Bird flu: Raw milk, food safety, and how ICE policies could worsen it all

While the people most at risk for bird flu (H5N1) are those who handle live birds, epidemiologists are growing more concerned about the general public. They’re worried that the bird flu could combine with the seasonal flu. The other fear is that ICE policies could make an outbreak worse.

This comes as health officials say the risk of bird flu to most New Yorkers remains low. No human cases have been reported in the city or state, but several city birds did test positive, prompting the temporary closures of live poultry markets.

Epicenter NYC spoke with Jessica Malaty Rivera, an infectious disease epidemiologist who specializes in avian flu, to learn why researchers are so concerned.

This conversation has been edited and condensed for clarity.

What should people know about bird flu right now?

The risk to the average person, who doesn’t have high touch points or proximity to farm animals, is quite low. 

That said, we are now dealing with an unprecedented outbreak of bird flu in more mammal species than we’ve ever experienced, and in mammals that have high proximity to humans, like cows. 

That is concerning because as viruses replicate, they make mistakes — we call those mutations. With each mutation, it can adapt in a way that could potentially make it modify to attack the upper respiratory tract. Right now it’s not able to do that. 

It’s why we’re so concerned about this ongoing flu outbreak. But it’s the combination of these two things that’s concerning. 

Why is that combination concerning?

It’s reassortment. Reassortment would be a farmer who has the seasonal flu, then gets exposed to the bird flu at the same time. And if he has both of those viruses — think about it like a deck of cards reshuffling. The virus can mutate into a new version of itself and perhaps then become transmissible from human to human. 

But we’re watching it with a bit of a limitation, because the CDC is not communicating the way we hope it would be.

How concerned should we be about human-to-human spread, especially considering the possibility of flu strains combining?

Right now, there is no confirmed human-to-human spread. The virus has not adapted in a way that allows it to do so. What we need to do is keep seasonal flu levels low. 

That’s why we’re urging people to get their flu shot — it’s not too late. If you’re sick, stay home. If you have to be out while sick, wear a mask and encourage others to do the same. 

Respiratory viruses are highly contagious, and we’re still in the middle of winter, when they spread more easily. While human-to-human transmission of bird flu hasn’t been identified, we can’t say for certain that it can’t or won’t happen.

 Why is the bird flu so concerning overall? 

If you had asked me 15 years ago what I thought the next pandemic would be, I would have put my money on bird flu. Because it is so ubiquitous, and it is one that we have worried about because of its potential high mortality rate. 

The mortality rate is not what a lot of people are saying it is. Because we’ve never actually known the full incidence of cases. Many people who have bird flu probably went undetected, including in this outbreak, which is why it’s so concerning. 

So in a lot of these cases, folks might have symptoms that make them think they have something else? So they aren’t going to test?

Exactly, and you have to think about this too: Who are these people, who are the farmers? A lot of them are undocumented migrants who probably have very legitimate low trust in their employers or in the state government or in the federal government to surrender to things like testing. They probably don’t understand that this is not a way to get genetic information about them or anything else. 

I can understand why they would be reluctant to do something like that. And we have not done a good enough job to have targeted communications to increase their trust and to increase their participation in trying to mitigate this outbreak. 

And recent anti-immigration policies might exacerbate the problem, where workers might think they might be targeted or their information collected?

Think about it. I would also have my eyebrows raised if you were hearing about ICE raids and massive deportations while you perhaps are an undocumented worker or have undocumented family members and you’re working in a very high-stress, high-risk job like poultry farming or dairy farming. I wouldn’t want to comply. I totally get that.

What about food safety? Should people worry about contaminated eggs or milk?

It’s very unlikely that contaminated eggs will reach grocery stores. Federal regulations require eggs to be washed and sanitized, and infected hens stop laying eggs. When an outbreak occurs, infected flocks are culled. As for milk, unpasteurized milk is much riskier. Pasteurization kills viruses and bacteria, including bird flu, so I strongly advise against consuming raw milk.

Sick birds usually die before they can lay an infected egg. This means eggs from unhealthy birds likely won’t make it into grocery stores. While unlikely, thoroughly cooking your eggs kills that small possibility. 

Is eating raw eggs or eggs over easy a bad idea right now?

Cooking eggs thoroughly is always a good practice. While I personally still eat my eggs over medium, heating the virus will kill it. 

There’s probably greater risk in contaminated milk, unpasteurized contaminated milk. I would never recommend unpasteurized milk in any context. There is no value at all. Anything about nutritional value being increased or not reduced because of pasteurization — it’s a lie. Pasteurization does not reduce the nutritional value and it only keeps milk safe. So folks need to prioritize pasteurization.

What about raw milk makes it high risk — besides the fact that you’re not killing any possible bird flu through heat? 

We know raw milk is a higher risk because cats and even monkeys have gotten very sick and died from drinking unpasteurized milk contaminated with H5N1. That confirms the presence of infectious virus in raw milk. This is why we always emphasize the dangers of unpasteurized milk — not just because of bird flu, but also due to other pathogens like listeria, E. coli, and salmonella. The risks of consuming unpasteurized milk far outweigh any perceived benefits.

It’s a big warning for farm owners who have cats that are domesticated, or cats on the farm, to never let them drink unpasteurized milk from the source, or unpasteurized milk in general. Give them pasteurized milk if that’s what you feed them.

And pasteurization will definitely kill the virus, so people don’t have to worry?

Yes. It will kill the pathogens in the milk.

Beyond avoiding unpasteurized milk, what other practical steps can people take to reduce their risk of bird flu?

The most important thing is to make sure that you get your flu vaccine. If you’re sick, stay home. If you are out, please wear a mask to reduce your risk of flu, and also to reduce the opportunities that bird flu has to enter our population. We want to keep this within the animals. We also want to prioritize protecting the animals, because the animals deserve to not be sick, and our food chain supplies depend on it as well.

How can we avoid misinformation about bird flu? 

That’s a tough one. Even when I’ve disagreed with the CDC, I’ve always maintained that it is the world’s premier public health agency. 

However, the CDC website currently has a banner stating that it is being modified to comply with Trump’s executive orders. That makes me super weary about the reliability of information that we are getting from some sources.

That said, relying on your state public health department is probably a very good idea. Speaking to your provider about what’s going on in your community related to respiratory illnesses is a good idea. And following science communicators like myself and many others on various platforms who are trying to share in real time as much information as we have access to about the ongoing situation, the emerging data and how to proceed with it — is probably the best we can do, at least for now.

You can find Jessica Malaty Rivera sharing more about the bird flu and all types of science information on Instagram at @jessicamalatyrivera, Bluesky at @jessicamalaty.bsky.social, and SubStack at @makingsciencemakesense. 

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