FRIDAY, March 17, 2023 (HealthDay News) -- A new theory about the start of the COVID-19 virus points to illegally traded raccoon dogs at a market in Wuhan, China.
Genetic data from swabs connected to these fox-like animals with a raccoon face offer tangible evidence of the virus's possible origin, according to an international team of virus experts. These animals are known to be able to transmit the coronavirus, The New York Times reported. A full report on the testing has not yet been published. The Atlantic first reported on the analysis.
The genetic data were collected on swabs starting in January 2020 from walls, floors, metal cages, and carts used to move cages in and around the Huanan Seafood Wholesale Market after Chinese authorities closed it because of its potential link to the virus. Large amounts of the genetic material were a match for the raccoon dog. Material from the raccoon dog and the virus were in the same places.
Researchers studied this using raw data from swabs that were posted to GISAID, an international repository of genetic sequences of viruses. Chinese scientists had previously released a study using market samples in February 2022. It had reported samples positive for severe acute respiratory syndrome coronavirus 2 but suggested the virus came from infected shoppers or workers, rather than animals. Those same researchers posted the raw data that international researchers used for their analysis.
Florence Débarre, Ph.D., an evolutionary biologist at the French National Center for Scientific Research in Paris, happened upon that data March 4. She set it aside and then logged in again last week, finding new data that virus experts had been waiting to see since the original study was published. Débarre alerted an international team of researchers, who started mining the data last week, according to The Times. Those researchers included Michael Worobey, an evolutionary biologist at the University of Arizona; Kristian Andersen, a virologist at the Scripps Research Institute in La Jolla, California; and Edward Holmes, a biologist at the University of Sydney in Australia.
"We were able to figure out relatively quickly that at least in one of these samples, there was a lot of raccoon dog nucleic acid, along with virus nucleic acid," Stephen Goldstein, Ph.D., a University of Utah virologist who worked on the new analysis, told The Times.
Researchers were interested in a swab taken from a cart linked to a specific market stall that Holmes had visited in 2014, noting that it contained raccoon dogs in a cage on top of a cage that held birds. Such an environment is conducive to the transmission of new viruses.
When the team reached out to the Chinese researchers who had uploaded the data to offer to collaborate, the sequences disappeared from GISAID. It is not clear why this happened.