Skip to main content

The coronavirus didn't really start at that Wuhan 'wet market'

The first case of SARS-CoV-2 didn't emerge from a Wuhan wet market, according to experts at the Wuhan Institute of Virology (WIV).

Instead, the live animal market may have been the site of a superspreader event, where one person spread the virus to many other people, one US-based expert told Live Science.

Since the early days of the coronavirus pandemic, reports have suggested that SARS-CoV-2 (the virus that causes COVID-19) jumped from animals to humans in Wuhan's Huanan Seafood Wholesale Market. Now, experts at the WIV have said publicly that the theory was wrong, and that the virus must have originated elsewhere, according to a Wall Street Journal report

"I haven't seen anything that makes me feel, as a researcher who studies zoonotic disease, that this market is a likely option," said Colin Carlson, a professor at Georgetown University who studies the spread of such zoonotic viruses, which transmit between animals and humans. Carlson does not work for the WIV.

Related: How does the new coronavirus compare with the flu?

The theory was plausible, he said. For a virus to jump from animals to humans, the animal host needs to come into contact with humans somewhere. And viruses often jump from one animal to another before breaking into the human population. In fact, the genome of SARS-CoV-2 is most closely related to coronaviruses isolated from horseshoe bats in China. From there, scientists suspect the virus may have jumped to another animal and then hopped to humans. Wet markets, where lots of different species of live animals are clustered, and lots of humans come into contact with them, offer opportunities for that sort of transmission. And the outbreak of another coronavirus, dubbed SARS, began at a similar market in 2002, after that virus spread from bats to civets.

A number of early cases of the outbreak in Wuhan were tied to the Huanan Seafood Wholesale Market. Later, researchers took environmental samples that suggested the virus had landed on surfaces in the market. But in the period since, tissue samples from the market's animals have revealed no trace of the virus. For the virus to jump from animals to humans, the animals have to actually be carrying it.

"None of the animals tested positive. So since January, this has not actually been particularly conclusive. But this has developed into a narrative," he said.

Carlson said his colleagues in China have been careful and precise in their work, publishing data according to international regulations that any scientist anywhere in the world can examine, and that strongly supports the conclusion that the Huanan Seafood Wholesale Market wasn't the source of the virus.

One reason this idea has gained such traction is that it dovetails with conservation efforts. Many wet markets sell exotic, endangered and highly trafficked animals such as pangolins. And it would be a victory for animal conservation, he said, if markets like this one were shut down after being blamed for the disease. But that doesn't mean that the evidence is there.

"This is an animal-origin virus that made the leap, maybe from bats to humans, maybe through… another animal, maybe through livestock. And we don't have the data yet to know where or how," he said. "That takes time. The study that really definitively showed the bats that SARS came from was published in 2017," roughly 15 years after the outbreak first occurred.

"It took that long to go through caves, to go through samples, and build an evidence base where we could confidently say: 'This was the sort of bat, in this cave, at this time," Carlson said.

So when will we know for sure where SARS-CoV-2 came from? Ruling out one site took a few months. Finding the definitive origin site will likely take much longer, he said.

Originally published on Live Science.

OFFER: Save 45% on 'How It Works' 'All About Space' and 'All About History'!

For a limited time, you can take out a digital subscription to any of our best-selling science magazines for just $2.38 per month, or 45% off the standard price for the first three months.View Deal

