– OPINION –
Let’s not bury our heads in the sand
Colleagues, it’s time to wake up and smell the coffee. Or, for a real reality check, just scan the regularly updated reports from the Department of Agriculture map and tables naming the many animals that have tested positive for highly pathogenic avian influenza (HPAI) in the US since May 2022.
Finding influenza A/H5N1 in wild birds, waterfowl and poultry is of course nothing new. However, in 2024, our country experienced its first-ever multi-state outbreak in dairy cows pumping milk heavily contaminated with the virus, as well as illness, deaths or detections in cats, goats, alpacas, skunks and house mice. among others. The last species found to harbor A/H5N1 was a backyard pig in Oregon . Once euthanized, the virus-laden tissues caused even more concern because pigs are classic mixing vessels in which human and bird flu viruses can recombine and form new, virulent strains.
Now for some less ominous news: the virus strain currently circulating in American dairy cows and poultry has not yet caused serious illness in humans. Based on very limited testing, about four dozen A/H5N1 infections so far, almost evenly distributed among dairy and poultry workers, have been mild or even asymptomatic. As a result, CDC continues to push forward say the risk for the general public is low.
That said, there is now one seriously ill teenager infected with H5N1 in Canada with unknown source of exposure. Furthermore, no knowledgeable expert would deny that influenza viruses are notoriously unpredictable and have caused more pandemics than any other pathogen during the past 500 years . Now consider the modern challenge of getting big agriculture, government and public health to work hand in hand on control measures while communicating clear, sensible advice to ordinary people already exhausted by COVID, some of whom also believe that raw milk is bad. Nature’s perfect food, without taking it into account previously proven dangers as mere nonsense.
So imagine that A/H5N1 will evolve further in 2025, leading to much more numerous and harmful infections in humans. If that happens, how will history judge our country’s political will and efforts to prevent this disaster? A day late and a dollar short? Or how about downright incompetent (to repeat one response from global experts )? Most importantly, what proactive measures and messages can continue to counter the growing risk of HPAI spreading from animals to humans in the future?
A well-known expert weighs in
In late October, the National Academies of Science held a two-day meeting virtual public workplace titled “Potential Research Priorities to Inform Preparedness and Response to Highly Pathogenic Avian Influenza A (H5N1).” Shortly before the event, Stephen Ostroff, MD – a highly respected public health expert who previously worked at both the CDC and the FDA (at the FDA, Ostroff was at various times the agency’s chief scientist and acting commissioner) – was asked to attend and provide commentary on possible gaps in a future research agenda.
After listening to a full day of “very smart” conversations, Ostroff made a key observation: that a glaring gap was a plan for systematic research into reasons why people might be reluctant to follow government recommendations on issues ranging from agricultural practices and the interstate movement of potentially infected animals for environmental surveillance and diagnostic, therapeutic and preventive purposes interventions for animals and people.
“It’s great to develop diagnostics, therapeutics and vaccines,” he told me later, “but the problem is: it’s a bit like the ‘Field of Dreams’ phenomenon. And that’s the analogy I used, which is – just like during COVID – there was the implicit assumption that ‘if you build it, they will come.’ What happens if they don’t come?”
Ostroff also highlighted other overlooked questions: For example, can previously sick cows be reinfected with A/H5N1? And what about the potential role of pets in transmitting the virus to humans?
“Given what we’ve already seen on some of these farms where barn cats drink the milk and end up with aggressive disease and 50% mortality rateI specifically mentioned: if people like to drink raw milk. . . the pets in the house probably drink it too.”
Finally, what if a cow goes to slaughter with an asymptomatic A/H5N1 infection? As Ostroff reminded me, certain people also feed their pets raw beef products. While working at the FDA, he even oversaw national recalls after Salmonella or another bacterial pathogen contaminating such products sickened not only a pet, but people in the same household. By 2025, ingesting raw milk, beef or chicken could be one of the ways a pet can become ill, shedding the A/H5N1 virus in its respiratory secretions or feces and exposing the owner.
More relevant facts and regulations
Not so long ago I visited the website of a leading supplier of raw milk here in California. That’s right: my home state is one of many in the US where it is currently legal to sell raw milk to people.
In light of this year’s cattle outbreaks now affecting 278 dairies in Central California, I expected the homepage to at least include a warning about HPAI. But this is what I found instead: a pop-up banner that reads “NEW PET FOOD, FROZEN RAW MILK – NOW AVAILABLE NATIONALLY.”
What?
After telling Ostroff this, the veteran regulator confirmed a pertinent fact: Although the FDA prohibits the interstate sale of raw milk for human consumption, that is not the case for raw milk intended for animals. At the same time, he added, “Even though the websites read [frozen raw milk] for pets, sometimes it’s essentially a “wink, wink, nod, nod” way to sell raw milk to people without having to adhere to state and federal requirements.
And to be clear, while pasteurization kills A/H5N1, freezing does not. In the words of Ostroff: “Viruses like to be frozen.”
Finally, Ostroff and I discussed a major breakthrough that may provide hope for some and stoke fear and distrust for others: new vaccines, for both cows and humans, designed to protect them against A/H5N1. If Ostroff had his druthers, the A/H5N1 component would eventually be added to our standard annual flu shot.
But no, we have not yet reached a point where experts recommend that people be vaccinated against HPAI. That said, dairy and poultry workers – many of whom are immigrants – will be an important group to target if and when that time comes.
My final concern? At that point, will employers, the agricultural industry, government, public health leaders and civil society finally have agreed on a full set of measures to prevent a pandemic? For now, we can only hope.
For more information on the best ways to protect yourself and advise patients on preventing infection with highly pathogenic bird flu, visit the CDC website.
About the author: Claire Panosian (Dunavan) MD, DTM&H (London), FIDSA, FASTMH, WGAwest
Professor of Medicine – Infectious Diseases, Emeritus – recalled
David Geffen School of Medicine at UCLA.
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