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上海專家:2-4周大部分患者將被治癒 2個月結束/ 紐約市長記者會未雨綢繆

作者:change?  於 2020-1-26 11:27 發表於 最熱鬧的華人社交網路--貝殼村

通用分類:健康生活|已有8評論



紐約市長:冠狀病毒將「趕早不趕晚」來襲紐約


Mayor de Blasio holds media availability at New York City Office of Emergency Management.

布拉西奧市長周五說:「我們必須根據這樣的假設行事。
紐約—市長比爾·德·布拉西奧(Bill de Blasio)市長周五警告紐約人,這種神秘而致命的冠狀病毒很可能正前往紐約市。
布拉西奧星期五早上說:「我們已經看到了如此迅速的傳播。」 「我們必須根據這樣的假設採取行動,不幸的是,紐約市將比現在早,而不是晚。
市長說,周五早上,市政府官員進行了一次演習,因為有消息傳出,這種病毒已經奪走了至少25人的生命,已經從中國武漢擴散到華盛頓州和芝加哥。
更新:根據州長安德魯·庫莫(Andrew Cuomo)辦公室星期五發布的新聞,周五在紐約州對三人進行了冠狀病毒檢測。第四個人進行了測試,發現沒有感染冠狀病毒。

市長說,紐約很可能會收到病例報告,因為該城市是亞洲以外世界上任何城市中華人人口最多的城市。
de Blasio告訴記者,截至周五早上,紐約市尚未報告任何病例。但他要求在過去兩周內到過武漢並出現流感樣癥狀的任何人立即去看醫生。
否則,市長說:「繼續生活。」

市衛生局長 Barbot說,紐約處於低風險和高準備狀態,但是該病毒需要保持警惕。
據Barbot說,目前尚不清楚該疾病如何在人與人之間傳播,並且還沒有疫苗或確定的治療方法。
「這很令人擔憂,」巴博特說。 「還有很多我們不知道的事情。」

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專家:2-4周大部分患者將被治癒 2個月結束武漢戰役

(原標題:上海醫療救治專家組組長:控制武漢新冠病毒感染的主體戰役應在1個月內結束,2個月內進入尾聲)

除夕之夜,國家徵召,全國數十支醫療隊伍奔赴武漢,是壯舉,是我們國家的體制優勢再次展現——這是今天上海市醫療救治專家組組長張文宏教授發在華山感染微信公眾號中提到的一句話,對於疫情的變化趨勢、熱點問題及相關注意事項,張文宏做了進一步解讀。

張文宏認為,華山醫院感染科感染重症病房徐斌主任醫生和全國數千名的醫生通道奔赴武漢,這種精神無疑給了大家戰勝新冠狀肺炎的必勝信念。

武漢的著名感染病專家華中科技大學附屬同濟醫院感染科主任寧琴教授告訴他,「今晚接緊急任務,同濟醫院漢陽中法新城院區,明天整體搬遷騰出1200張床為收治發熱病人眾志成城一夜騰出'小湯山'。"至此,國家在擊潰」新冠肺炎「的一盤大棋拉開序幕。不出意外,這是2003年成功控制傳染性非典(又稱SARS)的成功經驗將再次在中國上演。

他認為,中國不到一個月獲得了新冠病原體的基因信息,這是科學的勝利;但是控制病毒蔓延,我們還是要回到最古老的辦法,那就是「隔離救治」。就像美國醫學會雜誌在1918年全球大流感的時候所說的,「在這場流行病中,病毒對生命構成嚴重威脅,必須給每個病人實施最完善的隔離治療才能保證人們的安全」。

這幾天,大家的微信圈中充斥著武漢醫院內擁擠的病人,求一床而不得,民眾又因為武漢限行萌生了不安與恐懼。那麼,如今一夜之間,一所1200張的醫院騰出來了,據我所知,如果床位不夠,政府還可能在一周之內再打造一所新的1000多張床位的「武漢小湯山」。這樣,再加上目前武漢已經存在的各家定點醫院,收入所有的不明原因發熱病人已經不成問題。

至此,全國各地醫療志願軍逆向而行進入武漢的「陽謀」已經躍然而出。我們已經不是2003年的中國了。控制武漢新冠病毒感染的主體戰役應該在1個月內結束,2個月內進入尾聲。

英雄逆向而行。百姓怎樣過年?微信圈被鍾南山院士的過年微信刷屏。據說,鍾南山院士呼籲:「解決疫情最快,成本最低的方式就是全中國人民在家隔離兩周,這樣對全國經濟影響最小,對生命健康最有利。強烈建議全中國人民都在家過春節,不要走親訪友。

張文宏進一步說,其實,從分離出新冠病毒之後,就已經知道這是一種以急性感染為表現的病毒性疾病,一般不會出現長期慢性帶毒的情況。對於這樣的病毒,只要足夠時間的隔離,完全覆蓋掉潛伏期(目前所知該病毒最長潛伏期為2周),那麼所有潛在的病人將自動被篩選出進入醫院隔離治療,部分免疫力較強的患者則會自愈。兩周之後,社會將重歸秩序與繁榮。

所以對於武漢,已經採取了限行、停止公交、科普教育等措施,備足了床位與來自全國各地的醫療力量 那麼可以預見,2周內,所有已經發病或者即將發病的患者將會順利進入醫療點救治。經過2-4周治療,大部分患者將被治癒。這樣的話,2個月內結束武漢戰役不是一場夢。

武漢進入緊急狀態,病毒控制在即。2周內發病病例數勢必會出現下降。但是,剛剛進入輸入性疾病早期的全國各地呢?能否遵從「在家兩周」,過個「健康春節」呢?估計很難,不到最後關頭,能夠遵從健康建議的人只是少數,君不見控煙行動從未真正奏效嗎?那麼其他全國各地減少活動的困難可想而知。

「從全國各地英雄往武漢逆向奔襲之際,我們相信武漢戰役從一開始就是從勝利走向勝利。反之,我們下一步的目光更應該投向武漢之外的城市,我們決不允許武漢發生的新冠傳播和爆發再上演一次。」張文宏說。

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中國時評作家王亞軍(王歪嘴)剛剛為武漢募捐物資就被湖北XX威脅

最後一段話 真的讓人鼻酸 如果哪天中國人民起來反抗政府了 相信各界都會給予支持 畢竟你們的政府 太霸道了 對國外的人霸道就算了 還時常欺負自己人民?

看了這個視頻真的很心酸,淚在眼眶打轉,正義善舉反而被打擊,老哥一定要保重,國人都應該向您學習

看了好難過,真的。我自己在家族群發些境外的視頻,我表弟說要舉報我,我表哥逼我退群還說我造謠,再繼續傳播就抓我。哎

這有來自香港同胞的直持 都21世紀了,還有這麼一個無恥、流氓政府⋯

共產黨根本心思不在控制疫情上,到現在還忙著維穩

我一個最底層最底層都因言被喝過茶,何況你們這些有影響力的了。

他應該自豪,當收到老共的威脅時,就証明他是頂天立地的人





高興

感動

同情

搞笑

難過

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支持

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發表評論 評論 (8 個評論)

回復 change? 2020-1-26 11:54
novel coronavirus, designated as 2019-nCoV, emerged in Wuhan, China, at the end of 2019. As of January 24, 2020, at least 830 cases had been diagnosed in nine countries: China, Thailand, Japan, South Korea, Singapore, Vietnam, Taiwan, Nepal, and the United States. Twenty-six fatalities occurred, mainly in patients who had serious underlying illness.1 Although many details of the emergence of this virus — such as its origin and its ability to spread among humans — remain unknown, an increasing number of cases appear to have resulted from human-to-human transmission. Given the severe acute respiratory syndrome coronavirus (SARS-CoV) outbreak in 2002 and the Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak in 2012,2 2019-nCoV is the third coronavirus to emerge in the human population in the past two decades — an emergence that has put global public health institutions on high alert.

China responded quickly by informing the World Health Organization (WHO) of the outbreak and sharing sequence information with the international community after discovery of the causative agent. The WHO responded rapidly by coordinating diagnostics development; issuing guidance on patient monitoring, specimen collection, and treatment; and providing up-to-date information on the outbreak.3 Several countries in the region as well as the United States are screening travelers from Wuhan for fever, aiming to detect 2019-nCoV cases before the virus spreads further. Updates from China, Thailand, Korea, and Japan indicate that the disease associated with 2019-nCoV appears to be relatively mild as compared with SARS and MERS.

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Table 1.

Pathogenicity and Transmissibility Characteristics of Recently Emerged Viruses in Relation to Outbreak Containment.
Figure 1.

Surveillance Pyramid and Its Relation to Outbreak Containment.
After initial reports of a SARS-like virus emerging in Wuhan, it appears that 2019-nCoV may be less pathogenic than MERS-CoV and SARS-CoV (see table). However, the virus』s emergence raises an important question: What is the role of overall pathogenicity in our ability to contain emerging viruses, prevent large-scale spread, and prevent them from causing a pandemic or becoming endemic in the human population? Important questions regarding any emerging virus are, What is the shape of the disease pyramid? What proportion of infected people develop disease? And what proportion of those seek health care? These three questions inform the classic surveillance pyramid (see diagram).4 Emerging coronaviruses raise an additional question: How widespread is the virus in its reservoir? Currently, epidemiologic data that would allow us to draw this pyramid are largely unavailable (see diagram).

Clearly, efficient human-to-human transmission is a requirement for large-scale spread of this emerging virus. However, the severity of disease is an important indirect factor in a virus』s ability to spread, as well as in our ability to identify those infected and to contain it — a relationship that holds true whether an outbreak results from a single spillover event (SARS-CoV) or from repeated crossing of the species barrier (MERS-CoV).

If infection does not cause serious disease, infected people probably will not end up in health care centers. Instead, they will go to work and travel, thereby potentially spreading the virus to their contacts, possibly even internationally. Whether subclinical or mild disease from 2019-nCoV is also associated with a reduced risk of virus spread remains to be determined.

Much of our thinking regarding the relationship between transmissibility and pathogenicity of respiratory viruses has been influenced by our understanding of influenza A virus: the change in receptor specificity necessary for efficient human-to-human transmission of avian influenza viruses leads to a tropism shift from the lower to the upper respiratory tract, resulting in a lower disease burden. Two primary — and recent — examples are the pandemic H1N1 virus and the avian influenza H7N9 virus. Whereas the pandemic H1N1 virus — binding to receptors in the upper respiratory tract — caused relatively mild disease and became endemic in the population, the H7N9 virus — binding to receptors in the lower respiratory tract — has a case-fatality rate of approximately 40% and has so far resulted in only a few small clusters of human-to-human transmission.

