scholarly journals Review of Evidence of Aerosol Transmission of SARS-CoV-2 Particles

Author(s):  
Shehu Sharafadeen Aladodo ◽  
Clement Olufemi Akoshile ◽  
J. O. Otu

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causes Coronavirus disease (COVID-19) through multiple transmission routes and understanding the mode of transmission is very important for its containment and prevention. Consequently, inadequate attention has been given to the spread of respiratory droplets in indoor conditions under microclimatologic turbulent wind promoted by aerosol from talking (loud), coughing, sneezing, toilet flushing of an isolation room, and resuspension of the settled virus from the surfaces. To this end, this study is presenting an early review of the process and evidence of aerosol transmission of SARS-CoV-2 particles. There are significant results of many studies including those under peer review that support aerosol and airborne transmission which government agencies should consider for reducing the transmission rate.

2020 ◽  
Author(s):  
Silvia Ghezzi ◽  
Isabel Pagani ◽  
Guido Poli ◽  
Stefano Perboni ◽  
Elisa Vicenzi

AbstractSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), is transmitted person-to-person via respiratory droplets and, likely, via smaller droplet nuclei light enough to remain suspended in the air for hours and contaminate surfaces particularly in indoor conditions. Thus, effective measures are needed to prevent SARS-CoV-2 transmission in indoor environments. In this regard, we have investigated whether a system based on a filter combining Tungsten Trioxide-Based (WO3) photocatalysis and an antiviral fabric treated-copper nanocluster could inactivate SARS-CoV-2. To this purpose, an infectious SARS-CoV-2 suspension was introduced in the upper opening of a closed cylinder containing a WO3 filter and a lightbased system that activates WO3 and the antiviral fabric. From the bottom exit, aliquots of fluid were collected every 10 min (up to 60 min) and tested for their infectivity by means of a viral plaque assay in Vero cells whereas, in parallel, the viral RNA content was measured by quantitative PCR (qPCR). As we have previously shown for SARS-CoV, a 1:1,000 ratio of plaque forming units (PFU) vs. viral RNA copies was observed also for SARS-CoV-2. After 10 min, the infectious viral content was already decreased by 98.2% reaching 100% inactivation after 30 min whereas the SARS-CoV-2 RNA load was decreased of 1.5 log10 after 30 min. Thus, in spite of only a partial decrease of viral RNA, SARS-CoV-2 infectivity was completely abolished by the WO3 photocatalysis system by 30 min. These results support the hypothesis that this system could be exploited to achieve SARS-CoV-2 inactivation in indoor environments.


Author(s):  
Nicolás Guerrero ◽  
José M. Brito ◽  
Pablo Cornejo

AbstractAlthough there are some recent studies which intent to address the spread of respiratory droplets through the air, these correspond to indoor conditions or outdoor situations which not take into account realistic scenario. Less attention has been paid to the spread of respiratory droplets in outdoor environments under microclimatologic turbulent wind and which is of growing importance given the current COVID-19 epidemic. We implement a computational model describing a sneezing person in an urban scenario under a medium intensity climatological wind. Turbulence was described with a wall-modeled Large Eddy Simulation model and the spread of respiratory droplets by using a lagrangian approach. Results show the spread of respiratory droplets is characterized by the dynamics of two groups of droplets of different sizes: larger droplets (400 – 900 μm) are spread between 2–5 m during 2.3 s while smaller (100 – 200 μm) droplets are transported a larger range between 8–11 m by the action of the turbulent wind in 14.1 s average. Given the uncertainty of potential contagion over this way and with this reach, these efforts are an intent to contribute to shine a light on the possibility of adopting stricter self-care and distancing measures.


Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Bikash Debnath ◽  
Waikhom Somraj Singh ◽  
Kuntal Manna

: The coronavirus disease 2019 (COVID-19) first outbreak in Wuhan, China, and the infection is intense worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for COVID-19. The World Health Organization (WHO) confirmed total deaths had noted 4.20% globally (March 21, 2020). Between the intervals of four months (July 21, 2020), confirmed total deaths had recorded 4.17%, globally. In India, 909 confirmed cases and 19 deaths were reported by Health and Family Welfare, Government of India, March 28, 2020. Between the intervals of 123 days In India, 1638870 confirmed cases and 35684 deaths. COVID-19 can potentially spread from person to person through direct contact or respiratory droplets from coughing and sneezing. The most common symptoms are fever, dry cough, difficulty in breathing, and fatigue. A pregnant mother with COVID-19 has fewer chances to transfer this infection of her newborn babies. Children have less affected than an adult. A specific antiviral drug or vaccine has not been developed to cure the disease. Chloroquine, hydroxychloroquine, lopinavir, ritonavir, nafamostat, nitazoxanide, and remdesivir have effective drugs to treat COVID-19. Many vaccine candidates are under pre-clinical and clinical studies. In this review, we highlight the epidemiology, sign-symptoms, pathogenesis, mode of transmission, and effects of a pregnant mother with newborns, children, prevention, and drugs affective to COVID-19.


2021 ◽  
Vol 11 (7) ◽  
pp. 3081
Author(s):  
Luis Alberto Breda Mascarenhas ◽  
Fabricia Oliveira Oliveira ◽  
Eduardo Santos da Silva ◽  
Laerte Marlon Conceição dos Santos ◽  
Leticia de Alencar Pereira Rodrigues ◽  
...  

To control infectious diseases such as the severe acute respiratory syndrome coronavirus (Covid-19) that caused the current pandemic, disinfection measures are essential. Among building measures, disinfection chambers can help to decrease the transmission rate through the sanitizing capacity of the disinfectant used, which can thereby clean surfaces or humans. Out of existing biocides, ozone is considered one of the safest for humans, but one of the most powerful oxidizers, making the substance a better alternative as the biocidal solution in disinfection chambers. Analyses were carried out by using all patented documents related to disinfection chambers that used ozone as a disinfectant. A Derwent Innovation Index (DII) database search was undertaken to find these patents. Patent prospecting resulted in 620 patent documents that were divided into 134 patent families. There was no technology related to protective barriers for individuals, and the majority of patents in the retrieved data aimed at sterilizing medical devices and surfaces. Given that the specific Cooperative Patent Classification (CPC) code for ozone dissolved in liquid was used in the methodology search, but not included among the 10 most used codes in the patents, the use of ozonized water may be an innovative approach in the technology landscape of sterilization chambers.


Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 598
Author(s):  
Maren Bormann ◽  
Mira Alt ◽  
Leonie Schipper ◽  
Lukas van de Sand ◽  
Mona Otte ◽  
...  

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted from person to person by close contact, small aerosol respiratory droplets, and potentially via contact with contaminated surfaces. Herein, we investigated the effectiveness of commercial UVC-LED disinfection boxes in inactivating SARS-CoV-2-contaminated surfaces of personal items. We contaminated glass, metal, and plastic samples representing the surfaces of personal items such as smartphones, coins, or credit cards with SARS-CoV-2 formulated in an organic matrix mimicking human respiratory secretions. For disinfection, the samples were placed at different distances from UVC emitting LEDs inside commercial UVC-LED disinfection boxes and irradiated for different time periods (up to 10 min). High viral loads of SARS-CoV-2 were effectively inactivated on all surfaces after 3 min of irradiation. Even 10 s of UVC-exposure strongly reduced viral loads. Thus, UVC-LED boxes proved to be an effective method for disinfecting SARS-CoV-2-contaminated surfaces that are typically found on personal items.


2020 ◽  
Author(s):  
Sean Horoho ◽  
Stephen Musik ◽  
David Bryant ◽  
William Brooks ◽  
Ian M Porter

ABSTRACT It is well established that coronavirus disease 2019 is primarily transmitted through respiratory droplets, and there is mounting research speculation that it may also be transmitted via fomites. Several studies have shown that the virus can persist on both porous and nonporous surfaces for hours to days, depending upon the material. This article examines three cases of polymerase chain reaction–proven severe acute respiratory syndrome coronavirus 2 infection with several additional individuals meeting CDC close contact criteria. In 1 case, 195 downstream contacts were all tested to prevent a mass outbreak in a deployment posture. Analysis of these contacts yielded only a single positive test, which could be reasonably ascribed to respiratory droplet transmission. While these cases and their contacts ultimately represent a small sample size, we suggest fomite spread may not be a significant means of transmission for severe acute respiratory syndrome coronavirus 2 in real-world operational scenarios.


