Bird flu in milk is alarming — but not for the reason you think

The US Department of Agriculture’s failed response to bird flu in cows, explained.

Bird flu has had a busy couple of years.

Since 2022, it’s ravaged the US poultry industry, as more than 90 million farmed birds — mostly egg-laying hens and turkeys — have either died from the virus or have been brutally killed in an attempt to stop the spread.

Last month, confirmation that the virus — a strain of highly pathogenic avian influenza known as H5N1 — had infected US dairy cows alarmed infectious disease experts, who worry that transmission to cows will allow the virus more opportunities to evolve. One dairy worker fell ill, increasing concerns about human risk levels.

Now it’s in the milk supply. On Tuesday, the US Food and Drug Administration (FDA) confirmed that genetic evidence of the virus had been found in commercially purchased milk. However, it’s unclear whether the milk contains live virus or mere fragments of the virus that were killed by pasteurization, a process that destroys harmful bacteria, but remain detectable.

The FDA said it’ll soon release a nationwide survey of tested milk and that for now, the commercial milk supply remains safe, a claim that numerous independent experts have confirmed.

The news that the bird flu has been found in the US milk supply may raise alarm among some consumers, and the FDA has been criticized for prematurely assuring the safety of milk without hard data. But the real problem, which has received little attention, is the tepid and opaque response from the federal agency tasked with stopping the on-farm spread of the disease: the US Department of Agriculture (USDA).

Ever since the virus was detected on a Texas dairy farm in late March, infectious disease experts around the world have roundly criticized the USDA on multiple fronts.

It took nearly a month for the agency to upload data containing genetic sequences of the virus, which scientists use to better understand its threat level. And once the sequence was uploaded, it was incomplete, lacking specifics that researchers say they needed to properly study the data.

“It’s as if the USDA is intentionally trying to hide data from the world,” Rick Bright, a former director of the Biomedical Advanced Research and Development Authority at the US Department of Health and Human Services, told STAT. A Dutch virologist told STAT it should’ve taken the USDA days, not weeks, to share data and updates.

Beyond the data obfuscation, there’s insufficient monitoring. The virus may have started circulating on US dairy farms months before it was detected, according to Michael Worobey, a biology professor at the University of Arizona. That suggests the need for better and more proactive pathogen monitoring on the part of the USDA.

And once H5N1 was confirmed in dairy cows, the USDA didn’t require dairy farms to conduct routine testing nor report positive H5N1 tests. The USDA has even tolerated uncooperative farmers, despite the high stakes of the disease spread.

“There has been a little bit of reluctance for some of the producers to allow us to gather information from their farms,” said Michael Watson, administrator of USDA’s Animal and Plant Health Inspection Service, in a press conference on Wednesday. But, he added, “that has been improving.”

This voluntary approach is a recurring theme in USDA policy; there’s even uncertainty as to whether the agency is enforcing orders for farmersto toss milk from infected cows to ensure it doesn’t wind up in the food supply, which could explain how traces of it were found in store-bought milk.

Last week, the New York Times reported that North Carolina officials confirmed there were asymptomatic cows in the state, which could also explain why the virus was detected in the commercial milk supply. It also suggests more herds may be infected than previously thought.

On Wednesday, a month after the first confirmation, the USDA finally issued a federal order requiring that laboratories and state veterinarians report farms with positive H5N1 tests and that lactating dairy cows must test negative for bird flu before crossing state lines (and cooperate with investigators).At a Wednesday press conference, the agency didn’t specify how the order will be enforced.

The USDA’s sluggish response to a rapidly moving virus may leave some foreign observers scratching their heads. But much of it can be explained by an irresolvable conflict baked into its mission.

The agency, according to food industry scholars Gabriel Rosenberg and Jan Dutkiewicz, has “the oxymoronic double mandate of both promoting and regulating all of American agriculture—two disparate tasks that, when combined, effectively put the fox in charge of the henhouse.”

More often than not, it’s heavy on the promotion and light on the regulation.

The paradox has been at the center of its response to the bird flu’s decimation of the US poultry industry in recent years. While the USDA is developing several bird flu vaccines, it’s long been stubbornly opposed to a broad vaccination campaign due to industry fears that it’ll disrupt trade, a major source of revenue for US poultry companies, despite pleas from experts to give birds a bird flu shot.

USDA has also been deferential to industry on matters of pollution, labor, political corruption, false advertising, and animal cruelty across numerous sectors. And it’s not the only agency that too often takes a hands-off approach to problems stemming from food production.

The FDA has failed to stringently regulate antibiotics used in animal farming, a pressing public health threat that, in recent years, some European regulators have addressed in earnest. Agriculture is a top source of US water and air pollution, due in large part to congressional loopholes and weak enforcement on the part of the US Environmental Protection Agency.

It all adds up to what food industry experts call “agricultural exceptionalism,” in which the food industry operates under a different set of regulations than the rest of the economy. The justification of such exceptionalism is that it’s necessary, given the importance of an abundant food supply. But that’s all the more reason not to give farmers and ranchers carte blanche to let disease circulate on American farms unchecked.