“Viral” has become a familiar word in the English language, referring as it does to images, videos and text messages that appear suddenly and propagate rapidly thereafter over the Internet. Pandemics, during which actual viruses spread equally rapidly across national boundaries, provide the context for labelling these events as having “gone viral”. Such viral pandemics can readily provoke widespread anxiety and fear and may also encourage various forms of irrational behaviour. The recent outbreak of a viral illness in China appears to be developing into the latest global pandemic, with predictably similar effects.
Wuhan is the seventh most populous city in China, with a population of eleven million, yet many people in the West appear not to have heard of it before. The city is a major manufacturing centre, a financial powerhouse and an important transportation hub, situated on the Yangtze River in Hubei Province in central China. It was from here, on December 31 2019, that the Municipal Health Commission reported an outbreak of viral pneumonia involving a cluster of 27 people, caused by an as yet unidentified agent. By January 9 2020, the virus responsible had been definitively identified by the Shanghai Public Health Centre as a novel coronavirus (nCoV), which was then named as 2019-nCoV. Shortly thereafter, the entire genome (genetic sequence) was made available online to public databases worldwide.
Simultaneously, a public health investigation was undertaken in Wuhan. The source of the new coronavirus was traced back to “ground zero”- the Huanan “Seafood” Wholesale Market in Wuhan, which was promptly closed down on January 1 2020. This source of infection has, however, yet to be definitively confirmed. Similar “wet markets”, which sell live wild animals alongside farmed animals for human consumption, are a feature of many Chinese cities and towns. This sale of live animals for food is by no means uncommon, as many low-income households in China do not possess refrigerators, thereby prompting people to buy perishable “foods” immediately prior to consumption.
Wuhan was rapidly placed under “lockdown”- a measure of unprecedented proportions given the size of the city. Lockdown was soon also imposed on several other Chinese cities perceived to be at risk of coronavirus infection. All forms of transport in and out of Wuhan, including bus, rail, underground, ferries and flights, were suspended. Checkpoints were set up to prevent people from leaving the city. Residents were advised to stay indoors, to avoid the use of private cars, and to wear face masks in public places and at work. Municipal authorities assembled a fleet of taxis for essential travel by citizens within the city limits. All public gatherings were banned, along with access to public recreational spaces. A process of mass quarantine thereby transformed a once-bustling city into a ghost town overnight. This was especially noticeable in the normally busy run-up to the extended Chinese Lunar New Year/Spring Festival celebrations, at a time when many people choose to travel both within and outside the country. The effectiveness of these lockdown procedures remains to be seen, given the apparent porosity of the barriers that have been set up. Lockdown on such a major scale is also likely to lead to difficulties with supplying food, fuel and other provisions to the large numbers of people trapped within the boundaries of large cities.
Since the first reports, the new coronavirus has spread rapidly in several different directions- to other Asian countries, as well as to France, the US, Canada and Australia. This is a direct consequence of globalisation and the popularity of air travel, which has become the dominant mode of spread of pandemics, which usually spread by land or by sea routes in the past. Airports around the world have thus started to screen passengers coming from China, in particular documenting any symptoms and checking body temperatures using thermal sensors or thermometers. The effectiveness of these entry screening procedures remains debatable, as symptomless carriers of infection may easily pass undetected through the safety net. However, screening may allow the identification of passengers with a relevant travel history who have fever and respiratory symptoms. These people can then be isolated and undergo lab tests for coronavirus prior to being allowed back into the community as and when appropriate.
With any epidemic or evolving pandemic, it is important to identify the source as soon as possible, as part of the process of containment. Viruses are cellular parasites, incapable of living on their own, and can only replicate in other living cells. Coronaviruses, which are responsible for a variety of human respiratory illnesses including the “common cold”,thus usually thrive in animal reservoirs. Two previous major outbreaks of coronavirus infection-Severe Acute Respiratory Syndrome or SARS (2002-2003) and Middle East Respiratory Syndrome or MERS (2012)-are now believed to have resulted when the infection crossed over from bats to humans. It is anticipated that the source of the Wuhan epidemic will be identified within the ranks of the various live animal species being sold at its major wet market. This particular pandemic thus appears to be a direct result of the poorly regulated wild animal trade in China.
Once established in human hosts, further human-to-human spread is brought about by the airborne transfer of respiratory secretions in the form of “droplets”, such as by coughing and sneezing in close proximity. Contact transmission can also occur, when these droplets contaminate various surfaces, such as desks, counter -tops, water taps, handrails and door handles.
Most people infected with coronavirus probably only have a mild form of illness, and may hence not suffer from any symptoms whatsoever. This makes identifying those infected and controlling the spread of the infection a particularly difficult task. Symptoms of infection, which, when severe, can lead to respiratory failure and even death, include fever, cough and difficulty in breathing. In contrast with SARS, upper respiratory symptoms (sneezing, a runny nose and sore throat) and intestinal symptoms are much less likely.
Any epidemic or pandemic can lead to widespread anxiety and confusion in the minds of the public, which is compounded by information overload and the “viral” spread of misinformation. In the UK, it is important to follow advice from Public Health England and to avoid relying on unreliable advice and opinions from other sources, including reports in the media and statements by politicians. In particular, people in Britain who suspect that they might have acquired coronavirus infection are being advised to stay isolated at home and to ring 111 for help, rather than make their way to a GP surgery or an emergency department.
Our knowledge of this particular infection is, however, far from complete and continues to evolve with the passage of time. This means that actions related to the outbreak will continue to be updated. The WHO thus waited until January 30 to declare a Public Health Emergency of International Concern. By this time, over two hundred people had died from coronavirus infection in China, the virus had spread to at least nineteen countries, and there were reports of human-to-human transmission outside China. Despite this announcement, it is worth noting that the WHO did not, at the same time, recommend any restrictions on travel to, or trade with, China.
Notwithstanding the deficiencies in our knowledge of this new viral infection, simple infection-control measures such as frequent hand washing and covering one’s mouth and nose while coughing or sneezing must not be overlooked. While no specific treatment for coronavirus infection is available, it is just as well that most victims are likely to suffer only mild and self-limiting symptoms. This particular potential pandemic will undoubtedly provide an opportunity to review and accordingly update the nation’s response to future public health emergencies.
Ashis Banerjee
PS. The novel coronavirus has since been referred to as Covid-19 or SARS-CoV-2. The WHO finally declared a pandemic on 11 March 2020.