It is tempting to assume that this association would apply to other viruses as well, but such a similarity is not a given: two coronaviruses that use the same receptor (ACE2) — NL63 and SARS-CoV — cause disease of different severity. Whereas NL63 usually causes mild upper respiratory tract disease and is endemic in the human population, SARS-CoV induced severe lower respiratory tract disease with a case-fatality rate of about 11% (see table). SARS-CoV was eventually contained by means of syndromic surveillance, isolation of patients, and quarantine of their contacts. Thus, disease severity is not necessarily linked to transmission efficiency.

Even if a virus causes subclinical or mild disease in general, some people may be more susceptible and end up seeking care. The majority of SARS-CoV and MERS-CoV cases were associated with nosocomial transmission in hospitals,5 resulting at least in part from the use of aerosol-generating procedures in patients with respiratory disease. In particular, nosocomial super-spreader events appear to have driven large outbreaks within and between health care settings. For example, travel from Hong Kong to Toronto by one person with SARS-CoV resulted in 128 SARS cases in a local hospital. Similarly, the introduction of a single patient with MERS-CoV from Saudi Arabia into the South Korean health care system resulted in 186 MERS cases.

The substantial involvement of nosocomial transmission in both SARS-CoV and MERS-CoV outbreaks suggests that such transmission is a serious risk with other newly emerging respiratory coronaviruses. In addition to the vulnerability of health care settings to outbreaks of emerging coronaviruses, hospital populations are at significantly increased risk for complications from infection. Age and coexisting conditions (such as diabetes or heart disease) are independent predictors of adverse outcome in SARS-CoV and MERS-CoV. Thus, emerging viruses that may go undetected because of a lack of severe disease in healthy people can pose significant risk to vulnerable populations with underlying medical conditions.

A lack of severe disease manifestations affects our ability to contain the spread of the virus. Identification of chains of transmission and subsequent contact tracing are much more complicated if many infected people remain asymptomatic or mildly symptomatic (assuming that these people are able to transmit the virus). More pathogenic viruses that transmit well between humans can generally be contained effectively through syndromic (fever) surveillance and contact tracing, as exemplified by SARS-CoV and, more recently, Ebola virus. Although containment of the ongoing Ebola virus outbreak in the Democratic Republic of Congo is complicated by violent conflict, all previous outbreaks were contained through identification of cases and tracing of contacts, despite the virus』s efficient person-to-person transmission.

We currently do not know where 2019-nCoV falls on the scale of human-to-human transmissibility. But it is safe to assume that if this virus transmits efficiently, its seemingly lower pathogenicity as compared with SARS, possibly combined with super-spreader events in specific cases, could allow large-scale spread. In this manner, a virus that poses a low health threat on the individual level can pose a high risk on the population level, with the potential to cause disruptions of global public health systems and economic losses. This possibility warrants the current aggressive response aimed at tracing and diagnosing every infected patient and thereby breaking the transmission chain of 2019-nCoV.

Epidemiologic information on the pathogenicity and transmissibility of this virus obtained by means of molecular detection and serosurveillance is needed to fill in the details in the surveillance pyramid and guide the response to this outbreak. Moreover, the propensity of novel coronaviruses to spread in health care centers indicates a need for peripheral health care facilities to be on standby to identify potential cases as well. In addition, increased preparedness is needed at animal markets and other animal facilities, while the possible source of this emerging virus is being investigated. If we are proactive in these ways, perhaps we will never have to discover the true epidemic or pandemic potential of 2019-nCoV.

Disclosure forms provided by the authors are available at NEJM.org.

This article was published on January 24, 2020, at NEJM.org.

Author Affiliations
From the Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT (V.J.M., N.D., E.W.); and the Department of Viroscience, Erasmus Medical Center, Rotterdam, the Netherlands (M.K., D.R.).
回復 change? 2020-1-26 11:56
A Novel Coronavirus from Patients with Pneumonia in China, 2019
List of authors.
Na Zhu, Ph.D., Dingyu Zhang, M.D., Wenling Wang, Ph.D., Xinwang Li, M.D., Bo Yang, M.S., Jingdong Song, Ph.D., Xiang Zhao, Ph.D., Baoying Huang, Ph.D., Weifeng Shi, Ph.D., Roujian Lu, M.D., Peihua Niu, Ph.D., Faxian Zhan, Ph.D., et al., for the China Novel Coronavirus Investigating and Research Team
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 another 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.)

Emerging and reemerging pathogens are global challenges for public health.1 Coronaviruses are enveloped RNA viruses that are distributed broadly among humans, other mammals, and birds and that cause respiratory, enteric, hepatic, and neurologic diseases.2,3 Six coronavirus species are known to cause human disease.4 Four viruses — 229E, OC43, NL63, and HKU1 — are prevalent and typically cause common cold symptoms in immunocompetent individuals.4 The two other strains — severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) — are zoonotic in origin and have been linked to sometimes fatal illness.5 SARS-CoV was the causal agent of the severe acute respiratory syndrome outbreaks in 2002 and 2003 in Guangdong Province, China.6-8 MERS-CoV was the pathogen responsible for severe respiratory disease outbreaks in 2012 in the Middle East.9 Given the high prevalence and wide distribution of coronaviruses, the large genetic diversity and frequent recombination of their genomes, and increasing human–animal interface activities, novel coronaviruses are likely to emerge periodically in humans owing to frequent cross-species infections and occasional spillover events.5,10

In late December 2019, several local health facilities reported clusters of patients with pneumonia of unknown cause that were epidemiologically linked to a seafood and wet animal wholesale market in Wuhan, Hubei Province, China.11 On December 31, 2019, the Chinese Center for Disease Control and Prevention (China CDC) dispatched a rapid response team to accompany Hubei provincial and Wuhan city health authorities and to conduct an epidemiologic and etiologic investigation. We report the results of this investigation, identifying the source of the pneumonia clusters, and describe a novel coronavirus detected in patients with pneumonia whose specimens were tested by the China CDC at an early stage of the outbreak. We also describe clinical features of the pneumonia in two of these patients.

Methods
VIRAL DIAGNOSTIC METHODS
Four lower respiratory tract samples, including bronchoalveolar-lavage fluid, were collected from patients with pneumonia of unknown cause who were identified in Wuhan on December 21, 2019, or later and who had been present at the Huanan Seafood Market close to the time of their clinical presentation. Seven bronchoalveolar-lavage fluid specimens were collected from patients in Beijing hospitals with pneumonia of known cause to serve as control samples. Extraction of nucleic acids from clinical samples (including uninfected cultures that served as negative controls) was performed with a High Pure Viral Nucleic Acid Kit, as described by the manufacturer (Roche). Extracted nucleic acid samples were tested for viruses and bacteria by polymerase chain reaction (PCR), using the RespiFinderSmart22kit (PathoFinder BV) and the LightCycler 480 real-time PCR system, in accordance with manufacturer instructions.12 Samples were analyzed for 22 pathogens (18 viruses and 4 bacteria) as detailed in the Supplementary Appendix. In addition, unbiased, high-throughput sequencing, described previously,13 was used to discover microbial sequences not identifiable by the means described above. A real-time reverse trans**tion PCR (RT-PCR) assay was used to detect viral RNA by targeting a consensus RdRp region of pan β-CoV, as described in the Supplementary Appendix.

ISOLATION OF VIRUS
Bronchoalveolar-lavage fluid samples were collected in sterile cups to which virus transport medium was added. Samples were then centrifuged to remove cellular debris. The supernatant was inoculated on human airway epithelial cells,14 which had been obtained from airway specimens resected from patients undergoing surgery for lung cancer and were confirmed to be special-pathogen-free by NGS.13

Human airway epithelial cells were expanded on plastic substrate to generate passage-1 cells and were subsequently plated at a density of 2.5×105 cells per well on permeable Transwell-COL (12-mm diameter) supports. Human airway epithelial cell cultures were generated in an air–liquid interface for 4 to 6 weeks to form well-differentiated, polarized cultures resembling in vivo pseudostratified mucociliary epithelium.13

Prior to infection, apical surfaces of the human airway epithelial cells were washed three times with phosphate-buffered saline; 150 μl of supernatant from bronchoalveolar-lavage fluid samples was inoculated onto the apical surface of the cell cultures. After a 2-hour incubation at 37°C, unbound virus was removed by washing with 500 μl of phosphate-buffered saline for 10 minutes; human airway epithelial cells were maintained in an air–liquid interface incubated at 37°C with 5% carbon dioxide. Every 48 hours, 150 μl of phosphate-buffered saline was applied to the apical surfaces of the human airway epithelial cells, and after 10 minutes of incubation at 37°C the samples were harvested. Pseudostratified mucociliary epithelium cells were maintained in this environment; apical samples were passaged in a 1:3 diluted vial stock to new cells. The cells were monitored daily with light microscopy, for cytopathic effects, and with RT-PCR, for the presence of viral nucleic acid in the supernatant. After three passages, apical samples and human airway epithelial cells were prepared for transmission electron microscopy.

TRANSMISSION ELECTRON MICROSCOPY
Supernatant from human airway epithelial cell cultures that showed cytopathic effects was collected, inactivated with 2% paraformaldehyde for at least 2 hours, and ultracentrifuged to sediment virus particles. The enriched supernatant was negatively stained on film-coated grids for examination. Human airway epithelial cells showing cytopathic effects were collected and fixed with 2% paraformaldehyde–2.5% glutaraldehyde and were then fixed with 1% osmium tetroxide dehydrated with grade ethanol embedded with PON812 resin. Sections (80 nm) were cut from resin block and stained with uranyl acetate and lead citrate, separately. The negative stained grids and ultrathin sections were observed under transmission electron microscopy.

VIRAL GENOME SEQUENCING
RNA extracted from bronchoalveolar-lavage fluid and culture supernatants was used as a template to clone and sequence the genome. We used a combination of Illumina sequencing and nanopore sequencing to characterize the virus genome. Sequence reads were assembled into contig maps (a set of overlapping DNA segments) with the use of CLC Genomics software, version 4.6.1 (CLC Bio). Specific primers were subsequently designed for PCR, and 5′- or 3′- RACE (rapid amplification of cDNA ends) was used to fill genome gaps from conventional Sanger sequencing. These PCR products were purified from gels and sequenced with a BigDye Terminator v3.1 Cycle Sequencing Kit and a 3130XL Genetic Analyzer, in accordance with the manufacturers』 instructions.

