Definition of Food poisoning:

Food poisoning occurs when you swallow food or water that has been contaminated with certain types of bacteria, parasites, viruses, or toxins.

Most cases of food poisoning are due to common bacteria such as Staphylococcus or Escherichia coli (E. coli).

Causes, incidence, and risk factors:

Food poisoning more commonly occurs after eating at picnics, school cafeterias, large social functions, or restaurants. One or more people may become sick.

Food poisoning is caused by certain bacteria, viruses, parasites, or toxins. Types of food poisoning include:

• Botulism (Clostridium botulinum)
• Campylobacter enteritis
• Cholera
• E. coli enteritis
• Fish poisoning
• Listeria
• Staphylococcus aureus
• Salmonella
• Shigella

Bacteria may get into your food in different ways:

• Meat or poultry may come into contact with intestinal bacteria when being processed
• Water that is used during growing or shipping may contain animal or human waste
• Improper food handling or preparation

Food poisoning often occurs from eating or drinking:

• Any food prepared by someone who did not wash their hands properly
• Any food prepared using unclean cooking utensils, cutting boards, or other tools
• 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 vegetable or fruit juices and dairy
• Undercooked meats or eggs
• Water from a well or stream, or city or town water that has not been treated

Infants and elderly people are at the greatest risk for food poisoning. You are also at higher risk if:

• You have a serious medical condition, such as kidney disease or diabetes
• You have a weakened immune system
• You travel outside of the United States to areas where there is more exposure to germs that cause food poisoning

Pregnant and breastfeeding women have to be especially careful to avoid food poisoning.