Foodborne illnesses affect millions of Americans each year. Many persons who think they have the flu or a virus are really victims of mild cases of food poisoning, caused by bacteria and viruses found in food. Most foodborne illnesses are caused by eating food containing certain types of bacteria or viruses. After a person has eaten these foods, the microorganisms continue to grow, causing an infection.
Foods can also cause illness if they contain a toxin or poison produced by bacteria growing in food.
Several different kinds of bacteria can cause food poisoning. Clostridium perfringens may be present in raw meat, poultry, eggs, or unpasteurized dairy products, as well as in vegetables and crops that come into contact with soil. Infection may occur when soups, stew, and gravies made with meat, fish, or poultry are stored improperly or left unrefrigerated for several hours. Listeria mainly associated with raw foods of animal origins. Staphylococci occur normally on human skin and in the nose and throat.