Most of us don’t like any bugs, although many are beneficial. The bugs which pass illnesses through our food supply are called foodborne pathogens. These are mostly seen using a microscope, so they are called microorganisms.

The United States Public Health Service has identified the following pathogens as being the biggest culprits of illness. That’s either because of the seriousness of the sickness or the number of cases they cause. Here are ways to identify and avoid contact.

Campylobacter — Second most common bacterial cause of diarrhea in the United States. Sources: raw and undercooked poultry and other meat, raw milk and untreated water.

E. coli O157:H7 — A bacterium that can produce a deadly toxin and causes approximately 265,000 cases of foodborne illness and 100 deaths each year in the U.S.(2019 data). Sources: beef, especially undercooked or raw hamburger; produce; raw milk; and unpasteurized juices and ciders.

Listeria monocytogenes — Causes listeriosis, a serious disease for pregnant women, newborns and adults with a weakened immune system. Sources: unpasteurized dairy products, including soft cheeses; sliced deli meats; smoked fish; hot dogs; pate’; and deli-prepared salads (i.e. egg, ham, seafood, and chicken salads).

Norovirus — The leading viral cause of diarrhea in the United States. Poor hygiene causes Norovirus to be easily passed from person to person and from infected individuals to food items. Sources: Any food contaminated by someone who is infected with this virus.

Salmonella — Most common bacterial cause of diarrhea in the United States, and the most common cause of foodborne deaths. Responsible for 1.4 million cases of foodborne illness a year. Sources: raw and undercooked eggs, undercooked poultry and meat, fresh fruits and vegetables, and unpasteurized dairy products.

Staphylococcus aureus — This bacterium produces a toxin that causes vomiting shortly after being ingested. Sources: cooked foods high in protein (e.g. cooked ham, salads, bakery products, dairy products) that are held too long at room temperature.

Shigella — Causes an estimated 500,000 cases of diarrhea illnesses per year. Poor hygiene causes Shigella to be easily passed from person to person and from infected individuals to food items. Sources: salads, unclean water, and any food handled by someone who is infected with the bacterium.

Toxoplasma gondii — A parasite that causes toxoplasmosis, a very severe disease that can produce central nervous system disorders particularly mental retardation and visual impairment in children. Pregnant women and people with weakened immune systems are at higher risk; Sources: raw or undercooked pork.

Vibrio vulnificus — Causes gastroenteritis, wound infection, and severe bloodstream infections. People with liver diseases are especially at high risk. Sources: raw or undercooked seafood, particularly shellfish. Source:

As consumers, we need to handle raw foods as the grocery store and at home during meal preparation. By using good washing practices, we can prevent the spread of foodborne pathogens. As mentioned in many of the descriptions, proper hygiene can prevent the pathogens from spreading from one surface to another. Practicing good hygiene means we wash our hands before and after contact with food in warm water with soap, making suds and rub vigorously for at least 20 seconds, then rinse with water. Rinse all produce before cutting or eating.

Be aware of simple steps to practice proper handling of raw and cooked foods to help prevent the spread of the least wanted bugs: foodborne pathogens.

Julie Buck, EdD, RDN, is a registered dietitian, who is employed as a Family and Consumer Sciences Educator at the University of Idaho Extension, Bingham County. She can be reached at (208)785-8060 or