FINDINGS from a recent study by the World Health Organization’s (WHO) Scientific Advisory Group for the Origins on Novel Pathogens (SAGO), suggests that animals were present at the Huanan Seafood Wholesale Market, Wuhan, China shortly before the market had been cleared on 1 January 2020, as part of the public health measures by Chinese authorities.
By Staff Reporter
These results according SAGO will provide potential leads to identifying intermediate hosts of SARS-CoV-2 and potential sources of human infections in the market.
After discussions with the WHO secretariat and the SAGO Chair and Vice-Chair, a call was arranged on 12 March with the scientists involved from China CDC, and some of those who had accessed the data from GISAID, to gauge the significance of this data and the analyses of this data. WHO subsequently organized a meeting on 14 March 2023 with all SAGO members, and invited researchers from China CDC to present the updated analysis of their data. WHO and SAGO also invited the researchers who had informed WHO that they had accessed data from GISAID, to present their analysis of the temporarily released sequences.
The presentations from China CDC and invited international researchers indicated that there were newly available data from the Huanan Seafood Wholesale Market. This included metagenomic data of environmental samples from various stalls and wastewater collection sites collected as early as January 2020. Analyses of these data suggest that apart from SARS-CoV-2 sequences, some samples also contained human DNA, as well as mitochondrial DNA of several animal species, including some that are known to be susceptible to SARS-CoV-2. This included DNA from wild raccoon dogs, Malaysian porcupine, and bamboo rats among others, in SARS-CoV-2 positive environmental samples.
According to the Chinese’s authors pre-print (Liu et al 2022), of 1380, samples collected from the environment and animals within the market in early 2020, 73/923 environmental samples tested positive for SARS-CoV-2-specific RT-qPCR, from various stalls and sewerage systems in and around the market, but no virus was detected in 457 animal samples tested. The animal samples included animal bodies, frozen animal carcases and animal products, as well as stray animals around the market, and covered 18 species. According to the preprint, raccoon dogs were not amongst the animals tested. However, the presence of high levels of raccoon dog mitochondrial DNA in the metagenomics data from environmental samples identified in the new analysis, suggest that raccoon dog and other animals may have been present before the market was cleaned as part of the public health intervention.
Historical photographic evidence was provided that shows raccoon dogs and other animals were sold at these specific stalls in the past. Although this does not provide conclusive evidence as to the intermediate host or origins of the virus, the data provide further evidence of the presence of susceptible animals at the market that may have been a source of human infections.
SAGO will continue to evaluate any and all scientific data shared by Chinese and other researchers from anywhere in the world. SAGO encourages any and all data related to the studying of the origins of SARS-CoV-2 be made available immediately for robust and comprehensive review.
As mentioned in SAGO’s preliminary report (2), the SAGO strongly recommends that researchers in China investigate the upstream sources of the animals and animal products present in Huanan market just before its closure and removal of all animal products on 1 January 2020.
