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how does coronavirus spread | 13 | The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) in Dentistry. Management of Biological Risk in Dental Practice | The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a novel coronavirus first identified in Wuhan, China, and the etiological agent of Coronavirus Disease-2019 (COVID-19). This infection spreads mainly through direct contact with Flügge micro droplets or core droplets that remain suspended as aerosol. Moreover, it has been reported that infected subjects, both with and without clinical signs of COVID-19, can transmit the virus. Since the infection typically enters through mouth, nose, and eyes, dentistry is one of the medical practices at highest risk of infection due to the frequent production of aerosol and the constant presence of saliva. The World Health Organization (WHO) has suggested that only emergency/urgent procedures should be performed during the coronavirus outbreak. Considering the virus' route of transmission, a specific protocol should be applied to reduce the risk of infection in addition to measures that prevent the spread of infection from a patient to another person or medical tools and equipment (cross-infection). This protocol should be implemented by modifying both patient management and clinical practice, introducing particular devices and organizational practices. This paper aims to discuss and suggest the most appropriate procedures in every aspect of dental practice to reduce infection risk. | r5h8z259 |
how does coronavirus spread | 13 | A cluster of tertiary transmissions of 2019 novel coronavirus (SARS-CoV-2) in the community from infectors with common cold symptoms | Background/Aims: As the global impact of the novel coronavirus disease 2019 (COVID-19) has been severe, many countries have intensified containment activities to eliminate virus transmission, through early detection and isolation strategies. To establish a proper quarantine strategy, it is essential to understand how easily the virus can spread in the communities. Methods: In this study, we collected detailed information on the circumstances in which human-to-human transmission occurred in the tertiary transmission cases of COVID-19 in the community. Results: On January 26, 2020, an imported case of COVID-19 was confirmed, and by February 10, 2020, one secondary transmission and three tertiary transmissions were identified. Secondary transmission occurred on the first day of illness of the infector, and his symptoms were suggestive of a common cold. The transmission occurred during a 90-minute long meal together in a restaurant. The people were sitting within one meter of each other, and had no direct contact. The tertiary transmission also occurred on the first-day illness of the other infector, and his only symptom was slight chills. The transmission occurred at a church during 2-hour-long worship, and two rows separated them. Conclusions: Our findings suggest that mildly symptomatic patients with COVID-19 could transmit the virus from the first day of illness through daily activities in the community. Early detection and isolation of patients with COVID-19 may be challenging. | 1vc1h7kt |
how does coronavirus spread | 13 | Transmission of COVID-19 in the terminal stages of the incubation period: A familial cluster | We report a familial cluster of 2019 novel coronavirus disease (COVID-19) to assess its potential transmission during the incubation period. The first patient in this familial cluster was identified during the presymptomatic period, as a close contact of a confirmed patient. Five family members had close contact with this first patient during his incubation period, with four of them confirmed positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the subsequent sampling tests. | p116erdu |
how does coronavirus spread | 13 | Epidemiological analysis on a family cluster of COVID-19/ 中华流行病学杂志 | Objective@#To understand the possible transmission route of a family cluster of COVID-19 in Zhengzhou and the potential infectivity of COVID-19 in incubation period, and provide scientific evidence for the timely control of infectious source and curb the spread of the epidemic.@*Methods@#Epidemiological investigation was conducted for a family cluster of COVID-19 (8 cases) with descriptive epidemiological method, and respiratory tract samples of the cases were collected for the nucleic acid detection of 2019-nCoV by RT-PCR.@*Results@#Two primary cases, which occurred on 31 January and 1 February, 2020, respectively, had a common exposure history in Wuhan. The other six family members had onsets on 30 January, 31 January, 1 February (three cases) and 3 February, 2020.@*Conclusions@#In this family cluster of COVID-19, six family members were infected through common family exposure to the 2 primary cases. Five secondary cases had onsets earlier than or on the same day as the primary cases, indicating that COVID-19 is contagious in incubation period, and the home isolation in the early phase of the epidemic might lead to the risk of family cluster of COVID-19. | 7gl5lptp |
how does coronavirus spread | 13 | Possibility of Faecal-Oral Transmission of Novel Coronavirus (SARS-CoV-2) via Consumption of Contaminated Foods of Animal Origin: A Hypothesis | This article has no abstract DOI:10 18502/jfqhc 7 1 2445 | hyo1k7ig |
how does coronavirus spread | 13 | COVID-19: Transmission, prevention, and potential therapeutic opportunities | The novel coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global challenge. Despite intense research efforts worldwide, an effective vaccine and viable treatment options have eluded investigators. Therefore, infection prevention, early viral detection and identification of successful treatment protocols provide the best approach in controlling disease spread. In this review, current therapeutic options, preventive methods and transmission routes of COVID-19 are discussed. | 6jsbh5or |
how does coronavirus spread | 13 | Observations about sexual and other routes of SARS-CoV-2 (COVID-19) transmission and its prevention | v69tke5z |
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how does coronavirus spread | 13 | Unlikely SARS-CoV-2 vertical transmission from mother to child: A case report | As the 2019 novel coronavirus disease (COVID-19) rapidly spread across China and to more than 70 countries, an increasing number of pregnant women were affected. The vertical transmission potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great concern to the obstetrics, neonatologists, and public health agencies. Though some studies indicated the risk of vertical transmission is low, few cases have been reported with comprehensive serial tests from multiple specimens. In this case, a female preterm infant was born to a mother with confirmed COVID-19. She presented with mild respiratory distress and received general management and a short period of nasal continuous positive airway pressure support. During her stay at the hospital, a series of SARS-CoV-2 nucleic test from her throat and anal swab, serum, bronchoalveolar lavage fluid, and urine were negative. The nucleic acid test from the mother's amniotic fluid, vaginal secretions, cord blood, placenta, serum, anal swab, and breast milk were also negative. The most comprehensively tested case reported to date confirmed that the vertical transmission of COVID is unlikely, but still, more evidence is needed. | 6nqnvxz6 |
how does coronavirus spread | 13 | COVID-19 vulnerability: the potential impact of genetic susceptibility and airborne transmission | The recent coronavirus disease (COVID-19), caused by SARS-CoV-2, is inarguably the most challenging coronavirus outbreak relative to the previous outbreaks involving SARS-CoV and MERS-CoV. With the number of COVID-19 cases now exceeding 2 million worldwide, it is apparent that (i) transmission of SARS-CoV-2 is very high and (ii) there are large variations in disease severity, one component of which may be genetic variability in the response to the virus. Controlling current rates of infection and combating future waves require a better understanding of the routes of exposure to SARS-CoV-2 and the underlying genomic susceptibility to this disease. In this mini-review, we highlight possible genetic determinants of COVID-19 and the contribution of aerosol exposure as a potentially important transmission route of SARS-CoV-2. | kj6m72jt |
how does coronavirus spread | 13 | A Familial Cluster of Infection Associated With the 2019 Novel Coronavirus Indicating Possible Person-to-Person Transmission During the Incubation Period | An ongoing outbreak of pneumonia associated with 2019 novel coronavirus was reported in China. It is unclear whether the virus is infective exists during the incubation period, although person-to-person transmission has been reported elsewhere. We report the epidemiological features of a familial cluster of 4 patients in Shanghai, including an 88-year-old man with limited mobility who was exposed only to asymptomatic family members whose symptoms developed later. The epidemiological evidence has shown possible transmission of 2019 novel coronavirus during the incubation period. | yhdhy7t0 |
how does coronavirus spread | 13 | Airborne transmission of SARS-CoV-2: The world should face the reality | Hand washing and maintaining social distance are the main measures recommended by the World Health Organization (WHO) to avoid contracting COVID-19. Unfortunately, these measured do not prevent infection by inhalation of small droplets exhaled by an infected person that can travel distance of meters or tens of meters in the air and carry their viral content. Science explains the mechanisms of such transport and there is evidence that this is a significant route of infection in indoor environments. Despite this, no countries or authorities consider airborne spread of COVID-19 in their regulations to prevent infections transmission indoors. It is therefore extremely important, that the national authorities acknowledge the reality that the virus spreads through air, and recommend that adequate control measures be implemented to prevent further spread of the SARS-CoV-2 virus, in particularly removal of the virus-laden droplets from indoor air by ventilation. | e3rp7gtj |
how does coronavirus spread | 13 | Sexual transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): A new possible route of infection? | favozcb3 |
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how does coronavirus spread | 13 | Potential fecal transmission of SARS-CoV-2: Current evidence and implications for public health | Coronavirus disease 2019 (COVID-19) emerged in Hubei Province, China in December 2019 and has since become a global pandemic, with hundreds of thousands of cases and over 165 countries affected. Primary routes of transmission of the causative virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are through respiratory droplets and close person-to-person contact. While information about other potential modes of transmission are relatively sparse, evidence supporting the possibility of a fecally mediated mode of transmission has been accumulating. Here, current knowledge on the potential for fecal transmission is briefly reviewed and the possible implications are discussed from a public health perspective. | 12sbikmx |
how does coronavirus spread | 13 | Transmission routes of 2019-nCoV and controls in dental practice | A novel ß-coronavirus (2019-nCoV) caused severe and even fetal pneumonia explored in a seafood market of Wuhan city, Hubei province, China, and rapidly spread to other provinces of China and other countries. The 2019-nCoV was different from SARS-CoV, but shared the same host receptor the human angiotensin-converting enzyme 2 (ACE2). The natural host of 2019-nCoV may be the bat Rhinolophus affinis as 2019-nCoV showed 96.2% of whole-genome identity to BatCoV RaTG13. The person-to-person transmission routes of 2019-nCoV included direct transmission, such as cough, sneeze, droplet inhalation transmission, and contact transmission, such as the contact with oral, nasal, and eye mucous membranes. 2019-nCoV can also be transmitted through the saliva, and the fetal-oral routes may also be a potential person-to-person transmission route. The participants in dental practice expose to tremendous risk of 2019-nCoV infection due to the face-to-face communication and the exposure to saliva, blood, and other body fluids, and the handling of sharp instruments. Dental professionals play great roles in preventing the transmission of 2019-nCoV. Here we recommend the infection control measures during dental practice to block the person-to-person transmission routes in dental clinics and hospitals. | smhcvdn0 |
