Food poisoning occurs when you swallow food or water that contains bacteria, parasites, viruses, or toxins made by these germs. Most cases of food poisoning are from common bacteria such as Staphylococcus or E. coli.
Causes, incidence, and risk factors
Food poisoning can affect one person or a group of people who all ate the same contaminated food. It more commonly occurs after eating at picnics, school cafeterias, large social functions, or restaurants.
The germs may get into the food you eat (called contamination) in different ways:
Meat or poultry can come into contact with bacteria from the intestines of an animal that is being processed
Water that is used during growing or shipping can contain animal or human waste
Food handling or preparation in grocery stores, restaurants, or homes
Food poisoning often occurs from eating or drinking:
Any food prepared by someone who does not wash their hands properly
Any food prepared using cooking utensils, cutting boards, and other tools that are not fully cleaned
Dairy products or food containing mayonnaise (such as coleslaw or potato salad) that have been out of the refrigerator too long
Frozen or refrigerated foods that are not stored at the proper temperature or are not reheated properly
Raw fish or oysters
Raw fruits or vegetables that have not been washed well
Raw vegetables or fruit juices and dairy products (look for the word "pasteurized," which means the food has been treated to prevent contamination)
Undercooked meats or eggs
Water from a well or stream, or city or town water that has not been treated
Many types of germs may cause food poisoning, including:
If you have diarrhea and are unable to drink or keep down fluids, you may need fluids given through a vein (by IV). This is especially true for young children.
If you take diuretics, ask your health care provider if you need to stop taking the diuretic while you have diarrhea. Never stop or change medications without first talking to your health care provider.
For the most common causes of food poisoning, your doctor will NOT prescribe antibiotics.
You can buy medicines at the drugstore that help slow diarrhea.
Do not use these medicines without talking to your health care provider if you have bloody diarrhea, a fever, or the diarrhea is severe.
Do not give these medicines to children.
Most people fully recover from the most common types of food poisoning within 12 - 48 hours. Serious complications can occur, however, from certain types of food poisoning.
Death from food poisoning in people who are otherwise healthy is rare in the United States.
Dehydration is the most common complication. This can occur from any causes of food poisoning.
Less common, but much more serious complications depend on the bacteria that are causing the food poisoning. These may include:
Sodha SV, Griffin PM, Hughes JM. Foodborne disease. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 99.
Craig SA, Zich DK. Gastroenteritis. In: Marx JA, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier;2009:chap 92.
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.