After a month-long survey in Wuhan, the World Health Organization provided the best guess as to where the coronavirus came from and how it invaded the population.
A 120 pages Report released on Tuesday List potential virus outbreak scenarios In order of likelihood. At the top is the possibility that the coronavirus has spread from bats to people via intermediate animal hosts. However, the WHO team, who visited Wuhan from January to February, was unable to identify which bat population, or which intermediate species, had the virus.
However, the group determined that interspecific hops were most likely to occur on farms fed wildlife in southern China.
“They raise and breed exotic animals such as civets, porcupines, pangolins, raccoon dogs, and bamboo rats,” said Peter Dazak, a disease ecologist and member of the WHO team. Told NPR..
The WHO team believes that the spillover event, as is known, occurred in November or October 2019. China closed these types of wildlife farms in February 2020, Dazak said.
“There is a route that this virus could follow.”
Dazak said his team found evidence that wildlife farms in Yunnan and surrounding provinces in China supplied vendors at the Wuhan South China Seafood Wholesale Market. The first cluster of COVID-19 cases reported in December was associated with the market that sold live animals and frozen meat.
Two studies published last year found a new coronavirus 96% And 97.1% Comparison of the genetic code with the coronavirus found in the Chinese bat population of Yunnan Province, which borders Laos, Myanmar, and Vietnam.
“Animals known to be coronavirus reservoirs or capable of carrying coronavirus came from where the closest related virus was found,” Dazak said at a WHO press conference Tuesday. “There are routes that the virus could take to travel 800 to 1,000 miles from rural South China, Southeast Asia, to this market.”
WHO reports that intermediate host species that may have been bred on these wildlife farms include mink, pangolins, rabbits, raccoon dogs, and domestic cats. All of these species can be infected with the new coronavirus. The team is also considering these animals as potential hosts, as the ferret-badger, ferret-badger, and weasel were infected with the SARS corona virus and infected people in 2002.
Upon contact with infected animals, or animal products or feces, the virus can fly from animals to humans.
However, the WHO team did not find the infected animal
Dazak’s group collected 900 samples from the South China Market, which was closed in early January 2020. They searched for evidence of the virus, wiped the surface, examined carcasses of animals, and tested sewage. The results showed that the surface was actually contaminated with viral particles, but neither the carcasses of the animals studied nor the live animals brought to the scene were positive.
This suggests that humans, not animals, are more likely to bring the virus to market. In fact, the WHO team concluded that the virus had been epidemic in Wuhan for over a month before it broke out in Wuhan.
The WHO team also surveyed over 80,000 samples from cattle, sheep, chickens, ducks, geese and pigs in 31 states across China. There was no single positive case between them. He also did not have coronavirus-specific antibodies that would have indicated past infections.
Researchers were unable to test animals in wildlife on farms in southern China for evidence of infection, so they recommended doing so in follow-up.
Finding the first virus-bearing bat population may be easy
According to the WHO team’s wildlife veterinarian, Fabian Leendertz, the team is likely to find the first bat population inhabited by the virus, rather than the animal that passed the virus to humans.
“At this point, it’s likely that it has disappeared from the intermediate host, so sampling of bats in particular is probably most likely to produce results,” he said. Leendertz told Science..
Bats are a common viral host. Interspecific hops from bat populations have also led to the development of Ebola, SARS, and Nipah viruses.
Still, the WHO team tested more than 1,100 bat samples in Hubei Province, where Wuhan is located, but found no virus closely related to the new coronavirus. Its undiscovered gives credibility to the idea that the virus first jumped to people elsewhere in China.
However, Dazak is convinced that scientists will eventually find the bat population that was the original host of the coronavirus.
“It would have been unbelievable if there were bats with the exact same strain of virus,” he said. “We haven’t seen it yet. I think it will come in the future.”
Read the original article Business insider