how does coronavirus spread | 13 | Possible aerosol transmission of COVID-19 and special precautions in dentistry | Since its emergence in December 2019, corona virus disease 2019 (COVID-19) has impacted several countries, affecting more than 90 thousand patients and making it a global public threat. The routes of transmission are direct contact, and droplet and possible aerosol transmissions. Due to the unique nature of dentistry, most dental procedures generate significant amounts of droplets and aerosols, posing potential risks of infection transmission. Understanding the significance of aerosol transmission and its implications in dentistry can facilitate the identification and correction of negligence in daily dental practice. In addition to the standard precautions, some special precautions that should be implemented during an outbreak have been raised in this review. | fhaw3b6t |
how does coronavirus spread | 13 | Flattening the Curve: Insights From Queueing Theory | The worldwide outbreak of the coronavirus was first identified in 2019 in Wuhan, China. Since then, the disease has spread worldwide. As it currently spreading in the United States, policy makers, public health officials and citizens are racing to understand the impact of this virus on the United States healthcare system. They fear that the rapid influx of patients will overwhelm the healthcare system leading to unnecessary fatalities. Most countries and states in America have introduced mitigation strategies, such as social distancing, to decrease the rate of newly infected people, i.e. flattening the curve.In this paper, we analyze the time evolution of the number of people hospitalized due to the coronavirus using the methods of queueing theory. Given that the rate of new infections varies over time as the pandemic evolves, we model the number of coronavirus patients as a dynamical system based on the theory of infinite server queues with non-stationary Poisson arrival rates. With this model we are able to quantify how flattening the curve affects the peak demand for hospital resources. This allows us to characterize how aggressively society must flatten the curve in order to avoid overwhelming the capacity of healthcare system. We also demonstrate how flattening the curve impacts the elapsed time between the peak rate of hospitalizations and the time of the peak demand for the hospital resources. Finally, we present empirical evidence from China, South Korea, Italy and the United States that supports the insights from the model. | mzx1ye6t |
how does coronavirus spread | 13 | Risk of nosocomial transmission of coronavirus disease 2019: an experience in a general ward setting in Hong Kong | BACKGROUND: Coronavirus disease 2019 (COVID-19) was first reported in Wuhan in December 2019 and has rapidly spread across different cities within and outside China. Hong Kong started to prepare for COVID-19 on 31st December 2019 and infection control measures in public hospitals were tightened to limit nosocomial transmission within healthcare facilities. However, the recommendations on the transmission-based precautions required for COVID-19 in hospital settings vary from droplet and contact precautions, to contact and airborne precautions with placement of patients in airborne infection isolation rooms. AIM: To describe an outbreak investigation of a patient with COVID-19 who was nursed in an open cubicle of a general ward before the diagnosis was made. METHOD: Contacts were identified and risk categorized as 'close' or 'casual' for decisions on quarantine and/or medical surveillance. Respiratory specimens were collected from contacts who developed fever, and/or respiratory symptoms during the surveillance period and were tested for SARS-CoV-2. FINDINGS: A total of 71 staff and 49 patients were identified from contact tracing, seven staff and 10 patients fulfilled the criteria of 'close contact'. At the end of 28-day surveillance, 76 tests were performed on 52 contacts and all were negative, including all patient close contacts and six of the seven staff close contacts. The remaining contacts were asymptomatic throughout the surveillance period. CONCLUSION: Our findings suggest that SARS-CoV-2 is not spread by an airborne route, and nosocomial transmissions can be prevented through vigilant basic infection control measures, including wearing of surgical masks, hand and environmental hygiene. | 4lz45ywi |
how does coronavirus spread | 13 | The presence of SARS-CoV-2 RNA in the feces of COVID-19 patients | In December 2019, coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan, China, and has spread globally. However, the transmission route of SARS-CoV-2 has not been fully understood. In this study, we aimed to investigate SARS-CoV-2 shedding in the excreta of COVID-19 patients. Electronical medical records, including demographics, clinical characteristics, laboratory and radiological findings of enrolled patients were extracted and analyzed. Pharyngeal swab, stool, and urine specimens were collected and tested for SARS-CoV-2 RNA by real-time reverse transcription polymerase chain reaction. Viral shedding at multiple time points in specimens was recorded, and its correlation analyzed with clinical manifestations and the severity of illness. A total of 42 laboratory-confirmed patients were enrolled, 8 (19.05%) of whom had gastrointestinal symptoms. A total of 28 (66.67%) patients tested positive for SARS-CoV-2 RNA in stool specimens, and this was not associated with the presence of gastrointestinal symptoms and the severity of illness. Among them, 18 (64.29%) patients remained positive for viral RNA in the feces after the pharyngeal swabs turned negative. The duration of viral shedding from the feces after negative conversion in pharyngeal swabs was 7 (6-10) days, regardless of COVID-19 severity. The demographics, clinical characteristics, laboratory and radiologic findings did not differ between patients who tested positive and negative for SARS-CoV-2 RNA in the feces. Viral RNA was not detectable in urine specimens from 10 patients. Our results demonstrated the presence of SARS-CoV-2 RNA in the feces of COVID-19 patients and suggested the possibility of SARS-CoV-2 transmission via the fecal-oral route. | 2brbgvqo |
how does coronavirus spread | 13 | Vertical Transmission of Coronavirus Disease 19 (COVID-19) from Infected Pregnant Mothers to Neonates: A Review | Background: Since early December 2019, the Coronavirus Disease 19 (COVID-19) infection has been prevalent in China and eventually spread to other countries. There are a few published cases of COVID-19 occurring during pregnancy and due the possibility of mother-fetal vertical transmission, there is a concern that the fetuses may be at risk of congenital COVID-19. Methods: We reviewed the risk of vertical transmission of COVID-19 to the fetus of infected mothers by using data of published articles or official websites up to March 4, 2020. Results: A total of 31 infected pregnant mothers with COVID-19 were reported. No COVID-19 infection was detected in their neonates or placentas. Two mothers died from COVID-19-related respiratory complications after delivery. Conclusions: Currently, based on limited data, there is no evidence for intrauterine transmission of COVID-19 from infected pregnant women to their fetuses. Mothers may be at increased risk for more severe respiratory complications. | zkcaeeve |
how does coronavirus spread | 13 | Indirect Virus Transmission in Cluster of COVID-19 Cases, Wenzhou, China, 2020 | To determine possible modes of virus transmission, we investigated a cluster of coronavirus disease cases associated with a shopping mall in Wenzhou, China. Data indicated that indirect transmission of the causative virus occurred, perhaps resulting from virus contamination of common objects, virus aerosolization in a confined space, or spread from asymptomatic infected persons. | yp7bniwt |
how does coronavirus spread | 13 | On a knife's edge of a COVID-19 pandemic: is containment still possible? | x9nanc34 |
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how does coronavirus spread | 13 | COVID-19 transmission and blood transfusion: A case report | The recent outbreak of the novel coronavirus disease 2019 (COVID-19) has been labelled as a pandemic by the World Health Organization. Although person-to-person transmission of the etiologic agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been confirmed, it is not known whether COVID-19 may be transmitted by blood transfusion. Notwithstanding the urgent requirement of blood, it is critical to know whether the SARS-CoV-2 virus can be transmitted by blood transfusion because many individuals may be asymptomatic carriers and may donate blood. Several cases in which specific viral RNA could be detected in the serum from patients with COVID-19 have already been reported; these findings suggest that blood donation may be an unexplored route of transmission. However, the American Association of Blood Banks and Centers for Disease Control and Prevention have not recommended any specific SARS-CoV-2-related actions to be taken at blood collection centres at this time. In this report, we describe a case of a 21-year-old man with very severe aplastic anaemia who received apheresis platelet transfusion from an individual who was subsequently diagnosed with COVID-19. Our patient tested negative for COVID-19 and is awaiting allogeneic stem cell transplantation. | 444jnx7m |
how does coronavirus spread | 13 | SARS-CoV-2 is transmitted via contact and via the air between ferrets | SARS-CoV-2, a coronavirus that emerged in late 2019, has spread rapidly worldwide, and information about the modes of transmission of SARS-CoV-2 among humans is critical to apply appropriate infection control measures and to slow its spread. Here we show that SARS-CoV-2 is transmitted efficiently via direct contact and via the air (via respiratory droplets and/or aerosols) between ferrets, 1 to 3 days and 3 to 7 days after exposure respectively. The pattern of virus shedding in the direct contact and indirect recipient ferrets is similar to that of the inoculated ferrets and infectious virus is isolated from all positive animals, showing that ferrets are productively infected via either route. This study provides experimental evidence of robust transmission of SARS-CoV-2 via the air, supporting the implementation of community-level social distancing measures currently applied in many countries in the world and informing decisions on infection control measures in healthcare settings. | 5q49qq42 |
how does coronavirus spread | 13 | Pediatric anesthetic implications of COVID‐19—A review of current literature | Pediatric anesthetists have an important role to play in the management of patients suspected or confirmed to have COVID‐19. In many institutions, the COVID‐19 intubation teams are staffed with anesthetists as the proceduralists working throughout the hospitals also in the ICU and Emergency Departments. As practitioners who perform aerosol generating procedures involving the airway, we are at high risk of exposure to the virus SARS‐CoV‐2 and need to ensure we are well prepared and trained to manage such cases. This article reviews the relevant pediatric literature surrounding COVID‐19 and summarizes the key recommendations for anesthetists involved in the care of children during this pandemic. | w42jv02t |
how does coronavirus spread | 13 | Transmission routes of COVID-19 in the dental practice | vw2d7spi |
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how does coronavirus spread | 13 | Fecal transmission in COVID‐19: A potential shedding route | We read with interest recent article by Zhang et al 1 on the diagnosis of Coronavirus disease 2019 (COVID-19) by fecal specimen test. Following the recent outbreak of pneumonia with unknown pathogen in Hubei province in China, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated from human airway epithelial cells and the disease was named COVID-19.2 It is a public health emergency of international concern and rapidly spearing all over the world.3 This article is protected by copyright. All rights reserved. | 0bz4micv |
how does coronavirus spread | 13 | Transmission routes of SARS-CoV-2 | 4d6rq9qj |
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how does coronavirus spread | 13 | The Root Causes of COVID-19 Screech for Compassion | uih7alib |