Multiple-sequence alignment of the 2019-nCoV and reference sequences was performed with the use of Muscle. Phylogenetic analysis of the complete genomes was performed with RAxML (13) with 1000 bootstrap replicates and a general time-reversible model used as the nucleotide substitution model.

Results
PATIENTS
Figure 1.

Chest Radiographs.
Three adult patients presented with severe pneumonia and were admitted to a hospital in Wuhan on December 27, 2019. Patient 1 was a 49-year-old woman, Patient 2 was a 61-year-old man, and Patient 3 was a 32-year-old man. Clinical profiles were available for Patients 1 and 2. Patient 1 reported having no underlying chronic medical conditions but reported fever (temperature, 37°C to 38°C) and cough with chest discomfort on December 23, 2019. Four days after the onset of illness, her cough and chest discomfort worsened, but the fever was reduced; a diagnosis of pneumonia was based on computed tomographic (CT) scan. Her occupation was retailer in the seafood wholesale market. Patient 2 initially reported fever and cough on December 20, 2019; respiratory distress developed 7 days after the onset of illness and worsened over the next 2 days (see chest radiographs, Figure 1), at which time mechanical ventilation was started. He had been a frequent visitor to the seafood wholesale market. Patients 1 and 3 recovered and were discharged from the hospital on January 16, 2020. Patient 2 died on January 9, 2020. No biopsy specimens were obtained.

DETECTION AND ISOLATION OF A NOVEL CORONAVIRUS
Three bronchoalveolar-lavage samples were collected from Wuhan Jinyintan Hospital on December 30, 2019. No specific pathogens (including HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1) were detected in clinical specimens from these patients by the RespiFinderSmart22kit. RNA extracted from bronchoalveolar-lavage fluid from the patients was used as a template to clone and sequence a genome using a combination of Illumina sequencing and nanopore sequencing. More than 20,000 viral reads from individual specimens were obtained, and most contigs matched to the genome from lineage B of the genus betacoronavirus — showing more than 85% identity with a bat SARS-like CoV (bat-SL-CoVZC45, MG772933.1) genome published previously. Positive results were also obtained with use of a real-time RT-PCR assay for RNA targeting to a consensus RdRp region of pan β-CoV (although the cycle threshold value was higher than 34 for detected samples). Virus isolation from the clinical specimens was performed with human airway epithelial cells and Vero E6 and Huh-7 cell lines. The isolated virus was named 2019-nCoV.

Figure 2.

Cytopathic Effects in Human Airway Epithelial Cell Cultures after Inoculation with 2019-nCoV.
To determine whether virus particles could be visualized in 2019-nCoV–infected human airway epithelial cells, mock-infected and 2019-nCoV–infected human airway epithelial cultures were examined with light microscopy daily and with transmission electron microscopy 6 days after inoculation. Cytopathic effects were observed 96 hours after inoculation on surface layers of human airway epithelial cells; a lack of cilium beating was seen with light microcopy in the center of the focus (Figure 2). No specific cytopathic effects were observed in the Vero E6 and Huh-7 cell lines until 6 days after inoculation.

Figure 3.

Visualization of 2019-nCoV with Transmission Electron Microscopy.
Electron micrographs of negative-stained 2019-nCoV particles were generally spherical with some pleomorphism (Figure 3). Diameter varied from about 60 to 140 nm. Virus particles had quite distinctive spikes, about 9 to 12 nm, and gave virions the appearance of a solar corona. Extracellular free virus particles and inclusion bodies filled with virus particles in membrane-bound vesicles in cytoplasm were found in the human airway epithelial ultrathin sections. This observed morphology is consistent with the Coronaviridae family.

To further characterize the virus, de novo sequences of 2019-nCoV genome from clinical specimens (bronchoalveolar-lavage fluid) and human airway epithelial cell virus isolates were obtained by Illumina and nanopore sequencing. The novel coronavirus was identified from all three patients. Two nearly full-length coronavirus sequences were obtained from bronchoalveolar-lavage fluid (BetaCoV/Wuhan/IVDC-HB-04/2020, BetaCoV/Wuhan/IVDC-HB-05/2020|EPI_ISL_402121), and one full-length sequence was obtained from a virus isolated from a patient (BetaCoV/Wuhan/IVDC-HB-01/2020|EPI_ISL_402119). Complete genome sequences of the three novel coronaviruses were submitted to GASAID (BetaCoV/Wuhan/IVDC-HB-01/2019, accession ID: EPI_ISL_402119; BetaCoV/Wuhan/IVDC-HB-04/2020, accession ID: EPI_ISL_402120; BetaCoV/Wuhan/IVDC-HB-05/2019, accession ID: EPI_ISL_402121) and have a 86.9% nucleotide sequence identity to a previously published bat SARS-like CoV (bat-SL-CoVZC45, MG772933.1) genome. The three 2019-nCoV genomes clustered together and formed an independent subclade within the sarbecovirus subgenus, which shows the typical betacoronavirus organization: a 5′ untranslated region (UTR), replicase complex (orf1ab), S gene, E gene, M gene, N gene, 3′ UTR, and several unidentified nonstructural open reading frames.

Figure 4.

Phylogenetic Analysis of 2019-nCoV and Other Betacoronavirus Genomes in the Orthocoronavirinae Subfamily.
Although 2019-nCoV is similar to some betacoronaviruses detected in bats (Figure 4), it is distinct from SARS-CoV and MERS-CoV. The three 2019-nCoV coronaviruses from Wuhan, together with two bat-derived SARS-like strains, ZC45 and ZXC21, form a distinct clade in lineage B of the subgenus sarbecovirus. SARS-CoV strains from humans and genetically similar SARS-like coronaviruses from bats collected from southwestern China formed another clade within the subgenus sarbecovirus. Since the sequence identity in conserved replicase domains (ORF 1ab) is less than 90% between 2019-nCoV and other members of betacoronavirus, the 2019-nCoV — the likely causative agent of the viral pneumonia in Wuhan — is a novel betacoronavirus belonging to the sarbecovirus subgenus of Coronaviridae family.

Discussion
We report a novel CoV (2019-nCoV) that was identified in hospitalized patients in Wuhan, China, in December 2019 and January 2020. Evidence for the presence of this virus includes identification in bronchoalveolar-lavage fluid in three patients by whole-genome sequencing, direct PCR, and culture. The illness likely to have been caused by this CoV was named 「novel coronavirus-infected pneumonia」 (NCIP). Complete genomes were submitted to GASAID. Phylogenetic analysis revealed that 2019-nCoV falls into the genus betacoronavirus, which includes coronaviruses (SARS-CoV, bat SARS-like CoV, and others) discovered in humans, bats, and other wild animals.15 We report isolation of the virus and the initial des**tion of its specific cytopathic effects and morphology.

Molecular techniques have been used successfully to identify infectious agents for many years. Unbiased, high-throughput sequencing is a powerful tool for the discovery of pathogens.14,16 Next-generation sequencing and bioinformatics are changing the way we can respond to infectious disease outbreaks, improving our understanding of disease occurrence and transmission, accelerating the identification of pathogens, and promoting data sharing. We describe in this report the use of molecular techniques and unbiased DNA sequencing to discover a novel betacoronavirus that is likely to have been the cause of severe pneumonia in three patients in Wuhan, China.

Although establishing human airway epithelial cell cultures is labor intensive, they appear to be a valuable research tool for analysis of human respiratory pathogens.14 Our study showed that initial propagation of human respiratory secretions onto human airway epithelial cell cultures, followed by transmission electron microscopy and whole genome sequencing of culture supernatant, was successfully used for visualization and detection of new human coronavirus that can possibly elude identification by traditional approaches.

Further development of accurate and rapid methods to identify unknown respiratory pathogens is still needed. On the basis of analysis of three complete genomes obtained in this study, we designed several specific and sensitive assays targeting ORF1ab, N, and E regions of the 2019-nCoV genome to detect viral RNA in clinical specimens. The primer sets and standard operating procedures have been shared with the World Health Organization and are intended for surveillance and detection of 2019-nCoV infection globally and in China. More recent data show 2019-nCoV detection in 830 persons in China.17

Although our study does not fulfill Koch』s postulates, our analyses provide evidence implicating 2019-nCoV in the Wuhan outbreak. Additional evidence to confirm the etiologic significance of 2019-nCoV in the Wuhan outbreak include identification of a 2019-nCoV antigen in the lung tissue of patients by immunohistochemical analysis, detection of IgM and IgG antiviral antibodies in the serum samples from a patient at two time points to demonstrate seroconversion, and animal (monkey) experiments to provide evidence of pathogenicity. Of critical importance are epidemiologic investigations to characterize transmission modes, reproduction interval, and clinical spectrum resulting from infection to inform and refine strategies that can prevent, control, and stop the spread of 2019-nCoV.

This work was supported by grants from the National Key Research and Development Program of China (2016YFD0500301) and the National Major Project for Control and Prevention of Infectious Disease in China (2018ZX10101002).

Drs. Zhu, Zhang, W. Wang, Li, and Yang contributed equally to this article.

This article was published on January 24, 2020, at NEJM.org.

We thank Dr. Zhongjie Li, Dr. Guangxue He, Dr. Lance Rodewald, Yu Li, Fei Ye, Li Zhao, Weimin Zhou, Jun Liu, Yao Meng, Huijuan Wang, and many staff members at the China CDC for their contributions and assistance in this preparation and submission of an earlier version of the manus**t.

Author Affiliations
From the MHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (N.Z., W.W., J.S., X.Z., B.H., R.L., P.N., X.M., D.W., W.X., G.W., G.F.G., W.T.), and the Department of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University (X.L.) — both in Beijing; Wuhan Jinyintan Hospital (D.Z.), the Division for Viral Disease Detection, Hubei Provincial Center for Disease Control and Prevention (B.Y., F.Z.), and the Center for Biosafety Mega-Science, Chinese Academy of Sciences (W.T.) — all in Wuhan; and the Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China (W.S.).

