C. and E. wrote: “There are zero eggs at Whole Foods. There’s a sign limiting people to three boxes, but there aren’t any anyway!” (E. also noted there were no carrots or broccoli, and that’s its own post since carrots had a big recall due to e. coli and broccoli in 20 states was recalled due to a Listeria monocytogenes outbreak. My god.)

Whole Foods didn’t reply so I asked my friend Dan Horan, who created Five Acre Farms — distributors of local (and only local) dairy, eggs and apples. And it turns out it’s avian flu, which is now widespread in wild birds and spreading quickly among commercial birds. “It’s a nightmare,” he said. “It’s a brutally efficient killer for birds. They do not live. It’s not an egg safety question, but you are already 130 million birds down — the US flock is at its lowest in years. Whole Foods has its own farming standards, and those are right now too difficult to meet. It’s no longer a ‘farmer’s practice’ issue. Right now, there just aren’t enough birds and everything is upside down in the market.”

The USDA first confirmed cases in a commercial flock in 2022; now it has spread to flocks in nearly every state. In December alone, 52 backyard flocks and 70 commercial flocks became infected — adding up to 18 million birds on infected premises. Overall in two years it has hit 130 million poultry. The cost of the outbreak, according to The Takeout, a food news site, has reached $1 billion and driven egg prices up by 25 percent.

“Because of the massive spread,” The Takeout said, “infected birds are being culled across the U.S., sometimes numbering in the millions at a single location.”

But wait, there’s more. A quick Google on whether the avian flu pandemic is getting worse found stats from the CDC, which reports that there have been 66 cases of H5N1 avian influenza in humans, including one death. There is no person-to-person spread, and they said the risk is low. But there is spread now among mammals, which means the flu could be coming to the dairy industry as well as eggs.

Johns Hopkins published this Q&A this week with Meghan Davis, DVM, PhD ’12, MPH ’08, associate professor in Environmental Health and Engineering, and Andrew Pekosz, PhD, professor in Molecular Microbiology and Immunology, about the virus. It’s a big downer, so read with caution. I excerpted, so read the whole thing here.

Last week, there was a death from the bird flu. Where do things stand today?
Andy Pekosz: We’re seeing signs that this virus is really moving into humans. There was an infection in a person in Louisiana, who apparently acquired the infection because he had a backyard flock of chickens that had become exposed to wild birds. The chickens the person was raising, as well as the wild birds, were found dead. The person who was exposed to H5N1 was hospitalized, and died from the infection.

If that wasn’t serious enough, when the CDC scientists sequenced samples from this individual, they found that the virus had started to mutate at two particular sites that we know are important for H5N1 to adapt to better replicate in humans. This mirrors a case that happened about two months ago in British Columbia. We need to double down our efforts to make sure we limit H5N1 infections in humans, to try to lower the opportunity for this virus to learn how to infect humans effectively.

Does flu season complicate the situation?
AP: On the positive side, a lot of hospitals and areas are now testing extensively for influenza. That increases our monitoring, because if we find influenza-positive cases, we can determine whether they’re seasonal flu or H5N1. In that way, our testing is becoming more robust.

The concern is that in a person who is infected with both seasonal influenza and H5N1, those viruses may exchange genetic material and make a virus that’s better able to infect humans. That’s called reassortment. It’s a very rare event, but we know that reassortment has resulted in the influenza viruses that have caused the last three human pandemics.

Are we at a dangerous point with this virus?
Meghan Davis: We are if you’re a house cat. When this virus infects cats, it causes extremely severe disease and very high mortality rates.

We’ve had a number of product recalls linked to H5N1 cases, not just of contaminated raw milk, but also raw meat pet food products. If people are exposed to the virus through their pets, it may be a different kind of exposure than what we’ve seen before. In individuals who are immunocompromised, that could mean either different kinds of mutations in the virus or a different clinical manifestation of disease.

We still have a very large outbreak in cattle.
MD: Yes, although California, which is the leading dairy state and the epicenter of what we’re seeing currently, is starting to get a handle on it. We’ve seen a decrease in the new herds identified. But we’re still at over 300 herds nationally.

AP: It’s important to note that those two serious human influenza infections—the one in British Columbia and the one in Louisiana—are H5N1 viruses, but they’re a slightly different form of the virus than is infecting dairy cows.

H5N1 is a very dynamic virus. There’s lots of versions of it circulating in lots of different animals and birds, and it’s continuing to pose a greater and greater threat in terms of spillover and leading to a pandemic.

Should we be concerned about person-to-person transmission?
AP: Absolutely. The mutations that have been detected in infected people probably alone won’t allow the virus to transmit. We have no evidence of transmission yet, but we need to do more surveillance in broader populations that are at risk. We know that the virus can cause mild disease in certain situations, but that means we probably need to test more extensively to figure out how much of that mild disease is being caused in these spillovers into humans.

MD: It’s also important to mention that we have seen sustained animal-to-animal transmission, and not just in birds, but also in mammals, and not just dairy cows. There have been studies that have shown ferrets can transmit to other ferrets, and this is another species that is particularly susceptible to influenza viruses. This gives the virus more opportunities to “fine tune” if there is a mutation—to select for strains that could be more adapted to mammalian transmission.

What can we do going forward to avoid a pandemic?
MD: We should certainly be doing more animal surveillance, and we are starting to. For dairy cows, there’s a way to test en masse, using bulk milk tank tests. This means that you’re checking the pooled milk from hundreds of cows for H5N1. If you get a positive test, you can go back to the original farm to identify which cows may be infected. This is absolutely essential for controlling spread from dairy cow to dairy cow, whether through direct cow movement, personnel, equipment, or another mechanism.