The Most Common Causes of Food Poisoning
Infectious DiseasesFoodborne Infections

What Are Common Causes and Types of Foods That Can Trigger Food Poisoning?

What Are Common Causes and Types of Foods That Can Trigger Food Poisoning?
Everyday Health
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Updated on August 17, 2026
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Though many may not realize it, foodborne outbreaks cause millions of Americans to get sick each year: An estimated 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths occur each year as a result of foodborne germs.

From salmonella to E. coli and campylobacter, many causes of food poisoning can make you sick. Symptoms may include mild diarrhea and vomiting, but infections can quickly escalate to the point of being life-threatening.

Though you can’t see where the germs that cause food poisoning might be lurking, you can take steps to prevent being exposed to them. It often comes down to food safety: By storing, cleaning, preparing, and cooking foods properly, you can help yourself avoid some of the common causes, such as E. coli and salmonella, that typically cause food poisoning.

Types of Germs That Cause Food Poisoning

Food poisoning is a general term for gastrointestinal illness linked to consuming contaminated food or drinks, but it can be caused by a number of germs.

Salmonella

Most people are familiar with the term salmonella, but they may not know that there are more than 2,000 types of the bug. It’s usually associated with animal products like chicken, eggs, and milk, but raw vegetables and even water can carry salmonella, too.

Salmonella is usually introduced to foods at a processing plant or when the foods are handled. It’s a common diagnosis of infectious diarrhea in the United States.

“Symptoms of salmonellosis vary from a mild gastroenteritis [stomach and intestinal inflammation] to more severe and prolonged diarrhea,” says Kristina D. Mena, PhD, the El Paso dean for the UTHealth Houston School of Public Health.

E. Coli

While most E. coli is harmless and part of a healthy gut, this bacteria can sometimes cause infections like pneumonia and gastrointestinal illness. In the past, E. coli infections were commonly associated with undercooked ground beef, but the germ can show up in other places, as well.

“Outbreaks of E. coli have involved a wide variety of food, including fresh produce, beef, nuts, water, and cookie dough, to name a few,” Dr. Mena says. Symptoms can include nausea and vomiting, watery diarrhea, or sometimes bloody diarrhea, depending on the E. coli type.

Cyclosporiasis

Cyclosporiasis, an infection caused by the cyclospora parasite, isn’t typically life-threatening. However, it can cause severe diarrhea that may start from two days to two weeks after infection. Symptoms often resolve on their own in days but may persist or come and go for over a month.

Outbreaks in the United States have been linked to fresh produce, including leafy vegetables and berries.

 Mena notes that water is often cited as a way this parasite impacts food, but she says this refers to water used in crop irrigation. It doesn't refer to tap water, which is treated at a drinking water treatment facility.

Campylobacter

It’s not as well known as salmonella and E. coli, but campylobacter can be pretty nasty in its own right. “Campylobacter is identified more often than any other causative agent of gastroenteritis in the United States and Europe,” Mena says. This bacteria may also cause high fever, arthritis, and Guillain-Barré syndrome (a severe, progressive muscle weakness, she says. “Most often, infections and subsequent illnesses result from the consumption of contaminated poultry or poultry products,” Mena says.

Shigella

Though meat is commonly thought of as the transmitter of food poisoning germs, shigella can be passed along via vegetables, often related to breakdowns in food safety.

 “Transmission is most often associated with infected food handlers who pass the bacteria from person to person due to poor hygiene practices,” Mena says. “It has also been suggested that flies may have a role in its transmission.”
Symptoms typically include abdominal cramps and bloody stool. This infection can also cause fevers and tenesmus, which is the feeling that you need to pass stool, even though your bowels are already empty.

Listeria

Listeria outbreaks in the United States have been linked to produce; raw, unpasteurized milk and cheese; ice cream; and raw or undercooked poultry and seafood. Similar to other foodborne illnesses, a listeria infection can cause diarrhea and fever. These infections can be especially dangerous for certain people. For those with compromised immune systems, listeria infection could lead to bloodstream infections or meningitis, and for pregnant people, it could lead to stillbirth, miscarriage, premature birth, or life-threatening infection in the newborn.

Botulism

Although rare, botulism is one of the most serious causes of food poisoning; it is most commonly associated with improperly canned vegetables and cured pork and ham.

