Bird flu outbreak wake-up call for agriculture

Perhaps we can blame COVID fatigue for numbing us to the risks of other viruses. But it should be bigger news that a bird flu has mutated to spread through mammals and is ominously appearing among wild and domesticated animals around the globe. In the past, the inability to spread from one mammal to another was the barrier that prevented bird flu, H5N1 — which has a 50% fatality rate in humans — from becoming a human pandemic. It’s not clear this version, which spread through minks, would be easily transmitted in people, but it has made a step in a dangerous direction.

It’s unthinkable to consider lockdowns or mask mandates over some new disease, which is why it’s better to take simpler, less costly action early. What matters now is surveillance among farmed animals and giving up particularly dangerous practices. Maybe we just can’t have cheap eggs.

One reason there so many dangerous animal viruses around now is that the crowded conditions of mass-farmed animals tend to spread viruses — and there has never been more worldwide demand for meat, dairy products and eggs. As one investigation revealed, egg-laying chickens in big operations are genetically identical, have no immunity to influenza and make easy kindling for viral bonfires.

While it might cost money to move to safer chicken farming practices, doing nothing is expensive, too. Last year, egg prices rose as 58 million U.S. birds were destroyed in H5N1 outbreaks.

H5N1 has a natural host in wild waterfowl, and some of them carry the virus around the globe with their migrations. It was first discovered to be capable of jumping to humans in southern China and Hong Kong in the 1990s, and has been bubbling up around the world ever since. What’s worrisome now is that it’s getting into so may new hosts — eagles, owls, as well as foxes, grizzly bears and seals.

In birds, H5N1 is a gastrointestinal virus, spread by droppings, but it can become a respiratory virus in mammals, said Purdue University virologist David Sanders.

Sanders said the deadly 1918 flu pandemic started with a bird flu that jumped to humans, and the 2009 swine flu was a descendant of this virus, having jumped from humans to pigs in the 1920s before jumping back to humans.

As a point of counterintuitive reassurance, Sanders said that if H5N1 did start spreading in humans and it remained 50% lethal, it might be more easily contained, like SARS1 was in 2005. Plus, we already have a vaccine for H5N1, although it would take months to scale up production.

Even so, why wait to find out how deadly a human H5N1 pandemic would be? Cost-saving measures and mass farming already gave us foot and mouth disease and mad cow disease. And from the point of view of a virus, we humans, with our urban lifestyles, are just the equivalent of captive animals in one vast, interconnected worldwide farm.