The most common causes of foodborne illness outbreaks and how to lower your risk

Contaminated foods and beverages sicken an estimated 48 million Americans each year. The five bugs most likely to cause an outbreak: Norovirus, Salmonella, Clostridium perfringens, E. coli, and Campylobacter. Together, they accounted for roughly 9 out of 10 illnesses from outbreaks from 2011 to 2015.

Listeria monocytogenes isn’t in the top five, but it kills more people than most of the others.

Here’s what you need to know about the usual suspects—especially if you’re pregnant, under age 5, or 65 or older, or you have a weakened immune system.


a chef's hands preparing food

Typically found in: Fruits, vegetables, shellfish, any food an infected person touches.

Lower your risk: Rinse fruits and vegetables. Avoid raw oysters and other shellfish. Wash hands with soap and water. (Don’t rely on hand sanitizer.)

Clostridium perfringens

Typically found in: Cooked meat and poultry—think big roasts or stews—kept warm or at room temperature for hours.

Lower your risk: Serve meat and poultry hot. Refrigerate leftovers within two hours. (Divide large amounts into shallow containers for quick cooling.)


Typically found in: Raw milk, raw or undercooked poultry.

Lower your risk: Don’t wash raw poultry. (That can spread Campylobacter to foods, utensils, and kitchen surfaces.) Use a separate cutting board for poultry, and clean it well. Cook poultry to 165°F.


Typically found in: Almost any food: beef, pork, poultry, eggs, fruits, vegetables, spices, nuts, sprouts, and more.

Lower your risk: Cook poultry, meat, and eggs thoroughly (or use pasteurized eggs). Rinse fruits and vegetables, but not packaged pre-washed greens. You could contaminate them with bugs from your sink.

E. coli (Shiga toxin-producing)

Typically found in: Beef (especially ground), unpasteurized milk and juice, raw fruits and vegetables (like sprouts).

Lower your risk: Use a food thermometer to cook ground beef to 160°F. Avoid unpasteurized juices (like fresh apple cider). Don’t eat raw sprouts.


Typically found in: Raw milk, soft cheeses, raw sprouts, melon.

Lower your risk: Avoid raw milk and raw sprouts. Look for pasteurized milk in the ingredients list of soft cheeses like brie and camembert. Refrigerate cut melon for no more than a week.

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Sources: Centers for Disease Control and Prevention National Outbreak Reporting System and Surveillance for Foodborne Disease Outbreaks United States Annual Reports (2011-2015), Food and Drug Administration.

Photos: (top to bottom): Minerva Studio, Gresei, Vit Kovalcik, nblxer, Sergey Ryzhov, George Dolgikh.

The information in this post first appeared in the September 2018 issue of Nutrition Action Healthletter.

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