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how does coronavirus spread | 13 | Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 via Close Contact and Respiratory Droplets Among Human Angiotensin-Converting Enzyme 2 Mice | We simulated 3 transmission modes, including close-contact, respiratory droplets and aerosol routes, in the laboratory. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can be highly transmitted among naive human angiotensin-converting enzyme 2 (hACE2) mice via close contact because 7 of 13 naive hACE2 mice were SARS-CoV-2 antibody seropositive 14 days after being introduced into the same cage with 3 infected-hACE2 mice. For respiratory droplets, SARS-CoV-2 antibodies from 3 of 10 naive hACE2 mice showed seropositivity 14 days after introduction into the same cage with 3 infected-hACE2 mice, separated by grids. In addition, hACE2 mice cannot be experimentally infected via aerosol inoculation until continued up to 25 minutes with high viral concentrations. | obh0q8gg |
how does coronavirus spread | 13 | Intrauterine vertical transmission of SARS‐CoV‐2: what we know so far | baoqgu8v |
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how does coronavirus spread | 13 | Can Covid‐19 be a sexually transmitted disease? Posterity will judge | eab7i4f6 |
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how does coronavirus spread | 13 | Possible indirect transmission of COVID-19 at a squash court, Slovenia, March 2020: case report | Since the beginning of the COVID-19 epidemic, there is an ongoing debate and research regarding the possible ways of virus transmission. We conducted an epidemiological investigation which revealed a cluster of five COVID-19 cases, linked to playing squash at a sports venue in Maribor, Slovenia. Acquired data raises possibility that the transmission occurred indirectly through contaminated objects in changing room or squash hall or via aerosolisation in squash hall. | o3u52mhl |
how does coronavirus spread | 13 | Digestive system involvement of novel coronavirus infection: Prevention and control infection from a gastroenterology perspective | An epidemic of an acute respiratory syndrome caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in Wuhan, China, now known as coronavirus disease 2019 (COVID‐19), beginning in December 2019, has attracted an intense amount of attention worldwide. As the natural history and variety of clinical presentations of this disease unfolds, extrapulmonary symptoms of COVID‐19 have emerged, especially in the digestive system. While the respiratory mode of transmission is well known and is probably the principal mode of transmission of this disease, a possibility of the fecal‐oral route of transmission has also emerged in various case series and clinical scenarios. In this review article, we summarize four different aspects in published studies to date: (a) gastrointestinal manifestations of COVID‐19; (b) microbiological and virological investigations; (c) the role of fecal‐oral transmission; and (d) prevention and control of SARS‐CoV‐2 infection in the digestive endoscopy room. A timely understanding of the relationship between the disease and the digestive system and implementing effective preventive measures are of great importance for a favorable outcome of the disease and can help climnicians to mitigate further transmission by taking appropriate measures. | xj9md751 |
how does coronavirus spread | 13 | Middle East respiratory syndrome coronavirus: epidemiology and disease control measures | The emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in 2012 resulted in an increased concern of the spread of the infection globally. MERS-CoV infection had previously caused multiple health-care-associated outbreaks and resulted in transmission of the virus within families. Community onset MERS-CoV cases continue to occur. Dromedary camels are currently the most likely animal to be linked to human MERS-CoV cases. Serologic tests showed significant infection in adult camels compared to juvenile camels. The control of MERS-CoV infection relies on prompt identification of cases within health care facilities, with institutions applying appropriate infection control measures. In addition, determining the exact route of transmission from camels to humans would further add to the control measures of MERS-CoV infection. | nat8xl41 |
how does coronavirus spread | 13 | Lack of Middle East Respiratory Syndrome Coronavirus Transmission in Rabbits | Middle East respiratory syndrome coronavirus (MERS-CoV) transmission from dromedaries to humans has resulted in major outbreaks in the Middle East. Although some other livestock animal species have been shown to be susceptible to MERS-CoV, it is not fully understood why the spread of the virus in these animal species has not been observed in the field. In this study, we used rabbits to further characterize the transmission potential of MERS-CoV. In line with the presence of MERS-CoV receptor in the rabbit nasal epithelium, high levels of viral RNA were shed from the nose following virus inoculation. However, unlike MERS-CoV-infected dromedaries, these rabbits did not develop clinical manifestations including nasal discharge and did shed only limited amounts of infectious virus from the nose. Consistently, no transmission by contact or airborne routes was observed in rabbits. Our data indicate that despite relatively high viral RNA levels produced, low levels of infectious virus are excreted in the upper respiratory tract of rabbits as compared to dromedary camels, thus resulting in a lack of viral transmission. | eumuid3r |
coronavirus super spreaders | 14 | Searching for Superspreaders: Identifying Epidemic Patterns Associated with Superspreading Events in Stochastic Models | The importance of host transmissibility in disease emergence has been demonstrated in historical and recent pandemics that involve infectious individuals, known as superspreaders, who are capable of transmitting the infection to a large number of susceptible individuals. To investigate the impact of superspreaders on epidemic dynamics, we formulate deterministic and stochastic models that incorporate differences in superspreaders versus nonsuperspreaders. In particular, continuous-time Markov chain models are used to investigate epidemic features associated with the presence of superspreaders in a population. We parameterize the models for two case studies, Middle East respiratory syndrome (MERS) and Ebola. Through mathematical analysis and numerical simulations, we find that the probability of outbreaks increases and time to outbreaks decreases as the prevalence of superspreaders increases in the population. In particular, as disease outbreaks occur more rapidly and more frequently when initiated by superspreaders, our results emphasize the need for expeditious public health interventions. | 1tkevj8v |
coronavirus super spreaders | 14 | Epidemiologic, Clinical, and Laboratory Findings of the COVID-19 in the current pandemic | BACKGROUND: The COVID-19 caused the pandemic affected the world deeply, with more than 3,000,000 people infected and nearly 200,000 deaths. This article aimed to summarize the epidemiologic traits, clinical spectrum, CT results and laboratory findings of COVID-19 pandemic. METHODS: We scoped for relevant literatures published during 1st Dec 2019 to 23rd Apr 2020 based on four databases by using English and Chinese. The evidence was synthesized narratively. RESULTS: The COVID-19 pandemic was found to have a higher transmission rate compared to SARS and MERS, and involved 4 stages of evolution. The basic reproduction number (R0) is 3.32 (95% CI:3.24–3.39) and the incubation period was 5.24 days (95% CI:3.97–6.50, 5 studies) on average, and the average time for symptoms onset varied by countries. Common clinical spectrums identified included fever (38.1–39.0°C), cough and fatigue, with Acute Respiratory Distress Syndrome (ARDS) being the most common complication reported. Body temperatures above 39.0 °C, dyspnea, and anorexia were more common symptoms in severe patients. Aged over 60 years old, having co-morbidities, and developing complications were the commonest high-risk factors associated with severe conditions. Leucopenia and lymphopenia were the most common signs of infection while liver and kidney damage were rare but may cause bad outcomes for patients. The bilateral, multifocal Ground-Glass Opacification (GGO) on peripheral, and the consolidative pulmonary opacity were the most frequent CT results and the tendency of mortality rates differed by region. CONCLUSIONS: We provided a bird’s-eye view of the COVID-19 during the current pandemic, which will help better understanding the key traits of the disease. The findings could be used for disease’s future research, control and prevention. | jxu3056n |
coronavirus super spreaders | 14 | [Investigation of a cluster epidemic of COVID-19 in Ningbo]. | Objective: To investigate a cluster epidemic of COVID-19 after a mass gathering activity in Ningbo of Zhejiang province and analyze the transmission chain and status of infection cases of different generations. Methods: The tracking of all the close contacts of the first COVID-19 case and epidemiological investigation were conducted on January 29, 2020 after a cluster epidemic of COVID-19 related with a Buddhism rally on January 19 (the 1.19 rally) in Ningbo occurred. The swabs of nose/throat of the cases and close contacts were collected and tested for nucleic acids by real-time fluorescence quantitative RT-PCR. Results: From January 26 to February 20, 2020, a total of 67 COVID-19 cases and 15 asymptomatic infection cases related with the 1.19 rally were reported in Ningbo. The initial case was the infection source who infected 29 second generation cases and 4 asymptomatic infection cases, in whom 23 second generation cases and 3 asymptomatic infection cases once took bus with the initial case, the attack rate was 33.82% (23/68) and the infection rate was 38.24% (26/68). The risks of suffering from COVID-19 and being infected were 28.91 times and 26.01 times higher in rally participants taking bus with initial case compared with those taking no bus with initial case. In this epidemic, 37 third+ generation cases and 11 related asymptomatic infection cases occurred, the attack rate was 2.88% (37/1 283) and the infection rate was 4.76% (48/1 008). The main transmission routes included vehicle sharing and family transmission. Conclusion: It was a cluster epidemic of COVID-19 caused by a super spreader in a massive rally. The epidemic has been under effective control. | hsgx534y |
coronavirus super spreaders | 14 | Descriptive study of COVID-19 outbreak among passengers and crew on Diamond Princess cruise ship, Yokohama Port, Japan, 20 January to 9 February 2020. | An outbreak of coronavirus disease (COVID-19) occurred on the Diamond Princess cruise ship making an international journey, which led to quarantine of the ship at Yokohama Port, Japan. A suspected COVID-19 case was defined as a passenger or crew member who developed a fever or respiratory symptoms, and a confirmed COVID-19 case had laboratory-confirmation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Between 3 and 9 February 2020, 490 individuals were tested for SARS-CoV-2 and 172 were positive (152 passengers (median age: 70 years; interquartile range (IQR): 64-75; males: 45%) and 20 crew (median age: 40 years; IQR: 35-48.5; males: 80%). Other than the Hong Kong-related index case, symptom onset for the earliest confirmed case was 22 January, 2 days after the cruise ship left port. Attack rates among passengers were similar across the decks, while beverage (3.3%, 2/61) and food service staff (5.7%, 14/245) were most affected. Attack rates tended to increase with age. A comprehensive outbreak response was implemented, including surveillance, provision of essential medical care, food and medicine delivery, isolation, infection prevention and control, sampling and disembarkation. | 0av6gx7r |
coronavirus super spreaders | 14 | Significance of super spreader events in COVID-19. | The number of secondary cases from each primary case determines how fast an epidemic grows. It is known that all cases do not spread the infection equally; super spreaders play an important role as they contribute disproportionately to a much larger number of cases including in the ongoing COVID-19 pandemic. Super spreaders have been reported for more than a century, but limited information is available in scientific literature. An epidemic containment strategy needs to include early identification of super spreaders to limit an explosive growth. Super spreaders tend to get stigmatized, resulting in late reporting and hiding of cases. It is important for program managers to be sensitive to the manner in which related information is shared with media and general public. | na3vrf5q |
