The UK only has one real immediate defence against the coronavirus – quarantine

With four more confirmed cases, our chance of stopping the outbreak is reliant on more traditional ‘on-the-ground’ public health measures

The number of confirmed cases of the 2019 novel coronavirus (or the “2019-nCoV” as it is known as in medical circles) within the UK has doubled from four to eight this morning after an additional four cases were identified. These patients linked to a previously known cluster of cases in France after likely picking up the infection in Singapore.

As the UK government declares “a serious and imminent threat” to public health and outlined plans to allow forcible quarantine of suspected cases, the risk to the UK remains “moderate”. In the absence of a vaccine or effective antivirals, preventative measures such as isolation and quarantine are critical tools and are all we have against the novel coronavirus.

The novel coronavirus (a cousin of the Sars coronavirus) epidemic seems to have begun with a handful of cases in association with a live animal market in the city of Wuhan in central China in December last year. Over the last two months, the new human virus has spread rapidly to at least 37,000 people, killing 812 with over 6,000 still in a serious condition.

The mortality rate of novel coronavirus has been estimated to be between 1 and 2 per cent. Although the major burden of novel coronavirus remains in mainland China (the Hubei province in particular), the virus has made its way to 24 other countries across East Asia, Europe, the Middle East and North America.

While any person seems at-risk of catching the 2019-nCoV, there is a wide spectrum of diseases associated with infection. Originally detected due to a cluster of a fatal lung infection called pneumonia resulting in coughing, fever and shortness-of-breath, many cases remain mild, much like the cold. Given the tight association of novel coronavirus with the lung and respiratory tract, transmission is likely via coughs, sneezes or direct contact with respiratory secretions (basically snot) either through direct or indirect contact.

Evidenced by the rapid international spread of the novel coronavirus and confirmed clusters of cases of person-to-person transmission, it clearly moves efficiently. Epidemiologists have preliminarily estimated 2019-nCoV spreading in a number called R0, that on average each infected individual may infect 2-3 others (R0 = 2-3). Of course in real life, this average could hide a wide variation in how much it spreads, with many infections possibly failing to spread, while others associated with so-called “super-spreading” events go on to infect lots of people.

All methods to quell an outbreak focus on driving the R0 to less than one, meaning that over time the epidemic will peter out. Although you are likely most infectious when experiencing worse symptoms, there is evidence that 2019-nCoV spread is associated with milder disease that may not precipitate a trip to the hospital. Given that there is no vaccine against 2019-nCoV yet, our chances of stopping outbreaks rely on traditional "on-the-ground" public health measures such as isolation and treatment of confirmed cases; tracing of infected peoples contacts at-risk of catching the virus; and quarantine of any suspected cases waiting the 14 days corresponding to the longest incubation period.

The 2019-nCoV epidemic continues to highlight multiple disparities in preparedness across the world. On the one hand, within weeks of detections of the outbreak, scientists in China had identified the virus and shared its genome sequence with the world, allowing for the development of diagnostic kits. Similarly, rapid communication of the outbreak development allowed international preparedness and, as the scale of the outbreak changed, China enacted brave isolation/quarantine and treatment measures.

On the other hand, many unknowns persist surrounding the future of 2019-nCoV and the very real possibility that all our best efforts may only slow down an impending pandemic as international cases rise without links to China. This is especially true when you imagine the toll that a 2019-nCoV may take on public health systems in resource-poor countries across Africa and Asia.

Furthermore, there remains significant gaps in our ability to respond to epidemics from viruses previously unknown to science, in particular in the lack of proven therapeutics or prophylactics such as vaccines. Ultimately, it is research into these viruses and how they infect people and cause disease that will result in safe and effective ways to shut outbreaks down that may very well be crucial in our struggle against viruses like 2019-nCoV.