Over the past two decades, scientists have paid close attention to the spread of bird flu, a disease caused by the H5N1 virus that has high pandemic potential. Last spring, when the virus made the jump from wild birds to dairy cows, those fears of a new health crisis like COVID-19 were amplified. Though President Biden arguably didn’t do enough to stop the spread of H5N1 — which has infected at least 67 people — now President Trump is in charge of the problem, which is already causing trouble.
It’s not just the potential of anti-vaccine conspiracy theorist Robert F. Kennedy Jr. soon to helm the health departments responsible for monitoring disease outbreaks or Trump's recent pause on federal health communications, it’s also the president’s immigration policy that is making matters worse. Public health and immigration may not seem like issues that are interconnected, but like many things, neither exists in a vacuum. To understand why, we must first talk about dairy cow density.
A dairy farm detour
Luís Jimenez, an experienced dairy worker in New York state, works in a large dairy farm where about 1,400 cows are cared for by some twenty workers. The cows are kept indoors, in airy barns of about 250 cows packed together with just enough room to lie down. Jimenez and his co-workers are available on a 24-hour schedule to keep their charges healthy and well despite such a density of cattle.
“They depend on [us] to feed them, to move them from place to place, and to check them to be sure they are not sick,” Jimenez told Salon in Spanish in a telephone interview, translated by the author. “So in my opinion the cows depend very much on our presence on the farm because we are the ones who maintain their health, who keep them clean, who clean the stables. We ensure the cleanliness of the water they drink … the boss’ business depends on the cows and on their production.”
Indeed, producing more milk for less money is key to that business. Historically, the number of dairy farms in the U.S. has been in decline over the past fifty years. However, between the 2017 and 2022 censuses, that decline accelerated dramatically. Researchers at the University of Illinois at Urbana-Champaign have attributed this to financial stress in the sector, and note that economies of scale, mostly relating to the non-feed cost per quart of milk produced, make it hard to escape this stress. A drop in milk prices in 2018, for example, narrowed the gap between a farmer’s potential profit and the costs involved in earning it.
Unless, that is, a herd is extremely large. Over the 2017 to 2022 period, there were fewer farms selling milk at all herd sizes, except for farms with herds of 2,500 cows or more, which increased. The result? There were 39% fewer farms selling milk in the US in 2022 than five years before. Large farms — those with herds of 1,000 cows or more, often over 5,000, and even 10,000 or more — dominated the sector by 2022 as never before. By that year, they accounted for 66% of all milk sales — up from 57% in 2017.
A lot of dairy workers may be at risk of deportation now as the Trump administration escalates raids in immigrant communities.
The result has been a ramping up of the long-term trend favoring consolidation of smaller dairy farms into giant, corporate-owned enterprises: the rise of Big Agriculture, a trend seen to varying degrees in other areas of agriculture as a few owners gobble up farms of all kinds. As the U.S. Department of Agriculture explains in their 2020 Economic Research Service report on consolidation in dairy farming, “the number of licensed U.S. dairy herds fell by more than half between 2002 and 2019 … even as milk production continued to grow”.
With bigger, fewer farms has come a trend towards hired rather than owner-provided labor. A New York Times Magazine last year, in an article on the impact on milk prices of immigration crackdowns, put it starkly: “Undocumented labor quietly props up the entire American economy — but nowhere more dramatically than on dairy farms.”
As journalist Marcela Valdes describes in the story, declining prices for milk while everything else gets more expensive means smaller dairies are forced to cut costs wherever they can in hopes of edging out of the ‘high risk’ operating profit margin so many of them are in (a situation described in ESR’s 2024 report on the state of America’s farms and ranches). Cutting labor costs is the most significant way to do that, and undocumented workers are least able to demand better pay — or to insist on safety measures to protect themselves from infection, or to report infractions in rules intended to keep animals and workers healthy.
Jimenez, who is a co-founder and the current president of Alianza Agrícola — a worker-founded, worker-led organized group of undocumented migrant dairy farmworkers working across five counties in Western New York — believes that about 90% of his fellow workers are immigrants, mostly from Latin American countries. Cornell University research dating back to 2018 suggests that over 50% of New York workers lack proper immigration documents. This doesn’t stop them from being excellent, skillful workers, and workers who will do dangerous, hard work for which farmers have trouble finding enough hands.