coronavirus super spreaders | 14 | Transmission of severe acute respiratory syndrome in dynamical small-world networks | The outbreak of severe acute respiratory syndrome (SARS) is still threatening the world because of a possible resurgence. In the current situation that effective medical treatments such as antiviral drugs are not discovered yet, dynamical features of the epidemics should be clarified for establishing strategies for tracing, quarantine, isolation, and regulating social behavior of the public at appropriate costs. Here we propose a network model for SARS epidemics and discuss why superspreaders emerged and why SARS spread especially in hospitals, which were key factors of the recent outbreak. We suggest that superspreaders are biologically contagious patients, and they may amplify the spreads by going to potentially contagious places such as hospitals. To avoid mass transmission in hospitals, it may be a good measure to treat suspected cases without hospitalizing them. Finally, we indicate that SARS probably propagates in small-world networks associated with human contacts and that the biological nature of individuals and social group properties are factors more important than the heterogeneous rates of social contacts among individuals. This is in marked contrast with epidemics of sexually transmitted diseases or computer viruses to which scale-free network models often apply. | vpl2xu2r |
coronavirus super spreaders | 14 | Superspreading in Early Transmissions of COVID-19 in Indonesia | We estimate the basic reproduction number R0 and the overdispersion parameter K at two COVID-19 clusters in Indonesia: Jakarta-Depok and Batam. Based on the first 397 confirmed cases in both clusters, we find a high degree of individual-level variation in the transmission. The basic reproduction number R0 is estimated at 6.79 and 2.47, while the overdispersion parameter K of a negative-binomial distribution is estimated at 0.08 and 0.2 for Jakarta-Depok and Batam, respectively. This suggests that superspreading events played a key role in the early stage of the outbreak, i.e., a small number of infected individuals are responsible for large amounts of COVID-19 transmission. | ogrlidrs |
coronavirus super spreaders | 14 | Modeling COVID-19 on a network: super-spreaders, testing and containment | We use a model of covid-19 spread, an SEIR agent-based model on a graph, which takes into account several important real-life attributes of covid-19: Super-spreaders, realistic epidemiological parameters of the disease, testing and quarantine policies. We provide simulation results and mathematical arguments to argue that certain results of our simulations hold in more general settings. We find that mass-testing is much less effective than testing the symptomatic and contact tracing, and some blend of these with social distancing is required to get suppression. We also find that the fat tail of the degree distribution matters a lot for epidemic growth, and many standard models do not account for this. Additionally, the average reproduction number for individuals is not an upper bound for the effective reproduction number, R. Even with an expectation of less than one new case per person, this model shows that exponential spread is possible. The parameter which closely predicts growth rate is the ratio between 2nd to 1st moments of the degree distribution. | 7kovd82v |
coronavirus super spreaders | 14 | Power Laws in Superspreading Events: Evidence from Coronavirus Outbreaks and Implications for SIR Models | While they are rare, superspreading events (SSEs), wherein a few primary cases infect an extraordinarily large number of secondary cases, are recognized as a prominent determinant of aggregate infection rates (R0). Existing stochastic SIR models incorporate SSEs by fitting distributions with thin tails, or finite variance, and therefore predicting almost deterministic epidemiological outcomes in large populations. This paper documents evidence from recent coronavirus outbreaks, including SARS, MERS, and COVID-19, that SSEs follow a power law distribution with fat tails, or infinite variance. We then extend an otherwise standard SIR model with estimated power law distributions, and show that idiosyncratic uncertainties in SSEs will lead to large aggregate uncertainties in infection dynamics, even with large populations. That is, the timing and magnitude of outbreaks will be unpredictable. While such uncertainties have social costs, we also find that they on average decrease the herd immunity thresholds and the cumulative infections because per-period infection rates have decreasing marginal effects. Our findings have implications for social distancing interventions: targeting SSEs reduce not only the average rate of infection (R0) but also its uncertainty. To understand this effect, and to improve inference of the average reproduction numbers under fat tails, estimating the tail distribution of SSEs is vital. | jfeu4tho |
coronavirus super spreaders | 14 | Mobility network modeling explains higher SARS-CoV-2 infection rates among disadvantaged groups and informs reopening strategies | Fine-grained epidemiological modeling of the spread of SARS-CoV-2 -- capturing who is infected at which locations -- can aid the development of policy responses that account for heterogeneous risks of different locations as well as the disparities in infections among different demographic groups. Here, we develop a metapopulation SEIR disease model that uses dynamic mobility networks, derived from US cell phone data, to capture the hourly movements of millions of people from local neighborhoods (census block groups, or CBGs) to points of interest (POIs) such as restaurants, grocery stores, or religious establishments. We simulate the spread of SARS-CoV-2 from March 1-May 2, 2020 among a population of 105 million people in 10 of the largest US metropolitan statistical areas. We show that by integrating these mobility networks, which connect 60k CBGs to 565k POIs with a total of 5.4 billion hourly edges, even a relatively simple epidemiological model can accurately capture the case trajectory despite dramatic changes in population behavior due to the virus. Furthermore, by modeling detailed information about each POI, like visitor density and visit length, we can estimate the impacts of fine-grained reopening plans: we predict that a small minority of "superspreader" POIs account for a large majority of infections, that reopening some POI categories (like full-service restaurants) poses especially large risks, and that strategies restricting maximum occupancy at each POI are more effective than uniformly reducing mobility. Our models also predict higher infection rates among disadvantaged racial and socioeconomic groups solely from differences in mobility: disadvantaged groups have not been able to reduce mobility as sharply, and the POIs they visit (even within the same category) tend to be smaller, more crowded, and therefore more dangerous. By modeling who is infected at which locations, our model supports fine-grained analyses that can inform more effective and equitable policy responses to SARS-CoV-2. | q2d2sut8 |
coronavirus super spreaders | 14 | The Potential role of Particulate Matter in the Spreading of COVID-19 in Northern Italy: First Evidence-based Research Hypotheses | Background: An epidemic model based only on respiratory droplets and close contact could not fully explain the regional differences in the spread of the recent severe acute respiratory syndrome COVID-19 in Italy, which was fast and dramatic only in Lombardy and Po Valley. On March 16th 2020, we presented a Position Paper proposing a research hypothesis concerning the association between higher mortality rates due to COVID-19 observed in Northern Italy and the peaks of particulate matter concentrations, frequently exceeding the legal limit of 50 micrograms/m3 as PM10 daily average Methods: To assess environmental factors related to the spread of the COVID-19 in Italy from February 24th to March 13th (the date when the lockdown has been imposed over Italy), official daily data relevant to ambient PM10 levels were collected from all Italian Provinces between February 9th and February 29th , taking into account the average time (estimated in 17 days) elapsed between the initial infection and the recorded COVID positivity. In addition to the number of exceedances of PM10 daily limit value, we considered also population data and daily travelling information per each Province. Results. PM10 daily limit value exceedances appear to be a significant predictor (p <0.001) of infection in univariate analyses. Less polluted Provinces had a median of 0.03 infection cases over 1000 residents, while most polluted Provinces had a median of 0.26 cases over 1000 residents. Thirty-nine out of 41 Northern Italian Provinces resulted in the category with highest PM10 levels, while 62 out of 66 Southern Provinces presented low PM10 concentrations (p<0.001). In Milan, the average growth rate before the lockdown was significantly higher than Rome (0.34 vs. 0.27 per day, with a doubling time of 2.0 days vs. 2.6), suggesting a basic reproductive number R0>6.0, comparable with the highest values estimated for China. | hu6iwoab |
coronavirus super spreaders | 14 | Heterogeneity in SIR epidemics modeling: superspreaders | Deterministic epidemic models, such as the Susceptible-Infected-Recovered (SIR) model, are immensely useful even if they lack the nuance and complexity of social contacts at the heart of network science modeling. Here we present a simple modification of the SIR equations to include the heterogeneity of social connection networks. A typical power-law model of social interactions from network science reproduces the observation that individuals with a high number of contacts, ``hubs'' or ``superspreaders'', can become the primary conduits for transmission. Conversely, once the tail of the distribution is saturated, herd immunity sets in at a smaller overall recovered fraction than in the analogous SIR model. The new dynamical equations suggest that cutting off the tail of the social connection distribution, i.e., stopping superspreaders, is an efficient non-pharmaceutical intervention to slow the spread of a pandemic, such as COVID-19. | umz2n1os |
coronavirus super spreaders | 14 | Preliminary estimating the reproduction number of the coronavirus disease (COVID-19) outbreak in Republic of Korea and Italy by 5 March 2020 | The novel coronavirus disease 2019 (COVID-19) outbreak and Italy has caused 6088 cases and 41 deaths in Republic of Korea and 3144 cases and 107 death in Italy by 5 March 2020. We modeled the transmission process in Republic of Korea and Italy with a stochastic model and estimated the basic reproduction number R0 as 2.6 (95% CI: 2.3-2.9) or 3.2 (95% CI: 2.9-3.5) in Republic of Korea, under the assumption that the exponential growth starting on 31 January or 5 February 2020, and 2.6 (95% CI: 2.3-2.9) or 3.3 (95% CI: 3.0-3.6) in Italy, under the assumption that the exponential growth starting on 5 February or 10 February 2020. Estimates of dispersion term (k) were 10 (95% CI: 5-56) or 22 (95% CI: 8-61) in Republic of Korea, and 13 (95% CI: 5-61) or 37 (95% CI: 13-61) in Italy, and all of which imply few super-spreading events. | etl9uwt7 |
coronavirus super spreaders | 14 | Super-Spreader Businesses and Risk of COVID-19 Transmission | Purpose: The United States has the highest number of confirmed COVID-19 cases in the world to date, with over 94,000 COVID-19-related deaths. The true risk of a COVID-19 resurgence as states prepare to reopen businesses is unknown. This paper aims to classify businesses by their risk of transmission and quantify the relationship between the density of super-spreader businesses and COVID-19 cases. Methods: We constructed a COVID-19 Business Transmission Risk Index based upon the frequency and duration of visits and square footage of businesses pre-pandemic in 2019 in 8 states (Massachusetts, Rhode Island, Connecticut, New Hampshire, Vermont, Maine, New York, and California). We used this index to classify businesses as super-spreaders. Then, we analyzed the association between the density of super-spreader businesses in a county and the rate of COVID-19 cases. We performed significance testing using a negative binomial regression. The main outcome of interest is the cumulative number of COVID-19 cases each week. Results: We found a positive association between the density of super-spreader businesses and COVID-19 cases. A 1 percentage point increase in the density of super-spreader businesses is associated with 5% higher COVID-19 cases, all else equal. Conclusion: Higher densities of super-spreader businesses are associated with higher rates of COVID-19 cases. This may have important implications for how states reopen super-spreader businesses. | 8ngri1x0 |
