John Yang:
Almost from the start of the pandemic, debate about its origin has centered on two theories, that there was a natural source, that humans were first infected by a wild animal, or that the virus spread escaped from a laboratory.
Scientists say the natural transmission theory has been bolstered by new genetic evidence from the market in Wuhan, China, where there was a large outbreak of COVID in December 2019. Samples known to have the virus turned up. also found to contain genetic material from animals, many from the common raccoon dog, a small animal related to foxes.
Katherine Wu first reported this in “The Atlantic,” where she is an editor. She also has a doctorate. in microbiology.
Katherine, what have these scientists found that points them in the direction of a wild animal being the source?
Katherine Wu, “The Atlantic”: Right.
So that’s another clue really strengthening the case for a natural origin for this virus, which is the case for so many other viruses. Being able to take a sample from that market and extract the genetic material from the virus and from an animal known to be susceptible to the virus, such as the raccoon dog, is a pretty good indication that a infection of this animal, potentially of these raccoon dogs, may have occurred at the market at the time the pandemic began.
It’s not exactly a gun. The strongest evidence of a true natural origin would really be to be able to find evidence of an infected animal alive, for example, having a swab containing virus that was taken from an animal’s mouth or nose, e.g. example, or maybe be able to find, say, an infected raccoon dog in the wild now.
That’s not quite the case here, but it’s damn close. Knowing that there were already viral samples on the market and knowing that raccoon dogs can catch and transmit this virus helps pull this story together. Now we know that the virus and the raccoon dog were so close that we could get these swabs with genetic material from both.
It’s like finding a suspect’s fingerprints at a crime scene.