A study shows that the human H3N8 avian influenza virus can be transmitted through the air among ferrets. It is only one step away from breaking the barrier of human-to-human transmission and requires close attention. (Shutterstock)
[The Epoch Times, March 14, 2024](Comprehensive report by Epoch Times reporter Qiu Sheng) Eight scientists said in an interview with Reuters that since the deadly H5N1 avian influenza virus was introduced into South America in 2022, its spread among wild birds and Transmission among marine mammals is stronger than ever, posing an increasing threat to humans.
More worryingly, there is evidence that the disease, once mostly limited to birds, appears to be spreading among mammals, having killed a handful of dolphins in Chile and Peru, some 50,000 seals and sea lions along the coast, and throughout the At least 500,000 birds died in the area.
To confirm transmission among mammals, scientists may need to test live animals for infection.
“This almost certainly happened, and without mammal-to-mammalian transmission,” said virologist Richard Webby of St. Jude’s Children’s Research Hospital in Memphis, Tennessee. It is difficult to explain these large-scale infections and deaths.”
Scientists told Reuters the virus has appeared in dozens of bird species, including some migratory species, which could spread the virus beyond the region.
As climate change escalates, animals will be forced to migrate to new territories and mix with each other in new ways, potentially increasing the chance of viruses mutating further.
“It’s only a matter of time before the first South American strain is discovered in North America,” said Alonzo Alfaro-Nunez, a viral ecologist at the University of Copenhagen.
Growing concerns prompted health experts and officials from the 35 member countries of the Pan American Health Organization (PAHO) to convene a meeting in Rio de Janeiro this week.
An official from the Pan American Health Organization told Reuters that the organization plans to establish the world’s first regional committee to oversee the surveillance and response to avian influenza.
Since the avian influenza virus was first discovered in Colombia in October 2022, two cases of human infection have been detected in the South American continent, respectively in Ecuador and Chile. Both cases resulted from exposure to infected birds.
Although the two patients survived, H5N1 avian influenza is deadly to humans, with a global mortality rate of approximately 60%.
Experts say that without evidence of human-to-human transmission or the emergence of mutations adapted to human receptors, the World Health Organization is unlikely to raise the risk level to humans from the current “low” level.
Drugmakers including GSK and Moderna say they are developing bird flu vaccines for humans and have the capacity to produce hundreds of millions of doses over several months using seasonal flu vaccine production lines Bird flu vaccine.
Ralph Vanstrels, a UC Davis researcher who studies the South American variant of H5N1, is part of a team of scientists working to track the virus’s genetic mutations in South America. “We’re seeing very small steps in (the virus’s) evolution, but in the long run, we’re moving towards the possibility of infecting humans,” he said.
Every year, dense colonies of elephant seals nurse their pups on the windswept Peninsula Valdes on Argentina’s Atlantic coast.
Last November, Vanstrels saw a horrific sight: hundreds of cubs dead and rotting on the beach. Researchers estimate that 17,400 pups died, almost all of them born at the breeding site that year.
Scientists say it’s highly unlikely that each pup will be infected by the birds. Pups usually only have contact with their mothers, leading scientists to suspect that this is how the virus spreads.
In a draft paper posted on the website of the US Centers for Disease Control and Prevention, VanStrels’ team analyzed sea lions, seals and birds from the coast of the Valdes Peninsula. class sample. The team compared the genomes of these samples with samples collected in North America and Asia in 2022 and discovered nine new mutations.
The same mutation was found in samples collected in 2022 and 2023 in Chile and Peru, two countries that also witnessed mass die-offs of sea lions and birds.
“This is the first time this virus has adapted so well to wild animals, and clearly something happened in Peru and northern Chile where these new mutations emerged,” VanStrels said.
The researchers pointed out in a draft paper that the same mutation also appeared in one of the two human cases on the South American continent. The 53-year-old man lived only one block from the seaside where seabirds gather.
The case “highlights the potential threat these viruses pose to public health,” the researchers said.
As health officials and experts meet in Rio this week, Latin American countries are under increasing pressure to step up disease surveillance in the wild.
Scattered data and limited resources in the region make it difficult for scientists to understand how the disease spreads in the wild. The number of cases may also be much higher than reported. Scientists believe some cases may not have been sampled or lab tested.
Manuel Jose Sanchez Vazquez, Epidemiology Coordinator of the Center for Veterinary Health of the Pan American Health Organization, said that Bolivia did not register a single wild case last year, but the disease has been reported in neighboring countries. Found.
Sanchez noted that disease response management is also complex. Threats to humans are dealt with by public health officials, threats to poultry or livestock are dealt with by agricultural or veterinary authorities, and wildlife are usually the responsibility of environmental officers.
The new regional committee is expected to be announced on Thursday (March 14) to develop standard protocols for various government agencies to monitor, handle and report cases. It also helps focus lab resources, Sanchez said.
He said, “We are very worried and vigilant. The more adaptable the virus is to mammals, the more likely it is to be transmitted to humans.”
(This article refers to relevant reports from Reuters)
Editor in charge: Ren Zijun#
2024-03-14 00:57:15
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