coronavirus super spreaders | 14 | Minimising lockdown periods for regional elimination of covid-19 | Some nations have the option of pursuing a policy of complete elimination of covid-19 instead of a policy of "flattening the curve" so that the load the dis- ease places on medical facilities is bearable. A policy of elimination requires a rather onerous "lockdown". As the goal of elimination is approached, it is therefore important that there be an informed trade-off between the risk of disease re-emergence and the duration of the "lockdown". Here it is shown that an important factor in assessing this trade-off, is the distribution of secondary cases, not just the expected value of this distribution, R0 . It is shown that a distribution in which "super-spreaders" are more prominent in the epidemiology, allows for an earlier release from "lockdown" with reasonable safety despite some probability of asymptomatic cases. There is some evidence to support such a distribution for covid-19. Analytical calculations and simulations show that once there is only one recognised case in some subregion, release from "lockdown" will be reasonably safe after just one or two further incubation periods. | 1ir2ptuj |
coronavirus super spreaders | 14 | Multi-chain Fudan-CCDC model for COVID-19 -- a revisit to Singapore's case | Background: COVID-19 has been impacting on the whole world critically and constantly since late December 2019. Rapidly increasing infections has raised intense worldwide attention. How to model the evolution of COVID-19 effectively and efficiently is of great significance for prevention and control. Methods: We propose the multi-chain Fudan-CCDC model based on the original single-chain model in [8] to describe the evolution of COVID-19 in Singapore. Multi-chains can be considered as the superposition of several single chains with different characteristics. We identify parameters of models by minimizing the penalty function. Results: The numerical simulation results exhibit the multi-chain model performs well on data fitting. Though unsteady the increments are, they could still fall within the range of 25% fluctuation from simulation results. It is predicted by multi-chain models that Singapore are experiencing a nonnegligible risk of explosive outbreak, thus stronger measures are urgently needed to contain the epidemic. Conclusion: The multi-chain Fudan-CCDC model provides an effective way to early detect the appearance of imported infectors and super spreaders and forecast a second outbreak. It can also explain the data in those countries where the single-chain model shows deviation from the data. | etnf4i8v |
coronavirus super spreaders | 14 | Susceptibility-adjusted herd immunity threshold model and potential R0 distribution fitting the observed Covid-19 data in Stockholm | The reproduction number, R0, is commonly used, and sometimes misused, in conjunction with the classic Kermack and McKindrick theory based on the assumption of homogeneity, in order to estimate herd immunity threshold (HIT). This provides a crude first estimate of HIT, with more elaborate modelling required to arrive at a more realistic value. Early estimates of HIT for Covid-19 were based on this simplistic homogeneous approach, yielding high HIT values that have since been revised downwards with more sophisticated network modelling taking account of R0 heterogeneity and with reference to the low HIT found from serological sampling in Stockholm County. The aim of this paper is to describe a simple model in which host susceptibility is directly linked to the heterogeneous R0 distribution, to shed further light on the mechanisms involved and to arrive at a bimodal R0 distribution consistent with the Covid-19 HIT observed in Stockholm County. | hfd4eqkv |
coronavirus super spreaders | 14 | Evaluating transmission heterogeneity and super-spreading event of COVID-19 in a metropolis of China | Background: COVID-19 caused rapid mass infection worldwide. Understanding its transmission characteristics including heterogeneity is of vital importance for prediction and intervention of future epidemics. In addition, transmission heterogeneity usually envokes super spreading events (SSEs) where certain individuals infect large numbers of secondary cases. Till now, studies of transmission heterogeneity of COVID-19 and its underlying reason are far from reaching an agreement. MethodsWe collected information of all infected cases between January 21 and February 26, 2020 from official public sources in Tianjin, a metropolis of China. Utilizing a heterogeneous transmission model based on branching process along with a negative binomial offspring distribution, we estimated the reproductive number R and the dispersion parameter k which characterized the transmission potential and heterogeneity, respectively. Furthermore, we studied the SSE in Tianjin outbreak and evaluated the effect of control measures undertaken by local government based on the heterogeneous model. Results: A total of 135 confirmed cases (including 34 imported cases and 101 local infections) in Tianjin by February 26th 2020 entered the study. We grouped them into 43 transmission chains with the largest chain of 45 cases and the longest chain of 4 generations. The estimated reproduction number R was at 0.67 (95%CI: 0.54[~]0.84), and the dispersion parameter k was at 0.25 (95% CI: 0.13[~]0.88). A super spreader causing six infections in Tianjin, was identified. In addition, our simulation results showed that the outbreak in Tianjin would have caused 165 infections and sustained for 7.56 generations on average if no control measures had been taken by local government since January 28th. Conclusions: Our analysis suggested that the transmission of COVID-19 was subcritical but with significant heterogeneity and may incur SSE. More efforts are needed to verify the transmission heterogeneity of COVID-19 in other populations and its contributing factors, which is important for developing targeted measures to curb the pandemic. | uicvudil |
coronavirus super spreaders | 14 | Super-spreading events of SARS in a hospital setting: who, when, and why? | qhrvi9e7 |
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coronavirus super spreaders | 14 | Pattern of early human-to-human transmission of Wuhan 2019 novel coronavirus (2019-nCoV), December 2019 to January 2020 | Since December 2019, China has been experiencing a large outbreak of a novel coronavirus (2019-nCoV) which can cause respiratory disease and severe pneumonia. We estimated the basic reproduction number R0 of 2019-nCoV to be around 2.2 (90% high density interval: 1.4-3.8), indicating the potential for sustained human-to-human transmission. Transmission characteristics appear to be of similar magnitude to severe acute respiratory syndrome-related coronavirus (SARS-CoV) and pandemic influenza, indicating a risk of global spread. | fjwmp2fi |
coronavirus super spreaders | 14 | A Pandemic in Times of Global Tourism: Superspreading and Exportation of COVID-19 Cases from a Ski Area in Austria | ki9om3bq |
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coronavirus super spreaders | 14 | Propagation and mitigation of epidemics in a scale-free network | The epidemic curve and the final extent of the COVID-19 pandemic are usually predicted from the rate of early exponential raising using the SIR model. These predictions implicitly assume a full social mixing, which is not plausible generally. Here I am showing a counterexample to the these predictions, based on random propagation of an epidemic in Barab\'asi--Albert scale-free network models. The start of the epidemic suggests $R_0=2.6$, but unlike $\Omega\approx 70\%{}$ predicted by the SIR model, they reach a final extent of only $\Omega\approx 4\%{}$ without external mitigation and $\Omega\approx 0.5$--$1.5\%{}$ with mitigation. Daily infection rate at the top is also 1--1.5 orders of magnitude less than in SIR models. Quarantining only the 1.5\%{} most active superspreaders has similar effect on extent and top infection rate as blind quarantining a random 50\%{} of the full community. | byzemhvu |
coronavirus super spreaders | 14 | Inferring super-spreading from transmission clusters of COVID-19 in Hong Kong, Japan and Singapore | Super-spreading events in an outbreak can change the nature of an epidemic. Therefore, it is useful for public health teams to determine if an ongoing outbreak has any contribution from such events, which may be amenable to interventions. We estimated the basic reproductive number (R0) and the dispersion factor (k) from empirical data on clusters of epidemiologically-linked COVID-19 cases in Hong Kong, Japan and Singapore. This allowed us to infer the presence or absence of super-spreading events during the early phase of these outbreaks. The relatively large values of k implied that large cluster sizes, compatible with super-spreading, were unlikely. | 2t4fsfy9 |
coronavirus super spreaders | 14 | [Investigation of a cluster epidemic of COVID-19 in Ningbo] | Objective: To investigate a cluster epidemic of COVID-19 after a mass gathering activity in Ningbo of Zhejiang province and analyze the transmission chain and status of infection cases of different generations. Methods: The tracking of all the close contacts of the first COVID-19 case and epidemiological investigation were conducted on January 29, 2020 after a cluster epidemic of COVID-19 related with a Buddhism rally on January 19 (the 1.19 rally) in Ningbo occurred. The swabs of nose/throat of the cases and close contacts were collected and tested for nucleic acids by real-time fluorescence quantitative RT-PCR. Results: From January 26 to February 20, 2020, a total of 67 COVID-19 cases and 15 asymptomatic infection cases related with the 1.19 rally were reported in Ningbo. The initial case was the infection source who infected 29 second generation cases and 4 asymptomatic infection cases, in whom 23 second generation cases and 3 asymptomatic infection cases once took bus with the initial case, the attack rate was 33.82% (23/68) and the infection rate was 38.24% (26/68). The risks of suffering from COVID-19 and being infected were 28.91 times and 26.01 times higher in rally participants taking bus with initial case compared with those taking no bus with initial case. In this epidemic, 37 third+ generation cases and 11 related asymptomatic infection cases occurred, the attack rate was 2.88% (37/1 283) and the infection rate was 4.76% (48/1 008). The main transmission routes included vehicle sharing and family transmission. Conclusion: It was a cluster epidemic of COVID-19 caused by a super spreader in a massive rally. The epidemic has been under effective control. | x9c2ymra |
coronavirus super spreaders | 14 | Unlinking super-linkers: the topology of epidemic response (Covid-19) | A key characteristic of the spread of infectious diseases is their ability to use efficient transmission paths within contact graphs. This enables the pathogen to maximise infection rates and spread within a target population. In this work, we devise techniques to localise infections and decrease infection rates based on a principled analysis of disease transmission paths within human-contact networks (proximity graphs). Experimental results of disease spreading shows that that at low visibility rates contact tracing slows disease spreading. However to stop disease spreading, contact tracing requires both significant visibility (at least 60%) into the proximity graph and the ability to place half of the population under isolation. We find that pro-actively isolating super-links -- key proximity encounters -- has significant benefits: targeted isolation of a fourth of the population based on 35% visibility into the proximity graph prevents an epidemic outbreak. It turns out that isolating super-spreaders is more effective than contact tracing and testing but less effective than targeting super-links. We highlight the important role of topology in epidemic outbreaks. We argue that proactive innoculation of a population by disabling super-links and super-spreaders may have an important complimentary role alongside contact tracing and testing as part of a sophisticated public-health response to epidemic outbreaks. | qla3go2i |
