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Journal ArticleDOI

Evidences for a possible airborne transmission of SARS-CoV-2 in the COVID-19 crisis

TL;DR: In this article, les donnees preliminaires montrent the presence d'ARN viral dans l’air et sur des surfaces distantes des patients sources, mais aussi plus simplement la parole et la respiration, and donc la composition est majoritairement le fait de particules don le diametre est inferieur ou egal a 1μm.
Abstract: Resume La connaissance des modes de transmission du SARS-CoV-2 est un element fondamental dans l’elaboration des strategies de prevention en sante au travail et en sante publique dans le cadre de la gestion de crise du Covid-19. Le SARS-CoV-2 est retrouve dans les voies aeriennes des patients, y compris asymptomatiques. Les donnees recentes de la litterature suggerent un risque de transmission du SARS-CoV-2 par voie aerienne qui a probablement ete sous-estime, notamment via des aerosols generes par la toux ou les eternuements, mais aussi plus simplement la parole et la respiration, et donc la composition est majoritairement le fait de particules dont le diametre est inferieur ou egal a 1 μm. Des donnees preliminaires montrent la presence d’ARN viral dans l’air et sur des surfaces distantes des patients sources. Cependant, il est important de noter que la detection de materiel genetique viral par RT-PCR ne signifie pas que le virus soit vivant et infectant. En fonction de donnees sur la quantification du pouvoir infectant des aerosols de petite taille et si l’hypothese d’une telle transmission etait confirmee, les indications de port des protections respiratoires de type FFP2 meriteraient d’etre elargies, notamment en milieu de soin.
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Journal ArticleDOI
TL;DR: Findings from rapid reviews conducted regarding PPE for frontline primary care and community care staff are presented, and what circumstances may potentially put HCWs at risk of contagion are presented.
Abstract: The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is now a pandemic with devastating implications for populations, healthcare systems, and economies globally. Many healthcare workers (HCWs), including those in primary and community care settings, may be at increased risk of COVID-19 infection.1 COVID-19 is known to have three modes of transmission: contact (direct or via a fomite, that is, a contaminated surface or object), droplets (from the respiratory tract of an infected individual during coughing or sneezing transmitted onto a mucosal surface or conjunctiva of a susceptible individual), and aerosols (microbes within droplets that remain suspended in air for long periods).2,3 Personal protective equipment (PPE) reduces the transference of droplets or other body fluids onto HCWs’ skin and clothing or directly onto the mucous membranes of the eye or nasopharynx. PPE can also include respiratory protective equipment to protect against aerosol inhalation. Concerns have, however, been raised about PPE provision for preventing COVID-19 in primary and community care staff.4 This is a particularly pressing concern given the anxiety and stress of working in conditions that may pose a threat to health and which can negatively impact the productivity and care provided by HCWs.5 In this article we present findings from rapid reviews conducted regarding PPE for frontline primary care and community care staff, and what circumstances may potentially put HCWs at risk of contagion. Most guidance on PPE appears skewed to secondary care settings (emergency department or inpatient) and focuses mainly on ‘high-risk’ scenarios, for which full aerosol, droplet, and contact PPE (that is, disposable gloves, gown, eye protection, and respirator masks) are recommended. The highest number of contacts in many healthcare settings, however, will be within primary and community environments, including not just general practices but …

12 citations

Journal ArticleDOI
TL;DR: A step forward, although insufficient, towards the recognition of aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its consequences in terms of PPE choice.
Abstract: Sir, On the 6th of April, the WHO provided guidance about personal protective equipment (PPE) for healthcare workers (HCWs) in healthcare settings areas that have reported cases of COVID-19, stating that HCWs working in settings where aerosol-generating procedures were performed should wear a particulate respirator (N95 or FFP2), whereas in their previous recommendations, such masks were restricted to those who actually performed such procedures This a step forward, although insufficient, towards the recognition of aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its consequences in terms of PPE choice COVID-19 has been considered as a droplet transmitted disease by WHO, which means that it can be prevented using surgical masks and hand hygiene However, there is now increasing evidence …

6 citations

Journal ArticleDOI
TL;DR: There are still many grey areas concerning the pathophysiology and treatment of COVID-19 but strong data on its epidemiological characteristics and the clinical expression of this disease is now well described.
References
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Journal ArticleDOI
TL;DR: Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily, which is the seventh member of the family of coronaviruses that infect humans.
Abstract: In December 2019, a cluster of patients with pneumonia of unknown cause was linked to a seafood wholesale market in Wuhan, China. A previously unknown betacoronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily. Different from both MERS-CoV and SARS-CoV, 2019-nCoV is the seventh member of the family of coronaviruses that infect humans. Enhanced surveillance and further investigation are ongoing. (Funded by the National Key Research and Development Program of China and the National Major Project for Control and Prevention of Infectious Disease in China.).

21,455 citations

Journal ArticleDOI
TL;DR: Aerosol and Surface Stability of SARS-CoV-2 In this research letter, investigators report on the stability of Sars-CoVs and the viability of the two virus under experimental conditions.
Abstract: Aerosol and Surface Stability of SARS-CoV-2 In this research letter, investigators report on the stability of SARS-CoV-2 and SARS-CoV-1 under experimental conditions. The viability of the two virus...

