Post by Admin on Mar 17, 2023 21:28:01 GMT
A new report suggests the virus that causes COVID-19 may be linked to raccoon dogs that were illegally being sold at a wet seafood market in China.
First reported in The Atlantic, a team of scientists from around the world announced Thursday they believe the virus, SARS-CoV-2, originated at the Huanan Seafood Wholesale Market in Wuhan, where the outbreak began.
It comes amid swirling debate about the origins of the pandemic, after a report from the U.S. Department of Energy concluded with "low confidence" that it was the result of a lab leak.
According to the report, researchers at the Chinese Center for Disease Control and Prevention uploaded new data from swab samples collected in January 2020 at the market -- including of the floors, walls and cages containing animals -- to the open global genome sequencing database GISAID.
From there, the international team, which included virologists and biologists, downloaded the samples and analyzed them.
The samples that came back positive for the virus also contained genetic material of several animals, particularly large amounts matching the common raccoon dog.
"In samples with a hot amount of virus, there was not a trivial amount of DNA and RNA of raccoon dogs," Dr. Jeremy Kamil, an associate professor of microbiology and immunology at Louisiana State University Health Shreveport, who was not involved in the research, told ABC News.
The genetic data was drawn from swabs taken from in and around the Huanan Seafood Wholesale Market starting in January 2020, shortly after Chinese authorities had shut down the market because of suspicions that it was linked to the outbreak of a new virus. By then, the animals had been cleared out, but researchers swabbed walls, floors, metal cages and carts often used for transporting animal cages.
The jumbling together of genetic material from the virus and the animal does not prove that a raccoon dog itself was infected. And even if a raccoon dog had been infected, it would not be clear that the animal had spread the virus to people. Another animal could have passed the virus to people, or someone infected with the virus could have spread the virus to a raccoon dog.
But the analysis did establish that raccoon dogs — fluffy animals that are related to foxes and are known to be able to transmit the coronavirus — deposited genetic signatures in the same place where genetic material from the virus was left, three scientists involved in the analysis said. That evidence, they said, was consistent with a scenario in which the virus had spilled into humans from a wild animal.
A report with the full details of the international research team’s findings has not yet been published. Their analysis was first reported by The Atlantic.
Although this doesn't definitively prove that the virus definitely jumped from raccoon dogs to humans, the team said it is the strongest evidence to date of the natural transmission theory.
"This is a really strong indication that animals at the market were infected," Dr. Angela Rasmussen, one of the virologists involved in the new report, told The Atlantic. "There's really no other explanation that makes any sense."
Kamil agreed the evidence is not irrefutable, but that it raises serious questions about the trade of animals at these markets.
Members of the research team, who have not yet published their findings, did not immediately return ABC News' request for comment.
The findings also support other scientific research indicating that the virus likely spilled over from animals into people in and around the Huanan Seafood Wholesale Market.
In a briefing Friday morning, the World Health Organization addressed the reports of the potential link to raccoon dogs.
"Last Sunday, WHO was made aware of data published on the GISAID database in late January, and taken down again recently," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said. "The data, from the Chinese Center for Disease Control and Prevention, relates to samples taken at the Huanan market in Wuhan, in 2020, These data do not provide a definitive answer to the question of how the pandemic began, but every piece of data is important in moving us closer to that answer."
Raccoon dogs are known to harbor other viruses that jump from animals to humans. For example, a October 2003 report found a virus very similar to SARS-CoV-1, which a cousin of the new coronavirus, in a raccoon dog and among humans at a live animal market in Guangdong, China.
Although most experts now believe the SARS outbreak in 2002-03 in China was linked to bats, raccoon dogs are believed to have been brief accidental hosts of the virus.
Currently, four U.S. agencies and the National Intelligence Council say the virus was the result of natural transmission that jumped from animals to humans.
Late last month, the Department of Energy changed its stance from "undecided" to "low confidence" that the COVID-19 pandemic "most likely" was the result of a laboratory leak, becoming the second agency, after the FBI, to believe a lab accident resulted in the global health emergency.
