If you’ve even glanced at the news recently, you will have heard about the coronavirus. As of February 20 2020, Covid-19 has claimed 2130 lives, all but 11 inside China and the World Health Organisation has declared the outbreak a global health emergency.

What is the Coronavirus?

‘Coronavirus’ is a general term referring to a group of viruses that primarily affect animals, but are zoonotic, meaning the infection can spread between other animals and humans. There are seven strains of human coronavirus, including the recent Novel Coronavirus (‘novel’ acting as a placeholder name), which has been officially renamed Covid-19 (Coronavirus disease 2019) on February 11, 2020. Prior to this finalisation, the International Committee on Taxonomy of Viruses proposed the new virus to be named Sars-CoV-2 although this was met with resistance from the Chinese public (presumably due to the negative connotations of the name).

In humans, coronaviruses generally cause respiratory infections. Despite the severity of the current outbreak, most strains of coronavirus are relatively mild, including viruses causing the common cold. More dangerous forms include the SARS-Coronavirus which caused an epidemic of severe acute respiratory syndrome between 2002 and 2003. SARS was particularly dangerous because of its unique disease pathogenesis that affected both the upper and lower respiratory tract.

The Covid-19 Outbreak

Covid-19 was initially identified in late 2019 in Wuhan, the capital of China’s Hubei’s province. In December, a sudden cluster of 41 individuals suffering from pneumonia-like symptoms was confirmed as resulting from a new form of coronavirus.

The virus quickly spread to other Chinese provinces by early-to-mid January, helped by ‘Chunyun’: the period of travel in China with extremely high traffic load that begins around 15 days before Chinese New Year (25th January in 2020). International spread of the virus soon followed, initially to China’s major trade partners (e.g. Thailand- 13th January; Japan- 15th January). As of February 19, nine cases of Covid-19 have been confirmed in the UK with 8 out of the 9 people having completely recovered.

Determining the Origin Of the Covid-19

The majority of initial cases were found to be epidemiologically associated with the Huanan Seafood Wholesale Market.

Analyses of nine inpatients from three different hospitals in Wuhan were performed. Next Generation Sequencing was used to genetically analyse patients’ bronchoalveolar fluid (found in the lungs), allowing researchers to determine some of the genetic features of the Novel Coronavirus.

The viral genome sequences for the nine patients were extremely similar, with 99.98% of the sequence conserved between them. More notably, the Covid-19 sequence demonstrated 88% similarity to two forms of coronaviruses found in bats, while showing significant differences when compared to the SARS coronavirus.

Therefore, based on both genetic and epidemiological analysis, the proposed origin mechanism suggests that bats might have been the original host of the Covid-19, with animals sold at the Huanan market in Wuhan potentially acting as an intermediate host facilitating the transfer of the virus into humans.

What does the Covid-19 do to the human body?

Like most coronaviruses, symptoms are typically respiratory: cough and shortness of breath, together with a fever. Symptom severity can vary hugely between patients - pneumonia, kidney failure and death are all possible. The virus also causes much more damage in individuals with comorbidities such as diabetes or disorders affecting their immune system.

Worryingly, structural analysis of the Covid-19 virus has suggested that it may be able to bind to a specific receptor in the body called the angiotensin-converting enzyme 2 receptor. If these receptors are blocked, normal functioning of the heart and kidneys could be directly impaired.

The fatality rate after infection for the Covid-19 does not appear to be as high as the SARS strain, but given its rapid spread, it is difficult to predict exactly how serious its impact will be.

How does the Coronavirus spread?

Infected meat sold in wet markets can act as a disease reservoir for the virus, leading to a temporary ban on the trade and consumption of wild animals in China. It is migration and human-to-human transfer that has led to the novel Coronavirus spreading globally. Coronaviruses are spread primarily by close contact, particularly droplet infection (coughs and sneezes). There are some reports that even when the virus is in its incubation period, prior to symptom onset, it can be spread.

A Worrying Concern

Beyond the pathology of the Coronavirus epidemic, there are other troubling consequences. Recently, in the Chinatown district of Sydney, a 60-year-old man collapsed from a suspected myocardial infarction and was reportedly ‘left to die on the pavement’ because onlookers were too scared to perform CPR because of fears of the Coronavirus. Whilst concern about a severe epidemic is entirely understandable, it is unsettling that a perhaps preventable death, unrelated to the Coronavirus, occurred in such a manner.

Additionally, there has been a surge in racist incidents against Asian people with sharp declines in business in Chinese restaurants as well as students reporting racial incidents.

What Next?

There is currently no available vaccination for this new strain of coronavirus, which is one of the reasons why the spread has been so difficult to control. Since the virus’ genetic sequence was published on January 10th 2020, researchers have been working to develop a vaccine, but experts warn that the chances of the vaccine being developed in time to stop the current outbreak are slim, particularly as the clinical trials required to ensure that the vaccine is safe to be administered are extremely long processes. However, the Jenner Institute in Oxford has established a contract with Italian manufacturers ADVENT SRL for the first vaccine to be entered for clinical trials.

Whether it is better to focus on speed of treatment or absolute safety when developing new treatments for an epidemic is perhaps debatable, but for now it looks as though the only way to control the Covid-19 outbreak is by public health measures. The WHO has repeatedly stressed the importance of good hygiene, and quarantine and travel bans have been imposed on 15 cities in China, affecting over 40 million people.

Internationally, countries such as Australia, New Zealand, South Korea and more recently the UK have evacuated their citizens from Wuhan, placing them under quarantine.

The SARS epidemic was halted by international cooperation and quarantine. Therefore, experts are hopeful that careful public health measures and global unity can halt the spread of Covid-19 before it worsens significantly.