An analysis of genetic samples from the Huanan seafood market in Wuhan, China, has revealed a list of wild animals that are likely sources of the virus responsible for the COVID-19 pandemic.
While bats are considered the original carriers of the SARS-CoV-2 virus, it has been suggested that an intermediate host species became infected and then transmitted the virus at the market, which sold both live animals and seafood.
There is also speculation surrounding a potential escape of the virus from the Wuhan Institute of Virology, where researchers were studying bat coronaviruses. However, a new study conducted by an international team concludes that the virus most likely originated from wild animals sold at the market rather than through a lab leak. Researchers re-analyzed data from 800 samples collected by health authorities at the Huanan market starting January 1, 2020, and examined viral genomes from the earliest COVID-19 cases.
Research member Ed Holmes has indicated that investigators primarily focused on swabbing surfaces, freezers, drains, and cages to identify the presence of SARS-CoV-2.
“We analyzed the data to pinpoint which species were present in the market and their correlation to SARS-CoV-2 findings,” Holmes explained.
The findings contradict some previous claims made by local investigators, showing evidence of a variety of wildlife sold at the market that could have served as an intermediate host for the virus, such as common raccoon dogs, masked palm civets, and hoary bamboo rats.
Crucially, traces of these animals were found in the same stalls where SARS-CoV-2 was located, suggesting a likelihood of their infection. “This makes it very plausible that SARS-CoV-2 emerged in a live animal market,” Holmes stated.
“All scientific data consistently point towards SARS-CoV-2’s natural zoonotic origin in the Huanan market, Wuhan,” he added.
Genetic studies of the virus from the earliest COVID-19 cases indicated that few, if any, individuals were infected before the outbreak at the market. However, the possibility remains that an infected person may have introduced the virus to the market while handling animals.
Study collaborator Zach Hensel underscored the significant risks associated with human-wildlife interactions at the Huanan market, emphasizing the urgent need to address these risks in similar environments.
“Despite the prevalence of humans in the market, animal viruses were frequently observed, including one influenza virus with zoonotic spillover potential,” Hensel noted. “These conditions highlight the importance of implementing personal protective measures in settings like these to prevent outbreaks.”
Commenting on the study, an expert expressed confidence in the conclusions drawn about the origins of SARS-CoV-2, affirming that the data overwhelmingly supports the wet market as the source of multiple outbreaks.
