(How) Does Salmonella Grow on Trees? Answer: It Doesn’t

By Karen Davis, PhD, President of United Poultry Concerns

“Unfortunately, we’ve seen—specifically with ongoing outbreaks in the romaine lettuce industry in addition to all the other outbreaks that we’re acutely aware of— Listeria in cantaloupe, Salmonella, and others.” – “The food safety imperative: Talking with attorney Bill Marler,” Food Safety News, February 22, 2022.

stick figure made of veggies

The vegan delights featured in this collage by Beth Clifton can be contaminated with infectious microbes flowing from animal farms.

In the rare event that the mainstream media mentions an outbreak of Salmonella, E. coli, or other foodborne illness in people that the FDA or the USDA has traced to a fruit or vegetable such as lettuce or cantaloupe, the fact that the causative pathogen is of animal origin is seldom noted in the coverage. Little wonder, given that agribusiness and the U.S. Department of Agriculture resist implicating animal farming in their reports on these “plant-based” outbreaks.

People are accordingly led to believe that the fruits and vegetables they buy at the store or eat in a restaurant can somehow generate contamination by pathogens (disease-causing microbes) whose natural habitat is the intestines, liver or other organs of animals. While fruits and vegetables can carry these pathogens, they do not originate them. The cantaloupe is not the culprit.

Salmonella, E. coli, Campylobacter, and Listeria are common bacterial causes of sickness in people. They can contaminate plants such as spinach, tomatoes, lettuce, and melons via animal-based fertilizer, runoff from animal farming operations, and cross-contamination handling, as when a head of lettuce is touched by hands covered with infectious microbes that have been transferred to the hands from contaminated meat, eggs or dairy products. But don’t expect government or industry to trumpet this information.

It was thus refreshing to read a February 22 article in the online food science publication Food Safety News, in which the speaker connects contaminated fruits and vegetables with industrialized animal farming. In the article, Bill Marler, an attorney specializing in cases of foodborne illness outbreaks, and the founder, in 2008, of Food Safety News, has this to say:

“If you look at the outbreaks that have occurred in the last decade, specifically with respect to leafy greens, there’s always a cow somewhere in the equation. There’s always a feedlot nearby, or always a dairy farm nearby. And one of the frustrating things for FDA and USDA is being able to do the underlying research, to know that the source of the contamination really was that farm, or really wasn’t. But FDA inspectors cannot go onto cattle farms or feedlots. If we’re going to have ready-to-eat food, we’ve got to really start to think about the environment in which it’s grown.”

The Centers for Disease Control and Prevention, describing zoonotic diseases, meaning diseases that can spread between human and nonhuman animals under various conditions, observes that “Zoonotic diseases are very common, both in the United States and around the world. Scientists estimate that more than 6 out of every 10 known infectious diseases in people can be spread from animals, and 3 out of every 4 new or emerging infectious diseases in people come from animals.”

Concerning foodborne diseases, the CDC states that “Each year, 1 in 6 Americans get sick from eating contaminated food.” People get sick from eating or drinking “something unsafe, such as unpasteurized (raw) milk, undercooked meat or eggs, or raw fruits and vegetables that are contaminated with feces from an infected animal.”

An irony in most discussions of zoonotic diseases is that these diseases, bacterial and viral in particular, are not just transferable from nonhuman animals to humans, but that they are increasingly being transmitted from humans to nonhuman animals by way of the conditions under which humans are forcing nonhuman animals, worldwide, to live. Eroding animals’ natural habitats, jostling animals of different species together in unsanitary live animal markets, and confining billions of chickens, cows, pigs, turkeys, ducks, fishes and other animals in the cesspools we call factory farms – all of these conditions, including animal-research laboratories, are making animals sick with diseases that carry over into the human population.

Karen sitting with a rescued hen in her lap
Karen Davis, PhD and rescued hen blinded by ammonia fumes in a Tyson facility in Maryland. Photo © Bruce Andrew Peters

In “China’s Wet Markets, America’s Factory Farming,” Matthew Scully, author of DOMINION: The Power of Man, the Suffering of Animals, and the Call to Mercy, writes that while Western societies don’t normally eat “pangolins, turtles, civets, peacocks, monkeys, horses, foxes, and wolf cubs . . . for the animals we do eat, we have sprawling, toxic, industrial ‘mass-confinement’ farms that look like concentration camps. National ‘herds’ and ‘flocks’ that all would expire in their misery but for a massive use of antibiotics, among other techniques, to maintain their existence amid squalor and disease, are an infectious ‘time bomb’ closer to home as bacterial and viral pathogens gain in resistance.”

What Bill Marler calls “the environment” of agriculture starts inside the farmed animal confinement complexes. The misery, squalor, antibiotics and diseases in these places spill out into the surrounding environment contaminating water, fruits and vegetables, and making farm workers sick. These same animal farm elements travel to the supermarkets, restaurants, and home, and into people’s mouths, to be spilled back out into the environment in the form of zoonotic diseases that infect human and nonhuman animals and contaminate crops – the crops that are fed to the animals and those that are grown for direct human consumption.

So far, eating misery and the physical manifestations of misery prevails over eating healthy and humane in the habits of humanity. What will it take to bring these habits to a higher standard? We have the knowledge, we have the food; the question is, how do we empower the will?

To learn more about the health and ethics of diet, visit www.upc-online.org/diet.