Public health experts have warned that China’s live animal markets are a perfect breeding ground for emerging infectious diseases, with one expert branding them a “recipe for disaster”.
The source of the novel coronavirus, a new pneumonia-type illness which has infected nearly 600 people in China and killed 17, was a seafood market in the central Chinese city of Wuhan.
The animal source of the outbreak has not been identified but two recent research papers have pointed to bats and snakes as the possible culprits.
The market in Wuhan, now shut down, was home to stalls trading in many different animals, including snakes, marmots and poultry.
Purchasing food from these so-called “wet” markets is popular in China as consumers like to purchase their meat “warm” - that is, recently slaughtered.
Jonathan Ball, professor of molecular virology at the University of Nottingham, said it was poor practice to keep many different species of animals in “cramped conditions and in close proximity, and then also to add humans into the mix”.
“If you have a viral infected animal introduced into that they can first pass that virus among animals of their own species and amplify that infection. Second of all, they can pass it to other species which may act as an intermediary host and pass it more easily to humans.
“So live animals, lots of species and cramped conditions - it's a recipe for disaster,” he said.
China has been the source of many “zoonotic” disease outbreaks in recent years - diseases which jump from animals to humans.
The severe acute respiratory syndrome outbreak of 2002 to 2003 - a coronavirus closest genetically to this new strain - originated in civet cats, a delicacy in parts of China.
Dr Gordon Woo, a risk management specialist, said that in China, and other parts of Asia, eating wild animals was common.
“Wild animals are brought in from the forest and there is no regulation - the only way to control this is to ban the selling of wild animals. That won’t happen because there are livelihoods at stake. What is needed is very good disease surveillance in these markets so when a problem arises the authorities are quick to pounce on it,” he said.
The country has also seen a devastating outbreak of African swine fever - this disease does not harm humans but experts say it has emerged because of the number of pigs kept in unregulated, backyard farms.
In his book The End of Epidemics, Dr Jonathan Quick a former public health specialist for the World Health Organization, warned of the epidemic potential that zoonotic diseases pose.
He told the Telegraph that pathogens in farmed animals were well monitored - there have been several outbreaks of the highly pathogenic H5N1 avian influenza in poultry in recent years but none have spread to the human population because rigorous disease surveillance picks up the infection and the animals are culled.
“When you have this viral soup and you have a collection of pigs, poultry and bats as you had in that market in Wuhan it’s a perfect incubator of diseases,” he said.
Dr Michael Osterholm, director of the Centre for Infectious Disease Research and Policy at the University of Minnesota, said that live animal markets were a problem throughout Asia.
"I’ve been in a market in Bangkok which was almost a mile by a mile inside - you can find almost any animal imaginable. I have a picture where there are cages full of ferrets and on top of them are chickens. From an influenza standpoint, birds and animals together are not good,” he said.