7,412 citations

Journal ArticleDOI
01 Apr 2020-Nature
TL;DR: Detailed virological analysis of nine cases of coronavirus disease 2019 (COVID-19) provides proof of active replication of the SARS-CoV-2 virus in tissues of the upper respiratory tract.
Abstract: Coronavirus disease 2019 (COVID-19) is an acute infection of the respiratory tract that emerged in late 20191,2. Initial outbreaks in China involved 13.8% of cases with severe courses, and 6.1% of cases with critical courses3. This severe presentation may result from the virus using a virus receptor that is expressed predominantly in the lung2,4; the same receptor tropism is thought to have determined the pathogenicity—but also aided in the control—of severe acute respiratory syndrome (SARS) in 20035. However, there are reports of cases of COVID-19 in which the patient shows mild upper respiratory tract symptoms, which suggests the potential for pre- or oligosymptomatic transmission6–8. There is an urgent need for information on virus replication, immunity and infectivity in specific sites of the body. Here we report a detailed virological analysis of nine cases of COVID-19 that provides proof of active virus replication in tissues of the upper respiratory tract. Pharyngeal virus shedding was very high during the first week of symptoms, with a peak at 7.11 × 108 RNA copies per throat swab on day 4. Infectious virus was readily isolated from samples derived from the throat or lung, but not from stool samples—in spite of high concentrations of virus RNA. Blood and urine samples never yielded virus. Active replication in the throat was confirmed by the presence of viral replicative RNA intermediates in the throat samples. We consistently detected sequence-distinct virus populations in throat and lung samples from one patient, proving independent replication. The shedding of viral RNA from sputum outlasted the end of symptoms. Seroconversion occurred after 7 days in 50% of patients (and by day 14 in all patients), but was not followed by a rapid decline in viral load. COVID-19 can present as a mild illness of the upper respiratory tract. The confirmation of active virus replication in the upper respiratory tract has implications for the containment of COVID-19. Detailed virological analysis of nine cases of coronavirus disease 2019 (COVID-19) provides proof of active replication of the SARS-CoV-2 virus in tissues of the upper respiratory tract.

5,840 citations

Journal ArticleDOI
TL;DR: Results of an analysis of nasal and throat swabs from 17 patients in Zhuhai, China, who had received a diagnosis of Covid-19 and found SARS-CoV-2 Viral Load in Upper Respiratory Specimens positive.
Abstract: SARS-CoV-2 Viral Load in Upper Respiratory Specimens The authors report results of an analysis of nasal and throat swabs from 17 patients in Zhuhai, China, who had received a diagnosis of Covid-19....

4,236 citations

Journal ArticleDOI
TL;DR: These analyses provide insights into the receptor usage, cell entry, host cell infectivity and animal origin of 2019-nCoV and may help epidemic surveillance and preventive measures against 2019- nCoV.
Abstract: Recently, a novel coronavirus (2019-nCoV) has emerged from Wuhan, China, causing symptoms in humans similar to those caused by severe acute respiratory syndrome coronavirus (SARS-CoV). Since the SARS-CoV outbreak in 2002, extensive structural analyses have revealed key atomic-level interactions between the SARS-CoV spike protein receptor-binding domain (RBD) and its host receptor angiotensin-converting enzyme 2 (ACE2), which regulate both the cross-species and human-to-human transmissions of SARS-CoV. Here, we analyzed the potential receptor usage by 2019-nCoV, based on the rich knowledge about SARS-CoV and the newly released sequence of 2019-nCoV. First, the sequence of 2019-nCoV RBD, including its receptor-binding motif (RBM) that directly contacts ACE2, is similar to that of SARS-CoV, strongly suggesting that 2019-nCoV uses ACE2 as its receptor. Second, several critical residues in 2019-nCoV RBM (particularly Gln493) provide favorable interactions with human ACE2, consistent with 2019-nCoV's capacity for human cell infection. Third, several other critical residues in 2019-nCoV RBM (particularly Asn501) are compatible with, but not ideal for, binding human ACE2, suggesting that 2019-nCoV has acquired some capacity for human-to-human transmission. Last, while phylogenetic analysis indicates a bat origin of 2019-nCoV, 2019-nCoV also potentially recognizes ACE2 from a diversity of animal species (except mice and rats), implicating these animal species as possible intermediate hosts or animal models for 2019-nCoV infections. These analyses provide insights into the receptor usage, cell entry, host cell infectivity and animal origin of 2019-nCoV and may help epidemic surveillance and preventive measures against 2019-nCoV.IMPORTANCE The recent emergence of Wuhan coronavirus (2019-nCoV) puts the world on alert. 2019-nCoV is reminiscent of the SARS-CoV outbreak in 2002 to 2003. Our decade-long structural studies on the receptor recognition by SARS-CoV have identified key interactions between SARS-CoV spike protein and its host receptor angiotensin-converting enzyme 2 (ACE2), which regulate both the cross-species and human-to-human transmissions of SARS-CoV. One of the goals of SARS-CoV research was to build an atomic-level iterative framework of virus-receptor interactions to facilitate epidemic surveillance, predict species-specific receptor usage, and identify potential animal hosts and animal models of viruses. Based on the sequence of 2019-nCoV spike protein, we apply this predictive framework to provide novel insights into the receptor usage and likely host range of 2019-nCoV. This study provides a robust test of this reiterative framework, providing the basic, translational, and public health research communities with predictive insights that may help study and battle this novel 2019-nCoV.

3,527 citations