Wuhan coronavirus: Where did virus originate? Experts divided over Chinese seafood market origins
Initial evidence pointed toward the local seafood market because several of those infected in the beginning worked there. The market has been shut since January 1, 2020. Further, China has temporarily pulled the plug on all wildlife trade
The race to figure out the source of the deadly and mysterious Wuhan coronavirus is still on, as experts are yet to reach consensus on whether the virus originated from Wuhan's local seafood market where bats and snakes were being sold until recently.
The virus is zoonotic, meaning the virus jumped from animals to humans. Scientists have been trying to figure out the source of the infection. Initial evidence pointed toward the seafood market because several of those infected in the beginning worked there. The market has been shut since January 1, 2020. Further, China has temporarily pulled the plug on all wildlife trade.
Scientists with the Chinese Center for Disease Control and Prevention said tests show that the virus originated from Wuhan's seafood market, News.com.au reported, citing China’s state-owned Xinhua news agency. This is, however, unconfirmed at the moment.
Recently, researchers who read the genes of the Wuhan coronavirus suspected that it may have jumped to humans from snakes. However, other researchers were not convinced: they believed that the virus may have jumped from mammals like bats kept in the market, instead of snakes -- just like SARS, which is closely related to the Wuhan coronavirus.
But another study's findings suggest that the virus may not have originated from the seafood market. Now, a group of Chinese scientists released their analysis of the first 41 patients infected with the virus. Of them, 27 (66%) patients were directly exposed to the seafood market. Their data also show that, in total, 14 of the 41 cases had no link to the marketplace.
"That’s a big number with no link,” Daniel Lucey, an infectious disease specialist at Georgetown University, who was not involved in the study, told Science.
The first patient who showed symptoms on December 1, 2019, had no reported link to the seafood market, according to Science. “No epidemiological link was found between the first patient and later cases,” the authors wrote. However, it is possible the virus may have infected people in November and remained undetected until December. And those infected may have carried it to the seafood market, according to Lucey.
“The scenario of somebody being infected outside the market and then later bringing it to the market is one of the three scenarios we have considered that is still consistent with the data. It is entirely plausible given our current data and knowledge," Kristian Andersen, an evolutionary biologist at the Scripps Research Institute who has analyzed sequences of the Wuhan coronavirus, told Science.
According to experts, the most conclusive method would be to take samples from the animals in the market but the market has since been cleared and disinfected.
The key to solving this origin puzzle is retrospective analyses of blood samples in China from people and animals—including vendors from other animal markets, Lucey said. “There might be a clear signal among the noise,” he added. Many hope that genetic tests of animals or environmental sources, such as cages and containers, from the Wuhan market will turn up clues.