There are two kinds of food poisoning: poisoning by toxic agent or by infectious agent. Food infection is when the food contains bacteria or other microbes which infect the body after it is eaten. Food intoxication is when the food contains toxins, including bacterially produced exotoxins, which can happen even when the microbe that produced the toxin is no longer present or able to cause infection. Even though it is commonly called "food poisoning", most cases are caused by a variety of pathogenic bacteria, viruses, prions or parasites that contaminate food, rather than chemical or natural toxins which are what we usually call poison. According to the Centers for Disease Control and Prevention, about 76 million people in the United States become ill from the food they eat, and about 5,000 of them die every year.