Food poisoning, which is actually a foodborne illness, is transmitted by a virus, bacteria, parasite, or other pathogen present in the contaminated food that is consumed. Other causes of food poisoning include the presence of chemicals, toxins, or pesticides which contaminate food. The most common causes of food poisoning are:

• Campylobacter- The Center for Disease Control and Prevention estimate that nearly 2.5 million Americans are affected by Campylobacteriosis each year. The most common causes of the illness include raw poultry, either due to improper handling, preparation, or consumption, non-pasteurized milk, insufficiently cooked meat, pets carrying the infection, and water that has been contaminated.
• Botulism- A rare but serious illness caused by the bacterium Clostridium botulinum. Even a small quantity (as is extremely dangerous and can cause paralysis and death in humans. The most common source of foodborne botulism is home-canned products, though commercially canned products can be contaminated.
• Listeria- Listeriosis is an uncommon but serious illness that primarily affects persons with compromised immune systems.  Foods associated with Listeria are uncooked meat, uncooked and smoked fish, uncooked vegetables, non-pasteurized milk products, and some processed foods.
• E Coli- The Center for Disease Control and Prevention estimates that E. Coli affects 73,000 persons a year. The most common causes of E Coli are eating undercooked meat, drinking raw milk, or exposing oneself to contaminated water.
• Giardia- Giardia is caused by a parasite, not a bacterium or virus. Swallowing improperly treated water is a common means of contracting the illness.
• Norovirus and Rotavirus- Rotavirus is a common viral infection that primarily affects children. Noroviruses are a common type of foodborne illness that causes what is commonly referred to as the stomach flu.
• Salmonella- Salmonellosis is a very common foodborne illness, affected approximately 1.4 million Americans a year. Salmonella is usually contracted by the ingestion of food or drink that has been contaminated, either by animal feces or contact with infected animals.

The most common symptoms of food poisoning include abdominal cramps, diarrhea, nausea, and vomiting; this is because most foodborne illnesses enter the body through the gastrointestinal tract. It is often unclear whether a disease is foodborne because microbes can be transmitted in a number of ways. Food poisoning may be caused by improper or negligent safety procedures on the part of a food manufacturing or distributing company, or by a restaurant chain. In these cases, a food poisoning lawsuit may be filed against the offending company to recover for injuries sustained by consuming the contaminated food.