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In other words, a lot of dairy workers may be at risk of deportation now as the Trump administration escalates raids in immigrant communities. These are the people who do the hard work of keeping cows healthy, and containing infection when they are not.
“It’s sad and frustrating that we are critical in the farm, vital to the industry, and the owners do nothing to protect workers in this situation we’re in with respect to immigration,” Jimenez said.
What does this have to do with bird flu?
The timing for this crackdown could actually worsen the bird flu situation, with undocumented workers at these massive, tightly cow-packed facilities living in fear of Immigration and Customs Enforcement (ICE.) Whether this is mostly manufactured fear, or due to new, actual mass raids, given that the people in closest, most attentive contact with the cows are in danger of being involuntarily moved or changing location to avoid deportation, we risk failing to catch infection in cows, failing to report infection in humans, and potentially greater risk of viral transmission due to either workforce movement or lack of workers available to implement emergency measures to prevent or contain an outbreak.. Salon contacted ICE by email but did not receive a response.
At a briefing for reporters, Dr. Maurice Pitesky of the University of California, Davis, pointed out that undocumented workers are also unlikely to receive regular influenza vaccines, increasing their likelihood of harboring co-infections of human influenza and H5N1 or other types of highly pathogenic avian influenza. This is exactly the sort of scenario that makes viral evolution more likely, hastening the day when H5N1 achieves the very few mutations required for it to transmit easily from human-to-human. Jimenez says Alianza Agrícola has organized health clinics for farmworkers, most recently last month, where they can get their blood pressure checked and receive COVID and flu vaccines. Without this form of organizing and workers’ courage to be open about it, education on the value of vaccines and access to them would both be unlikely to occur at their employers’ behest.
It’s already made the leap
Consolidation in the dairy sector is far more intense than that general trend in agriculture as a whole. There are many implications of this, not least the dramatic social change that results as small family farms gradually throw in the towel. A more surprising implication, though, is the dramatic risk the accelerating dairy consolidation trend in recent years poses to human as well as animal health. That’s because H5N1 continues to spread from its avian origin into other species, most recently mammals, including humans.
"The bosses don’t offer this kind of information … there are very few farms that are informing their workers [about H5N1]."
The Centers for Disease Control (CDC) describes the current situation is an “ongoing multi-state outbreak” in dairy cows (959 confirmed cattle infections across 16 states, according to latest USDA data), while there are “sporadic outbreaks” in both commercial and backyard poultry flocks and “sporadic infections” in mammals. There have been many deaths of cats infected through raw milk or food containing it, numerous human cases, and a small handful of deaths among humans, including some with no obvious connection to wild birds, poultry or dairy cows.
The first U.S. case of bird flu in a pig was identified in October. This is worrisome because like cows, pigs are in close proximity to humans, they’re also confined to the close quarters that facilitate disease spread, and they’re particularly susceptible to influenza, offering plenty of opportunity for different flu viruses to swap genes — all of which makes them a likely vector for a highly dangerous strain or one capable of human-to-human transmission.
At this point, there are so many potential sources of bird to human or mammal to human transmission, the H5N1 genie is out of the bottle. On Wednesday last week, in fact, the USDA announced that D1.1, a subtype or clade of H5N1 previously only ever found in wild birds and poultry, had turned up in Nevada dairy cows. Not only wild birds and poultry — the Louisiana patient who died in the first week of January was one of very few humans known to have been infected by D1.1, from a backyard flock. (This strain may well be more dangerous to humans than the B3.13 genotype found in other U.S. dairy cows to date — the teenage girl in Canada who only survived her brush with bird flu from an unknown source thanks to weeks of intensive medical intervention was also infected with this type.) So now there are at least two versions in cattle, along with the other strains circulating in other animals, waiting to make the leap to new species.
All in all, we are currently only a few small mutations away from a serious pandemic. Even a single mutation to H5N1’s surface protein would be enough, as a NIH-funded study found in December, to more easily transmit between humans.
When humans are ill with infectious disease, the prevailing wisdom (if not common practice these days) is to quarantine them. Or at least to put a little healthy distance between the sick person and everyone else. Which is why it’s notable that trends in agriculture do the opposite for cows and poultry.
The density of cows and viral evolution
Fewer and larger farms, but greater milk production. There are two ways to achieve this: get each cow to produce more milk, or pack more cows onto each farm. As it turns out, large farms are working on both.
