Coronavirus 2019 Disease Outbreak

Corona virus

What is Coronavirus? About Corona virus 

The coronavirus epidemic in 2019 [283] [Note 29] is a global pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) [284]. The outbreak first broke out in Wuhan City, Hubei Province, People's Republic of China in the winter of 2019, and then quickly spread to many countries around the world in early 2020, gradually becoming a global plague [285], the world's most serious face since World War II. Severe crisis [286] [287]. As of April 12, 2020, more than 200 countries and regions have reported cumulatively more than 1.6 million confirmed cases worldwide, resulting in the death of more than 100,000 patients [288].

The currently accepted statistics show that the time of the first infection is December 1, 2019 [289] [Note 3] The first patient to go to the hospital may appear on December 12 [292]. On December 26, Zhang Jixian, a respiratory and intensive care medical doctor in Wuhan, first discovered and reported this unexplained pneumonia and suspected that the disease was an infectious disease [293] [294] [295] Subsequently, the disease experienced a large-scale epidemic in Wuhan [294]. On January 23, 2020, Wuhan City ’s New Coronary Pneumonia Epidemic Prevention and Control Headquarters announced the adoption of blockade and isolation measures in epidemic areas [296] [297], which is the first example in modern public health history to blockade large cities with a population of 11 million [298 ]. On March 12, the National Health Commission of the People ’s Republic of China announced that, on the whole, the epidemic peak of this round of epidemic in mainland China has passed [299]. On March 23, Li Keqiang, the prime minister of the State Council of the People's Republic of China and the head of the Central Response Team, announced that the spread of the local Chinese epidemic with Wuhan as the main battlefield has been basically blocked, and the initial success of the anti-epidemic [300] [301].

Since January 13, the epidemic has spread to countries such as Thailand, Japan, and South Korea [302] [303] [304], and it spread to Seattle, the United States, on January 21, making it the first confirmed case outside Asia [305]. It was confirmed on January 30 that there were community transmissions in three countries outside China. The World Health Organization declared the epidemic as an "international public health emergency" on that day. At the end of February, the number of confirmed diagnoses in Italy, South Korea, and Iran increased rapidly. On 29th, WHO raised the global risk level of the epidemic to "very high" [306]. On March 11, WHO announced that the epidemic has constituted a "global pandemic" [307] [308] [309], and on March 13 WHO stated that Europe has become the center of the current pandemic plague [310 ].

The incubation period of the virus is generally up to 14 days, with individual cases up to 24 days [311]. Even if there is no fever, an infected person who has no signs of infection or has only slight signs of infection can transmit the virus to others, and symptom screening cannot be effectively detected [312] [313]. This means that it is more difficult to control than the outbreak of Middle East Respiratory Syndrome (MERS) or Severe Acute Respiratory Syndrome (SARS)

System [314] [315]. In fact, this epidemic took only a quarter of the time to cause ten times the number of confirmed SARS incidents. There are currently no preventive vaccines and treatments for new coronaviruses [316]. Bruce Elward, assistant director general of the World Health Organization, believes that redcive is currently the "only possible drug with real efficacy" [317] [318]; and symptomatic treatment is currently the main treatment method. There are currently at least three new preventive vaccines against coronavirus pneumonia in the experimental stage. At present, there is still a knowledge gap in the study of diseases, including key factors such as the source of the virus, the source of the virus, the pathogenesis, the pathogenicity of the virus and the ability to spread [319].

While the epidemic crisis continued, it also encountered the problem of insufficient supply of medical supplies worldwide. The spread of the epidemic has a huge impact on global aviation, tourism, entertainment, sports, oil markets, and financial markets.

Main article: Severe acute respiratory syndrome coronavirus 2 epidemiology

After collecting samples from the South China Seafood Market in Wuhan on January 1, 2020, the Chinese Center for Disease Control and Prevention [320] published the test results on January 7, indicating that the pathogen of "unexplained viral pneumonia" was initially determined as a new coronavirus [321] [322] [323]. January 21, Shanghai Institute of Pasteur, Chinese Academy of Sciences and Institute of Plant Physiology and Ecology, Chinese Academy of Sciences

And the Key Laboratory of Synthetic Biology of the Institute of Plant Physiology and Ecology, Chinese Academy of Sciences and other institutions published a report in the journal "Science in China: Life Science", indicating that the virus belongs to the genus Betacoronavirus. The coronavirus type B is a positive-stranded single-stranded RNA virus encapsulated in protein, capable of parasitizing and infecting humans and other higher animals. In the position of the evolutionary tree, it is adjacent to the SARS virus and SARS virus-like groups, but it does not belong to the SARS and SARS virus-like groups [324]. On February 3, Nature magazine published a paper by the team of Shi Zhengli of the Wuhan Virus Research Institute, which revealed that compared with the previous bat coronavirus RaTG13 detected by Shi Zhengli on Yunnan chrysanthemum bat, the new coronavirus was 96.2% of the whole genome with RaTG13 consistency. [325].

Regarding the investigation of the primary case (Patient No. 0), the first patient who went to the hospital for treatment became ill on December 8, 2019 and went to the hospital on December 12 [326] [325]. On January 14, 2020, Huang Chaolin et al. Published a paper in the journal "Needle Needle", which pointed out that the earliest symptomatic cases among the existing patients can be traced back to December 1 [289] [Note 3].

With regard to the source of viral vectors, the academic community has not yet determined the natural source of the virus. On the one hand, a paper published in the "Chinese Science: Life Science" by the Shanghai Pasteur Institute of the Chinese Academy of Sciences on January 21, 2020 [324] [327] and the Xishuangbanna Tropical Botanical Garden, the South China Agricultural University and Beijing on February 22 The report of the research team of the Brain Center [1] believes that the natural host of the virus may be bats [324] [1]. On the other hand, the paper [328] [329] published by Guan Yi and Hu Yanling on February 18 and the report issued by South China Agricultural University on February 7 [330] [331] [332] believed that pangolins were potential intermediate hosts, but . In addition, a paper published in the Journal of Medical Virology by Peking University and other institutions on January 22 believed that snakes were the most likely animals to carry new coronaviruses [333].

Regarding the investigation of the origin of the original epidemic, the government and society had generally believed that the South China Seafood Market in Wuhan was the source of the virus [326] [334]. However, further research results suggest that the seafood market in South China is not the source of the epidemic [289]. A paper published by Huang Chaolin and others in the "Needle Needle" journal stated that at the time, the patient with the new coronary pneumonia that had occurred on December 1 had not been to the South China Seafood Market in Wuhan, and 13 of the 41 confirmed cases initially admitted to South China Seafood The market has nothing to do, so I think South ChinaThe seafood market is not the origin of the epidemic [289]. On the other hand, He Dayi [335], Simo Galli [336], Giuseppe Remuzi [337] and others considered Wuhan as the source of the epidemic. Zhong Nanshan [338] and others believed that there was no evidence that the source of the epidemic was in Wuhan. Cao Bin [339] and others believe that the actual source of the virus is not yet clear and further research is needed. Daniel Lucy pointed out in Science that retrospective analysis of blood samples from animals and their suppliers, and blood samples from diagnosed patients, may reveal the origin of the new coronavirus [339]..