Big ag causes pandemics and ABRs

That’s because we eat a ton of meat, and the vast majority of it comes from factory farms. In these huge industrialized facilities that supply more than 90 percent of meat globally — and around 99 percent of America’s meat — animals are tightly packed together and live under harsh and unsanitary conditions.

“When we overcrowd animals by the thousands, in cramped football-field-size sheds, to lie beak to beak or snout to snout, and there’s stress crippling their immune systems, and there’s ammonia from the decomposing waste burning their lungs, and there’s a lack of fresh air and sunlight — put all these factors together and you have a perfect-storm environment for the emergence and spread of disease,“ said Michael Greger, the author of Bird Flu: A Virus of Our Own Hatching.

To make matters worse, selection for specific genes in farmed animals (for desirable traits like large chicken breasts) has made these animals almost genetically identical. That means that a virus can easily spread from animal to animal without encountering any genetic variants that might stop it in its tracks. As it rips through a flock or herd, the virus can grow even more virulent.

Greger puts it bluntly: “If you actually want to create global pandemics, then build factory farms.”

For years, expert bodies like the World Health Organization and the Centers for Disease Control and Prevention have been warning that most emerging infectious diseases come from animals and that our industrialized farming practices are ratcheting up the risk. “Livestock health is the weakest link in our global health chain,” noted the Food and Agriculture Organization of the United Nations in a 2013 report.

We know from past experience that farmed animals can lead to serious zoonotic diseases (those transmitted from animals to humans). Just think back to 2009, when the H1N1 swine flu circulated in pig farms in North America, then jumped to humans. That novel influenza quickly became a global pandemic, killing hundreds of thousands of people.

To be clear, scientists believe the novel coronavirus originated in wild bats, not factory farms. But it has awakened us all to the crushing effect a pandemic can have on our lives. Now that we’ve come face to face with this reality, the question is: Do we have the political and cultural will to do something major — changing the way we eat — to sharply decrease the likelihood of the next pandemic?

What we talk about when we talk about pandemics

When we talk about the risk of pandemics, we’re actually talking about two different types of outbreaks. The first is a viral pandemic; examples include the 1918 influenza pandemic and Covid-19. The second is a bacterial pandemic; the prime example is the bubonic plague, the “Black Death” that wracked Europe in the Middle Ages.

Factory farming presents a risk in both these categories.

Sonia Shah, author of the 2017 book Pandemic, worries about viruses and bacteria alike. “When I was writing my book, I asked my sources what keeps them awake at night. They usually had two answers: virulent avian influenza and highly drug-resistant forms of bacterial pathogens,” she told me. “Both those things are driven by the crowding in factory farms. These are ticking time bombs.”

Our environmental practices make pandemics like the coronavirus more likely

Let’s focus on avian influenza first. Bird flu is caused by viruses and it’s a massive risk coming out of factory farms (as is swine flu). That’s both because the birds in these farms are squeezed together by the thousands in close proximity and because they’re bred to be almost identical genetically. That’s a recipe for a highly virulent virus to emerge, spread, and kill rapidly.

“Factory farms are the best way to select for the most dangerous pathogens possible,” said Rob Wallace, an evolutionary biologist at the Agroecology and Rural Economics Research Corps in St. Paul, Minnesota. To explain why, he offered a crash course in zoonotic transmission, from the point of view of the pathogen.

“If you’re a pathogen in a host,” Wallace said, “you don’t want to kill your host too fast before you can get into the next host — otherwise you’re cutting off your own line of transmission. So there’s a cap on how much of a badass you can be. The faster you replicate, the more likely you end up killing your host before the next host can come along.”

If you’re deep in the wilderness or on a small farm, you (the pathogen) are not going to regularly come across hosts, so you’ve got to keep your virulence, or harm inflicted on the host, pretty low so that you don’t run out of hosts. “But if you get into a barn with 15,000 turkeys or 250,000 layer chickens, you can just burn right through,” Wallace said. “There’s no cap on your being a badass.”

This is part of why factory farms are a bigger risk for zoonotic outbreaks than the natural world or small farms.