coronavirus super spreaders | 14 | Clinical and Transmission Characteristics of Covid-19 - A Retrospective Study of 25 Cases from a Single Thoracic Surgery Department | The outbreak of corona virus disease 2019 (Covid-19) imposes a major challenge in managing patients undergoing surgical operation. In this study, we analyzed clinical and transmission features of 25 cases of Covid-19 from a single thoracic department, including 13 patients and 12 health care staff. There were 13 males and 12 females. The median age of the patients was 61 (range: 51 to 69) years. The median age of the health care staff was 35 (range: 22 to 51) years. By the end of follow-up date (Mar. 3, 2020), there were 16 non-severe cases (64%) and 9 severe cases (36%), 5 cases were dead (20%). Nineteen (76%) of the infected cases were confirmed by SARS-CoV-2 nucleic acid test, the rest were clinically diagnosed as suspected Covid-19 cases, and 19 (76%) of the infected cases had positive exposure history. We found that COPD was significantly associated with severity and death (P=0.040, and P=0.038, respectively), and chest operation was significantly associated with death for Covid-19 patients (P=0.039). A potential "super spreader" may be the source of the transmission before the implementation of quarantine and comprehensive protection. It was concluded that Covid-19 is associated with poor prognosis for patients undergoing thoracic operation, especially for those with COPD. Implementation of comprehensive protective measures is important to control nosocomial infection. | xwqxji63 |
coronavirus super spreaders | 14 | A note on community-detection (Kemeny) based testing for COVID-19 | The Kemeny constant of a graph can be used to identify and analyse bridges between communities in a graph. Testing, tracking and tracing abilities have been identified as pivotal in helping countries to safely reopen activities after the first wave of the COVID-19 virus. Tracing techniques aim at reconstructing past history of contacts, but can face practical limits in an exponential growth of either testing or overly conservative quarantining. We show how this application of graph theory can be conveniently used to efficiently intercept new virus outbreaks, when they are still in their early stage. Simulations provide promising results in early identification and blocking of possible"super-spreader links that transmit disease between different communities. | eofrf2em |
coronavirus super spreaders | 14 | Chest tube with air leaks is a potential "super spreader" of COVID-19 | z19xdrxu |
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coronavirus super spreaders | 14 | Significance of super spreader events in COVID-19 | The number of secondary cases from each primary case determines how fast an epidemic grows. It is known that all cases do not spread the infection equally; super spreaders play an important role as they contribute disproportionately to a much larger number of cases including in the ongoing COVID-19 pandemic. Super spreaders have been reported for more than a century, but limited information is available in scientific literature. An epidemic containment strategy needs to include early identification of super spreaders to limit an explosive growth. Super spreaders tend to get stigmatized, resulting in late reporting and hiding of cases. It is important for program managers to be sensitive to the manner in which related information is shared with media and general public. | p48bw6s4 |
coronavirus super spreaders | 14 | Evaluating Transmission Heterogeneity and Super-Spreading Event of COVID-19 in a Metropolis of China | COVID-19 caused rapid mass infection worldwide. Understanding its transmission characteristics, including heterogeneity and the emergence of super spreading events (SSEs) where certain individuals infect large numbers of secondary cases, is of vital importance for prediction and intervention of future epidemics. Here, we collected information of all infected cases (135 cases) between 21 January and 26 February 2020 from official public sources in Tianjin, a metropolis of China, and grouped them into 43 transmission chains with the largest chain of 45 cases and the longest chain of four generations. Utilizing a heterogeneous transmission model based on branching process along with a negative binomial offspring distribution, we estimated the reproductive number R and the dispersion parameter k (lower value indicating higher heterogeneity) to be 0.67 (95% CI: 0.54-0.84) and 0.25 (95% CI: 0.13-0.88), respectively. A super-spreader causing six infections was identified in Tianjin. In addition, our simulation allowing for heterogeneity showed that the outbreak in Tianjin would have caused 165 infections and sustained for 7.56 generations on average if no control measures had been taken by local government since 28 January. Our results highlighted more efforts are needed to verify the transmission heterogeneity of COVID-19 in other populations and its contributing factors. | uo7ixk9r |
coronavirus super spreaders | 14 | Super-spreading events and contribution to transmission of MERS, SARS, and SARS-CoV-2 (COVID-19) | zpib6e2z |
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coronavirus super spreaders | 14 | A super-spreader of COVID-19 in Ningbo city in China | An outbreak of Coronavirus Disease 2019 (COVID-19) has spread rapidly. It is imperative to control the epidemic by understanding the epidemiological feature, preventative quarantine, and effective hygiene measures. In the present study, we report a case of super-spreader who transmitted the disease to over twenty-eight persons in Ningbo, Zhejiang. Identifying and isolated super-spreaders, understanding the reasons behind the efficient transmission ability are important for the control and management of the ongoing COVID-19 pandemic. | 37katpp3 |
coronavirus super spreaders | 14 | COVID-19 Super-spreaders: Definitional Quandaries and Implications | Uncertainty around the role 'super-spreaders' play in the transmission and escalation of infectious disease is compounded by its broad and vague definition. It is a term that has been much used in relation to COVID-19, particularly in social media. On its widest definition, it refers to a propensity to infect a larger than average number of people. Given the biological, behavioural and environmental variables relevant to infectivity, this might be pertinent to almost any infected individual who is not physically isolated from others. Nor is the term confined to individuals with a propensity to spread infectious disease: it can potentially be used to describe events, policies or settings. This article explores the use of the term and considers circumstances in which the wide definition can be problematic. One problem is that it can lead to undeserved apportionment of moral blame to alleged super-spreaders. Another is that it can detract from scientific investigation of the heterogeneity of COVID-19 transmission. The author calls for a clearer epidemiological definition. | v0vjkwy9 |
coronavirus super spreaders | 14 | Mathematical Modeling of COVID-19 Transmission Dynamics with a Case Study of Wuhan | Abstract We propose a compartmental mathematical model for the spread of the COVID-19 disease with special focus on the transmissibility of super-spreaders individuals. We compute the basic reproduction number threshold, we study the local stability of the disease free equilibrium in terms of the basic reproduction number, and we investigate the sensitivity of the model with respect to the variation of each one of its parameters. Numerical simulations show the suitability of the proposed COVID-19 model for the outbreak that occurred in Wuhan, China. | h2gwzypy |
coronavirus super spreaders | 14 | Pausing super spreader events for COVID-19 mitigation: International Hajj pilgrimage cancellation | k6ijng66 |
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coronavirus super spreaders | 14 | Estimating finite-population reproductive numbers in heterogeneous populations | Abstract The basic reproductive number, R 0 , is one of the most important epidemiological quantities. R 0 provides a threshold for elimination and determines when a disease can spread or when a disease will die out. Classically, R 0 is calculated assuming an infinite population of identical hosts. Previous work has shown that heterogeneity in the host mixing rate increases R 0 in an infinite population. However, it has been suggested that in a finite population, heterogeneity in the mixing rate may actually decrease the finite-population reproductive numbers. Here, we outline a framework for discussing different types of heterogeneity in disease parameters, and how these affect disease spread and control. We calculate “finite-population reproductive numbers” with different types of heterogeneity, and show that in a finite population, heterogeneity has complicated effects on the reproductive number. We find that simple heterogeneity decreases the finite-population reproductive number, whereas heterogeneity in the intrinsic mixing rate (which affects both infectiousness and susceptibility) increases the finite-population reproductive number when R 0 is small relative to the size of the population and decreases the finite-population reproductive number when R 0 is large relative to the size of the population. Although heterogeneity has complicated effects on the finite-population reproductive numbers, its implications for control are straightforward: when R 0 is large relative to the size of the population, heterogeneity decreases the finite-population reproductive numbers, making disease control or elimination easier than predicted by R 0 . | ao2w4v71 |
coronavirus super spreaders | 14 | The prominence of asymptomatic superspreaders in transmission mean universal face masking should be part of COVID-19 de-escalation strategies | 3zlpkidj |
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coronavirus super spreaders | 14 | Identifying and Interrupting Superspreading Events—Implications for Control of Severe Acute Respiratory Syndrome Coronavirus 2 | It appears inevitable that severe acute respiratory syndrome coronavirus 2 will continue to spread. Although we still have limited information on the epidemiology of this virus, there have been multiple reports of superspreading events (SSEs), which are associated with both explosive growth early in an outbreak and sustained transmission in later stages. Although SSEs appear to be difficult to predict and therefore difficult to prevent, core public health actions can prevent and reduce the number and impact of SSEs. To prevent and control of SSEs, speed is essential. Prevention and mitigation of SSEs depends, first and foremost, on quickly recognizing and understanding these events, particularly within healthcare settings. Better understanding transmission dynamics associated with SSEs, identifying and mitigating high-risk settings, strict adherence to healthcare infection prevention and control measures, and timely implementation of nonpharmaceutical interventions can help prevent and control severe acute respiratory syndrome coronavirus 2, as well as future infectious disease outbreaks. | 582h1w0h |
coronavirus super spreaders | 14 | Superspreaders and the spread pattern of COVID-19: Response to: “Do superspreaders generate new superspreaders? A hypothesis to explain the propagation pattern of COVID-19”, International Journal of Infectious Diseases 96 (2020) 461–463 | g83oxgig |
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coronavirus super spreaders | 14 | Novel Percutaneous Tracheostomy for Critically Ill Patients with COVID-19 | Abstract Background COVID-19 is a worldwide pandemic, with many patients requiring prolonged mechanical ventilation. Tracheostomy is not recommended by current guidelines as it is considered a super-spreading event due to aerosolization that unduly risks healthcare workers. Methods Patients with severe COVID-19 that were on mechanical ventilation ≥ 5 days were evaluated for percutaneous dilational tracheostomy. We developed a novel percutaneous tracheostomy technique that placed the bronchoscope alongside the endotracheal tube, not inside it. This improved visualization during the procedure and continued standard mechanical ventilation after positioning the inflated endotracheal tube cuff in the distal trachea. This technique offers a significant mitigation for the risk of virus aerosolization during the procedure. Results From March 10 to April 15, 2020, 270 patients with COVID-19 required invasive mechanical ventilation at New York University Langone Health Manhattan’s campus of which 98 patients underwent percutaneous dilational tracheostomy. The mean time from intubation to the procedure was 10.6 days (SD ±5 days). Currently, thirty-two (33%) patients do not require mechanical ventilatory support, 19 (19%) have their tracheostomy tube downsized and 8 (8%) were decannulated. Forty (41%) patients remain on full ventilator support, while 19 (19%) are weaning from mechanical ventilation. Seven (7%) died as result of respiratory and multiorgan failure. Tracheostomy related bleeding was the most common complication (5 patients). None of health care providers have developed symptoms or tested positive for COVID-19. Conclusions Our percutaneous tracheostomy technique appears to be safe and effective for COVID-19 patients and safe for healthcare workers. | qhq3slti |
