The ZJE Institute (Zhejiang University - University of Edinburgh)

The only thing we fear is fear itself ?

Prof. Sue Welburn, Executive Dean of Zhejiang University-University of Edinburgh Institute and Chair of Medical and Veterinary Molecular Epidemiology, has analyzed several possible outcomes of 2019-nCoV

Portrait photo of professor Sue Welburn

As humans, we have lots of fears; fear of snakes, fear of heights, fear of spiders and of course fear of diseases. In 1933, Franklin D Roosevelt the 32nd President of the US at the lowest point of the Great Depression said “let me assert my firm belief that the only thing we have to fear is...fear itself — nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance”. These words are as important today as they were back in 1933, as China now battles an unseen enemy causing fear and heartbreak in communities. Fear can cause unjustified terror that impedes public health efforts to contain the spread of infection.

In December 2019, a new illness emerged in Wuhan, caused by a novel RNA coronavirus, 2019-nCoV – a virus that seemingly came from nowhere, unknown to science. Suddenly, everyone was working day and night to manage the impact of this tiny little pathogen, to try and stop its spread regionally and globally, and to work to develop drugs and vaccines to prevent a global pandemic. The speed at which 2019-nCoV is spreading is truly incredible and the response of the PRC (and globally) is unprecedented.

The disease is so new and there are so many unknowns. We do not know where it came from, how it spreads or how deadly it really is? We don’t know how the outbreak will end, but experience tells us that it will end. There are several possible outcomes.

Firstly, that the spread of 2019-nCoV is brought under control by extensive public health interventions (fast diagnosis, isolation and effective treatment of affected individuals, close identification of close contacts and their treatment). This is how two previous coronavirus outbreaks - SARS and MERS ended. Both viruses had made the jump from animals to humans and spread between them. SARS infected 8,096 people, and killed 774 people across 17 countries, but by 2004 SARS was no longer a public health problem. For SARS, health authorities identified cases quickly isolating and treating infected cases to prevent the infection spreading. Airports screened international travelers to establish whether they had been in contact with the virus. Today SARS may still exist in reservoir animal hosts, for example the forest civet, but it is not spreading among humans.

SARS could be contained, infected people, mostly did not spread the virus until they were showing symptoms, so when someone was sick, they were identified quickly, placed in quarantine and transmission was stopped.

2019-nCoV appears to be able to spread before any symptoms arise making it harder to contain. People do not know they are sick before they spread the virus to other people, and as they are not feeling ill, they will not seek medical care. SARS also conveniently tended to stay within the hospital or healthcare setting with transmission fueled by a few “super-spreaders” who were disproportionately infectious.

The 2019-nCoV outbreak has outpaced SARS. A new mathematical model published in The Lancet suggests that up 75,800 people in Wuhan may have been infected by January 25 but also showed that if transmission could be reduced by a quarter, the growth rate of the outbreak would slow down.

Secondly, the virus might die out after it infects all or most of the people that are most susceptible to it. Disease outbreaks need susceptible individuals to spread and a virus outbreak will stop when there are no susceptible people left to infect. The 2015-2016 Zika virus epidemic infected >35,000 people but died out when the number of susceptible individuals reduced. People who were most at risk of coming into contact with Zika carrying mosquitoes had already been exposed to the disease. Zika is still around today but is not spreading. If 2019-nCoV runs low on susceptible individuals to infect, for example people showing some immunity, then public health interventions can finish it off. 

Lastly, 2019-nCoV may become yet another common seasonal virus, as has been seen before for flu. In 2009, a new flu strain H1N1 emerged and became pandemic but eventually became part of the normal flu architecture each flu season. 2019-nCoV could become another one of the 4 coronavirus strains that commonly infect humans every year, in China or globally. 

Ultimately, the outbreak of 2019-nCoV will likely be ended with the invention of a new vaccine(s) but development and deployment may take some time. In the mean while we need to support a strong public health response such as is being launched in China. It is important to keep fear at bay and this virus in perspective, each year globally 500,000 people die of flu and many more would die of flu if we did not have flu vaccination programmes for high-risk groups.