  • Ralph J. Cook
    I wonder why it has taken so long for the science media to catch up with something I knew and published on my Facebook account in February. It was obvious that the outbreak did not begin at Wuhan wet market once it was known that patient zero, an elderly housebound man had been admitted to hospital on 1st December and the virus causing his illness had been isolated on the 8th of that month. The Wuhan patients from the market started being admitted to hospital by mid-December so it is clear they were introduced to the disease after the elderly man, who himself must have been infected by someone who caught the virus around 15th-25th November. Furthermore several studies looking at mutations in the virus have predicted the virus infecting humans before mid November and one has implied August 2019 as the date of first infection. No-one really knows and it is equally possible that this virus has resided in humans for years. It is likely that the virus emerged in a rural area, anywhere between several years and a few months before December last year, circulating at a low level in the local population, gradually adapting to life in its "new" human host. I also doubt infection arose from contact between humans and any of the animals so far proposed as possible intermediary hosts. My personal theory is that not enough attention has been focused on the Chinese intensive meat-rearing industry - particularly pig farms. The only attempt I know about to introduce the virus to swine was one in which a virus sample was applied to the nose of pigs, this apparently failed to secure infection. Yet we know that pigs are very susceptible to coronavirus infection and we know a pig became infected with SARS-Cov in 2004 by its owner. Whilst I recognise that is not in anyway conclusive, I am suspicious as to why there has been so little interest in the possible link between pigs and Covid-19.
  • S at Cumae
    How will we ever know the truth? This took place in a cruel and repressive dictatorship. The corrupt and mendacious Chinese Government will always lie, as it has lied about the number of deaths and cases. The deaths are doubtless in the millions.
    We cannot trust ANY data or information that comes from the twisted mouths of these tyrants.
  • raywood
    This article provides a welcome change of direction from the politicized LiveScience article published on March 21. It would have been better if LiveScience had not required two months to think about my rebuttal, among the many that pointed out flaws in that March 21 article. Let it be a reminder that politicizing science in order to feel superior to people of a different viewpoint may just set you up to look ridiculous.
  • JoeF
    Ralph J. Cook said:
    I wonder why it has taken so long for the science media to catch up with something I knew and published on my Facebook account in February.

    You were doing well to work it out in Feb, I published it on 4 April - in
    Were China and WHO too slow?
    It's become obvious from Italy and America that this thing never starts with a pneumonia cluster but wanders round for several months until it just happens to hit enough severe cases to get noticed.

    By the way, it probably did but it is not even guaranteed it came from China. Wuhan gets so many people going in and out from abroad it could have come from anywhere. 'Variant C' the European one not found in China, might in fact be the ancestral strain. I think everyone in Europe should be checking their case lists back as far as September, like the doctor in France who found his old CV case from mid December among his pneumonia cases.
  • Willie
    Well, I don't know where it came from, but I had it in early December before it was popular. I got it from a relative who had it around Thanksgiving. My brother and his wife, 1000 miles away had it in January and his wife was hospitalized. Interesting to note that the relative I got it from works in the school district of the location that became the first hot spot of that state when it became popular. I was not sure if I really had it until a month ago when a contractor that works at the same site as me came back from his 14 day quarantine and described all his symptoms to me. It was like an instant replay of my first two weeks of December 2019. BTW, I live in South NJ across the river from Philadelphia PA. Might explain why North Jersey was later a hot spot but South Jersey had very few reported cases because we already had it. I think it is accurate to say that the novel corona virus has been around for quite some time. I just want to add that the CDC statistics for the 2017-2018 flu season for the US sites over 61,000 deaths and nobody even blinked an eye and that number is the highest number of flu deaths in the CDC 2010-2018 time frame.
  • sarajo
    it did come fom China -it was Wuhan where it started -next thing we know the whole world has caught it so Thanks a lot China1!!
  • Duaney
    This virus has certainly been one of the worse of all time. As severe as it's been, it isn't hard to believe that it could have been engineered somehow. If it is eventually found to have come from some exotic animal, then all steps need to be taken to insure that it never happens again. China's actions have been reprehensible and they're guilty of crimes against humanity. If I'm not mistaken, there are still a group of Chinese whistle blowers that are unaccounted for.
  • neulon2
    admin said:
    It looks like early reports that COVID-19 first infected humans at a particular live animal market in Wuhan were wrong.

    The coronavirus didn't really start at that Wuhan 'wet market' : Read more
    do any of you remember the research crew who died in that plane crash coming from antartica it was about a year ago they seemed to be running from something maybe im wrong they may have all been sick cover up posible
  • sarajo
    It did start in China -in Wuhan I double checked it & it is confirmed on a website that it DID start in an animal market apparently from bats

    If you check out various old new s websites it will indeed confirm its origin which is in Wuhan