Is the milk safe to drink?

MARY REICHARD, HOST: Coming up next on The World and Everything in It: bird flu in cows.

NICK EICHER, HOST: That’s right. Back in March, the Centers for Disease Control and Prevention, the CDC, found a strain of bird flu that causes disease in dairy cattle. Now 12 states have reported finding it among livestock. Then in April, bird flu made the leap from dairy cattle to humans. The CDC thinks that’s the first instance of animal-to-human spread of the disease.

REICHARD: So should we be worried about another pandemic or about the milk we drink?

WORLD Radio’s Mary Muncy reports.

MARY MUNCY: Jamie Fagan and her husband own a dairy farm in Indiana. They heard about avian flu on the news.

JAMIE FAGAN: If you Google right now, avian flu, oh, my, so many headlines come up that are scary.

Things like “Is the flu in your milk?” and “Cows are dying.” But then she asked their vet about it, and she said just to watch their cattle.

FAGAN: You can tell pretty quickly if the cow's not feeling well, by the way she walks in the barn and maybe she's not eating, she has slower movement. You can just tell when she doesn't feel well.

The United States Department of Agriculture is asking anyone who works with cattle to take some extra precautions: things like wearing gloves and washing uniforms often, as well as paying extra attention to their cattle. But Fagan says they’ve been watching even when there wasn’t an avian flu risk.

FAGAN: You know, if she is acting not right, her milk doesn't go into the tank.

With the COVID-19 pandemic not that far in the rear view mirror, some are watching this strain of avian flu closely just to make sure there isn’t another mass infection.

A New York Times article on Monday quoted some virologists asking for more action to build up vaccine stores. And other news outlets have wondered whether this is the start of a new pandemic or if there could be a threat to the national food supply.

So what does the virus do to cows and their milk, and should Americans be worried?

BRIAN BOHL: A lot of these dairies that were initially infected, a lot of them have recovered.

Officials believe Texas is the first place where migratory birds in March started infecting dairy cattle with H5N1, a strain of avian flu.

BOHL: So you had maybe 20 percent of the animals got sick, the mid-lactational dairy cows, and with very little mortalities at all.

There is also concern over egg prices because avian flu kills chickens, and the U.S. requires farmers to cull a flock where infection is found. But bird flu has already been plaguing the poultry industry on and off for several years, and while egg prices have spiked a few times, and it hit some poultry farmers hard, there hasn’t been a wide scale collapse.

On the other hand, Bohl says cattle seem to be more resilient so there shouldn’t be a big drop in milk production, that is, if the milk is safe to drink.

Last month, the Food and Drug Administration tested almost 300 milk samples from pasteurized dairy products across the country for avian flu. None of the samples contained virus that could infect people.

BOHL: In those cases, it demonstrated that pasteurization works, and it's safe, and the milk is safe.

But earlier this month the FDA released a letter saying it was uncertain if the virus could show up in raw milk, encouraging states that allow the sale of unpasteurized milk to monitor those farms more closely.

So what about the human factor?

Peter Kasson is a researcher on emerging viruses and professor at Georgia Institute of Technology and the University of Virginia.

PETER KASSON: The fact that there's transmission between mammals, although not to our knowledge, between people, is something that I think makes everyone a little bit worried.

Since the first case in April, the CDC has reported two more cases of avian flu making the jump from cattle to humans in the U.S. The symptoms were mild and like other flus—things like fever, cough, and a sore throat—and they were all in direct contact with infected cattle.

KASSON: One of the things that the CDC does when they're evaluating pandemic risk for unusual influenza viruses is they do a lot of experiments looking at both disease and transmission in ferrets.

Ferrets are a good animal model system for humans. The CDC found that the virus spread among the ferrets via direct contact, but not through the respiratory system.

KASSON: And that means the likelihood of someone walking down the street getting this is low. If you had respiratory transmission, then onward transmission from one sick dairy worker to friends and family in the community becomes higher.

Kasson says it’s much easier to control transmission when the virus requires extensive contact with bodily fluids.

KASSON: The hard question is how much do we invest in preparing vaccines at this point?

There are a lot of different theories as to why and how some viruses make the jump from animals to humans, and that makes it hard to know what H5N1 will do.

The CDC says it has two existing vaccine candidates that work against H5N1 though it hasn’t kicked them into high production because that costs a lot of money.

KASSON: You don't want to say, we saw the train coming and we didn't get out of the way. And, on the other hand, you don't want to be Chicken Little and always running around saying the sky is falling, if you're wrong in either direction there are consequences.

For now, Kasson says they’re trying to slow transmission as much as possible without putting a strain on the dairy industry.

Dairy farmer Fagan says that while she’s one of the ones most at risk, the most immediate way avian flu could affect her business is if people stop buying her milk.

FAGAN: We have only had one or two people even ask about it. Really best thing is to talk to your farmer. If you know your farmer, You know your food.

Reporting for WORLD, I’m Mary Muncy.

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