“Improvements in milk yields reflect steady improvements in dairy cow genetics, feed formulations, and on-farm practices,” write the authors of the USDA report. Due to the communications freeze imposed on National Institutes of Health staff, Salon was unable to speak with the authors of papers like this one in Nature, which describes the mammal-to-mammal spread of H5N1, its emergence in U.S. dairy cows and then in barn cats, its spread from cow to cow via milking equipment, and the expansion of what was once a single outbreak to new farms as infected cows, or infected equipment, were transported across state lines. The latter is one of several hypotheses (in fact, all of them may be correct) of how bird flu has spread. Transmission to humans might first have involved dairy workers infected by their cattle.
“We don’t understand why yet, but the information we have as workers and as part of the organization, we get it from other institutions and other organizations that bring this information to keep workers informed,” Jimenez explained. “The bosses don’t offer this kind of information … there are very few farms that are informing their workers [about H5N1].”
And workers who become sick, lacking health care and perhaps afraid to seek it, may not receive timely or any treatment, nor are bosses likely to learn that H5N1 is spreading through their workforce given that veteran workers like Jimenez nevertheless have no social security, disability or retirement benefits if they become unable to work. Like Jimenez, who on the day he spoke with Salon had finally sought an X-ray for pain from a work injury to his finger that he’d ignored for days, many workers avoid treatment for issues that only seem minor at first.
During the early days of the COVID pandemic, Alianza Agrícola organized to provide some of the information and support workers weren’t getting from their bosses. H5N1 doesn’t seem to have hit New York’s herds yet (though seven cases were recently detected in poultry), but Jimenez says he’s going to have to resort to the same mutual aid strategies if and when it does.
Until then, close monitoring of the virus is necessary. Not until April 29th did the USDA begin to require testing of cattle before they are allowed to cross state lines. By that point, the horse had left the barn, so to speak.
Speaking of barns, the consolidation of dairy farming into massive operations where cows are confined to tight spaces and feedlots rather than grazing makes transmission from one sick cow to an entire herd far easier than it would have been on smaller farms: “Cows are less likely to graze in pastures and are more likely to be confined within large barns and lots,” write the authors of the ERS report.
H5N1 surveillance
Monitoring for bird flu in humans is the province of the CDC, which so far has not reported person to person spread. However, they noted last week, in the process of recommending rapid subtyping of influenza A positive specimens from hospitalized patients to quickly detect human cases of bird flu (which is the bird version of influenza A), that there were 66 identified human cases in the U.S. last year. But the CDC has been embattled in recent days, with a freeze on external communications imposed on all federal health agencies Jan. 21. It was supposed to be lifted by Feb.1, but there’s been no word from the Department of Health and Human Services on the current status of communications.
Like the CDC, the USDA provides periodic briefings about bird flu. Or at least they did — funding for various programs is already being frozen in chaotic fashion and it’s not clear what might be next. That said, they did announce the D1.1 finding last week. But NIH-funded research on critical mutations to the H5N1 genome is also at risk.
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It’s worth noting that, as described by Science last month, the USDA’s ERS was gutted by Trump during his first term in office. Jim MacDonald, an economist at ERS who among other things has tracked the consolidation in the livestock industry, told Science that, “without ERS, USDA would be left with relying on commodity trade groups and advocacy groups to make stuff up,” he asserted. “The information would be lower quality, and it would be packed with lies.”
MacDonald retired in 2019 when faced with a forced move that decimated the experienced workforce. Although the agency was rebuilt, Jeffrey Mervis describes in Science’s report, there’s less expertise and reportedly less willingness to explore controversial issues and share politically unpalatable findings, such as one study ERS presented back in 2018 that found the wealthiest farmers benefited most from Trump’s 2017 tax cuts.
This could translate into reluctance to carry out studies relating to the risk of H5N1 in relation to the labor force, safety measures, ventilation, density or other factors unpopular with the current administration.
And if farm owners fail to defend their migrant workforce by advocating against deportations and for regularization of status, they will lose the people quickest to notice when a cow takes ill. Indeed, the welfare of humans at risk of a true bird flu pandemic may depend on the people who care for the welfare of animals, with little recognition and fewer rights.
“I believe the reality is that if we don’t raise our voices and don’t tell anyone [about undocumented workers and the value of our work], no one knows that we exist because they’ve always kept us quiet,” Jimenez told Salon.
With a pandemic that could put COVID to shame brewing in tightly packed herds across the country, silence could prove fatal.
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