Wuhan Coronavirus Outbreak

An outbreak of a novel coronavirus was initially identified during mid-December 2019 in the city of Wuhan in central China, as an emerging cluster of people with pneumonia with no clear cause, which was linked primarily to stallholders who worked at the Huanan Seafood Wholesale Market, which also sold live animals. Chinese scientists subsequently isolated a new strain of coronavirus – given the initial designation of 2019-nCoV – which has been found to be at least 70 percent similar in genome sequence to SARS-CoV. With the development of a specific diagnostic PCR test for detecting the infection, a number of cases were confirmed in people directly linked to the market and in those who were not directly associated with it. Whether this virus is of the same severity or lethality as SARS is unclear.


On 20 January 2020, Chinese premier Li Keqiang urged decisive and effective efforts to prevent and control the pneumonia epidemic caused by a novel coronavirus. As of 24 January 2020, 26 deaths have occurred, all in China, and there is evidence of human-to-human transmission. Extensive testing has revealed over 900 confirmed cases in China, some of whom are healthcare workers. Confirmed cases have also been reported in Thailand, South Korea, Japan, Taiwan, Macau, Hong Kong, the United States, Singapore, Vietnam , France and Nepal.


On 23 January 2020, the WHO decided against declaring the outbreak a public health emergency of international concern. The WHO had previously warned that a wider outbreak was possible, and there were concerns of further transmission during China's peak travel season around the Chinese New Year. Many New Year events have been closed over fear of transmission, including the Forbidden City in Beijing, traditional temple fairs, and other celebratory gatherings. The sudden increase in occurrences of the disease has raised questions relating to its origin, wildlife trade, uncertainties surrounding the virus's ability to spread and cause harm, whether the virus has been circulating for longer than previously thought, and the possibility of the outbreak being a super-spreader event.


The first suspected cases were notified to WHO on 31 December 2019, with the first instances of symptomatic illness appearing just over three weeks earlier on 8 December 2019.  The market was closed off on 1 January 2020, and people who showed signs and symptoms of the coronavirus infection were isolated. Over 700 people, including more than 400 healthcare workers who came into close contact with possibly infected individuals, were initially monitored. After the development of a specific diagnostic PCR test for detecting the infection, the presence of 2019-nCoV was subsequently confirmed in 41 people in the original Wuhan cluster. Of those 41 people, two were later reported to be a married couple, one of whom had not been present in the marketplace, and another three were members of the same family that worked at the marketplace's seafood stalls. The first confirmed death from the coronavirus infection occurred on 9 January 2020.


On 23 January 2020, Wuhan was placed under quarantine, in which all public transport in and out of Wuhan has been suspended. The nearby cities of Huanggang, Ezhou, Chibi, Jingzhou, and Zhijiang were also placed under quarantine from 24 January.


Background


In Wuhan, during December 2019, an inaugural cluster of cases displaying the symptoms of a "pneumonia of unknown cause" was linked to a wholesale animal and fish market, which had a thousand stalls selling chickens, pheasants, bats, marmots, venomous snakes, spotted deer and the organs of rabbits and other wild animals (ye wei), i.e. bushmeat, the immediate hypothesis was that this was a novel coronavirus from an animal source (a zoonosis).


Coronaviruses mainly circulate among animals, but have been known to evolve and infect humans in the past as has been seen with SARS, MERS together with four further coronaviruses found in humans that cause mild respiratory symptoms like the common cold.


All six of those already known coronaviruses can spread from human to human. In 2002, with an origin in horseshoe bats, then via civets from live animal markets, an outbreak of SARS started in mainland China, and with the help of a few super-spreaders and international air travel, reached as far as Canada and the United States, resulting in over 700 deaths worldwide. The last case occurred in 2004. At the time, China was criticised by the WHO for its handling of the epidemic. Ten years after the onset of SARS, the dromedary-camel-related coronavirus, MERS, has resulted in more than 850 deaths in 27 countries. The Wuhan outbreak's association with a large seafood and animal market has led to the presumption of the illness having an animal source. This has resulted in the fear that it would be similar to the previous SARS outbreak, a concern exacerbated by the expectation of a high numbers of travellers for Chinese New Year, which begins on 25 January 2020.


Wuhan is the capital of Hubei province and is the seventh-largest city in China, with a population of more than 11 million people. It is a major transportation hub of the country, long known as the "Nine Provinces' Thoroughfare" (九省通衢). It is approximately 1,100 km (700 mi) south of Beijing, 800 km (500 mi) west of Shanghai, and 970 km (600 mi) north of Hong Kong. It is considered today as the political, economic, financial, commercial, cultural and educational centre of Central China. Direct flights from Wuhan also connect with Europe: six flights weekly to Paris, three weekly to London, and five weekly to Rome.


Since 2000, the World Health Organization has coordinated international reactions against several new diseases such as MERS, SARS (2003–2004), 2009 swine flu, and others.


Epidemiology


Confirmed cases outside of mainland China include four women and one man in Thailand, one man in Japan, one woman in South Korea, one woman and two men in Taiwan, two men in Hong Kong, two men in Vietnam, two men and one woman in Singapore, one man and one woman in the United States, and one man in Macau. The figures are supported by experts including Michael Osterholm.


On 17 January, an Imperial College group in the UK published a Fermi estimate that there had been 1,723 cases (95% confidence interval, 427–4,471) with onset of symptoms by 12 January 2020. This was based on the pattern of the initial spread to Thailand and Japan. They also concluded that "self-sustaining human-to-human transmission should not be ruled out", which has since been confirmed as happening. As further cases came to light, they later recalculated that "4,000 cases of 2019-nCoV in Wuhan City... had onset of symptoms by 18th January 2020".  A Hong Kong University group has reached a similar conclusion as the earlier study, with additional detail on transport within China.


On 20 January, China reported a sharp rise in cases with nearly 140 new patients, including two people in Beijing and one in Shenzhen. As of 24 January, the number of laboratory-confirmed cases stands at 911, including 889 in Mainland China, 5 in Thailand, 3 in Singapore, 3 in Taiwan, 2 in Hong Kong, 2 in Macau, 2 in Vietnam, 2 in Japan, 2 in South Korea and one in the United States.


                          https://en.wikipedia.org/wiki/2019–20_Wuhan_coronavirus_outbreak