The Most Common Foodborne Bacteria and How to Avoid Getting Sick

It only takes one bite of contaminated food to leave you feeling miserable. Each year, foodborne pathogens are responsible for about 48 million illnesses in the U.S., according to the Centers for Disease Control and Prevention (CDC). That’s one in six people and many of these cases could be prevented with the right safety measures.

Foodborne illnesses aren’t just caused by “bad” food. Germs can slip into the food supply at nearly every stage, from contaminated irrigation water and animal products to poor kitchen hygiene. And while the phrase “food poisoning” gets tossed around frequently, it’s actually a catchall term for a variety of infections and toxin-related illnesses.

Below, we break down the seven most common types of foodborne bacteria and viruses, how they affect your body, and most importantly how to avoid them.

1. Norovirus

This highly contagious virus is the world’s leading cause of foodborne illness, linked to more than 685 million cases globally each year.

• Common sources: Raw fruits and vegetables, shellfish, and ready-to-eat items like salads and sandwiches touched by infected hands.

• Symptoms: Vomiting, diarrhea, nausea, abdominal pain (12–48 hours after exposure).

Prevention tips:

• Wash hands with soap and water for at least 20 seconds.

• Disinfect surfaces and linens that may be contaminated.

• Avoid preparing food for others while symptomatic and for two days afterward.

2. Salmonella

Known for contaminating raw eggs and poultry, salmonella can also show up in unexpected foods like nuts, produce, and even pet treats.

• Common sources: Undercooked meat and eggs, unpasteurized milk, raw produce, and sprouts.

• Symptoms: Diarrhea, nausea, fever, abdominal cramping (6 hours to 6 days after exposure).

Prevention tips:

• Cook meats and eggs thoroughly.

• Avoid raw or undercooked animal products.

• Only consume pasteurized dairy products.

3. Clostridium Perfringens

This bacteria isn’t spread person-to-person but is one of the most common culprits in food-related outbreaks, often linked to leftovers and buffet foods.

• Common sources: Meat, poultry, and foods left out at unsafe temperatures.

• Symptoms: Diarrhea, abdominal cramps, vomiting (6–24 hours after eating).

Prevention tips:

• Keep hot foods above 140°F and cold foods below 40°F.

• Refrigerate or reheat food within two hours of serving.

• Reheat leftovers to at least 165°F.

4. Campylobacter

This bacteria infects around 1.5 million people each year in the U.S. and can cause severe gastrointestinal distress.

• Common sources: Raw or undercooked poultry, unpasteurized milk, contaminated water.

• Symptoms: Diarrhea (sometimes bloody), fever, cramping, vomiting (2–5 days after exposure).

Prevention tips:

• Drink only pasteurized milk and treated water.

• Cook poultry to an internal temperature of 165°F.

• Wash hands after handling raw meat.

5. E. Coli (Pathogenic Strains)

While most strains are harmless, some E. coli variants can cause serious illness and even life-threatening complications.

• Common sources: Raw or undercooked ground beef, unpasteurized dairy, fresh produce.

• Symptoms: Bloody diarrhea, stomach cramps, vomiting (1–10 days after exposure). Severe cases may develop into hemolytic uremic syndrome (HUS), which affects the kidneys.

Prevention tips:

• Cook ground beef to at least 160°F.

• Wash produce thoroughly.

• Avoid unpasteurized milk, juice, and cheese.

6. Listeria

Listeria is particularly dangerous for pregnant people, older adults, and those with weakened immune systems due to its ability to cause systemic illness.

• Common sources: Unpasteurized dairy, deli meats, smoked seafood, raw produce.

• Symptoms: Fever, diarrhea, muscle stiffness, confusion (7–70 days after exposure).

Prevention tips:

• Avoid high-risk foods if you're immunocompromised or pregnant.

• Thoroughly cook reheated meats and fish.

• Check labels for "pasteurized" dairy products.

7. Staphylococcus Aureus

This bacteria lives on the skin and can contaminate food during preparation, especially when it’s not cooked after handling.

• Common sources: Deli meats, prepared salads, pastries.

• Symptoms: Sudden nausea, vomiting, cramps (30 minutes to 8 hours after ingestion).

Prevention tips:

• Keep food out of the temperature danger zone.

• Don’t prepare food if you’re sick.

• Practice frequent and thorough handwashing.

A Few Extra Tips to Stay Safe

• Temperature matters: Bacteria thrive between 40°F and 140°F. Always refrigerate or reheat food promptly.

• Small batches cool faster: Divide large servings into smaller containers to chill more quickly.

• Hand hygiene is key: Wash hands before and after handling food, especially after touching raw meat or using the restroom.

Foodborne illness can range from mild to severe but in most cases, it's avoidable. With some basic precautions and attention to hygiene and temperature, you can significantly lower your risk and keep your meals both delicious and safe.

Found this helpful? Share it with others or subscribe to our newsletter for more science-backed wellness tips.