First reported in The Atlantic, a team of scientists from around the world announced Thursday they believe the virus, SARS-CoV-2, originated at the Huanan Seafood Wholesale Market in Wuhan, where the outbreak began.
It comes amid swirling debate about the origins of the pandemic, after a report from the U.S. Department of Energy concluded with "low confidence" that it was the result of a lab leak.
According to the report, researchers at the Chinese Center for Disease Control and Prevention uploaded new data from swab samples collected in January 2020 at the market -- including of the floors, walls and cages containing animals -- to the open global genome sequencing database GISAID.
From there, the international team, which included virologists and biologists, downloaded the samples and analyzed them.
The samples that came back positive for the virus also contained genetic material of several animals, particularly large amounts matching the common raccoon dog.
"In samples with a hot amount of virus, there was not a trivial amount of DNA and RNA of raccoon dogs," Dr. Jeremy Kamil, an associate professor of microbiology and immunology at Louisiana State University Health Shreveport, who was not involved in the research, told ABC News.
The genetic data was drawn from swabs taken from in and around the Huanan Seafood Wholesale Market starting in January 2020, shortly after Chinese authorities had shut down the market because of suspicions that it was linked to the outbreak of a new virus. By then, the animals had been cleared out, but researchers swabbed walls, floors, metal cages and carts often used for transporting animal cages.
The jumbling together of genetic material from the virus and the animal does not prove that a raccoon dog itself was infected. And even if a raccoon dog had been infected, it would not be clear that the animal had spread the virus to people. Another animal could have passed the virus to people, or someone infected with the virus could have spread the virus to a raccoon dog.
But the analysis did establish that raccoon dogs — fluffy animals that are related to foxes and are known to be able to transmit the coronavirus — deposited genetic signatures in the same place where genetic material from the virus was left, three scientists involved in the analysis said. That evidence, they said, was consistent with a scenario in which the virus had spilled into humans from a wild animal.
A report with the full details of the international research team’s findings has not yet been published. Their analysis was first reported by The Atlantic.
Although this doesn't definitively prove that the virus definitely jumped from raccoon dogs to humans, the team said it is the strongest evidence to date of the natural transmission theory.
"This is a really strong indication that animals at the market were infected," Dr. Angela Rasmussen, one of the virologists involved in the new report, told The Atlantic. "There's really no other explanation that makes any sense."
Kamil agreed the evidence is not irrefutable, but that it raises serious questions about the trade of animals at these markets.
Members of the research team, who have not yet published their findings, did not immediately return ABC News' request for comment.
The findings also support other scientific research indicating that the virus likely spilled over from animals into people in and around the Huanan Seafood Wholesale Market.
In a briefing Friday morning, the World Health Organization addressed the reports of the potential link to raccoon dogs.
"Last Sunday, WHO was made aware of data published on the GISAID database in late January, and taken down again recently," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said. "The data, from the Chinese Center for Disease Control and Prevention, relates to samples taken at the Huanan market in Wuhan, in 2020, These data do not provide a definitive answer to the question of how the pandemic began, but every piece of data is important in moving us closer to that answer."
Raccoon dogs are known to harbor other viruses that jump from animals to humans. For example, a October 2003 report found a virus very similar to SARS-CoV-1, which a cousin of the new coronavirus, in a raccoon dog and among humans at a live animal market in Guangdong, China.
Although most experts now believe the SARS outbreak in 2002-03 in China was linked to bats, raccoon dogs are believed to have been brief accidental hosts of the virus.
Currently, four U.S. agencies and the National Intelligence Council say the virus was the result of natural transmission that jumped from animals to humans.
Late last month, the Department of Energy changed its stance from "undecided" to "low confidence" that the COVID-19 pandemic "most likely" was the result of a laboratory leak, becoming the second agency, after the FBI, to believe a lab accident resulted in the global health emergency.