The virus detected in this cat had genetic characteristics of adaptation to mammals. As noted previously, the avian influenza virus can occasionally infect mammals due to genomic mutations. However, it is important to verify that these phenomena remain sporadic and that the viruses that have acquired this ability to cross into mammals are not detected on poultry farms.
Genetic investigations carried out by ANSES confirmed that only the cat was a carrier of this mutant virus and that this mutation was not present, at this stage, in the ducks on the farm where contamination occurred.
The largest ever bird flu outbreak had already spilled over into otters and foxes in the UK, with about 70 mammals having tested positive for the (HPAI) H5N1 virus. The seal carcasses were sent for screening last year and the results have come back positive, according to the Scottish Marine Animal Strandings Scheme (SMASS).
The new report highlights how different parts of the intelligence community have arrived at disparate judgments about the pandemic’s origin. The Energy Department now joins the Federal Bureau of Investigation in saying the virus likely spread via a mishap at a Chinese laboratory. Four other agencies, along with a national intelligence panel, still judge that it was likely the result of a natural transmission, and two are undecided.
The Energy Department’s conclusion is the result of new intelligence and is significant because the agency has considerable scientific expertise and oversees a network of U.S. national laboratories, some of which conduct advanced biological research.
The Energy Department made its judgment with “low confidence,” according to people who have read the classified report.
Samples containing viral RNA, which had been collected at the Huanan Seafood Wholesale Market in early 2020, also contained genetic material from raccoon dogs—a foxlike type of canid apparently sold at the market—as well as other animals. The genetic material came from the same areas of the market where SARS-CoV-2 was found, suggesting that the raccoon dogs may have been infected with the virus (possibly by other animals) and could have been the first to spread the virus to humans.