A wild animal related to the dog seems to be the best hypothesis for the theory of animal transmission of covid-19 to humans. Data from a new investigation into the DNA collected at the market in Wuhan, China, at the beginning of 2020, when the still unknown disease was beginning to spread, establish a relationship between SAR-CoV-2 and the raccoon dog, sold for human consumption in Chinese markets.
It’s another ride on the carousel of theories and emotions surrounding science in discovering the origin of the worst pandemic in the last 100 years, which killed millions of people around the world, more than 26 thousand in Portugal. An investigation led by Florence Debarre, principal investigator at the Institute of Ecology and Environmental Sciences in Paris, France, found a link between covid-19 and an animal originating in Japan, but spread throughout Asia and even in Eastern Europe, the raccoon dog, also known by the Japanese name of the tanuki.
Debarre, who confesses to having been obsessed with the origin of the covid-19 virus, found a genetic database of animals for sale at the Live Animal Market in Wuhan, China, where the epidemic was first noticed, still in the last months of 2019. In the early days of 2020, when the still unknown disease was spreading in that city, the Chinese Center for Disease Control (CDC) collected DNA samples from that market. The data were put online in January in the GISAID genetic code base, where scientists share this information, a mandatory procedure to validate the result of investigations.
“The data is three years old – it’s an absolute scandal that it took so long to see the light of day,” said Eddie Holmes of the University of Sydney in Australia, who was also involved in the investigation. “We have to go beyond politics and get back to pure science,” he added, quoted by the British channel BBC.
Indifferent to the process, Debarre’s team accessed the database and tried to understand which animal species matched the virus samples in the Wuhan market. “We saw the results appearing on the screens and it was just: raccoon dog, raccoon dog, raccoon dog, raccoon dog”, recalls the researcher, in statements to the BBC program “Science in Action”. “We find viruses and animals together,” she argued. “It doesn’t prove that the animals were infected, but that’s the most plausible interpretation of what we’ve seen,” she added.
Eddie Holmes, from the University of Sydney, believes that this “is the best evidence” that Science could have about the animal origin of the virus. “We’ll never find the dead-intermediate,” he told the BBC. “But it’s extraordinary that the genetic data found these ghosts – and tells us what species were there and exactly where they were on the market.”
By placing samples of virus and infected animals in the same space and time, the investigation gives more visibility to the theory of transmission from an animal to humans. The outbreak started in the market,” said Holmes. “And now we can see why – the main animals are there,” added the Australian researcher.
“It didn’t start around the lab, which is 30 kilometers away. And there’s not a single piece of data that shows the first cases in the lab,” added Holmes. Statement that diverts the focus from the US theory recently presented by the FBI, which considers a leak of genetic material from the Wuhan virology laboratory as the “most likely” scenario for the outbreak.
“For some time, the FBI has been evaluating a possible incident at the Wuhan laboratory as the source of the pandemic,” said FBI Director Christopher Wray. In statements to the television channel “Fox News”, on March 1, he accused the Chinese government of “doing everything possible to try to frustrate and overshadow” efforts by the US and other countries to learn more about the origins of the pandemic.
Wray’s statements came after a report by the US newspaper “The Wall Street Journal”, claiming that the US Department of Energy had concluded, albeit with low confidence, that the pandemic resulted from an unintentional leak from a laboratory in China. .
In 2021, a joint investigation between China and the World Health Organization (WHO) found the laboratory escape theory “extremely unlikely”. The report concluded that the disease likely passed from bats to humans, and that there was no evidence to suggest a laboratory origin.
The research was deeply criticized and the director general of the WHO called for a new investigation. A year later, that organization recommended an in-depth investigation into the hypothesis that covid-19 originated in a laboratory accident.
Some top WHO members were frustrated with China during the initial outbreak. Also for the way China has sought to restrict research into the origins of the pandemic.
At a press conference on March 17, Tedros Adhanom Ghebreyesus, director-general of the WHO, said that “all data” is important to get us closer to answering the big question about the origin of the virus. “And all data related to the study of the origins of covid-19 needs to be shared with the international community immediately,” he added.
It is unclear whether Tedro was criticizing China’s stance. The fact is that the data that led to this conclusion were placed in GISAID in January, discreetly, without anyone noticing. They were discovered three months later and used in the study by Debarre’s team, but as soon as the Chinese realized they had been downloaded, they removed them from the international system again.
The virus was first identified in Wuhan in December 2019 before spreading across the world, infecting 675 million people – nearly seven million have died. In Portugal, 5.5 million people were infected and more than 26 thousand died.
Identifying the source of the disease can take years. It took more than a decade for scientists to identify the bat species that served as a natural reservoir for severe acute respiratory syndrome (SARS), another coronavirus, detected in southern China in late 2002.