The biologist added that because we’re increasingly trading poultry and livestock across international borders, we’re ramping up the danger even more. Strains that were previously isolated from each other on opposite sides of the world can now recombine.

“Take influenza,” Wallace said. “It has a segmented genome, so it trades its genomic parts like card players on a Saturday night. Usually, most hands are not too terrible, but some hands come out much more dangerous. An increase in the rate of recombination means an explosion in terms of the diversity of pathogens that are evolving.”

The world has already seen a really frightening example of this. Between 1997 and 2006, highly pathogenic strains of H5N1 bird flu were linked to poultry farms in China.

“Our entire understanding of how bad a pandemic could potentially be changed in 1997 with the emergence of the H5N1 avian influenza virus. All of a sudden, there was a flu virus that was killing over half the people it infected,” Greger said.

When people became infected with H5N1, it had a 60 percent mortality rate. For comparison, experts estimate that Covid-19’s mortality rate is probably somewhere in the neighborhood of 1 percent to 3 percent, though these estimates continue to evolve and vary widely by country and by age. (If you’re wondering why H5N1 didn’t become as big a deal as Covid-19, it’s because it mostly infected poultry rather than people; it wasn’t as good at infecting humans as the coronavirus unfortunately is.)

“These new bird flu viruses have been tied to the industrialization — the ‘Tysonization’ — of our poultry production,” Greger said, citing evidence that exporting the factory farming model to Asia led to an unprecedented explosion of viruses infecting birds and people starting in the 1990s.

It’s not only birds we need to worry about. Remember that pigs are also highly effective carriers of viruses. A decade before the swine flu struck in 2009, the Nipah virus emerged in Malaysian pig farms. It caused encephalitis (inflammation of the brain) in hundreds of people, killing about 40 percent of the patients who were hospitalized with serious neurological disease.

Factory farming and the urgent problem of antibiotic resistance

The other pandemic risk associated with factory farms has to do with “highly drug-resistant forms of bacterial pathogens,” as Shah put it — that is, antibiotic resistance.

When a new antibiotic is introduced, it can have great, even life-saving results — for a while. But as we start to use and overuse antibiotics in the treatment of humans, crops, and animals, the bacteria evolve, with those that have a mutation to survive the antibiotic becoming more dominant. Gradually, the antibiotic becomes less effective, and we’re left with a disease that we can no longer treat.

A farmer tends to his hogs in Polo, Illinois, on January 25. Brendan Smialowski/AFP via Getty Images

The CDC warned in a major report last year that the post-antibiotic era is already here: We’re living in a time when our antibiotics are becoming useless and drug-resistant bugs, like C. difficile and N. gonorrhoeae, can all too easily decimate our health. Every 15 minutes, one person in the US dies because of an infection that antibiotics can no longer treat effectively.

Yet we continue to dole out too many antibiotics, driving the resistance. Animal farmers use antibiotics copiously on livestock and poultry, sometimes to compensate for poor industrial farming conditions.

“We have abundant evidence documenting the fact that when you put animals in crowded, unsanitary conditions and use low-dose antibiotics for disease prevention, you set up a perfect incubator for spontaneous mutations in the DNA of the bacteria,” said Robert Lawrence, a professor emeritus of environmental health at John Hopkins University.

“With more spontaneous mutations,” he explained, “the odds increase that one of those mutations will provide resistance to the antibiotic that’s present in the environment.” Those resistant bacteria could become strains that spread all over the world. “That’s the biggest human health risk of factory farms.”

In fact, factory farming presents us with a double bacterial risk. Say a bacterial outbreak emerges among chickens. The poultry can pass that bacteria on to us humans, causing serious infection. We’d normally then want to use antibiotics to treat that infection, but precisely because we’ve already overused antibiotics on our farmed animals, the bacteria may be resistant to the antibiotic. If the infection happens to be one that transmits well between people, we can end up with an untreatable bacterial pandemic.

When asked how he’d compare the pandemic risks posed by factory farms with those posed by China’s wet markets carrying live animals, Lawrence said, “With factory farming, the opportunity to start a viral pandemic may be less, but the opportunity for acquiring an antibiotic-resistant bacterial infection is greater.”