Swabs collected from stalls and equipment at the Huanan Market in Wuhan, China, that tested positive for traces of the virus that causes Covid-19 also, in some cases, contained traces of DNA from animals known to be susceptible to infection, according to a new analysis by an international team of researchers.
In the analysis, Tuesday, the researchers say their findings add to evidence that live animals traded at the market could have passed the coronavirus to humans, pointing to a natural origin for the Covid-19 pandemic.
The swabs were collected by scientists affiliated with China’s Centers for Disease Control in early 2020,shortly after China closed the market, which was an early hot spot for Covid-19 infections.
No one had seen the raw data from that testing until Chinese researchers quietly uploaded details from their sampling to the genetic data-sharing platform GISAID.
The data was noticed by an international collaboration of researchers probing the pandemic’s origins in early March and downloaded for further study.
The new analysis last week after several media reports characterized its findings and World Health Organization officials discussed them in a news briefing. The analysis had not been made public until Tuesday, when it was posted online as a preprint study, ahead of peer review.
The species included in the analysis included raccoon dogs as well as red foxes, rabbits, cats and dogs. Genetic material from other mammals was also identified, including Amur hedgehogs, Malayan porcupines, hoary bamboo rats, Himalayan marmots, masked palm civets, Siberian weasels and hog badgers.