Address reprint requests to Dr. Tan at the NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, China CDC, 155 Changbai Road, Changping District, Beijing 102206, China; or at tanwj@ivdc.chinacdc.cn, Dr. Gao at the National Institute for Viral Disease Control and Prevention, China CDC, Beijing 102206, China, or at gaof@im.ac.cn, or Dr. Wu at the NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, China CDC, Beijing 102206, China, or at wugz@ivdc.chinacdc.cn.
回復 change? 2020-1-26 11:58
Another Decade, Another Coronavirus
List of authors.
Stanley Perlman, M.D., Ph.D.

or the third time in as many decades, a zoonotic coronavirus has crossed species to infect human populations. This virus, provisionally called 2019-nCoV, was first identified in Wuhan, China, in persons exposed to a seafood or wet market. The rapid response of the Chinese public health, clinical, and scientific communities facilitated recognition of the clinical disease and initial understanding of the epidemiology of the infection. First reports indicated that human-to-human transmission was limited or nonexistent, but we now know that such transmission occurs, although to what extent remains unknown. Like outbreaks caused by two other pathogenic human respiratory coronaviruses (severe acute respiratory syndrome coronavirus [SARS-CoV] and Middle East respiratory syndrome coronavirus [MERS-CoV]), 2019-nCoV causes respiratory disease that is often severe.1 As of January 24, 2020, there were more than 800 reported cases, with a mortality rate of 3% (https://promedmail.org/. opens in new tab).

As now reported in the Journal, Zhu et al.2 have identified and characterized 2019-nCoV. The viral genome has been sequenced, and these results in conjunction with other reports show that it is 75 to 80% identical to the SARS-CoV and even more closely related to several bat coronaviruses.3 It can be propagated in the same cells that are useful for growing SARS-CoV and MERS-CoV, but notably, 2019-nCoV grows better in primary human airway epithelial cells than in standard tissue-culture cells, unlike SARS-CoV or MERS-CoV. Identification of the virus will allow the development of reagents to address key unknowns about this new coronavirus infection and guide the development of antiviral therapies. First, knowing the sequence of the genome facilitates the development of sensitive quantitative reverse-trans**tase–polymerase-chain-reaction assays to rapidly detect the virus. Second, the development of serologic assays will allow assessment of the prevalence of the infection in humans and in potential zoonotic sources of the virus in wet markets and other settings. These reagents will also be useful for assessing whether the human infection is more widespread than originally thought, since wet markets are present throughout China. Third, having the virus in hand will spur efforts to develop antiviral therapies and vaccines, as well as experimental animal models.

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Much still needs to be learned about this infection. Most important, the extent of interhuman transmission and the spectrum of clinical disease need to be determined. Transmission of SARS-CoV and MERS-CoV occurred to a large extent by means of superspreading events.4,5 Superspreading events have been implicated in 2019-nCoV transmission, but their relative importance is unknown. Both SARS-CoV and MERS-CoV infect intrapulmonary epithelial cells more than cells of the upper airways.4,6 Consequently, transmission occurs primarily from patients with recognized illness and not from patients with mild, nonspecific signs. It appears that 2019-nCoV uses the same cellular receptor as SARS-CoV (human angiotensin-converting enzyme 2 [hACE2]),3 so transmission is expected only after signs of lower respiratory tract disease develop. SARS-CoV mutated over the 2002–2004 epidemic to better bind to its cellular receptor and to optimize replication in human cells, enhancing virulence.7 Adaptation readily occurs because coronaviruses have error-prone RNA-dependent RNA polymerases, making mutations and recombination events frequent. By contrast, MERS-CoV has not mutated substantially to enhance human infectivity since it was detected in 2012.8

It is likely that 2019-nCoV will behave more like SARS-CoV and further adapt to the human host, with enhanced binding to hACE2. Consequently, it will be important to obtain as many temporally and geographically unrelated clinical isolates as possible to assess the degree to which the virus is mutating and to assess whether these mutations indicate adaptation to the human host. Furthermore, if 2019-nCoV is similar to SARS-CoV, the virus will spread systemically.9 Obtaining patient samples at autopsy will help elucidate the pathogenesis of the infection and modify therapeutic interventions rationally. It will also help validate results obtained from experimental infections of laboratory animals.

A second key question is identification of the zoonotic origin of the virus. Given its close similarity to bat coronaviruses, it is likely that bats are the primary reservoir for the virus. SARS-CoV was transmitted to humans from exotic animals in wet markets, whereas MERS-CoV is transmitted from camels to humans.10 In both cases, the ancestral hosts were probably bats. Whether 2019-nCoV is transmitted directly from bats or by means of intermediate hosts is important to understand and will help define zoonotic transmission patterns.

A striking feature of the SARS epidemic was that fear played a major role in the economic and social consequences. Although specific anticoronaviral therapies are still in development, we now know much more about how to control such infections in the community and hospitals, which should alleviate some of this fear. Transmission of 2019-nCoV probably occurs by means of large droplets and contact and less so by means of aerosols and fomites, on the basis of our experience with SARS-CoV and MERS-CoV.4,5 Public health measures, including quarantining in the community as well as timely diagnosis and strict adherence to universal precautions in health care settings, were critical in controlling SARS and MERS. Institution of similar measures will be important and, it is hoped, successful in reducing the transmission of 2019-nCoV.
回復 change? 2020-1-26 12:17
摘要
2019年12月,一群原因不明的肺炎患者與中國武漢的海鮮批發市場有關。通過對肺炎患者樣本進行無偏測序,發現了先前未知的β冠狀病毒。人類氣道上皮細胞被用於分離一種新型冠狀病毒,命名為2019-nCoV,該冠狀病毒在sarbecovirus亞屬Orthocoronavirinae亞科內形成了另一個進化枝。與MERS-CoV和SARS-CoV不同的是,2019-nCoV是感染人類的​​冠狀病毒家族的第七個成員。加強監視和進一步調查正在進行中。 (由中國國家重點研究發展計劃和中國國家傳染病預防控制重大項目資助。)

新興和重新出現的病原體是公共衛生面臨的全球挑戰。1冠狀病毒是被包膜的RNA病毒,廣泛分佈於人類,其他哺乳動物和鳥類中,並引起呼吸系統,腸道,肝臟和神經系統疾病。2,3已知六種冠狀病毒引起人類疾病。4四種病毒-229E,OC43,NL63和HKU1-普遍存在,通常會在具有免疫能力的個體中引起普通感冒癥狀。4其他兩種病毒株-嚴重急性呼吸綜合征冠狀病毒(SARS-CoV)和中東呼吸道病毒綜合征冠狀病毒(MERS-CoV)—起源於人畜共患病,有時與致命疾病相關。5SARS-CoV是2002年和2003年中國廣東省嚴重急性呼吸道綜合症暴發的病因。6-8MERS -冠狀病毒是導致2012年中東地區嚴重呼吸道疾病暴發的病原體。9由於冠狀病毒的高流行和廣泛分佈,大規模的基因潛水由於其頻繁發生的跨物種感染和偶然的外溢事件,其基因組的稀有性和頻繁的重組以及人類與動物之間的界面活動不斷增加,新型冠狀病毒很可能會定期在人體內出現。5,10

2019年12月下旬,幾家當地衛生機構報告了一群原因不明的肺炎,這些流行病學與中國湖北省武漢市的海鮮和濕動物批發市場有關.11 2019年12月31日,中國疾病預防控制中心疾病預防控制中心派出了一個快速反應小組,陪同湖北省和武漢市衛生部門開展流行病學和病因學調查。我們報告了這項調查的結果,確定了肺炎簇的來源,並描述了在疾病爆發早期由中國疾病預防控制中心檢測其標本的肺炎患者中檢測到的新型冠狀病毒。我們還描述了其中兩名患者的肺炎的臨床特徵。

方法
病毒診斷方法
從2019年12月21日或以後在武漢發現的,原因不明的肺炎患者中收集了四個下呼吸道樣本,包括支氣管肺泡灌洗液,這些樣本在他們離開時已出現在華南海鮮市場臨床表現。從北京醫院因已知原因引起的肺炎患者中收集了七個支氣管肺泡灌洗液樣本作為對照樣本。如製造商(Roche)所述,用高純病毒核酸試劑盒從臨床樣品(包括用作陰性對照的未感染培養物)中提取核酸。根據製造商的說明,使用RespiFinderSmart22kit(PathoFinder BV)和LightCycler 480實時PCR系統,通過聚合酶鏈反應(PCR)對提取的核酸樣品進行病毒和細菌測試.12根據分析,對樣品中的22種病原體進行了分析(18病毒和4種細菌),如補充附錄中所述。此外,先前所述的無偏,高通量測序[13]用於發現無法通過上述方法鑒定的微生物序列。如補充附錄中所述,通過靶向泛β-CoV的共有RdRp區,使用實時逆轉錄PCR(RT-PCR)分析來檢測病毒RNA。

病毒隔離
在無菌杯中收集支氣管肺泡灌洗液樣品,並向其中加入病毒轉運介質。然後將樣品離心以除去細胞碎片。將上清液接種在人氣道上皮細胞上,14這是從接受肺癌手術的患者切除的氣道標本中獲得的,並經NGS確認不含特殊病原體。13

將人氣道上皮細胞在塑料基質上擴增以產生第1代細胞,然後以每孔2.5×105個細胞的密度接種在可滲透的Transwell-COL(直徑12毫米)支持物上。人氣道上皮細胞培養物在氣液界面上產生4到6周,形成分化良好的極化培養物,類似於體內假復層粘膜纖毛上皮。13

感染前,用磷酸鹽緩衝液將人氣道上皮細胞的頂端表面清洗三遍;將150μl來自支氣管肺泡灌洗液樣品的上清液接種到細胞培養物的頂表面上。在37°C下孵育2小時后,用500μl磷酸鹽緩衝液洗滌10分鐘以去除未結合的病毒;人的氣道上皮細胞保持在氣液界面,並在37°C與5%的二氧化碳溫育。每48小時,將150μl磷酸鹽緩衝鹽水施加到人氣道上皮細胞的頂表面,並在37°C孵育10分鐘后,收集樣品。偽分層的粘膜纖毛上皮細胞保持在這種環境中。頂端樣品以1:3稀釋的小瓶原液傳代至新細胞。每天用光學顯微鏡監測細胞的細胞病變作用,並用RT-PCR監測上清液中病毒核酸的存在。經過三次傳代,準備了頂端樣品和人氣道上皮細胞用於透射電子顯微鏡。

