Listeria monocytogenes
Why it’s special: Listeria is one of the few foodborne pathogens that grows at refrigerator temperatures. This makes ready-to-eat refrigerated foods — deli meats, soft cheeses, smoked seafood, pre-cut produce — the highest-risk category. Heating to 165 °F kills Listeria, but ready-to-eat means the food is consumed without that cooking step.
Vulnerable populations: pregnant women (about 10 times more likely than the general population to get listeriosis; infection can cause miscarriage, stillbirth, or premature delivery), newborns, adults over 65, and people with weakened immune systems. Healthy younger adults are much less likely to develop serious disease.
Symptoms: fever, muscle aches, sometimes nausea or diarrhea. Severe cases can develop into meningitis or bloodstream infection. Symptoms can appear up to 70 days after exposure, which is why Listeria outbreaks often involve recall notices well after the affected product is off shelves.
Why detection triggers Class I: any detection of Listeria in a ready-to-eat food product almost always triggers a Class I recall under both FDA and USDA rules, regardless of whether confirmed illnesses have been reported.
Salmonella
Why it’s common: Salmonella is responsible for the largest share of US foodborne illness by case count. It’s found in raw poultry, raw eggs, raw produce (especially sprouts and leafy greens), and occasionally in dry products like flour, peanut butter, and dry pet food. Cross-contamination in the home kitchen is a major source of human infection.
Vulnerable populations: infants and young children, adults over 65, and immunocompromised people are at highest risk for severe illness. The CDC estimates Salmonella is responsible for about 26,500 hospitalizations and 420 deaths in the US every year.
Symptoms: diarrhea (often bloody), fever, and abdominal cramps starting 6 hours to 6 days after exposure. Symptoms typically last 4 to 7 days; most people recover without treatment.
Why detection triggers recalls: Salmonella in a cooked or ready-to-eat product is treated as a Class I FDA recall. Salmonella in a raw product like ground beef or chicken is treated differently because consumers are expected to cook it — these recalls are typically Class II unless illnesses are confirmed.
E. coli O157:H7 (Shiga-toxin-producing E. coli)
Why it’s dangerous: Most E. coli strains are harmless. E. coli O157:H7 produces Shiga toxin, which can cause severe disease at very low infectious doses. The strain is associated with ground beef and leafy greens (especially romaine lettuce, which has been linked to several major outbreaks since 2018) but also appears in raw milk, raw flour, and unpasteurized cider.
Vulnerable populations: children under 5 are at highest risk for hemolytic uremic syndrome (HUS), a severe complication that can cause kidney failure. Adults over 65 and immunocompromised people are also at elevated risk.
Symptoms: severe stomach cramps, bloody diarrhea, and sometimes vomiting, starting 3 to 4 days after exposure. About 5 to 10 percent of cases develop HUS, which can be life-threatening and may require hospitalization, dialysis, or blood transfusion.
Why detection triggers Class I: any detection of Shiga-toxin-producing E. coli in any finished food product is a Class I recall.
Botulism (Clostridium botulinum)
Why it’s rare but serious: Botulism is uncommon — typically only a few hundred US cases a year — but it can be fatal if untreated. The toxin is produced by Clostridium botulinum bacteria in low-oxygen environments, which makes improperly home-canned foods and certain commercially canned or jarred products the main risk category. Infant botulism, a distinct form, is associated with raw honey and some processed foods.
Symptoms: blurred vision, drooping eyelids, difficulty swallowing, muscle weakness, and eventually paralysis, starting 12 to 36 hours after exposure. Botulism is a medical emergency — call 911 if you suspect it.
Why detection triggers Class I: any product recall related to botulism risk — failed canning seals, low-acid shelf-stable products with inadequate processing, infant-targeted products with honey — is treated as a Class I recall regardless of confirmed illness reports.
Hepatitis A
Why it’s in food recalls: Hepatitis A is a liver virus that spreads via the fecal-oral route — typically food handled by an infected worker who didn’t wash their hands. It also shows up in raw or undercooked shellfish from contaminated waters and in frozen berries from international suppliers. Hepatitis A vaccination prevents infection but isn’t universal in the US.
Symptoms: fatigue, nausea, abdominal discomfort, and jaundice (yellowing of skin and eyes), starting 15 to 50 days after exposure. Most people recover fully but the illness can be severe in adults over 50 and people with chronic liver disease.
Post-exposure prophylaxis: if you’ve been exposed to Hepatitis A through a recalled food product and you aren’t vaccinated, the CDC recommends Hepatitis A vaccine or immunoglobulin within two weeks of exposure. Talk to your doctor.