The terms "food poisoning" and "ptomaine poisoning" are frequently used in the diagnosis of an acute illness characterized by vomiting, cramps, diarrhea and elevation of temperature. Both terms are unsatisfactory but, of the two, "ptomaine poisoning" is the more misleading and incorrect, for actual food poisoning rarely if ever occurs. Since vomiting is often the first symptom, it is perhaps natural that suspicion should be directed to the food eaten and vomited.
Investigators in food poisoning have suggested various classifications; none have been found satisfactory unless they are based on etiology. In general, food poisoning is classified in two groups: infection and toxemia. Food infection is the result of contamination of food with various types of living bacteria. Food toxemia is due to the ingestion of food which contains preformed bacterial toxins; botulism is the example in this class.
Rosenau1 says: "Most instances of food poisoning are from food
BROWN EG, COMBS GR, WRIGHT E. FOOD-BORNE INFECTION WITH SALMONELLA AERTRYCKE. JAMA. 1940;114(8):642-644. doi:10.1001/jama.1940.02810080014004