2020 ◽  
Author(s):  
Lei Shuai ◽  
Gongxun Zhong ◽  
Quan Yuan ◽  
Zhiyuan Wen ◽  
Chong Wang ◽  
...  

Abstract Minks are raised in many countries and have transmitted severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) to humans. However, the biologic properties of SARS-CoV-2 in minks are largely unknown. Here, we investigated and found that SARS-CoV-2 replicates efficiently in both the upper and lower respiratory tracts, and transmits efficiently in minks via respiratory droplets; pulmonary lesions caused by SARS-CoV-2 in minks are similar to those seen in humans with COVID-19. We further found that a spike protein-based subunit vaccine largely prevented SARS-CoV-2 replication and lung damage caused by SARS-CoV-2 infection in minks. Our study indicates that minks are a useful animal model for evaluating the efficacy of drugs or vaccines against COVID-19 and that vaccination is a potential strategy to prevent minks from transmitting SARS-CoV-2.


2020 ◽  
pp. 870-877
Author(s):  
Jan H. ter Meulen

Filoviruses are large RNA viruses, of which Ebola virus and Marburg virus cause the most severe forms of viral haemorrhagic fever and have been best-studied because of fear of their misuse as bioterrorism agents. These are zoonotic viruses with reservoirs, most likely fruit-eating bats, in the rainforests of tropical Africa, where they cause sporadic infections and outbreaks among great apes and humans. The primary mode of transmission of Ebola virus to humans often involves contact of hunters with dead animals that serve as amplifying hosts, especially gorillas, chimpanzees, and forest antelopes, whose meat is consumed as ‘bush meat’. Contact with bats has been implicated for both Marburg and Ebola virus. However, the viruses are highly infectious and are transmitted from the index case and subsequently from person to person by all body fluids, including sweat, respiratory droplets, and semen. The viruses can persist in convalescent patients for many months.


2020 ◽  
Vol 222 (10) ◽  
pp. 1635-1640
Author(s):  
Nobuhiko Sugano ◽  
Wataru Ando ◽  
Wakaba Fukushima

Abstract Background It is important to understand the mode of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for disease control. We aimed to clarify how soon SARS-CoV-2 transmission can occur after infection by asymptomatically infected individuals. Methods We analyzed the publicly available epidemiological information for a cluster of 108 cases of coronavirus disease 2019 (COVID-19) cases in Osaka, Japan. Results Among cases, 51 cases attended a live music club only once and were considered to have a single visit. Ten remained asymptomatic at the time of COVID-19 diagnosis by reverse-transcription polymerase chain reaction, which was on average 20 days after exposure. Three routes of secondary transmission were identified, with 2–4 days from infection to transmission. All index cases for secondary transmission were asymptomatic at the time of contact with other people. Based on the date of symptom onset in the remaining 41 cases, the period from exposure to illness ranged from 2 to 17 days. Conclusions Seemingly healthy people could spread SARS-CoV-2 during intense activities in enclosed environments without sufficient ventilation. Asymptomatically infected persons can transmit the virus as soon as 2 days after infection. Continuous efforts to avoid crowding and to maintain personal hygiene are needed for effective control of COVID-19.


2020 ◽  
Vol 12 (5) ◽  
pp. 193-201 ◽  
Author(s):  
Sammer Tang ◽  
Mike Brady ◽  
Jo Mildenhall ◽  
Ursula Rolfe ◽  
Alexandra Bowles ◽  
...  

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that causes the new disease COVID-19. Symptoms range from mild to severe with a higher incidence of severe cases in patients with risk factors such as older age and comorbidities. COVID-19 is mainly spread through the inhalation of respiratory droplets from coughing or sneezing or via contact with droplet-contaminated surfaces. Paramedics should be aware that some aerosol-generating procedures may put them at a higher risk of contracting the virus via possible airborne transmission. Use of remote triage clinical assessment is likely to increase as a result of the pandemic. There is no curative drug treatment for the virus and some medications may exacerbate its effects or make patients more susceptible to it. Evidence and guidelines are evolving on SARS-CoV-2 and COVID-19. Paramedics should keep up to date with the latest clinical guidance from their employers.


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