the analytically optimal bandwidth allocation strategy to maximize the total sum rate of the proposed scheme. Numerical results are presented to demonstrate the performance gain of the proposed scheme over the nonoptimal scheme.