‘Big leap’ in bird virus threatens yet another pandemic

Ritzau Scanpix/Mads Claus Rasmussen via Reuters

The same highly pathogenic bird flu virus that has killed tens of millions of chickens and other birds in the past year is also much closer to infecting people.

An unusual outbreak of the H5N1 virus in mink, a relative of weasels, at a Spanish fur farm last fall also exposed farm staff to the virus. Quick action by health authorities helped prevent any human infection. This time.

But bird flu is not going away. And as H5N1 continues to circulate in domestic and wild birds, causing millions of animal deaths and reducing the supply of eggs, it also moves ever closer to the human population. “This…avian influenza has the potential to become a major problem for humans,” Adel Talaat, a professor of pathobiological sciences at the University of Wisconsin-Madison, told The Daily Beast.

It may be a matter of time before H5N1 achieves a large-scale “zoonosis” and makes the leap to the human species. If and when that happens, we could have another major viral crisis on our hands. In addition to the COVID pandemic, the worsening of seasonal RSV, the occasional outbreak of monkeypox, and annual bouts of flu.

Reports this week suggested that the current wave of bird flu might be passing to mammals more regularly. Scientists found traces of bird flu in seals that died in a “mass mortality event” in the Caspian Sea in December, and the BBC reported this week that tests in Britain had found the virus in a range of mammals around the world. country. On January 9, the World Health Organization was informed that a 9-year-old girl in Ecuador had tested positive.

Bird flu is not new. Scientists first identified the virus in the 1870s. There have been dozens of major outbreaks over the years, and they have become more frequent and more severe as the world’s domestic poultry population has expanded. to feed a growing human population.

H5N1, a more serious “highly pathogenic avian influenza” virus, or HPAI, first appeared in China in the 1990s. It and other HPAIs have achieved small-scale zoonoses, mainly in Asia. Several dozen people have died from bird flu in recent decades.

But so far, bird flu has mainly infected, well, birds. That makes it a big problem for poultry farmers. And for the people who buy eggs, of course. The current H5N1 outbreak has killed or forced farmers to cull nearly 60 million chickens, turkeys, geese, and ducks in the United States alone. The culls pushed the price of eggs to nearly $5 a dozen in US grocery stores last fall, according to the US Department of Agriculture. That’s several times the long-term average price.

Avian flu takes the leap

Higher egg prices will be the least of our problems if large-scale zoonosis ever triggers a human bird flu pandemic. And that’s why scientists and health officials keep a close eye on H5N1 and related HPAIs as they spread and mutate. For epidemiologists, the bird flu outbreak at the mink farm in northwestern Spain was a big red flag. An ominous sign that a major zoonosis could become increasingly likely.

Spanish health authorities first noticed the outbreak in early October, when the mortality rate among mink on a large farm in Galicia tripled. Biological samples from the 52,000 mink on the farm contained H5N1. It was the first time that bird flu had infected farmed mink in Europe.

Authorities ordered the culling of all mink on the affected farm. At the same time, they quarantined and tested all 11 farm workers. Luckily, none had contracted the virus.

It was a close decision. And even more worrying because no one knows for sure what happened. “The origin of the outbreak is unknown,” reported a team led by virologist Montserrat Agüero in the latest issue of Eurosurveillance, a journal of epidemiology. Wild birds may transmit the virus to mink. It is also possible that the pathogen was present in the mink’s food, which contains raw chicken.

Equally troubling, the virus didn’t just spread from birds to mink. It may also have spread from mink to other minks, too, Agüero’s team discovered. “This is suggested by the increasing number of infected animals identified after confirmation of the disease.

That post-zoonosis transmission inside a new species is how an animal virus like H5N1 could cause a new pandemic. This is what happened with COVID, after the SARS-CoV-2 virus spread from bats or pangolins to people in late 2019. This is what happened with monkeypox, after that pathogen jumped for the first time from monkeys and rodents to humans, possibly decades ago.

How China’s COVID crisis could spawn a disastrous virus ‘jump’

“The ability to achieve sustained transmission in a mammal is a huge leap for influenza viruses, so the mink event is a big problem,” James Lawler, an infectious disease expert at the Medical Center, told The Daily Beast. from the University of Nebraska. “It definitely increases the risk of [a] species-jump to humans.”

The bird flu outbreak in Spain has a happy ending for everyone involved, except for those 52,000 mink, of course. But the next outbreak might not end so well. Not if scientists notice a zoonotic jump late, or if viral transmission exceeds the ability of health officials to euthanize affected animals, quarantine exposed people, and isolate the virus.

Bird flu, more than many viruses, requires constant vigilance. It’s infecting more birds than ever before, jumping into mammals in more places, and learning new genetic tricks that increase the risk to humans.

All of which means that our avian flu problem could get worse before it gets better. “The ongoing widespread outbreaks of HPAI are concerning across the board,” Lawler said.

Read more at The Daily Beast.

Get the Daily Beast’s biggest scoops and scandals delivered straight to your inbox. Register now.

Stay informed and get unlimited access to Daily Beast’s unmatched reports. Sign up now.

Leave a Reply

Your email address will not be published. Required fields are marked *