Thousands of live animals sold in Wuhan markets before Covid-19 began: Study
More than 47,000 live wild animals were sold from wet markets in the central Chinese city of Wuhan between 2017 and 2019 before the first cases of Covid-19 were officially reported from the city, a new scientific paper says.
Researched by international scientists including from China, the paper said that as many as 47,381 animals from 38 species were sold in 17 markets in Wuhan between May 2017 and November 2019, including 31 protected species.
The animals were kept in cages with poor welfare and hygiene, raising health risks.
The Chinese government says the first Covid-19 cases were detected in Wuhan in early December, the infection at that time described as a kind of pneumonia.
Many of the earliest cases of human Covid-19 infection were linked to Wuhan’s Huanan seafood market, initially identified as where SARS-CoV-2 first jumped to humans through a zoonotic process, but a similar number of cases were associated with other markets as well.
The new paper, written by researchers from China, Britain and Canada and published in the open access journal Scientific Reports on June 7, said there was no evidence that live bats or pangolins were sold in Wuhan, but mink, raccoon dogs, squirrels and foxes were all available. “We note that no pangolins or bats were traded, supporting reformed opinion that pangolins were not likely the spillover host at the source of the current coronavirus (Covid-19) pandemic,” the authors wrote in the report.
The experts added, “While we caution against the misattribution of Covid-19’s origins, the wild animals on sale in Wuhan suffered poor welfare and hygiene conditions and we detail a range of other zoonotic infections they can potentially vector.”
The traded species were capable of hosting a wide range of infectious zoonotic diseases or disease-baring parasites, the researchers found.
Following the outbreak and its rapid spread, the Chinese government temporarily banned all wildlife trade on January 26, 2020, three days after Wuhan, a city of more than 11 million, was locked down.
The government permanently banned eating and trading terrestrial wild (non-livestock) animals for food on February 24, the same year. “These interventions, intended to protect human health, redress previous trading and enforcement inconsistencies, and will have collateral benefits for global biodiversity conservation and animal welfare,” the paper said.
The authors said the study showed the range and extent of wildlife exploitation in Wuhan markets, prior to new trading bans linked to the Covid-19 outbreak, along with the poor conditions under which these animals were kept prior to sale.
“Circumstantially, the absence of pangolins (and bats, not typically eaten in central China; media footage generally depicts Indonesia) from our comprehensive survey data corroborates that pangolins are unlikely implicated as spill-over hosts in the Covid-19 outbreak. This is unsurprising because live pangolin trading has largely ceased in China.”
A joint study conducted by the World Health Organization (WHO) and China in 2021 and published in March said it could not be verified if wild animals were sold at the Huanan market.
“The WHO sent an investigative team to Wuhan, from 14 January-10 February 2021, to try to retrospectively ascertain what wildlife was being sold in local wet markets in this region. Their findings were inconclusive, with markets having been closed down completely at that point for 4 months; however, they did recommend that pangolins should be included in the search for possible natural hosts or intermediate hosts of the novel coronaviruses.”
Incidentally, the experts collated the data from monthly surveys of wet markets unrelated and prior to the outbreak.
The two-and-half years survey was intended to identify the source of the tick-borne (no human-to-human transmission) Severe Fever with Thrombocytopenia Syndrome (SFTS) following an earlier outbreak in the province, the researchers said in the paper.
There is ongoing speculation that SARS-CoV-2 could have been leaked from a high-security Wuhan bio laboratory that researched coronaviruses.
The disease, however, is widely believed to have originated in bats with the closest natural match found in a cave in Yunnan in southwestern China.