Animal trade in spotlight as China seeks source of coronavirus

Officials in China are searching to uncover the origin of the coronavirus outbreak, amid heightened scrutiny of the country’s poorly regulated animal trade.

Related: What is the coronavirus and how worried should we be?

Authorities believe the new strain of coronavirus came from a seafood market in Wuhan where wildlife was sold illegally. The World Health Organization has stated that an animal appears most likely to be the primary source, with experts suggesting it may have been carried by bats, badgers, rats or snakes.

The virus is from the same family of viruses as Sars, which was passed to humans from bats by the masked pam civets, and Mers, which was carried from bats to humans by camels.

Ian Jones, professor of virology at Reading University, said it was likely that the Wuhan virus had also been transmitted in the same way – passed from bats to humans through an intermediate host. “Something in the local area will have picked up this virus and it’s this something that would have been on sale in the wet market,” said Jones.

Though the 2002-03 Sars outbreak, which killed nearly 800 people, prompted efforts to regulate the wildlife trade in China, the tradition of eating endangered wild animals, or using wildlife to produce medicines, remains popular. Conservationists and health experts warn that such animals are being sold in unhygienic and cramped markets, allowing viruses to thrive.

Media reports suggest that about 50 wild animals, including endangered pangolins, were on sale at the market in Wuhan before it was closed at the end of last year. Photographs taken before its closure show snakes, porcupines and foxes crammed into cages. The sister of a vendor infected by the virus told China Business Journal, a state-owned paper, that snakes, ducks and wild rabbits were common at the market.

“The animal welfare part of this is obvious, but much more hidden is this stashing and mixing of all these species together in a very small area, with secretions and urine mixed up together,” Christian Walzer, executive director of the New York-based Wildlife Conservation Society, told Reuters.

The environment creates a perfect system to spread viruses, he said: “You couldn’t do it any better if you tried.”

Research published on Wednesday in the Journal of Medical Virology, which used analysis of the protein codes favoured by the new coronavirus, suggested it may have been snakes at the market that passed the virus to humans.

Some argue that the virus is more likely to have been passed on by a mammal. “In my view it’s very unlikely to be a snake because the jump from a reptile to a person is evolutionarily quite a long way,” said Jones, who added that while snake handling is common in the region, he is not aware of any individuals contracting this kind of virus after direct handling of snakes.

Badgers and rats were both cited as possible sources by Chinese government medical adviser Zhong Nanshan. The sale of live poultry has been banned in Wahun, where all outbound public transport has also been suspended.

Identifying the origin of the virus would not only enable officials to prevent its circulation, but could also allow scientists to understand if the virus has further evolved after infecting people.

On Wednesday, China’s national health commission vice-minister Li Bin told reporters there was evidence of respiratory transmission of the virus from patient to patient. Among those infected are 15 medical staff.

Reuters contributed to this report.