透射電子顯微鏡
收集顯示出細胞病變作用的人氣道上皮細胞培養物的上清液,用2%多聚甲醛將其滅活至少2小時,然後超速離心以沉澱病毒顆粒。將富集的上清液在膜包被的格柵上進行負染以進行檢查。收集顯示出細胞病變作用的人氣道上皮細胞,並用2%多聚甲醛–2.5%戊二醛固定,然後用1%四氧化固定,其中四氧化經PON812樹脂包埋的等級乙醇脫水。從樹脂塊上切下切片(80nm),並分別用乙酸鈾醯和檸檬酸鉛染色。在透射電子顯微鏡下觀察到負染色的網格和超薄切片。

病毒基因組測序
從支氣管肺泡灌洗液和培養上清液中提取的RNA被用作模板來克隆和測序基因組。我們結合使用Illumina測序和納米孔測序來表徵病毒基因組。使用CLC Genomics軟體4.6.1版(CLC Bio)將序列讀數組裝成重疊群圖(一組重疊的DNA片段)。隨後設計了特異性引物用於PCR,並使用5'-或3'-RACE(cDNA末端的快速擴增)填補了傳統Sanger測序的基因組空白。這些PCR產物已從凝膠中純化,並按照製造商的說明使用BigDye Terminator v3.1循環測序試劑盒和3130XL基因分析儀進行測序。

使用Muscle對2019-nCoV和參考序列進行多序列比對。用具有1000個自舉重複的RAxML(13)和完整的時間可逆模型作為核苷酸取代模型,進行了完整基因組的系統發育分析。

結果
患者
圖1。

胸部X光片。
三名患有嚴重肺炎的成年患者於2019年12月27日入武漢醫院。患者1是一名49歲的女性,患者2是61歲的男性,患者3是32歲的男性歲的男人。患者1和2可獲得臨床資料。患者1報告於2019年12月23日無基礎慢性疾病,但報告有發燒(溫度37°C至38°C)和咳嗽伴有胸部不適。疾病,咳嗽和胸部不適加劇,但發燒減少;肺炎的診斷基於計算機斷層掃描(CT)掃描。她的職業是海鮮批發市場的零售商。患者2最初於2019年12月20日報告發燒和咳嗽;發病後7天出現呼吸窘迫,並在接下來的2天內惡化(見胸部X線片,圖1),此時開始進行機械通氣。他是海鮮批發市場的常客。患者1和3已康復,並於2020年1月16日出院。患者2於2020年1月9日死亡。未獲得活檢標本。

新型冠狀病毒的檢測與分離
2019年12月30日,從武漢金銀灘醫院收集了3份支氣管肺泡灌洗液樣本。 。從患者的支氣管肺泡灌洗液中提取的RNA用作模板,結合Illumina測序和納米孔測序對基因組進行克隆和測序。從單個標本中獲得了超過20,000個病毒讀數,並且大多數重疊群與beta冠狀病毒屬B的基因組相匹配-與蝙蝠SARS樣冠狀病毒(bat-SL-CoVZC45,MG772933.1)的同一性超過85%基因組先前已發表。使用實時RT-PCR測定RNA靶向泛β-CoV的共有RdRp區也獲得了積極的結果(儘管對於檢測到的樣品,其循環閾值高於34)。使用人氣道上皮細胞以及Vero E6和Huh-7細胞系從臨床標本中分離病毒。分離出的病毒命名為2019-nCoV。

為了確定是否可以在2019-nCoV感染的人氣道上皮細胞中看到病毒顆粒,接種后6天每天用光學顯微鏡和透射電子顯微鏡檢查模擬感染和2019-nCoV感染的人氣道上皮培養物。接種人氣道上皮細胞表面層96小時后觀察到細胞病變作用。用光學顯微鏡在焦點中心觀察到缺乏纖毛的跳動(圖2)。直到接種后6天,在Vero E6和Huh-7細胞系中都沒有觀察到特異性的細胞病變作用。

圖3。

用透射電子顯微鏡可視化2019-nCoV。
負染色的2019-nCoV粒子的電子顯微照片通常是球形的,具有一些多態性(圖3)。直徑在約60至140nm之間變化。病毒顆粒具有非常獨特的尖峰,大約9至12 nm,並且使病毒體具有太陽日冕的外觀。在人氣道上皮超薄切片中發現細胞外遊離病毒顆粒和在細胞質膜結合囊泡中充滿病毒顆粒的包涵體。該觀察到的形態與冠狀病毒科一致。

為了進一步表徵病毒,通過Illumina和納米孔測序獲得了臨床標本(支氣管肺泡灌洗液)和人氣道上皮細胞病毒分離株的2019-nCoV基因組從頭序列。從所有三名患者中鑒定出新的冠狀病毒。從支氣管肺泡灌洗液中獲得了兩個接近全長的冠狀病毒序列(BetaCoV /武漢/ IVDC-HB-04 / 2020,BetaCoV /武漢/ IVDC-HB-05 / 2020 | EPI_ISL_402121),並且獲得了一個全長序列。分離自患者的病毒(BetaCoV / Wuhan / IVDC-HB-01 / 2020 | EPI_ISL_402119)。將三種新型冠狀病毒的完整基因組序列提交給GASAID(BetaCoV / Wuhan / IVDC-HB-01 / 2019,登錄號:EPI_ISL_402119; BetaCoV /武漢/ IVDC-HB-04 / 2020,登錄號:EPI_ISL_402120; BetaCoV / Wuhan / IVDC-HB-05 / 2019,登錄號:EPI_ISL_402121),與先前發布的蝙蝠SARS樣冠狀病毒(bat-SL-CoVZC45,MG772933.1)基因組具有86.9%的核苷酸序列同一性。三個2019-nCoV基因組聚集在一起並在sarbecovirus亞屬內形成一個獨立的亞群,顯示了典型的β冠狀病毒組織:5'非翻譯區(UTR),複製酶複合體(orf1ab),S基因,E基因,M基因,N基因,3'UTR和一些不確定的非結構性開放閱讀框。

儘管2019-nCoV與在蝙蝠中檢測到的某些β-冠狀病毒相似(圖4),但它與SARS-CoV和MERS-CoV不同。來自武漢的三種2019-nCoV冠狀病毒,以及兩種蝙蝠衍生的SARS樣菌株ZC45和ZXC21,在sarbecovirus亞類B系中形成了獨特的進化枝。來自人類的SARS-CoV病毒株和從中國西南地區收集的蝙蝠的遺傳相似的SARS樣冠狀病毒形成了sarbecovirus亞屬內的另一個進化枝。由於保守複製酶結構域(ORF 1ab)中的序列同一性在2019-nCoV和乙型冠狀病毒的其他成員之間小於90%,因此2019-nCoV-武漢病毒性肺炎的可能病原體-是一種新的乙型冠狀病毒,屬於冠狀病毒科的sarbecovirus亞屬。

討論
我們報告了一種新的CoV(2019-nCoV),該病毒已於2019年12月和2020年1月在中國武漢的住院患者中鑒定出。該病毒的存在包括通過全基因組測序在三名患者的支氣管肺泡灌洗液中進行鑒定,直接PCR和培養。該冠狀病毒可能引起的疾病被稱為「新型冠狀病毒感染的肺炎」(NCIP)。完整的基因組已提交給GASAID。系統發育分析表明,2019-nCoV屬於beta冠狀病毒屬,其中包括在人,蝙蝠和其他野生動物中發現的冠狀病毒(SARS-CoV,蝙蝠SARS狀CoV等)15。對其特定細胞病變效應和形態的初步描述。

分子技術已成功用於鑒定傳染原已有多年。無偏倚的高通量測序是發現病原體的有力工具。14,16下一代測序和生物信息學正在改變我們應對傳染病暴發的方式,加深了我們對疾病發生和傳播的理解,加速了對病原體的識別。病原體,促進數據共享。我們在本報告中描述了分子技術和無偏DNA測序的使用,以發現一種新型的β冠狀病毒,該病毒可能已在中國武漢的三名患者中引起嚴重的肺炎。

儘管建立人呼吸道上皮細胞培養物是勞動密集型的,但它們似乎是分析人呼吸道病原體的有價值的研究工具。14我們的研究表明,人呼吸道分泌物最初在人氣道上皮細胞培養物中的傳播,然後是透射電子顯微鏡和培養物上清液的全基因組測序已成功用於可視化和檢測新的人類冠狀病毒,這可能無法通過傳統方法進行鑒定。

仍然需要進一步發展準確快速的方法來鑒定未知的呼吸道病原體。在對本研究中獲得的三個完整基因組進行分析的基礎上,我們設計了針對2019-nCoV基因組的ORF1ab,N和E區域的幾種特異性和靈敏測定法,以檢測臨床標本中的病毒RNA。引物組和標準操作程序已與世界衛生組織共享,目的是在全球和中國範圍內監視和檢測2019-nCoV感染。最新數據顯示,中國830人中2019-nCoV的檢測17。

儘管我們的研究未能滿足科赫的假設,但我們的分析提供了與武漢爆發的2019-nCoV有關的證據。證實2019-nCoV在武漢爆發中的病因學意義的其他證據包括通過免疫組織化學分析鑒定患者肺組織中的2019-nCoV抗原,兩次檢測患者血清樣品中的IgM和IgG抗病毒抗體證明血清轉化,並通過動物(猴子)實驗提供致病性證據。至關重要的是流行病學調查,以表徵感染導致的傳播方式,繁殖間隔和臨床範圍,以告知和完善可以預防,控制和阻止2019-nCoV傳播的策略。

這項工作得到了中國國家重點研究發展計劃(2016YFD0500301)和中國國家傳染病控制與預防重大項目(2018ZX10101002)的資助。

博士Zhu,Zhang,W。Wang,Li和Yang對本文做出了同樣的貢獻。

本文於2020年1月24日在NEJM.org上發布。

我們感謝李忠傑博士,何光學博士,蘭斯·羅德瓦爾德博士,於立,葉飛,李立,趙為民,周軍,劉軍,孟瑤,王慧娟以及中國疾控中心的許多工作人員所做的貢獻和感謝。協助編寫和提交較早版本的手稿。