“This bacterium produces a neurotoxin that results in paralysis,” Mena says. “Besides paralysis, symptoms may include body aches, nausea, vomiting, weakness, and an inability to swallow. People who are not treated immediately have a much higher chance of dying.”

Enteric Viruses

Enteric, or intestinal, viruses like norovirus and hepatitis A are tied to an increasing number of food poisoning outbreaks, Mena says. “Noroviruses are the viruses that have been implicated in the string of cruise ship outbreaks,” she says. “Besides diarrhea, people also typically experience vomiting. Norovirus outbreaks have been associated with a variety of food, including shellfish.”

Hepatitis A outbreaks can typically be traced back to poor food safety during food handling. “Hepatitis A infections may result in nausea, malaise, and jaundice, with the more severe illnesses occurring in older individuals,” Mena says.

Staphylococcus Aureus

Staphylococcal food poisoning is caused by eating foods contaminated with toxins produced by the bacterium Staphylococcus aureus. Food handlers carrying the bacteria can contaminate food through improper handling and inadequate temperature controls, allowing more toxins to be ingested.

Symptoms start fairly quickly (30 minutes to 8 hours) after eating contaminated food. Mayonnaise and cream pies are frequent culprits, although meat, eggs, and produce can be contaminated as well. The main symptom is vomiting that usually lasts less than 24 hours. Abdominal cramping and diarrhea are common symptoms as well.

Bacillus Cereus

This bacteria can grow when cooked rice is unrefrigerated too long. Other foods that can cause this illness include cheese and starchy foods like pasta, potatoes, and sushi. Symptoms of B. cereus food poisoning include vomiting and diarrhea. Symptoms often resolve within hours but may last about two days.

Top Foods Likely to Cause Food Poisoning

Certain foods are more likely to contain harmful microbes than others:

  • Fresh produce
  • Raw and undercooked meat and poultry
  • Raw and lightly cooked eggs
  • Unpasteurized milk, cheese, and other dairy products
  • Seafood and raw shellfish
  • Raw flour
  • Processed meat (like deli meat)

Preventing Food Poisoning

The foods that cause food poisoning may vary, but many of the food safety tips for preventing them are the same. Here’s what Mena recommends:

  • Wash your hands thoroughly with soap and hot water before and after preparing food, as well as after handling each kind of food.
  • Keep raw and cooked food separate at all times before cooking, and keep them apart as much as possible when you start to cook.
  • Maintain separate cutting boards for meats and vegetables, and wash knives and surfaces when changing from raw meats to raw vegetables (or vice versa).
  • Hot foods should be maintained above 140 degrees F, and cold foods should be stored below 40 degrees F.
  • Use a food thermometer and be sure to cook meat thoroughly and at adequately high temperatures (165 degrees F for chicken and turkey, for example).
  • Refrigerate leftovers promptly and keep them properly refrigerated, and be sure to heat leftovers thoroughly if you eat them at a later time.
  • Avoid foods that have been kept at room temperature for more than two hours.
  • Be wary of potlucks, especially involving perishable foods and if you’re not sure when the food was prepared or how long it has been stored at potentially improper temperatures.

Additional reporting by Ashley Welch.

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Facts About Food Poisoning. Centers for Disease Control and Prevention . November 24, 2025.
  2. About Salmonella Infection. Centers for Disease Control and Prevention. October 4, 2024.
  3. About Escherichia coli Infection. Centers for Disease Control and Prevention. May 14, 2024.
  4. E. coli. Mayo Clinic. June 2, 2026.
  5. About Cyclosporiasis. Centers for Disease Control and Prevention. July 27, 2026.
  6. About Campylobacter infection. Centers for Disease Control and Prevention. August 12, 2026.
  7. How Shigella Spreads. Centers for Disease Control and Prevention. March 14, 2024.
  8. Signs and Symptoms of Shigella Infection. Centers for Disease Control and Prevention. March 14, 2024.
  9. Listeria infection. Mayo Clinic. December 17, 2025.
  10. About Botulism. Centers for Disease Control and Prevention. February 26, 2026.
  11. Hepatitis A. Centers for Disease Control and Prevention. July 2, 2024.
  12. Staphylococcal Food Poisoning. Centers for Disease Control and Prevention. April 16, 2024.
  13. Bacillus cereus. Cleveland Clinic. January 23, 2026.
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