4 ms·

The progenitor of the SARS-1 outbreak in 2003 wasn't found until a decade later in 2013. There's a lot of research which is getting closer: https://www.resear

• tim333 5y ago
  The immediate source - palm civets at a local market was found almost as soon as they looked, about four months after the outbreak. Tracing back where they got it from took longer.
  • lamontcg 5y ago
    After the discovery of WIV1 in bats it was found that it efficiently infected human airway epithelial cells, and since the palm civets were never linked to any outbreaks it is possible that the virus had directly hopped to humans from bats and that the palm civets were unnecessary as an intermediate species. It was also later found that it infects racoon dogs, ferret badgers and domestic cats. There was never any conclusive proof that raccoon dogs were responsible/required and that now looks unnecessary, which is a good example of how over a decade later what we think we know can change.
    • tripletao 5y ago
      I believe that: 1. The closest known animal viruses to human SARS-1 were found in civet cats in 2003, within about a year of the first discovery of the virus in humans. 2. No animal viruses closer to SARS-1 have since been discovered. Dr. Shi discovered various viruses in bats that we believe are ancestral to SARS-1, including WIV-1 in 2013. This is significant because we believe SARS-1 evolved primarily in bats, but those viruses have lower genetic identity with SARS-1 than does the virus found in the civets. If you disagree, please link a paper. Based on the above, I don't understand why you'd think 2013 is the important date. Within about a year of the emergence of both of the previous two novel coronaviruses in humans (SARS-1 and MERS), a near-identical virus was discovered in animals (civets and camels). This is suggestive but not conclusive evidence that those animals first infected humans, and strong evidence that those viruses existed in nature--somewhere, even if not exclusively in those animals--before they emerged in humans. For SARS-CoV-2, no such evidence has yet been found. This doesn't prove that SARS-CoV-2 is of unnatural origin, and I assume you'll mention the uncertainty in Ebola's zoonotic hosts shortly; but I don't see how anyone could treat that as irrelevant, except out of willful blindness.
      • lamontcg 5y ago
        Discovery of WIV1: [Isolation and characterization of a bat SARS-like coronavirus that uses the ACE2 receptor](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5389864/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5389864/) WIV1 grows in primary human airway epithelial cell cultures: [SARS-like WIV1-CoV poised for human emergence](https://www.pnas.org/content/113/11/3048 https://www.pnas.org/content/113/11/3048) > Together, the data demonstrate that the WIV1-CoV spike can mediate infection of human airway cultures with no significant adaptation required. And thanks for putting words in my mouth but no, I'm not confusing those with MERS.
        • tripletao 5y ago
          I didn't mean to suggest that you were confusing anything with MERS. I just brought MERS up to show that not only had we found an animal infected with SARS-1 within about a year of its emergence in humans, but we'd also found such an animal for MERS, on a similar timescale. This means that SARS-CoV-2 is the 1/3 for which we haven't, not impossible just by chance but slightly more surprising than just 1/2. And yeah, you'd mentioned WIV-1 above, and I'd assumed that's what you meant from the 2013 date. I noted this in point (2) of my grandparent comment. I just don't understand why you think that's more significant than finding the near-identical virus in civets. The SARS-1 civets might not have first transmitted SARS-1 to humans, but the WIV-1 bats definitely didn't--they're very different viruses, and while WIV-1 might indeed be able to infect humans it's definitely not what caused the actual outbreak. So why pick 2013 and not 2003?