Is it time to worry about bird flu?

Novogen Brown chickens at an egg farm in Briones, California, on February 14, 2023. | David Paul Morris/Bloomberg/Getty Images

You may have noticed egg prices going up, and even eggs being scarce. Bird flu is to blame, but it doesn’t just affect egg prices — and it doesn’t just affect birds. Avian flu is responsible for the deaths of mammals all over the globe. And this January, the US reported a human death from bird flu.

All this raises the question: If bird flu is killing animals right and left, and has killed at least one human, should we be worried?

To answer that, I spoke with dozens of experts to create the video below. I also spoke with Sean Collins, a news editor at Vox and the host of the Today, Explained newsletter, about everything I’d learned in the course of my reporting. Check out our conversation (edited for length and clarity), below.

What is bird flu?

Avian flu — or bird flu — is an influenza virus that seems to originate in waterfowl (like ducks or geese), but that can spread to any animal, including humans. When waterfowl spread the virus — usually through their droppings or bodily fluids — we can see some pretty bad effects in birds. In domesticated poultry, we see an almost 100 percent mortality rate.

**Are we in a bird flu pandemic? **

The term pandemic tends to refer to the unchecked spread of a disease among humans; experts told me what we’re seeing here is a panzootic, which is essentially a pandemic that affects animals. This strain of bird flu is on every continent except Australia — and Australia has its own deadly strain going around. It’s also in our waters. It’s in dolphins, in seals, and in sea lions — in 2023, 24,000 sea lions washed up in South America, dead from avian flu.

The flu has been devastating for poultry populations. You see birds acting almost like they’re drunk, struggling to walk, before they just collapse. To try to stop the spread, farms are mass culling chickens, often in horrible ways.

The amount of mammals that bird flu is infecting right now is astronomical.

**Do humans have to worry about this sparking a pandemic? **

Humans can get bird flu. Infections that have crossed over into humans are typically mild, but worth monitoring: At least one person has died from this, though experts see that death as an outlier.

There are lots of viruses out there that make animals sick, but that don’t pose a threat to humans because they don’t have the characteristics needed for human-to-human spread. Right now, you can catch bird flu from an animal, but you're not going to give it to somebody else. Unless that changes, we’re not in pandemic territory.

The thing experts are keeping an eye on is the amount of contact humans (and species that have a lot in common with humans) have with infected animals. The more contact this strain of bird flu has with various animals, the more opportunities it has to replicate. With each replication comes the possibility for genetic reassortment and mutations — basically for changes to the virus’s structure that could alter its characteristics. Those changes could make it into something that spreads more easily among humans.

That’s a lot of coulds, which is why, while you should know that avian flu does have pandemic potential, you shouldn't panic about it.

What can people do to protect themselves?

Be aware that the flu is circulating among animals we’re frequently around, like chickens and cows. If you work on a farm, some experts are advising PPE, particularly for dairy and poultry professionals.

Don’t consume animal products that haven’t undergone safety treatments. That means don’t — do not — drink raw milk. Pasteurized milk is very safe. The same goes for meat: Don’t eat it raw right now.

If you see a bird acting funny, stay away from them.

Get your flu shot. While it won't protect against avian flu, it will help protect against seasonal influenza. Again, reassortment is one of the big dangers here, and should someone have seasonal flu and bird flu at the same time, that creates an opportunity for bird flu to change in ways that could make it more dangerous to humans.

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