This is one of the major reasons China has been such a hot spot for new influenza viruses: Nowhere else on earth do so many people have such close contact with so many birds.
At least two flu pandemics in the past century—in and —originated in the Middle Kingdom and were triggered by avian viruses that evolved to become easily transmissible between humans. Although health authorities have increasingly tried to ban the practice, millions of live birds are still kept, sold and slaughtered in crowded markets each year.
In Chongzhou, a city near the Sichuan provincial capital of Chengdu, the New Era Poultry Market was reportedly closed for two months at the end of last year. Half a dozen forlorn ducks, legs tied, lay on a tiled and blood-spattered floor, alongside dozens of caged chickens. Open vats bubbled with a dark oleaginous resin used to remove feathers. Poultry cages were draped with the pelts of freshly skinned rabbits. These areas—often poorly ventilated, with multiple species jammed together—create ideal conditions for spreading disease through shared water utensils or airborne droplets of blood and other secretions.
Shutting live-bird markets can help contain a bird flu outbreak. Back in , the H5N1 virus traveled from mainland China to Hong Kong, where it started killing chickens and later spread to 18 people, leaving six dead.
In mainland China, though, the demand for live poultry remains incredibly high. And unlike the Hong Kong epidemic, which visibly affected its avian hosts, the birds carrying H7N9 initially appeared healthy themselves. For that reason, shuttering markets has been a particularly hard sell.
He has been working with Chinese authorities since , when he was part of a Western public health delegation invited to Beijing. He and a colleague were eager to collect blood samples from Chinese farm animals. At a state-run pig farm, Webster recalls, he was allowed to get a blood sample from one pig.
The experience taught Webster something about the two sides of Chinese bureaucracy. If you forcibly close down government live-poultry markets, the transactions will simply go underground. Famed for his work with animal viruses, Guan is square-jawed and intense. Some call him driven. In another incarnation, he might have been a chain-smoking private investigator. They discovered three separate virus strains in three different species of Rhinolophus bat, commonly known as horseshoe bat.
Further experiments showed that the receptor binding domain of the viruses had a high affinity for human ACE2 receptors. This was comparable to the affinity of SARS-CoV-2 strains that scientists discovered at the beginning of the pandemic, suggesting these viruses could infect humans directly.
Last year, scientists detected a similar virus in Yunnan, in Southwest China. It was Holmes said. This means that the functional core of the virus exists in nature, so there is no need to think that the virus was somehow created or adapted in a lab.
Further doubt was cast on the assumption that the virus responsible for the COVID pandemic originated in Wuhan with another preprint submitted to Nature. Researchers in China tested some 30, wild, farmed and domestic animals in and but found no evidence of active or past SARS-CoV-2 infection, except in some cats in Wuhan in March 5. The explosive way in which the outbreak took off in Wuhan in December suggests that the virus was probably introduced once, through the wildlife trade, says Daszak.
He says future testing should focus on farmed wild animals. Carrat, F. PubMed Article Google Scholar. Amendola, A. Apolone, G. Tumori J. Liu, P. Health 2 , — Zhang, Q. Download references. Article 10 NOV Nature Index 27 OCT News 11 NOV It's really urgent to teach people how to deal with the virus and just change our normal behavior to decrease the risk of virus transfer. You have got the Rhinolophus horseshoe bats right here in this cave with all these tourists going through.
The bats here in this cave are the same bats that carry SARS virus. Bats live in the cave all day long, because they're nocturnal. And when they're up there, they urinate and defecate, right on top of the tourists that are walking through. And all you have got to do is be that one person to breathe in at the wrong time, and suddenly you have been infected with a virus that is not only potentially lethal to people.
It could cause a future pandemic. Daszak and his team have used mathematical models to try to understand what is driving these diseases. And we said, what are the things that are going on in those places? Rapid global response to disease outbreaks is essential to stopping transmission and saving lives.
But Daszak and his team of virus hunters believe that forecasting where outbreaks are most likely to occur is a critical part of a defensive strategy needed to prevent outbreaks before they emerge. Support Provided By: Learn more. Friday, Nov The Latest. World Agents for Change. Health Long-Term Care. For Teachers. NewsHour Shop.
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