coronavirus super spreaders | 14 | Short communication: Low risk of transmission of severe acute respiratory syndrome on airplanes: the Singapore experience | The risk of transmission of severe acute respiratory syndrome (SARS) on airplanes is of major concern to the public and airline industry. We examined data from flights to Singapore with SARS patients on board in order to assess this risk. In‐flight transmission occurred only in one of the three flights with symptomatic SARS patients on board. The incidence was estimated to be 1 out of 156 passengers. The risk of in‐flight transmission of SARS appears to be far lower than that reported for influenza, but may be increased with superspreaders on board. | 58tj4csz |
coronavirus super spreaders | 14 | Evolving Transmission Network Dynamics of COVID-19 Cluster Infections in South Korea: a descriptive study | Background. Extensive contact tracing and testing in South Korea allows us to investigate the transmission dynamics of the COVID-19 into diverse local communities. Objective. Understand the critical aspects of transmission dynamics in a different age, sex, and clusters with various activities. Methods. We conducted a retrospective observational study with 3,127 confirmed cases' contact tracing data from the Center for Disease and Prevention (CDC) of South Korea. We investigated network property concerning infected persons' demographics and different infection clusters. Findings. Overall, women had higher centrality scores than men after week four, when the confirmed cases rapidly increased. Older adults have higher centrality than young/middle-aged adults after week 9. In the infection clusters, young/middle-aged adults' infection clusters (such as religious gatherings and gym facilities) have higher average path lengths and diameter than older adults' nursing home infection clusters. Interpretation. Some women had higher reproduction numbers and bridged successive transmission than men when the confirmed cases rapidly increased. Similarly, some older adults (who were not residents of nursing homes) had higher reproduction numbers and bridged successive transmission than young/middle-aged adults after the peak has passed. The young/middle-aged adults' religious gatherings and group workout have caused long successive transmissions. In contrast, the older adults' nursing homes were a small world where the transmissions within a few steps can reach out to many persons. | 5w70yhvy |
coronavirus super spreaders | 14 | Epidemiological characteristics of the first 100 cases of coronavirus disease 2019 (COVID-19) in Hong Kong Special Administrative Region, China, a city with a stringent containment policy | BACKGROUND: Hong Kong (HK) is a densely populated city near the epicentre of the coronavirus disease 2019 (COVID-19) outbreak. Stringent border control together with aggressive case finding, contact tracing, social distancing and quarantine measures were implemented to halt the importation and spread of the virus. METHODS: We performed an epidemiological study using government information covering the first 100 confirmed cases to examine the epidemic curve, incidence, clusters, reproduction number (R(t)), incubation period and time to containment. RESULTS: A total of 93 of the 100 cases were HK residents (6 infected in Mainland China, 10 on the Diamond Princess Cruise). Seven were visitors infected in Mainland China before entering HK. The majority (76%) were aged ≥45 years, and the incidence increased with age (P < 0.001). Escalation of border control measures correlated with a decrease in the proportion (62.5% to 0%) of cases imported from Mainland China, and a reduction in R(t) (1.07 to 0.75). The median incubation period was 4.2 days [95% confidence interval (CI), 4.0–4.5; 5th and 95th percentiles: 1.3 and 14.0). Most clusters with identifiable epidemiological links were households involving 2–4 people. Three medium-spreading events were identified: two from New Year gatherings (6–11 people), and another from environmental contamination of a worship hall (12 people). Despite intensified contact tracing, containment was delayed in 78.9% of cases (mean = 5.96 days, range = 0–24 days). An unusual transmission in a multi-storey building via faulty toilet plumbing was suspected with >100 residents evacuated overnight. Our analysis indicated that faulty plumbing was unlikely to be the source of this transmission. CONCLUSIONS: Timely stringent containment policies minimized the importation and transmission of COVID-19 in HK. | hmi061vn |
coronavirus super spreaders | 14 | COVID-19: Facts, Cultural Considerations, and Risk of Stigmatization | Data on COVID-19 supports targeted social distancing could be an effective way to reduce morbidity and mortality, but could inadvertently increase stigma for affected populations. As health care providers we must be aware of the facts of COVID-19, cultural implications, and potential for stigmatization of populations affected by COVID-2019. It is important to consider the real economic impact related to lost workdays due to quarantine and social isolation efforts as well as travel restrictions that may negatively impact access to care and ability to pay for care. Efforts geared towards general education about the disease and the rationale for quarantine and public health information provided to the general public can reduce stigmatization. Countries who are successful at aggressive screening, early identification, patient isolation, contact tracing, quarantine, and infection control methods should also address the risk of stigmatization among populations and the negative effects which could occur. The cases of COVID-19 will continue to rise and the virus will be sustainable for future infections. Timely and appropriate public health interventions addressing cultural impact and risk for stigmatization along with proper screening, treatment, and follow up for affected individuals and close contacts can reduce the number of infections, serious illness, and deaths. | pmc55dw0 |
coronavirus super spreaders | 14 | Secondary attack rate and superspreading events for SARS-CoV-2 | r03x527x |
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coronavirus super spreaders | 14 | Preparing for the Next Wave of COVID-19: Resilience in the Face of a Spreading Pandemic | COVID-19 painfully demonstrates how little resilience our societies have to novel viruses. Societies, decision makers, and scientists lack (1) a comprehensive understanding of the complexity of viral outbreaks and their impact on society; (2) intervention portfolios; and (3) a global crisis and resilience policy, all of which are required to develop appropriate measures and to improve societal resilience. We highlight COVID-19 immunity as one key benchmark in preparation for the next wave of the pandemic. Specifically, using network scenarios, we demonstrate the substantial advantage of reintegrating health care workers with acquired COVID-19 immunity in epidemic hotspots, which would not only enable their safe contribution to the health care system but also drastically contain further spread. | hdt7aooi |
coronavirus super spreaders | 14 | Summary of the COVID-19 outbreak in Vietnam – Lessons and suggestions | 0gvizlt9 |
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coronavirus super spreaders | 14 | Chest tube with air leaks is a potential “super spreader” of COVID-19 | y42o6exe |
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coronavirus super spreaders | 14 | COVID-19: preparing for superspreader potential among Umrah pilgrims to Saudi Arabia | n1zvt5wu |
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coronavirus outside body | 15 | Identification of SARS-CoV-2 RNA in Healthcare Heating, Ventilation, and Air Conditioning Units | Available information on Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission by small particle aerosols continues to evolve rapidly. To assess the potential role of heating, ventilation, and air conditioning (HVAC) systems in airborne viral transmission, this study sought to determine the viral presence, if any, on air handling units in a healthcare setting where Coronavirus Disease 2019 (COVID-19) patients were being treated. The presence of SARS-CoV-2 RNA was detected in approximately 25% of samples taken from nine different locations in multiple air handlers. While samples were not evaluated for viral infectivity, the presence of viral RNA in air handlers raises the possibility that viral particles can enter and travel within the air handling system of a hospital, from room return air through high efficiency MERV-15 filters and into supply air ducts. Although no known transmission events were determined to be associated with these specimens, the findings suggest the potential for HVAC systems to facilitate transmission by environmental contamination via shared air volumes with locations remote from areas where infected persons reside. More work is needed to further evaluate the risk of SARS-CoV-2 transmission via HVAC systems and to verify effectiveness of building operations mitigation strategies for the protection of building occupants. These results are important within and outside of healthcare settings and may present a matter of some urgency for building operators of facilities that are not equipped with high-efficiency filtration. | cjt2y67m |
coronavirus outside body | 15 | Modelling aerosol transport and virus exposure with numerical simulations in relation to SARS-CoV-2 transmission by inhalation indoors | We provide research findings on the physics of aerosol dispersion relevant to the hypothesized aerosol transmission of SARS-CoV-2. We utilize physics-based modeling at different levels of complexity, and literature on coronaviruses, to investigate the possibility of airborne transmission. The previous literature, our 0D-3D simulations by various physics-based models, and theoretical calculations, indicate that the typical size range of speech and cough originated droplets (d<20microns) allows lingering in the air for O(1h) so that they could be inhaled. Consistent with the previous literature, numerical evidence on the rapid drying process of even large droplets, up to sizes O(100microns), into droplet nuclei/aerosols is provided. Based on the literature and the public media sources, we provide evidence that the infected individuals could have been exposed to aerosols/droplet nuclei by inhaling them in significant numbers e.g. O(100). By 3D computational fluid dynamics (CFD) simulations, we give examples on the transport and dilution of aerosols (d<20microns) over distances O(10m) in generic environments. We study susceptible and infected individuals in generic public places by Monte-Carlo modeling. The model accounts for the locally varying aerosol concentration levels which the susceptible accumulate via inhalation. The introduced concept, 'exposure time' to virus containing aerosols is proposed to complement the traditional 'safety distance' thinking. We show that the exposure time to inhale O(100) aerosols could range from O(1s) to O(1min) or even to O(1h) depending on the situation. The Monte Carlo analysis provides clear quantitative insight to the exposure time in different public indoor environments. | 0n8x3i0v |
coronavirus outside body | 15 | A Guide to COVID-19: a global pandemic caused by the novel coronavirus SARS-CoV-2 | The emergence of the SARS-CoV-2 strain of the human coronavirus has thrown the world into the midst of a new pandemic. In the human body, the virus causes COVID-19, a disease characterized by shortness of breath, fever, and pneumonia, which can be fatal in vulnerable individuals. SARS-CoV-2 has characteristics of past human coronaviruses, with close genomic similarities to SARS-CoV, the virus that causes the disease SARS. Like these related coronaviruses, SARS-CoV-2 is transmitted through the inhalation of droplets and interaction with contaminated surfaces. Across the world, laboratories are developing candidate vaccines for the virus - with vaccine trials underway in the United States and the United Kingdom - and considering various drugs for possible treatments and prophylaxis. Here, we provide an overview of SARS-CoV-2 by analyzing its virology, epidemiology, and modes of transmission while examining the current progress of testing procedures and possible treatments through drugs and vaccines. | wq7ljx2f |
