Norovirus is the biggest cause of foodborne illness in the United States, responsible for an estimated 58% of all domestically acquired foodborne illnesses from known pathogens. That translates to roughly 5.5 million infections every year. While norovirus dominates in sheer number of cases, it’s not the deadliest. Salmonella holds that distinction, causing more deaths annually than any other foodborne pathogen.
How the Top Pathogens Compare
The CDC tracks seven major foodborne pathogens and estimates their annual toll. The gap between norovirus and everything else is enormous when it comes to total illnesses:
- Norovirus: 5,540,000 illnesses, 22,400 hospitalizations, 174 deaths
- Campylobacter: 1,870,000 illnesses, 13,000 hospitalizations, 197 deaths
- Salmonella: 1,280,000 illnesses, 12,500 hospitalizations, 238 deaths
- C. perfringens: 889,000 illnesses, 338 hospitalizations, 41 deaths
- STEC (E. coli): 357,000 illnesses, 3,150 hospitalizations, 66 deaths
Together, these five pathogens and two others (Listeria and Toxoplasma) cause roughly 9.9 million domestically acquired foodborne illnesses, 53,300 hospitalizations, and 931 deaths each year in the U.S. alone. Most people who get sick recover without medical care, but the numbers add up fast: foodborne illness is far more common than most people realize.
Why Norovirus Spreads So Easily
Norovirus is extraordinarily contagious, and it doesn’t need raw chicken or undercooked beef to reach you. Most norovirus outbreaks trace back to an infected person who touched or prepared food while sick. Tiny amounts of the virus, invisible to the eye, transfer from hands to plates, utensils, and serving surfaces. Even microscopic droplets of vomit can become airborne and land on food or countertops.
This is why norovirus outbreaks cluster in restaurants, cruise ships, schools, and catering events. A single sick food worker can contaminate an entire buffet line. Unlike bacteria that need time to multiply on food left at the wrong temperature, norovirus arrives ready to infect. It also survives on surfaces for days and resists many common disinfectants, making it difficult to eliminate once it’s in a kitchen.
Salmonella: Fewer Cases, More Deaths
While norovirus causes the most illness, Salmonella is the leading cause of foodborne death in the U.S., killing an estimated 238 people per year. It also sends about 12,500 people to the hospital annually. Salmonella infections tend to be more severe than norovirus, producing fever, bloody diarrhea, and cramps that can last four to seven days. Symptoms typically begin 6 to 48 hours after eating contaminated food, though onset can take up to 10 days in some cases.
Poultry and eggs are the foods most commonly linked to Salmonella outbreaks, but the bacteria also show up in produce, pork, and even processed foods like peanut butter. Meat and poultry are the most common sources of fatal foodborne infections overall, largely because of Salmonella and Listeria.
Listeria: Rare but Dangerous
Listeria doesn’t make the top five for total illnesses, but it’s disproportionately deadly. Nearly everyone who gets a Listeria infection ends up hospitalized. The people most vulnerable are pregnant women, adults over 65, and anyone with a weakened immune system. In pregnant women, Listeria can cause miscarriage, stillbirth, premature delivery, or life-threatening infection in the newborn, even when the mother’s own symptoms are mild (often just fever, fatigue, and muscle aches).
Deli meats are a well-known vehicle for Listeria. A 2024 outbreak linked to sliced deli meats hospitalized all 57 confirmed patients and killed 9. Three large Listeria outbreaks tied to processed deli turkey have significantly shaped how the CDC attributes foodborne deaths to poultry products.
Which Foods Cause the Most Illness
Produce, especially leafy greens, accounts for nearly half of all foodborne illnesses. That may seem surprising since people tend to associate food poisoning with meat. The reason is norovirus: 46% of illnesses linked to leafy vegetables are caused by the virus, usually because an infected person handled the greens before they reached your plate. Since salads and similar items aren’t cooked, there’s no heat step to kill the virus.
Meat and poultry, on the other hand, cause fewer total illnesses but more hospitalizations and deaths. An analysis of over 10,700 outbreaks from 2005 to 2016 found that beef, chicken, pork, turkey, and eggs were all implicated in outbreaks far more often than you’d expect given how frequently people eat them. Beef appeared in 2.3% of outbreak-linked foods but made up only 0.6% of foods consumed. Turkey showed an even wider gap: 1.5% of outbreak foods versus just 0.2% of consumption. Pasteurized dairy, grains, and root vegetables, by contrast, caused outbreaks much less often than their consumption rates would predict.
How Quickly Symptoms Appear
One reason people struggle to identify what made them sick is that different pathogens have very different timelines. Norovirus symptoms typically hit 24 to 48 hours after exposure, though the window ranges from 15 to 77 hours. Salmonella usually strikes within 6 to 48 hours. E. coli O157:H7, the strain that causes the most serious complications, takes longer: symptoms generally appear 3 to 4 days after exposure, with a range of 1 to 10 days.
This means the meal you blame for your food poisoning often isn’t the actual culprit. If you got sick on a Tuesday evening, the contaminated food may have been something you ate Sunday or Monday, not that day’s lunch.
Reducing Your Risk
The most effective protection depends on which pathogen you’re trying to avoid. For norovirus, the key is hand hygiene. Wash your hands thoroughly with soap and water (hand sanitizer is less effective against norovirus) before eating or preparing food, and especially after using the bathroom. If you’re sick with vomiting or diarrhea, stay away from the kitchen entirely.
For bacterial pathogens like Salmonella and E. coli, cooking temperatures matter. The FDA recommends heating poultry (including ground poultry) to an internal temperature of 165°F, ground beef and pork to 160°F, and fish to 145°F. Use a food thermometer rather than judging by color. Keep raw meat separate from produce and ready-to-eat foods, and refrigerate leftovers within two hours.
For Listeria, the risk concentrates in ready-to-eat foods that aren’t reheated: deli meats, soft cheeses, and smoked seafood. If you’re pregnant, over 65, or immunocompromised, heating deli meats to 165°F before eating them significantly lowers the risk. Washing produce under running water helps reduce, though not eliminate, surface contamination from any pathogen.