作者單位
來自中國疾病預防控制中心國家疾病預防控制中心病毒疾病預防控制中心MHC生物安全重點實驗室(NZ,WW,JS,XZ,BH,RL,PN,XM,DW,WX,GW,GFG,WT ),以及首都醫科大學附屬北京地壇醫院傳染病科-都在北京;武漢市金銀潭醫院(D.Z.),湖北省疾病預防控制中心病毒病檢測科和中國科學院(W.T.)生物安全大科學中心-都在武漢;以及山東第一醫科大學和山東醫學科學院,中國濟南。

在北京市疾病預防控制中心病毒疾病預防控制所國家衛生總局生物安全重點實驗室,中國北京昌平區昌百路155號,向譚博士致函轉載請求102102;或發送至tanwj@ivdc.chinacdc.cn,中國疾病預防控制中心國家病毒性疾病預防控制研究所的高博士,北京102206,或gaof@im.ac.cn,或NHC Key的吳博士。中國疾病預防控制中心,國家疾病預防控制中心,生物安全實驗室,北京102206,或發送電子郵件至wugz@ivdc.chinacdc.cn。
回復 change? 2020-1-26 12:36
中國出現的新型冠狀病毒—影響評估的關鍵問題
作者列表。
Vincent J.Munster博士,Marion Koopmans博士,Neeltje van Doremalen博士,Debby van Riel博士和Emmie de Wit博士

於2019年底,在中國武漢出現了新型的冠狀病毒,命名為2019-nCoV。截至2020年1月24日,在九個國家(中國,泰國,日本,韓國,新加坡,越南,台灣,尼泊爾和美國。發生了26例死亡,主要是在患有嚴重基礎疾病的患者中發生的。1儘管這種病毒的出現的許多細節(例如其起源和在人類中傳播的能力)仍然未知,但似乎導致這種情況的病例越來越多從人與人之間的傳播。考慮到2002年爆發的嚴重急性呼吸系統綜合症冠狀病毒(SARS-CoV)和2012年發生的中東呼吸系統綜合症冠狀病毒(MERS-CoV)2,2019-nCoV是過去二十年來人類中出現的第三種冠狀病毒-這種現象使全球公共衛生機構倍受戒備。

中國迅速做出反應,將疫情通報世界衛生組織(WHO),並在發現病原體后與國際社會共享序列信息。世衛組織通過協調診斷髮展迅速作出反應;發布有關患者監測,標本採集和治療的指南; 3該地區的幾個國家以及美國正在對來自武漢的旅行者進行發燒篩查,目的是在病毒進一步傳播之前發現2019-nCoV病例。來自中國,泰國,韓國和日本的最新消息表明,與SARS和MERS相比,與2019-nCoV相關的疾病似乎相對較輕。

在武漢出現SARS樣病毒的初步報道之後,看來2019-nCoV的致病性可能低於MERS-CoV和SARS-CoV(見表)。但是,這種病毒的出現提出了一個重要的問題:總體致病性在我們遏制新興病毒,防止大規模傳播並防止其在人類中引起大流行或成為地方性流行的能力方面起什麼作用?關於任何新興病毒的重要問題是,疾病金字塔的形狀是什麼?有多少比例的感染者患上疾病?當中有百分之幾的人尋求醫療保健?這三個問題代表了經典的監視金字塔(見圖)。4新興的冠狀病毒提出了另一個問題:病毒在其儲存庫中的傳播程度如何?當前,尚無可用來繪製金字塔的流行病學數據(見圖)。

顯然,有效的人際傳播是這種新興病毒大規模傳播的要求。但是,疾病的嚴重性是病毒傳播能力以及我們識別感染者並加以控制的能力的重要間接因素。這種關係對於爆發是否是由單個外溢事件引起的(SARS- CoV)或物種壁壘的反覆穿越(MERS-CoV)。

如果感染沒有引起嚴重的疾病,被感染的人可能最終不會進入醫療中心。取而代之的是,他們將去上班和旅行,從而有可能將病毒傳播給他們的聯繫人,甚至可能傳播到國際上。從2019-nCoV開始的亞臨床或輕度疾病是否也與病毒傳播風險降低相關,尚待確定。

我們對呼吸道病毒的可傳播性和致病性之間關係的許多思考都受到我們對甲型流感病毒的理解的影響:禽流感病毒在人與人之間有效傳播所必需的受體特異性的變化會導致從降低至上呼吸道,從而降低疾病負擔。大流行的H1N1病毒和禽流感H7N9病毒是兩個主要的(也是最近的)例子。大流行的H1N1病毒(與上呼吸道的受體結合)引起相對較輕的疾病並在人群中流行,而H7N9病毒(與下呼吸道的受體結合)的病死率約為40%,迄今為止,僅導致了少數人與人之間的傳播。

試圖假定這種關聯也適用於其他病毒,但並沒有給出這樣的相似性:使用相同受體(ACE2)的兩種冠狀病毒-NL63和SARS-CoV-引起不同嚴重程度的疾病。 NL63通常會引起輕度的上呼吸道疾病,並且在人類中很流行,而SARS-CoV會導致嚴重的下呼吸道疾病,病死率約為11%(參見表)。 SARS-CoV最終通過癥狀監測,隔離患者以及隔離他們的接觸者而得到遏制。因此,疾病的嚴重程度不一定與傳播效率有關。

即使病毒通常引起亞臨床或輕度疾病,某些人也可能更易感染並最終尋求治療。大多數SARS-CoV和MERS-CoV病例與醫院的院內傳播有關,5至少部分是由於在呼吸系統疾病患者中使用了產生氣溶膠的程序。特別是,醫院內超級傳播事件似乎已導致衛生保健機構內部和之間的大規模爆發。例如,一名SARS-CoV患者從香港到多倫多的旅行在當地醫院導致128例SARS病例。同樣,沙烏地阿拉伯將一名MERS-CoV患者引入韓國衛生保健系統,導致186例MERS病例。

院內傳播大量參與SARS-CoV和MERS-CoV暴發表明,這種傳播是其他新興呼吸道冠狀病毒的嚴重危險。除了醫療機構容易受到新興冠狀病毒爆發的影響外,醫院人群感染併發症的風險也大大增加。年齡和並存疾病(例如糖尿病或心臟病)是SARS-CoV和MERS-CoV不良後果的獨立預測因子。因此,由於健康人缺乏嚴重疾病,可能無法發現的新興病毒可能會對處於基礎疾病中的脆弱人群造成重大風險。

缺乏嚴重的疾病表現會影響我們遏制病毒傳播的能力。如果許多感染者無癥狀或輕度有癥狀(假設這些人能夠傳播病毒),則鑒定傳播鏈和隨後的接觸者追蹤要複雜得多。通常,可通過癥狀(發燒)監視和接觸者追蹤有效地遏制更多在人類之間傳播的病原性病毒,例如SARS-CoV和最近的埃博拉病毒。儘管暴力衝突使剛果民主共和國持續控制埃博拉病毒爆發變得複雜,但儘管該病毒能有效地進行人與人之間的傳播,但以前的所有爆發都是通過病例鑒定和接觸者追蹤來控制的。

我們目前尚不知道2019-nCoV在人與人之間的傳播能力範圍之內。但是可以肯定地說,如果這種病毒有效地傳播,與SARS相比,其看起來較低的致病性,在特定情況下可能與超級傳播者事件相結合,可以大規模傳播。以這種方式,在個人層面上對健康構成低威脅的病毒可能在人口層面上構成高風險,並有可能造成全球公共衛生系統中斷和經濟損失。這種可能性保證了當前的積極反應,旨在追蹤和診斷每個感染患者,從而打破了2019-nCoV的傳播鏈。

需要通過分子檢測和血清監測獲得的有關該病毒的致病性和傳播性的流行病學信息,以填寫監視金字塔中的詳細信息並指導對這種暴發的反應。此外,新型冠狀病毒易於在醫療中心傳播,這表明還需要外圍醫療設施隨時待命,以識別潛在病例。另外,在動物市場和其他動物設施上需要提高防範能力,同時正在研究這種新興病毒的可能來源。如果我們以這些方式積極進取,也許我們將永遠不必去發現2019-nCoV的真正流行或大流行潛力。

本文於2020年1月24日在NEJM.org上發布。

作者單位
來自美國國立衛生研究院國家過敏和傳染病研究所病毒學實驗室,密歇根州漢密爾頓(V.J.M.,N.D.,E.W.);荷蘭鹿特丹伊拉斯姆斯醫學中心病毒科學系(M.K.,D.R.)。
回復 change? 2020-1-26 12:42
社論

又一個十年,又一個冠狀病毒
作者列表。
斯坦利·珀爾曼(Stanley Perlman),醫學博士

人畜共患冠狀病毒已經是三十年來的第三次跨物種感染人類。該病毒臨時稱為2019-nCoV,最初在中國武漢被發現於暴露於海鮮或潮濕市場的人群中。中國公共衛生,臨床和科學界的迅速反應促進了對臨床疾病的認識和對感染流行病學的初步了解。最初的報道表明人與人之間的傳播是有限的或不存在的,但是我們現在知道發生了這種傳播,儘管在何種程度上尚不清楚。就像其他兩種致病性人類呼吸道冠狀病毒(嚴重急性呼吸綜合征冠狀病毒[SARS-CoV]和中東呼吸綜合征冠狀病毒[MERS-CoV])引起的暴發一樣,2019-nCoV引起的呼吸道疾病也很嚴重。1截至1月24日到2020年,報告的病例超過800個,死亡率為3%(https://promedmail.org/。在新標籤中打開)。

正如《華爾街日報》報道的那樣,Zhu等人2已經確定並表徵了2019-nCoV。已對病毒基因組進行了測序,這些結果與其他報告一起顯示,它與SARS-CoV的同源性為75%至80%,並且與幾種蝙蝠冠狀病毒的親緣關係更為密切。3它可以在與有助於SARS-CoV和MERS-CoV的生長,但值得注意的是,與SARS-CoV或MERS-CoV不同,2019-nCoV在原代人氣道上皮細胞中的生長要好於標準組織培養細胞。病毒的鑒定將允許開發試劑來解決有關這種新冠狀病毒感染的關鍵未知因素,並指導抗病毒療法的發展。首先,了解基因組序列有助於開發靈敏的定量逆轉錄酶-聚合酶鏈反應測定法,以快速檢測病毒。其次,血清學檢測方法的發展將允許評估在潮濕市場和其他環境中人類以及潛在的人畜共患病毒感染的流行率。由於整個中國都存在濕貨市場,因此這些試劑也可用於評估人類感染是否比最初想象的更為廣泛。第三,掌握病毒將刺激開發抗病毒療法和疫苗以及實驗動物模型的努力。

