Every year, there are multiple warnings about beef products contaminated by E. coli. There were two recalls of Romaine lettuce for similar reasons in 2018. Listeria bacteria showed up in spinach recently. Salmonella has infected peanut and almond butters.

Part of this is better monitoring. We see more contamination because we’re getting better at detecting and diagnosing it. We’re far removed from the lax days Upton Sinclair memorialized in his journalistic novel The Jungle, which exposed unsanitary conditions in a Chicago meat-packing plant. Government agencies like the Centers for Disease Control and Prevention (CDC) and the United States Department of Agriculture (USDA) help regulate hygienic standards for food products.

But we’re also seeing the darker side of of industrialized foodways. The drive for productivity and profitability sometimes trumps food safety. Bacterial outbreaks are one symptom of this problem.

It’s important to know the usual suspects for contamination, how they infect our food, and what to look out for. Here you’ll find the most dangerous common contaminants in our crops and meat.

  1. E. coli:

    E. coli outbreaks have become common in both meat and produce. Originating in animal intestines, most species of this notorious bacteria are relatively harmless. But some groups, like the O157 strain, can cause serious discomfort, damage, and even death.

    This microbe usually moves from animal intestines to human innards by moving from feces into meat or from manure onto plants or into water sources. Better monitoring of water sources, adherence to sanitary standards in meat storage and processing, and less dependence on irrigation could help minimize exposure to this dangerous contaminant.

  2. Salmonella:

    Salmonella is the most frequent source of food contamination. Ingestion results in nausea, diarrhea, and vomiting. Although the disease is not usually life-threatening, excess loss of fluids without electrolyte replacement can trigger dehydration and put patients in critical condition.

    Its ubiquity comes from its presence in many farm animals and pets, from pigs and chickens to turtles, cats, and dogs. The sheer number of potential vectors for transmission as well as the bacillus’s resilience make it a formidable infectant. Concerns about some strains of salmonella evolving resistance to antibiotics is a source of growing concern.

    Only vigilance and thoroughness in decontamination at every stage of contact with animals and meat products can protect us from salmonella.

  3. Listeria

    In 2011, cantaloupes tainted with a deadly strain of listeria struck, infecting 147 people in 28 states. Of those who contracted the bacteria, 33 died.

    Listeria is one of the rarest but most lethal bacterial strains that infects our food. Although it’s pervasive in our environment and can survive even under inhospitable conditions for long periods of time, it rarely infects. When it does, it typically afflicts vulnerable populations like children and pregnant women. With a mortality rate of almost one in five, listeriosis is a serious threat when contracted.

    Controlling listeria is difficult. Infected animals may be asymptomatic, making it hard to diagnose. It can survive in extreme conditions of hot and cold, in acidic and alkaline environments, and it defies all but the most thorough decontamination protocols. In some meat-packing plants, it has been known to survive as long as ten years in dormancy. Only extremely thorough sanitary measures at every step in the food production process and cooking foods to temperature can ward off listeria.