It's also raising questions about how it could happen again after the lessons learned from the 2002-2003 outbreak of SARS, or Severe Acute Respiratory Syndrome, which was traced to consumption of wild animals in the southern city of Guangzhou.
Demand for wild animals in Asia, especially China, is hastening the extinction of many species, on top of posing a perennial health threat that authorities have failed to fully address despite growing risks of a global pandemic.
In response to the crisis that has been centered in the big industrial city of Wuhan, China's Agriculture Ministry issued an order earlier this week ordering tightened controls on trade in wildlife.
The New York-based Wildlife Conservation Society, meanwhile, appealed for an end to wildlife markets everywhere, not just in China.
Zoonotic diseases, or those contracted by humans that originated in other species, account for a large share of human infectious illnesses. Not all of them come from the wildlife trade: rabies is endemic across many species and one of the biggest causes of death in the developing world. But mixing species of wild animals increases the risk of diseases mutating and growing more virulent as they spread in unregulated markets, experts say.
The emergence of such diseases is a "numbers game," said Christian Walzer, executive director of the Wildlife Conservation Society's health program.
"If these markets persist, and human consumption of illegal and unregulated wildlife persists, then the public will continue to face heightened risks from emerging new viruses, potentially more lethal and the source of future pandemic spread," he said. "These are perfect laboratories for creating opportunities for these viruses to emerge."
The order issued by the Ministry of Agriculture and Rural Affairs, dated Jan. 21, banned all shipments of wild animals out of Wuhan. It also called for stepped up inspections and for raising public awareness about the risks of eating them.
Researchers have not yet announced a definitive source for this latest outbreak, which like many other viruses can infect multiple species.
One of the first measures taken by Wuhan authorities was to close down the Huanan Seafood Wholesale Market, where 41 of the first cases originated.
"That's the big black box right now," said Jon Epstein, an epidemiologist with the Ecohealth Alliance.
He was in China following the SARS outbreak and helped the ongoing global effort over nearly two decades to find the wild source of that virus, which sickened more than 8,000 and killed less than 800. SARS has been linked to various animals, including bats and the cat-like masked palm civet.
Bats are known to harbor coronaviruses, but scientists have yet to fully understand the new virus and how it leapt from animals to people.
Epstein said researchers suspect but haven't proven that the Wuhan virus came from bats. Before it infected humans, it likely first jumped to an as yet unidentified mammal.
"There's no plausible evidence to support snakes being involved with this virus," Epstein said, referring to recent media speculation criticized by a recent article in Nature. Researchers don't know which species exactly were sold in the Wuhan market, but Epstein said mammals commonly found in such markets—such as ferret badgers, raccoon dogs or civets—might be involved in the transmission of the new virus to people.
The crackdown on wildlife trafficking and sales persisted only about six months after the SARS outbreak faded in mid-2003, Walzer said.
"The solution is simple," he said. "In the sense that we know where the problem is."
In cities like Beijing, Shanghai and Hong Kong, there's little sign of markets catering to gourmands seeking "ye wei," or "wild flavors."
But in provincial cities and in some parts of Laos, Vietnam, Cambodia and other Southeast Asian countries, those determined to eat such exotic dishes can find all sorts of creatures for sale: pangolins, badgers, salamanders, scorpions, hedgehogs and even wolf puppies.
A photo of a menu list from a vendor in the Wuhan market called "Wild Game Livestock for the Masses," circulated online, showed more than 110 species for sale.
Court records show that authorities in Hubei, the province where Wuhan is located, investigated 250 cases related to wildlife trafficking and poaching in 2019 alone. According to local media reports, since 2018 an estimated 16,000 wild animals were hunted in the province of more than 60 million people.
Hubei is home to Shennongjia, a UNESCO World Heritage nature reserve that is a habitat of great biodiversity with many rare species including the clouded leopard, golden snub-nosed monkey and the Chinese giant salamander.
Video footage filmed by a conservation activist in eastern China's Zhejiang and Anhui provinces, which also have a long tradition of consuming wild species, showed many wild species laid out for inspection in a market.
In most cases, vendors are registered to sell some unprotected species, usually a limited amount of just a few, such as hares, wild boar and muntjac, a kind of tiny deer.
But enforcement is "not that strict," said Tian Jiang Ming of the Anti-Poaching Squad, a group of volunteers who visit markets are report on illegal wildlife sales. The illegal offerings tend to be kept hidden away in back freezers, he said.
"The vendors are selling illegally poached animals with these licenses in hand," he told The Associated Press.
Only in 2014 did China criminalize consumption of protected species with a law specifying a maximum three-year jail term. But it also has allowed commercial farming of certain species, including tigers — a practice that conservation advocates say encourages illicit trafficking in protected species.
It's difficult to secure prosecution since it's hard to prove animals have been poached, Tian Jiang Ming said.
"The forestry department needs to prove illegal poaching by the sellers but they don't have the investigative resources to find them," he said.