Study shows no evidence of SARS-CoV-2 virus in animal samples from Huanan seafood market
A study published in Nature on April 5 analyzed environmental and animal samples for SARS-CoV-2 in the Huanan seafood market, Wuhan, China, in early 2020.
The study detected the virus in environmental swabs but not in samples taken from animals.
Raccoon dogs, which have been hypothesized to be potential intermediate hosts for the virus, were present at the market, but the study did not find any animal species to be infected.
The absence of the virus in samples collected from raccoon dogs and the inability of the study to establish the origin of the virus contradicts the conclusions of a team led by evolutionary biologist Michael Worobey.
George F. Gao and colleagues from China’s Center for Disease Control and Prevention (CDCP), who carried out the study, found the virus in the environmental samples in the Huanan seafood market during the early stages of the pandemic.
However, no animal samples (including raccoon dogs) tested positive, and the study has not been able to provide evidence of potential spillover of the virus from animals to humans. Environmental samples alone cannot prove that animals were infected with the virus.
Even if the animals were infected, the study cannot rule out the possibility of human-to-animal transmission since the sampling time was after the human infection in the market.
The possibility of the virus being introduced to the market through infected humans or cold chain products cannot be ruled out.
A report by Michael Worobey’s team contradicts the findings of this study, as his team was able to establish the origin of the virus using genome data from GISAID.
The researchers collected 1,380 samples from the environment and animals in and around the market from January 1 to March 30, 2020.
The virus was detected in 73 environmental samples but none of the animal samples.
Three live viruses were successfully isolated, and they were found to be 99.99-100% similar to the human isolates.
