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New coronavirus may have started in bats. But how did it hop to humans?

a closeup on the face of a horseshoe bat
(Image: © Shutterstock)

As a new coronavirus spreads in China and around the world, scientists are scrambling to find out exactly where it came from. Now, a new study provides more clues to the virus' origins, and points to bats as the most likely hosts.

In the study, published today (Jan. 29) in the journal The Lancet, the researchers analyzed 10 genome sequences of the novel coronavirus, dubbed 2019-nCoV, obtained from nine patients in China who were sick with the virus. 

They found that all 10 of the genome sequences were extremely similar — they shared more than 99.98% of the same genetic sequence, the authors said. This suggests the virus made its "jump" to humans very recently, because if that jump had happened long ago, the virus sequences would have differed more, given the fast rate at which viruses tend to mutate and evolve.

"It is striking that the sequences of 2019-nCoV described here from different patients were almost identical," study co-lead author Weifeng Shi, a professor at the Key Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in Universities of Shandong Province, affiliated with Shandong First Medical University, said in a statement. "This finding suggests that 2019-nCoV originated from one source within a very short period and was detected relatively rapidly." 

Related: 10 deadly diseases that hopped across species

Despite emerging in humans only recently, the virus has already infected about 6,000 people and caused 132 deaths in China, while spreading to 15 other countries, according to the World Health Organization. Most of the initial cases occurred in people who worked at or visited the Huanan seafood market in Wuhan, China, where a variety of wild animals were sold.

To learn more about the virus' origins, the researchers compared the 2019-nCoV genetic sequence with those in a library of viral sequences, and found that the most closely related viruses were two coronaviruses that originated in bats; both of those coronaviruses shared 88% of their genetic sequence with that of 2019-nCoV. (When compared with two other coronaviruses known to infect people — SARS and MERS —  2019-nCoV shared about 79% of its genetic sequence with SARS and 50% with MERS.)

Based on these results, the authors said the 2019-nCoV likely originated in bats. However, no bats were sold at the Huanan seafood market, which suggests that another yet-to-be-identified animal acted as a steppingstone of sorts to transmit the virus to humans.

"It seems likely that another animal host is acting as an intermediate host between bats and humans," said study co-lead author Guizhen Wu, of the Chinese Center for Disease Control and Prevention.

Overall, the outbreak of 2019-nCoV "again highlights the hidden virus reservoir in wild animals and their potential to occasionally spill over into human populations," the authors wrote.

A previous study suggested snakes, which were sold at the Huanan seafood market, as a possible source of 2019-nCoV. However, some experts have criticized the study, saying it's unclear if coronaviruses can infect snakes. 

Originally published on Live Science. 

  • Lovescience
    "However, some experts have criticized the study, saying it's unclear if coronaviruses can infect snakes." Snakes could still be a carrier even if they aren't infected.
    Reply
  • Phoenixtonia
    Yes but how would bats get the virus?
    Reply
  • Alphavillan
    I blame Batman he shouldn't have kissed that bat when The Joker dared him to.
    Reply
  • Trythone
    Lovescience said:
    "However, some experts have criticized the study, saying it's unclear if coronaviruses can infect snakes." Snakes could still be a carrier even if they aren't infected.
    No, they couldn't. The carriers are still infected, i.e. the virus lives and reproduces in them. It is just not numerous enough to provoke symptoms. But coronaviruses can't live in cold-blooded animals at all.

    Moreover, the evidence in the "snake" paper is very weak itself. They do not compare the sequence of nCov with any actual snake virus. They just use similarity in codon usage bias in nCov and in two snake species as an argument. But same codon usage patterns can arise independently in different species. It is not a direct evidence.
    Reply
  • Truthseeker007
    First it was snakes now it is bats. How about it was created in a laboratory. Scientists can do that you know and they can make new variations of Coronaviruses. That is like when they were saying AIDS came from monkeys when later it was found AIDS was created in a laboratory and spread through a" new type" of Hepatitis vaccine. The mainstream news won't tell you that though. Pushed right under the rug.
    Reply
  • sohosaints
    Hi - first time I've posted here,

    I'm a science student from the UK & have been seeing the whole virus unfold via news,fake news etc - its hard seprating the truth to the resident evil beginnings sci fi also.

    Nobody says the truth so I will - not wanting to offend but countries like china have such a odd way of living, from the pollution of mass manufacture to the high end eatries - we know that resturants & supermarkets in china sell animal products to use & eat, I've seen vidoes of even leemas being eaten, bats with the stomaches open filled with food & the truth is they have eaten a speices which is a step too far & its going to bite us all if action isn't taken, I don't think this outbreak will become an epidemic but the next one might.

    Before everybody sdays racist, bigot etc, oh the young guy from england is a fool, I'm from a mixed race background myself & part of my background has french & poss spanish in it so that agruement won't wash. My view is liberal of science & life, being a young homosexual male has that effect.

