The Basics of Food Borne Illness

What Is Foodborne Illness?

Foodborne illness often presents itself as flu-like symptoms such as nausea, vomiting, diarrhea, or fever, so many people may not recognize the illness is caused by bacteria or other pathogens in food.

Thousands of types of bacteria are naturally present in our environment. Not all bacteria cause disease in humans. For example, some bacteria are used beneficially in making cheese and yogurt.

Bacteria that cause disease are called pathogens. When certain pathogens enter the food supply, they can cause foodborne illness. Millions of cases of foodborne illness occur each year. Most cases of foodborne illness can be prevented. Proper cooking or processing of food destroys bacteria.

Age and physical condition place some persons at higher risk than others, no matter what type of bacteria is implicated. Very young children, pregnant women, the elderly and people with compromised immune systems are at greatest risk from any pathogen. Some persons may become ill after ingesting only a few harmful bacteria; others may remain symptom free after ingesting thousands.

How Bacteria Get in Food

Bacteria may be present on products when you purchase them. Plastic-wrapped boneless chicken breasts and ground meat, for example, were once part of live chickens or cattle. Raw meat, poultry, seafood, and eggs are not sterile. Neither is fresh produce such as lettuce, tomatoes, sprouts, and melons.

Foods, including safely cooked, ready-to-eat foods, can become cross-contaminated with bacteria transferred from raw products, meat juices or other contaminated products, or from food handlers with poor personal hygiene.

The "Danger Zone"

  • Bacteria multiply rapidly between 40°F and 140°F. To keep food out of this "danger zone," keep cold food cold and hot food hot.
  • Store food in the refrigerator (40°F or below) or freezer (0°F or below).
  • Cook food to 160°F (145°F for roasts, steaks, and chops of beef, veal, and lamb).
  • Maintain hot cooked food at 140°F or above.
  • When reheating cooked food, reheat to 165°F.

Provided by the United States Department of Agriculture