How the coronavirus started in China — and why that's actually a saving grace
By Simon Reid
Updated about 9 hours ago
PHOTO: China is one country that has undergone the most substantial and rapid transformation in its human demography. (Reuters: China Daily CDIC)
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The emergence of a new coronavirus in China has once again raised the spectre of a global pandemic.
It wasn't that long ago that we had our last pandemic (the H1N1 virus in 2009, also known as "swine flu") and less than 20 years since the 2003 emergence of SARS, another coronavirus that was highly lethal to humans.
The emergence of the "new" disease requires the virus to spill over or "jump species" from its reservoir into people. This event is complex and needs close contact, as well as a virus that can infect humans (not many animal viruses can).
To truly emerge, the virus then has to possess the ability to infect other humans (even fewer can do this).
The concern now is that the
new coronavirus is showing it can do this last step, albeit, in a limited way so far.
The human-animal interface
Humans mostly interact with domesticated animals directly through agriculture and as pets.
In the past, this has led to the emergence of human diseases that are still with us — for example, measles from cattle and whooping cough from dogs.
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Humans also interact with wildlife through hunting and as a consequence of our use of their habitat to grow food and houses. This leads to diseases such as Hendra and Ebola.
The wildcard in all this is human behaviour driven by cultural and social norms. For example, the presence of live animal markets in parts of Asia is strongly associated with the spread of avian influenza and the origin of SARS — and we're seeing it again this time with the
Wuhan coronavirus developing in China.
Basically, the more we interact, the greater the probability of a spillover of a pathogen.
The more often that happens, the greater the chance of us receiving one that is perfectly suited to human-human transmission.
The most significant driver of emergence, however, is food production.
PHOTO: The presence of live animal markets in parts of Asia is strongly associated with the spread of avian influenza and the origin of SARS. (Reuters: David Gray)
So why is it happening in China?
The rate of emergence of new human pathogens appears to be accelerating. A recent study suggested that over half of all emergences are associated with food production.
This is directly related to the size and prosperity of the human population. In order to grow food, we use land, water and energy.
If you consider that human activity is a necessary requirement, then China is one country that has undergone the most substantial and rapid transformation in its human demography and land use.
PHOTO: The emergence of the "new" disease requires the virus to spill-over or "jump species" from its reservoir into people. (Reuters)
There have been rapid shifts in where people live (urbanisation), what they eat and how they use the land.
The food production systems needed to support this transformation are highly complex and on an industrial scale.
At the same time, there remains a strong cultural preference for live animal marketing and the consumption of a wide variety of different animal species.
Newly emerging viruses may well be a sentinel of a system that is out of balance.
What can be done to reduce the risk?
Solving the problem is not as simple as changing diets, however.
We still have to grow what we eat, largely using land, and while farmed animals are the source of many human pathogens, an increasing number come from wildlife (including bats and wild birds).
Wuhan virus 'super-spreaders'
One of China's top health experts warns potential "super-spreaders" could worsen the impact of the new coronavirus strain, which can now be passed between humans.
There is no guarantee that switching away from animal diets will solve the problem, because the changes needed in the food system could have unintended impacts on other parts of our ecosystem, such as natural forests and their wildlife.
There are also extremely strong cultural preferences around diet, so it may be the hardest change to make.
The biggest risk now is the
rise of "super-spreaders". A single person (super-spreader) was responsible for moving SARS from China to a single hotel floor in Hong Kong and from there to multiple countries.
A super-spreader is a bit like a large ember in a bushfire. If an ember falls in a place with no fuel there is no fire. If it falls where there is an unlimited amount of fuel and the conditions are right, we get a wildfire.
The ideal fuel conditions for a new virus are lots of humans living and interacting close together — like a large city.
That is not to say there is nothing we can do.
PHOTO: The ideal fuel conditions for a new virus are lots of humans living and interacting close together — like a large city. (AP: Andy Wong)
Reducing the "conflict" between human and natural systems — for example, by reimagining how we use land to make better allowances for natural habitat — will help take pressure off food systems, while addressing other environmental concerns like climate change, deforestation and land degradation.
Stopping the spread
Despite the risk of "super-spreaders", the emergence of new diseases in places like China is actually a saving grace.
China has an excellent system and massive capacity to investigate and control diseases, and the country's response to recent disease emergences has been highly transparent, competent and effective.
PHOTO: China has an excellent system and massive capacity to investigate and control diseases. (Reuters)
There is a global effort to monitor infectious diseases and coordinate response and information-sharing, led by the World Health Organisation.
It requires countries to demonstrate they have holistic systems that include cooperation between animal and human health agencies (One Health).
This works well in rich countries, but many poorer nations need support.
The scariest threat is the prospect of antimicrobial resistance.
PHOTO: There is a global effort to monitor infectious diseases and coordinate response and information sharing. (AP: Mark Schiefelbein)
If we lose antibiotics, then we are back to square one, with simple skin infections and seasonal influenza outbreaks resulting in high death tolls.
Our biggest risk now is human apathy. Unfortunately, antimicrobial resistance does not raise the pulse of politicians like a good outbreak of SARS.