關於這種感染,仍然需要學習很多知識。最重要的是,需要確定人際傳播的程度和臨床疾病的範圍。 SARS-CoV和MERS-CoV的傳播在很大程度上是通過超級傳播事件發生的。4,5超級傳播事件與2019-nCoV傳播有關,但它們的相對重要性未知。 SARS-CoV和MERS-CoV感染肺上皮細胞的程度均高於上呼吸道細胞[4,6]。因此,傳播主要是從已確診疾病的患者而不是輕度,非特異性體征的患者發生的。看來2019-nCoV使用與SARS-CoV相同的細胞受體(人類血管緊張素轉換酶2 [hACE2])3,因此只有在出現下呼吸道疾病的跡象后才有望傳播。 SARS-CoV在2002-2004年的流行中發生了突變,可以更好地與其細胞受體結合併優化在人類細胞中的複製,從而提高毒力。7由於冠狀病毒具有易於出錯的RNA依賴性RNA聚合酶,因此容易發生適應,從而使突變和重組事件頻繁發生。相比之下,自2012年被檢測到以來,MERS-CoV並未發生實質性突變以增強人類感染力。

2019-nCoV的行為可能更像SARS-CoV,並通過增強與hACE2的結合進一步適應人類宿主。因此,重要的是要獲得儘可能多的時間和地理上無關的臨床分離株,以評估病毒突變的程度並評估這些突變是否表明對人宿主的適應性。此外,如果2019-nCoV與SARS-CoV相似,則該病毒會全身傳播。9進行屍檢時獲取患者樣本將有助於闡明感染的發病機制,併合理地調整治療干預措施。它還將有助於驗證從實驗動物的實驗性感染獲得的結果。

第二個關鍵問題是病毒的人畜共患病源的鑒定。由於其與蝙蝠冠狀病毒非常相似,因此蝙蝠可能是該病毒的主要宿主。 SARS-CoV是從濕市場中的外來動物傳播給人類的,而MERS-CoV是從駱駝傳播給人類的。10在這兩種情況下,祖先的宿主都可能是蝙蝠。了解2019-nCoV是直接從蝙蝠傳播還是通過中間宿主傳播,對理解這一點很重要,這將有助於定義人畜共患病的傳播方式。

SARS流行的一個顯著特徵是恐懼在經濟和社會後果中起著重要作用。儘管仍在開發特定的抗冠狀病毒療法,但我們現在對如何控制社區和醫院中的此類感染了解更多,這應該可以減輕這種恐懼。根據我們對SARS-CoV和MERS-CoV的經驗,2019-nCoV的傳播可能通過大液滴和接觸發生,較少通過氣溶膠和毒氣傳播.4,5公共衛生措施,包括隔離社區以及及時診斷和嚴格遵守醫療機構中的普遍預防措施,對於控制SARS和MERS至關重要。採取類似措施非常重要,希望能夠成功減少2019-nCoV的傳播。


該社論於2020年1月24日在NEJM.org上發布。

作者單位
來自愛荷華市愛荷華大學微生物學和免疫學系。
回復 change? 2020-1-26 12:59
Coronavirus Infections—More Than Just the Common Cold
Catharine I. Paules, MD1; Hilary D. Marston, MD, MPH2; Anthony S. Fauci, MD2
Author Affiliations Article Information
JAMA. Published online January 23, 2020. doi:10.1001/jama.2020.0757
Human coronaviruses (HCoVs) have long been considered inconsequential pathogens, causing the 「common cold」 in otherwise healthy people. However, in the 21st century, 2 highly pathogenic HCoVs—severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV)—emerged from animal reservoirs to cause global epidemics with alarming morbidity and mortality. In December 2019, yet another pathogenic HCoV, 2019 novel coronavirus (2019-nCoV), was recognized in Wuhan, China, and has caused serious illness and death. The ultimate scope and effect of this outbreak is unclear at present as the situation is rapidly evolving.

Coronaviruses are large, enveloped, positive-strand RNA viruses that can be divided into 4 genera: alpha, beta, delta, and gamma, of which alpha and beta CoVs are known to infect humans.1 Four HCoVs (HCoV 229E, NL63, OC43, and HKU1) are endemic globally and account for 10% to 30% of upper respiratory tract infections in adults. Coronaviruses are ecologically diverse with the greatest variety seen in bats, suggesting that they are the reservoirs for many of these viruses.2 Peridomestic mammals may serve as intermediate hosts, facilitating recombination and mutation events with expansion of genetic diversity. The surface spike (S) glycoprotein is critical for binding of host cell receptors and is believed to represent a key determinant of host range restriction.1

Until recently, HCoVs received relatively little attention due to their mild phenotypes in humans. This changed in 2002, when cases of severe atypical pneumonia were described in Guangdong Province, China, causing worldwide concern as disease spread via international travel to more than 2 dozen countries.2 The new disease became known as severe acute respiratory syndrome (SARS), and a beta-HCoV, named SARS-CoV, was identified as the causative agent. Because early cases shared a history of human-animal contact at live game markets, zoonotic transmission of the virus was strongly suspected.3 Palm civets and raccoon dogs were initially thought to be the animal reservoir(s); however, as more viral sequence data became available, consensus emerged that bats were the natural hosts.

Common symptoms of SARS included fever, cough, dyspnea, and occasionally watery diarrhea.2 Of infected patients, 20% to 30% required mechanical ventilation and 10% died, with higher fatality rates in older patients and those with medical comorbidities. Human-to-human transmission was documented, mostly in health care settings. This nosocomial spread may be explained by basic virology: the predominant human receptor for the SARS S glycoprotein, human angiotensin-converting enzyme 2 (ACE2), is found primarily in the lower respiratory tract, rather than in the upper airway. Receptor distribution may account for both the dearth of upper respiratory tract symptoms and the finding that peak viral shedding occurred late (≈10 days) in illness when individuals were already hospitalized. SARS care often necessitated aerosol-generating procedures such as intubation, which also may have contributed to the prominent nosocomial spread.

Several important transmission events did occur in the community, such as the well-characterized mini-outbreak in the Hotel Metropole in Hong Kong from where infected patrons traveled and spread SARS internationally. Another outbreak occurred at the Amoy Gardens housing complex where more than 300 residents were infected, providing evidence that airborne transmission of SARS-CoV can sometimes occur.4 Nearly 20 years later, the factors associated with transmission of SARS-CoV, ranging from self-limited animal-to-human transmission to human superspreader events, remain poorly understood.

Ultimately, classic public health measures brought the SARS pandemic to an end, but not before 8098 individuals were infected and 774 died.2 The pandemic cost the global economy an estimated $30 billion to $100 billion.1 SARS-CoV demonstrated that animal CoVs could jump the species barrier, thereby expanding perception of pandemic threats.

In 2012, another highly pathogenic beta-CoV made the species jump when Middle East respiratory syndrome (MERS) was recognized and MERS-CoV was identified in the sputum of a Saudi man who died from respiratory failure.3 Unlike SARS-CoV, which rapidly spread across the globe and was contained and eliminated in relatively short order, MERS has smoldered, characterized by sporadic zoonotic transmission and limited chains of human spread. MERS-CoV has not yet sustained community spread; instead, it has caused explosive nosocomial transmission events, in some cases linked to a single superspreader, which are devastating for health care systems. According to the World Health Organization (WHO), as of November 2019, MERS-CoV has caused a total of 2494 cases and 858 deaths, the majority in Saudi Arabia. The natural reservoir of MERS-CoV is presumed to be bats, yet human transmission events have primarily been attributed to an intermediate host, the dromedary camel.

MERS shares many clinical features with SARS such as severe atypical pneumonia, yet key differences are evident. Patients with MERS have prominent gastrointestinal symptoms and often acute kidney failure, likely explained by the binding of the MERS-CoV S glycoprotein to dipeptidyl peptidase 4 (DPP4), which is present in the lower airway as well as the gastrointestinal tract and kidney.3 MERS necessitates mechanical ventilation in 50% to 89% of patients and has a case fatality rate of 36%.2

While MERS has not caused the international panic seen with SARS, the emergence of this second, highly pathogenic zoonotic HCoV illustrates the threat posed by this viral family. In 2017, the WHO placed SARS-CoV and MERS-CoV on its Priority Pathogen list, hoping to galvanize research and the development of countermeasures against CoVs.

The action of the WHO proved prescient. On December 31, 2019, Chinese authorities reported a cluster of pneumonia cases in Wuhan, China, most of which included patients who reported exposure to a large seafood market selling many species of live animals. Emergence of another pathogenic zoonotic HCoV was suspected, and by January 10, 2020, researchers from the Shanghai Public Health Clinical Center & School of Public Health and their collaborators released a full genomic sequence of 2019-nCoV to public databases, exemplifying prompt data sharing in outbreak response. Preliminary analyses indicate that 2019-nCoV has some amino acid homology to SARS-CoV and may be able to use ACE2 as a receptor. This has important implications for predicting pandemic potential moving forward. The situation with 2019-nCoV is evolving rapidly, with the case count currently growing into the hundreds. Human-to-human transmission of 2019-nCoV occurs, as evidenced by the infection of 15 health care practitioners in a Wuhan hospital. The extent, if any, to which such transmission might lead to a sustained epidemic remains an open and critical question. So far, it appears that the fatality rate of 2019-nCoV is lower than that of SARS-CoV and MERS-CoV; however, the ultimate scope and effects of the outbreak remain to be seen.

Drawing on experience from prior zoonotic CoV outbreaks, public health authorities have initiated preparedness and response activities. Wuhan leaders closed and disinfected the first identified market. The United States and several other countries have initiated entry screening of passengers from Wuhan at major ports of entry. Health practitioners in other Chinese cities, Thailand, Japan, and South Korea promptly identified travel-related cases, isolating individuals for further care. The first travel-related case in the United States occurred on January 21 in a young Chinese man who had visited Wuhan.