    Another thing that has really annoyed me is the fact that - this is a possible epidemic - why WHY hasn't any government thought right lts a must quarentine everybody, stop all flights, all cargos & goods shipping out. I've seen various things about people still travelling to & from china, I saw a report yesterday that a news crew from the UK sent 50 odd staff to cover the story, they came back & did not quarentine themselves at all - I sent them an email asking about this & they refused to answer - what the hell I say it was the BBC & well all know thwey are as baised & dumb as it comes, this example of the stupidity of humans proves my theroey that we will wipe ourselevs out through just plain simple dumbness. Another story I saw from a london news site - a buisinessman came home from China & did not have time to read the articles therefore only qaurentines himself 3 days after coming home - thats enough time to spread a germ to 100's maybe 1'000s of people.

    One last theory - how do we know that this virus does not lay dorment - ie say a mobile phone made in china with somebody infected - its shipped & say I buy it 3 months down the line - is that infected???

    This whole thing doesn't scare me - I just think its a eqauliser to todays mass over population of our planet & sad but worrying sign that the future is dark for many of us.

    OH one last thing - blaming bats snakes etc isn't cool, next we'll blame koalas for the aussie fires, I love bats - also its Valencia cfs embalem - one of my fav soccer clubs is tarnished now.
    Reply
  • Occams_Razr.
    Truthseeker007 said:
    First it was snakes now it is bats. How about it was created in a laboratory. Scientists can do that you know and they can make new variations of Coronaviruses. That is like when they were saying AIDS came from monkeys when later it was found AIDS was created in a laboratory and spread through a" new type" of Hepatitis vaccine. The mainstream news won't tell you that though. Pushed right under the rug.

    Do you count as main stream news American Journal of Public Health ("Rumors and Realities: Making Sense of HIV/AIDS Conspiracy Narratives and Contemporary Legends"), or a host of other science journals?
    Reply
  • MrKeilloh
    Truthseeker007 said:
    First it was snakes now it is bats. How about it was created in a laboratory. Scientists can do that you know and they can make new variations of Coronaviruses. That is like when they were saying AIDS came from monkeys when later it was found AIDS was created in a laboratory and spread through a" new type" of Hepatitis vaccine. The mainstream news won't tell you that though. Pushed right under the rug.

    Just a quick correction on the creation / spreading of the HIV virus theory. The vaccine was for polio, there are some fascinating papers on this subject if your in for an interesting read.
    Reply
  • Truthseeker007
    sohosaints said:
    Hi - first time I've posted here,

    I'm a science student from the UK & have been seeing the whole virus unfold via news,fake news etc - its hard seprating the truth to the resident evil beginnings sci fi also.

    Nobody says the truth so I will - not wanting to offend but countries like china have such a odd way of living, from the pollution of mass manufacture to the high end eatries - we know that resturants & supermarkets in china sell animal products to use & eat, I've seen vidoes of even leemas being eaten, bats with the stomaches open filled with food & the truth is they have eaten a speices which is a step too far & its going to bite us all if action isn't taken, I don't think this outbreak will become an epidemic but the next one might.

    Before everybody sdays racist, bigot etc, oh the young guy from england is a fool, I'm from a mixed race background myself & part of my background has french & poss spanish in it so that agruement won't wash. My view is liberal of science & life, being a young homosexual male has that effect.

    Another thing that has really annoyed me is the fact that - this is a possible epidemic - why WHY hasn't any government thought right lts a must quarentine everybody, stop all flights, all cargos & goods shipping out. I've seen various things about people still travelling to & from china, I saw a report yesterday that a news crew from the UK sent 50 odd staff to cover the story, they came back & did not quarentine themselves at all - I sent them an email asking about this & they refused to answer - what the hell I say it was the BBC & well all know thwey are as baised & dumb as it comes, this example of the stupidity of humans proves my theroey that we will wipe ourselevs out through just plain simple dumbness. Another story I saw from a london news site - a buisinessman came home from China & did not have time to read the articles therefore only qaurentines himself 3 days after coming home - thats enough time to spread a germ to 100's maybe 1'000s of people.

    One last theory - how do we know that this virus does not lay dorment - ie say a mobile phone made in china with somebody infected - its shipped & say I buy it 3 months down the line - is that infected???

    This whole thing doesn't scare me - I just think its a eqauliser to todays mass over population of our planet & sad but worrying sign that the future is dark for many of us.

    OH one last thing - blaming bats snakes etc isn't cool, next we'll blame koalas for the aussie fires, I love bats - also its Valencia cfs embalem - one of my fav soccer clubs is tarnished now.

    Welcome sohosaints! I think you have made some good points. Never be afraid to question everything and even what you have been taught. You seem very intelligent. Keep up on researching and keep an open mind. Sometimes what is actually really going on can be hard to believe. But I think you have made a good start in questioning things.
    Reply
  • Truthseeker007
    MrKeilloh said:
    Just a quick correction on the creation / spreading of the HIV virus theory. The vaccine was for polio, there are some fascinating papers on this subject if your in for an interesting read.

    That is interesting. I just remember reading a long time ago it was Hepatitis but you may be correct it may have been polio also. Maybe a bit of both depending in what area of the world or state.
    Reply