Food poisoning develops when people eat food that is contaminated with bacteria or other toxins. Food can be contaminated when it is not handled or cooked properly. Most of the bacteria that cause food poisoning are commonly found in the environment, including Salmonella, Shigella, Campylobacter jejuni, a particular strain of Eschericia coli and Clostridium botulinum, according to the University of Maryland Medical Center. Beef, poultry and seafood are common sources of food poisoning, but dairy products, canned goods, fruits, vegetables and water can also be contaminated. Food poisoning symptoms typically develop within six hours of eating the contaminated food, and can persist for a week or more.
Diarrhea
Diarrhea is a common sign of severe food poisoning, and in some cases it can be so severe as to cause dehydration because of excess fluid loss. E. coli contamination often results in severe food poisoning and can cause watery and bloody diarrhea, according to the Penn State Milton S. Hershey Medical Center. The bloody diarrhea typically develops about 24 hours after symptoms become evident, and it can last between one and eight days. Other types of bacterial contamination that can cause severe diarrhea include Shigella and Campylobacter.
Nausea and Vomiting
Nausea and vomiting are common signs of food poisoning, and in some cases the vomiting can be severe. Several types of bacterial contamination can cause nausea and vomiting, including Salmonella, Shigella, Campylobacter and Staphylococcus aureus, according to the Milton S. Hershey Medical Center. Although E. coli can cause severe food poisoning, it does not commonly result in vomiting. In addition to nausea and vomiting, some people also suffer from severe abdominal cramps and abdominal pain.
Fever
Another sign of severe food poisoning is a fever and sometimes headaches and chills, according to the National Institutes of Health. Several types of contamination can cause fever and chills, but it is not generally associated with food poisoning caused by E. coli. When fever and chills do develop, it is typically in conjunction with other symptoms such as diarrhea and nausea and vomiting.
Botulism
The most severe type of food poisoning is caused by Clostridium botulinum, which can contaminate canned goods and foods canned at home. C. botulinum causes botulism, a severe neurological condition that causes blurred or double vision, light sensitivity, trouble swallowing or speaking and weakness, according to the University of Maryland Medical Center. As the condition progresses, the body becomes paralyzed with its victim experiencing respiratory failure and eventually, death.
Hemolytic-uremic Syndrome
In rare cases, people suffering from severe food poisoning can develop hemolytic-uremic syndrome. In these situations, platelet counts can drop dangerously low and the kidneys can fail. Hemolytic-uremic syndrome, which can be fatal, most commonly develops in children younger than 5 and the elderly, according to the Milton S. Hershey Medical Center.