Additionally, biomedical researchers are initiating countermeasure development for 2019-nCoV using SARS-CoV and MERS-CoV as prototypes. For example, platform diagnostic modalities are being rapidly adapted to include 2019-nCoV, allowing early recognition and isolation of cases. Broad-spectrum antivirals, such as remdesivir, an RNA polymerase inhibitor, as well as lopinavir/ritonavir and interferon beta have shown promise against MERS-CoV in animal models and are being assessed for activity against 2019-nCoV.5 Vaccines, which have adapted approaches used for SARS-CoV or MERS-CoV, are also being pursued. For example, scientists at the National Institute of Allergy and Infectious Diseases Vaccine Research Center have used nucleic acid vaccine platform approaches.6 During SARS, researchers moved from obtaining the genomic sequence of SARS-CoV to a phase 1 clinical trial of a DNA vaccine in 20 months and have since compressed that timeline to 3.25 months for other viral diseases. For 2019-nCoV, they hope to move even faster, using messenger RNA (mRNA) vaccine technology. Other researchers are similarly poised to construct viral vectors and subunit vaccines.

While the trajectory of this outbreak is impossible to predict, effective response requires prompt action from the standpoint of classic public health strategies to the timely development and implementation of effective countermeasures. The emergence of yet another outbreak of human disease caused by a pathogen from a viral family formerly thought to be relatively benign underscores the perpetual challenge of emerging infectious diseases and the importance of sustained preparedness.

Back to topArticle Information
Corresponding Author: Anthony S. Fauci, MD, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, 31 Center Dr, MSC 2520, Bldg 31, Room 7A-03, Bethesda, MD 20892-2520 (afauci@niaid.nih.gov).

Published Online: January 23, 2020. doi:10.1001/jama.2020.0757
回復 change? 2020-1-26 13:03
冠狀病毒感染—不僅僅是普通感冒
凱瑟琳·鮑爾斯(MD1);希拉里·馬斯頓(Hilary D.Marston),醫學博士,MPH2;安東尼·福西(MD2)
作者所屬文章信息
賈瑪在線發佈於2020年1月23日。doi:10.1001 / jama.2020.0757
人類冠狀病毒(HCoV)長期以來一直被認為是無關緊要的病原體,在原本健康的人中引起「普通感冒」。然而,在21世紀,動物蓄水池中出現了2種高致病性HCoV,即嚴重的急性呼吸綜合症冠狀病毒(SARS-CoV)和中東呼吸綜合症冠狀病毒(MERS-CoV),導致全球流行,其發病率和死亡率令人震驚。 2019年12月,另一種致病性HCoV,即2019年新型冠狀病毒(2019-nCoV)在中國武漢被確認,已造成嚴重的疾病和死亡。隨著局勢的迅速發展,目前尚不清楚該暴發的最終範圍和影響。

冠狀病毒是大型的,有包膜的正鏈RNA病毒,可分為4個屬:α,β,δ和γ,其中已知α和βCoV感染人類。1四種HCoV(HCoV 229E,NL63,OC43 ,和HKU1)是全球性流行病,占成年人上呼吸道感染的10%至30%。冠狀病毒在生態上是多樣的,在蝙蝠中觀察到的種類最多,表明它們是這些病毒中許多病毒的貯藏庫。2周生哺乳動物可作為中間宿主,促進重組和突變事件,並擴大遺傳多樣性。表面刺突糖蛋白對宿主細胞受體的結合至關重要,被認為是限制宿主範圍的關鍵因素。1

直到最近,由於HCoV在人類中的表型較輕,因此受到的關注相對較少。這種情況在2002年發生了變化,當時在中國廣東省描述了嚴重的非典型肺炎病例,引起了全世界的關注,因為該疾病是通過國際旅行傳播到2多個國家/地區。2這種新疾病被稱為嚴重急性呼吸道綜合症(SARS), β-HCoV(稱為SARS-CoV)被確定為病原體。由於早期病例在現場遊戲市場上有人類-動物接觸的歷史,因此強烈懷疑該病毒的人畜共患性傳播。3最初認為棕櫚c和狗是動物的水庫。然而,隨著更多病毒序列數據的出現,人們逐漸達成共識,蝙蝠是自然宿主。
SARS的常見癥狀包括發燒,咳嗽,呼吸困難,偶爾還有水樣腹瀉。2在感染患者中,有20%至30%的患者需要機械通氣,有10%死亡,老年患者和患有合併症的患者死亡率更高。人與人之間的傳播已有記錄,主要是在衛生保健機構中。這種醫院傳播可能是由基本病毒學解釋的:SARS S糖蛋白的主要人類受體,即人類血管緊張素轉換酶2(ACE2),主要在下呼吸道而不是上呼吸道中發現。受體的分佈可能既解釋了上呼吸道癥狀的缺乏,又解釋了當患者已經住院時,病毒的高峰釋放發生在疾病的晚期(約10天)。 SARS護理通常需要氣霧生成程序(例如插管),這也可能導致醫院內廣泛傳播。

社區確實發生了幾起重要的傳播事件,例如,在香港大都會酒店中,特徵鮮明的小型暴發流行,受感染的顧客從那裡傳播並在國際上傳播SARS。另一個暴發發生在淘大花園住宅區,有300多名居民受到感染,這提供了有時可發生SARS-CoV空中傳播的證據。4近20年後,與SARS-CoV傳播有關的因素包括自有限的從動物到人類的傳播給人類超級傳播者的事件仍然知之甚少。

最終,經典的公共衛生措施終結了SARS的大流行,但在8098人被感染並造成774人死亡之前未曾發生。2大流行使全球經濟損失了300億至1000億美元。1SARS-CoV證明動物冠狀病毒可能會跳躍物種屏障,從而擴大了對大流行威脅的認識。

2012年,另一種高致病性的β-CoV在識別出中東呼吸綜合症(MERS)並在一名因呼吸衰竭而死亡的沙特男子的痰液中發現了MERS-CoV時使該物種跳躍。3與SARS-CoV迅速MERS散布在全球各地,並在相對較短的時間內被遏制和消除,其特徵是零散的人畜共患病傳播和有限的人類傳播鏈。 MERS-CoV尚未持續傳播社區;相反,它引起了爆炸性的醫院傳播事件,在某些情況下與單個超級吊具有關,這對醫療保健系統造成了災難性的破壞。根據世界衛生組織(WHO)的數據,截至2019年11月,MERS-CoV總共造成2494例病例和858例死亡,其中大部分在沙烏地阿拉伯。 MERS-CoV的天然庫被認為是蝙蝠,但人類傳播事件主要歸因於中間宿主,即單峰駱駝。
MERS與SARS具有許多臨床特徵,例如嚴重的非典型肺炎,但主要區別顯而易見。患有MERS的患者具有明顯的胃腸道癥狀,並常常出現急性腎功能衰竭,這可能是由於MERS-CoV S糖蛋白與下呼吸道以及胃腸道和腎臟中存在的二肽基肽酶4(DPP4)結合所致。中東呼吸綜合征需要50%至89%的患者進行機械通氣,病死率為36%.2

儘管MERS並未引起SARS引起的國際恐慌,但第二種高致病性人畜共患病毒HCoV的出現說明了該病毒家族的威脅。 2017年,世衛組織將SARS-CoV和MERS-CoV列入其優先病原體名單,希望藉此激發研究和制定針對CoV的對策。

世衛組織的行動證明是有先見之明的。 2019年12月31日,中國當局報告了中國武漢市發生的一系列肺炎病例,其中大多數病例報告有暴露於出售許多活體動物的大型海鮮市場的患者。懷疑另一種致病性人畜共患病毒HCoV的出現,到2020年1月10日,上海公共衛生臨床中心和公共衛生學院的研究人員及其合作者向公共資料庫發布了完整的2019-nCoV基因組序列,證明了在爆發反應。初步分析表明,2019-nCoV與SARS-CoV具有某些氨基酸同源性,並且可能能夠使用ACE2作為受體。這對於預測大流行潛力的發展具有重要意義。 2019-nCoV的情況正在迅速發展,目前案件數已增加到數百個。武漢市一家醫院的15名醫療保健從業人員感染證明了2019-nCoV的人際傳播。這種傳播可能導致持續流行的程度(如果有的話)仍然是一個懸而未決的關鍵問題。到目前為止,看來2019-nCoV的死亡率低於SARS-CoV和MERS-CoV的死亡率;但是,爆發的最終範圍和影響尚待觀察。

借鑒先前人畜共患病暴發的經驗,公共衛生當局已啟動了備災和應對活動。武漢市領導關閉並消毒了第一個確定的市場。美國和其他幾個國家已經開始對主要入境口岸武漢的旅客進行入境檢查。其他中國城市(泰國,日本和韓國)的衛生從業人員迅速發現了與旅行有關的病例,隔離了個體以進行進一步護理。美國首例與旅行有關的案件發生在1月21日,發生在一名年輕的中國男子,他去了武漢。
此外,生物醫學研究人員正在以SARS-CoV和MERS-CoV為原型開始針對2019-nCoV的對策開發。例如,平台診斷模式正在迅速適應包括2019-nCoV的功能,從而可以及早識別和隔離病例。廣譜抗病毒藥,例如remdesivir,一種RNA聚合酶抑製劑以及lopinavir / ritonavir和干擾素beta在動物模型中顯示出抗MERS-CoV的前景,並正在評估其對2019-nCoV.5疫苗的活性。也正在追求用於SARS-CoV或MERS-CoV的方法。例如,美國國家過敏和傳染病研究所疫苗研究中心的科學家已經使用了核酸疫苗平台方法。6在SARS期間,研究人員從獲得SARS-CoV的基因組序列轉向了DNA疫苗的1期臨床試驗。自20個月以來,對於其他病毒性疾病,該時間表已縮短為3.25個月。對於2019-nCoV,他們希望使用Messenger RNA(mRNA)疫苗技術更快地發展。類似地,其他研究人員也準備構建病毒載體和亞單位疫苗。

儘管無法預測這種暴發的軌跡,但要從經典的公共衛生策略的角度出發,要迅速採取行動,就必須及時採取行動,並及時制定和實施有效的對策。以前被認為是相對良性的病毒家族病原體引起的另一次人類疾病暴發凸顯了新興傳染病的長期挑戰以及持續防備的重要性。

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通訊作者:美國國家過敏和傳染病研究所免疫調節實驗室Anthony S.Fauci博士,MSC 2520中心博士,MSC 2520,Bldg 31,Bethesda,7A-03室,MD 20892-2520(afauci@niaid.nih。 gov)。

在線發布:2020年1月23日。doi:10.1001 / jama.2020.0757

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