The novel coronavirus originating in Wuhan (2019-nCoV) is a zoonotic disease. It is an infection that has passed from animals to humans.
Humans have not developed immunity to such infections. That in turn means they are often more deadly, and spread rapidly.
According to the World Health Organisation, new zoonotic infections are becoming more frequent because of climate change and other human behaviour.
Zoonotic diseases are more likely to occur when populations of animals and humans that do not normally interact come into contact with each other. Climate change makes this more likely in a number of ways.
In areas affected by climate change there is more likely to be movement of human and animal populations, as habitats change. Encroachment of human settlements on animal habitat, and destruction and degradation of ecosystems, reduces the habitat available to wildlife and results in animals living closer to humans. Urbanisation also increases the populations of animals such as rodents and mosquitoes that commonly transmit zoonotic diseases to humans.
Human movement into new areas can also lead to increased farming of animals in the area. This brings new farm animal populations in contact with humans, and the nutrient-rich waste that results can increase the number of other animals such as insects and ticks that feed from it.
Populations affected by climate change are often under increased social and economic stress, which weakens the immune system, making infections more likely, and more widely spread.
As the world becomes hotter, our own immune system response of increasing body temperature in response to infection may become less effective against new pathogens. Increased temperatures are broadening the areas that mosquitoes can live in, and they are frequently responsible for transmitting diseases to humans.
A rise in sea levels results in more flood plains, and increased exposure of human populations to sea wildlife such as shell fish.
Our ability to produce medicines to combat illness is partly dependent on the availability of diverse ecosystems. For example, 25 % of modern medicines are derived from rainforest plants. Climate change and human behaviour continues to reduce these areas of rich diversity.
As well as causing climate change, a societal focus on trade and profit exacerbates the problem in additional ways.
The "wet market" in Wuhan has been implicated in the spread of 2019-nCoV. However the first cases of the virus are thought to have had no connection with the market. Economic conditions have led to impoverished farmers in China increasingly "farming" wild-life domestically to increase their income, and more farmers living in close quarters with wildlife.
More broadly, the misuse of antibiotics in intensive meat farming has led to resistant zoonotic bacteria such as MRSA in pig farming.
Concerns about trade and international relations, as well as the desire of government to control their population, are likely to be at the root of the suppression of whistleblowers in China. If Dr Li Wenliang’s warnings had been heeded, then containment of the virus could have started six weeks earlier.
Zoonotic pandemics can have global implications, such as the 1918 flu pandemic that originated in birds and killed at least 45 million people.
The increasing risk of zoonotic pandemics is a global threat and require a global response. The current outbreak demonstrates that capitalist states are capable of international collaboration, and rapid technological investment in the face of this current "health emergency". But the action is largely being taken "after the horse has bolted".
To decrease the risk of future outbreaks, ongoing rational measures are required on the basis of human need rather than profit. These include:
• Reforestation – by replanting forests, and conserving existing forests, ecosystems can be protected, climate change reduced, and sources of future medications preserved. Projects such as "One Health" have demonstrated that the preservation of ecosystems can reduce zoonotic disease.
• Technology and research – for the benefit and use of humanity rather than for profit. Researching medications that will be useful in future outbreaks. Studying further the risk factors so preventative measures can be taken.
• Public health – of animals and humans, as well as social and economic measures to reduce stress and illness.
• Decrease in animal farming – and with it reduction in use of antibiotics, and of close contact between humans and animals.