On March 12, 2023, WHO became aware of new SARS-CoV-2 sequences and associated metagenomic data for samples collected from the Huanan Seafood Wholesale Market, Wuhan, China, as of January 2020, which became available. at GISAID for a short period of time. . Subsequently, several researchers from various countries downloaded the data. Access was restricted shortly thereafter, ostensibly to allow for further data updates by the China CDC. The WHO then immediately contacted the China CDC and the President and Vice President of SAGO. Following discussions between the WHO and Chinese colleagues, it was explained that the genomic data is the basis for an expected update of the existing data. Liu et al. 2022 preprint (1), which is in the process of being forwarded for publication to Nature by the China CDC.
After discussions with the WHO secretariat and the president and vice president of SAGO, a call was organized on March 12 with the scientists involved from the China CDC and some of those who had accessed the GISAID data, to gauge the importance of these data and analyzes of these data. Subsequently, WHO organized a meeting on March 14, 2023 with all SAGO members and invited researchers from China CDC to present the updated analysis of their data. WHO and SAGO also invited researchers who had informed WHO that they had accessed GISAID data, to submit their analysis of the temporarily published sequences.
Presentations from the China CDC and invited international researchers indicated that new data was available from the Huanan Seafood Wholesale Market.. This included metagenomic data from environmental samples from various wastewater collection posts and sites collected since January 2020. Analyzes of these data suggest that, in addition to SARS-CoV-2 sequences, some samples also contained human DNA, as well as mitochondrial DNA from various animal species, including some known to be susceptible to SARS-CoV-2. This included DNA from wild raccoon dogs, Malaysian porcupines, and bamboo rats, among others, in SARS-CoV-2-positive environmental samples.
The findings suggest that the animals were present at the market shortly before the market was cleared on January 1, 2020, as part of public health measures by the Chinese authorities. These results provide potential clues to identify intermediate hosts of SARS-CoV-2 and potential sources of human infections on the market.
According to the preprint of the Chinese authors (Liu et al. 2022), of 1,380 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 sewer systems in the market and its surroundings, but no virus was detected in 457 animal samples tested. Animal samples included animal carcasses, frozen animal carcasses and animal products, as well as market stray animals, and covered 18 species. According to the preprint, raccoon dogs were not among the animals tested. However, the presence of high levels of raccoon dog mitochondrial DNA in the metagenomic data from the environmental samples identified in the new analysis suggests that the 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 showing that 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 does provide additional evidence for the presence of susceptible animals in the marketplace 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 study of the origins of SARS-CoV-2 to be immediately available for robust and comprehensive review.
As mentioned in SAGO Preliminary report (2), SAGO strongly recommends that investigators in China investigate the prior sources of animals and animal products present in the Huanan market just before its closure and removal of all animal products on January 1, 2020.
In addition, SAGO would like to encourage any and all available sequencing and metagenomic data to be made public in GISAID, or any other sequence database, and preprints that are under review to be shared as soon as possible. so that the scientific community has the opportunity to analyze them further. Additionally, SAGO encourages researchers to use this data to collaborate and interact with Chinese researchers. WHO and SAGO are pleased to facilitate these collaborations.
(1) Liu et al, 2022. Surveillance of SARS-CoV-2 in the environment and animal samples from Huanan Seafood Market 2, available: https://www.researchsquare.com/article/rs-1370392/v1
(2) Preliminary report of the Scientific Advisory Group on Novel Pathogen Origins (SAGO), June 2022, available: https://www.who.int/publications/m/item/scientific-advisory-group-on-the – Report on the origins of new pathogens
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