coronavirus outside body | 15 | Infection Control in Dental Practice During the COVID-19 Pandemic | COVID-19 is the disease supported by SARS-CoV-2 infection, which causes a severe form of pneumonia. Due to the pathophysiological characteristics of the COVID-19 syndrome, the particular transmissibility of SARS-CoV-2, and the high globalization of our era, the epidemic emergency from China has spread rapidly all over the world. Human-to-human transmission seems to occur mainly through close contact with symptomatic people affected by COVID-19, and the main way of contagion is via the inhalation of respiratory droplets, for example when patients talk, sneeze or cough. The ability of the virus to survive outside living organisms, in aerosol or on fomites has also been recognized. The dental practitioners are particularly exposed to a high risk of SARS-CoV-2 infection because they cannot always respect the interpersonal distance of more than a meter and are exposed to saliva, blood, and other body fluids during surgical procedures. Moreover, many dental surgeries can generate aerosol, and the risk of airborne infection is to be considered higher. The aim of this paper is to provide practical advice for dentists based on the recent literature, which may be useful in reducing the risk of spreading COVID-19 during clinical practice. | 1d4gf7kr |
coronavirus outside body | 15 | Stability and Viability of SARS-CoV-2 | wyh7t6rr |
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coronavirus outside body | 15 | Evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as coronavirus disease 2019 (COVID-19) pandemic: A global health emergency | According to data compiled by researchers at Johns Hopkins University in Baltimore, Maryland, more than two and half million cases of coronavirus disease 2019 (COVID-19), caused by a newly discovered virus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have been confirmed on April 20, 2020 (Nature, 2020b). Since the emergence of this infectious disease in Asia (Wuhan, China) late last year, it has been subsequently span to every continent of the world except Antarctica (Rodríguez-Morales et al., 2020). Along with a foothold in every country, the current disease pandemic is disrupting practically every aspect of life all over the world. As the outbreak are continuing to evolve, several research activities have been conducted for better understanding the origin, functions, treatments, and preventions of this novel coronavirus. This review will be a summa of the key features of novel coronavirus (nCoV), the virus causing disease 2019 and the present epidemic situation worldwide up to April 20, 2020. It is expected that this record will play an important role to take more preventive measures for overcoming the challenges faced during this current pandemic. | hpx4723v |
coronavirus outside body | 15 | SARS-CoV-2 Virulence: Interplay of Floating Virus-Laden Particles, Climate, and Humans | With the emergence of COVID-19, it is important to address the possible scenarios of SARS-CoV-2 virulence. Although several researchers have addressed the possible mechanisms of enveloped virus transfection, for example, influenza, here, the relationship between exhaled virus laden-particles, the climate, and transfection probability is discussed by interpreting the findings of prior studies. Importantly, the higher probability of viral transfection in cold and dry public spaces such as near cold shelves of groceries is illustrated. Thus, additional protective measures in such spaces are recommended. | e138dm8k |
coronavirus outside body | 15 | The influenza virus, SARS-CoV-2, and the airways: Clarification for the otorhinolaryngologist | The influenza virus and SARS-CoV-2 cause trivial upper and severe lower respiratory infections (Influenza virus 290,000 to 650,000 deaths/year). These viruses come into contact with the airways either by direct projection, by secondary inhalation of airborne droplets, or by handling (fomites). The objective of this article is to clarify the mechanisms of production and penetration of droplets of secretions emitted during all expiratory phenomena likely to transport these viruses and come into contact with the respiratory mucosa. The droplets>5µm follow the laws of ballistics, those<5µm follow Brownian motion and remain suspended in the air. The aerosols of droplets are very heterogeneous whether the subject is healthy or sick. During an infectious period, not all droplets contain viral RNA. If these RNAs are detectable around patients, on surfaces, and in the ambient air at variable distances according to the studies (from 0.5m to beyond the patient's room), this is without prejudice to the infectious nature (viability) of the virus and the minimum infectious dose. There is a time lag between the patient's infectious period and that of RNA detection for both viruses. Subsequently, the inhaled particles must meet the laws of fluid dynamics (filtration) to settle in the respiratory tree. All of this partly explains the contagiousness and the clinical expression of these two viruses from the olfactory cleft to the alveoli. | nr42k23h |
coronavirus outside body | 15 | A chronicle of SARS-CoV-2: Part-I - Epidemiology, diagnosis, prognosis, transmission and treatment | In order to benefit the public, community workers and scientific community, we hereby present a chronicle of SARS-CoV-2 that leads to the unseen precedent of social distancing and lockdown owing to coronavirus disease (COVID-19). Information on this life-threatening pandemic of COVID-19 is sparse and discrete; and the urgency is such that the dissemination of information is increasing with numerous daily publications on the topic. Therefore, we developed a comprehensive review on various aspects of SARS-CoV-2 and COVID-19. We scientifically compiled published research, news, and reports from various sources to comprehend and summarize the information and findings on Coronaviruses. The review explicitly covers the aspects like genome and pedigree of SARS-CoV-2; epidemiology, prognosis, pathogenesis, symptoms and diagnosis of COVID-19 in order to catalog the right information on transmission route, and influence of environmental factors on virus transmissions, for the robust understanding of right strategical steps for proper COVID-19 management. We have explicitly highlighted several useful information and facts like: i) No established relationship between progression of SARS-CoV-2 with temperature, humidity and/or both, ii) The underlying mechanism of SARS-CoV-2 is not fully understood, iii) Respiratory droplet size determines drop and airborne-based transmission, iv) Prognosis of COVID-19 can be done by its effects on various body organs, v) Infection can be stopped by restricting the binding of S protein and AE2, vi) Hydroxychloroquine is believed to be better than chloroquine for COVID-19, vii) Ivermectin with Vero-hSLAM cells is able to reduce infection by ~5000 time within 2 days, and viii) Nafamostat mesylate can inhibit SARS-CoV-2 S protein-initiated membrane fusion. We have also suggested future research perspectives, challenges and scope. | daprgv9i |
coronavirus outside body | 15 | SARS‐CoV‐2 Virulence: Interplay of Floating Virus‐Laden Particles, Climate, and Humans | With the emergence of COVID‐19, it is important to address the possible scenarios of SARS‐CoV‐2 virulence. Although several researchers have addressed the possible mechanisms of enveloped virus transfection, for example, influenza, here, the relationship between exhaled virus laden‐particles, the climate, and transfection probability is discussed by interpreting the findings of prior studies. Importantly, the higher probability of viral transfection in cold and dry public spaces such as near cold shelves of groceries is illustrated. Thus, additional protective measures in such spaces are recommended. | 92ijxah4 |
coronavirus outside body | 15 | Protections against the Risk of Airborne SARS-CoV-2 Infection | 3n0widf9 |
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coronavirus outside body | 15 | Overview of transnational recommendations for COVID‐19 transmission control in dental care settings | On 11 March 2020, the World Health Organization (WHO) declared the coronavirus disease (COVID‐19) caused by severe acute respiratory syndrome coronavirus (SARS‐CoV‐2) as a pandemic. Until an effective treatment or a vaccine is developed, the current recommendations are to contain the disease, and control its transmission. It is now clear that the primary mode of SARS‐CoV‐2 transmission is aerosol/droplet spread, and by contacting virus‐contaminated surfaces acting as fomites (inanimate vectors). Furthermore, recent data indicate that the live virus particles are present in saliva, and, more alarmingly, asymptomatic individuals may transmit the infection. By virtue of the nature of the practice of dentistry where intrinsically, a high volume of aerosols is produced, as well as the close proximity of dentists and patients during treatment, dentists and allied health staff are considered the highest risk health professional group for acquiring SARS‐CoV‐2 during patient management. Therefore, several organizations and specialty associations have proposed guidelines and recommendations for limiting the transmission of SARS‐COV‐2 from carriers to dentists and vice versa. This paper aims to provide a review of these guidelines, and concludes with a brief look at how the practice of dentistry may be impacted by COVID‐19, in the post‐pandemic era. | gc1wwcpo |
coronavirus outside body | 15 | Forensic DNA testing during the SARS-CoV-2 pandemic | The aggressive nature of the new SARS-2 corona virus now referred to as SARS-CoV-2 ; the seriousness and length of the period of infection; the fast and far-reaching transmissibility via liquid droplets that become air-borne when someone coughs, sneezes or speaks with increasing evidence to support actual airborne transmission; the presence of viral particles especially in body fluids and tissues, of viral positive individuals; and the persistence of the virus on different types of surfaces pose serious concerns for forensic practitioners, including forensic DNA analysts. Many forensic laboratories and law enforcement agencies need to address the inevitable changes that must be made in forensic DNA testing. In this article, we explore the effects of the COVID-19 pandemic on the collection, handling, storage and transport of biological samples for downstream DNA testing. This paper aims to open discussions on the urgency of balancing the need to conduct investigations in order to maintain public order with the requirements of effective biosafety protocols specifically formulated to protect human resources within the forensic science community. | 40bpu5nk |
coronavirus outside body | 15 | Novel coronavirus transmission to water bodies; risk of COVID-19 pneumonia to aquatic mammals | [Figure: see text] | 34m7y2l1 |
coronavirus outside body | 15 | Editorial: Stay safe during this coronavirus crisis | 6305q2f5 |
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coronavirus outside body | 15 | The influenza virus, SARS-CoV-2, and the airways: clarification for the otorhinolaryngologist | Abstract The influenza virus and SARS-CoV-2 cause trivial upper and severe lower respiratory infections (Influenza virus 290,000 to 650,000 deaths/year). These viruses come into contact with the airways either by direct projection, by secondary inhalation of airborne droplets, or by handling (fomites). The objective of this article is to clarify the mechanisms of production and penetration of droplets of secretions emitted during all expiratory phenomena likely to transport these viruses and come into contact with the respiratory mucosa. The droplets > 5 µm follow the laws of ballistics, those < 5 µm follow Brownian motion and remain suspended in the air. The aerosols of droplets are very heterogeneous whether the subject is healthy or sick. During an infectious period, not all droplets contain viral RNA. If these RNAs are detectable around patients, on surfaces, and in the ambient air at variable distances according to the studies (from 0.5 m to beyond the patient’s room), this is without prejudice to the infectious nature (viability) of the virus and the minimum infectious dose. There is a time lag between the patient’s infectious period and that of RNA detection for both viruses. Subsequently, the inhaled particles must meet the laws of fluid dynamics (filtration) to settle in the respiratory tree. All of this partly explains the contagiousness and the clinical expression of these two viruses from the olfactory cleft to the alveoli. | 9is5vmxu |