Food Poisoning Symptoms

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About Food Poisoning

Food poisoning results from eating food contaminated with bacteria (or their toxins) or other pathogens such as parasites or viruses. The illnesses range from upset stomach to more serious symptoms, including diarrhea, fever, vomiting, abdominal cramps, and dehydration.

Causes

Harmful bacteria are the most common causes of food poisoning. Some bacteria may be present on foods when you purchase them. Raw foods are not sterile. Raw meat and poultry may become contaminated during slaughter. Seafood may become contaminated during harvest or through processing.

One in 20,000 eggs may be contaminated with Salmonella inside the egg shell. Produce such as lettuce, tomatoes, sprouts, and melons can become contaminated with Salmonella, Shigella, or Escherichia coli (E. coli) O157:H7. Contamination can occur during growing, harvesting, processing, storing, shipping, or final preparation.

Symptoms

In most cases of food poisoning, symptoms resemble intestinal flu and may last a few hours or even several days. Symptoms can range from mild to serious and include

abdominal cramps
nausea
vomiting
diarrhea
fever
dehydration

Risk Factors

Some people are at greater risk for bacterial infections because of their age or immune status. Young children, pregnant women and their fetuses, the elderly, and people with lowered immunity are at greatest risk.

Complications

Some Complications from micro-organisms, such as Listeria monocytogenes and Clostridium botulinum, cause far more serious illness than vomiting or diarrhea. They can cause spontaneous abortion or death.

Diagnosis

Your doctor may be able to diagnose food poisoning from a list of what you've recently eaten and results from the proper laboratory tests. Diagnostic tests for food poisoning should include examination of the feces. A sample of the suspected food, if available, can also be tested for bacteria and their toxins as well as for viruses and parasites.

Treatment

Most cases of food poisoning are mild and can be treated by increasing fluid intake, either orally or intravenously, to replace lost fluids and electrolytes. In cases with gastrointestinal or neurologic symptoms, people should seek medical attention.

In the most severe situations, such as HUS, the patient may need hospitalization in order to receive supportive nutritional and medical therapy. Maintaining adequate fluid and electrolyte balance and controlling blood pressure are important. Doctors will try to minimize the impact of reduced kidney function. Early dialysis is crucial until the kidneys can function normally again, and blood transfusions may be needed.

Prevention

Most cases of food poisoning can be prevented through proper cooking or processing of food, which kills bacteria. In addition, because bacteria multiply rapidly between 40°F and 140°F, food must be kept out of this "danger zone."

To prevent harmful bacteria from growing in food, always

Refrigerate foods promptly. If you let prepared food stand at room temperature for more than 2 hours, it may not be safe to eat. Set your refrigerator at 40°F or lower and your freezer at 0°F.
Cook food to the appropriate temperature (145°F for roasts, steaks, and chops of beef, veal, and lamb; 160°F for pork, ground veal, and ground beef; 165°F for ground poultry; and 180°F for whole poultry). Use a thermometer to be sure! Foods are properly cooked only when they are heated long enough and at a high enough temperature to kill the harmful bacteria that cause illness.
Prevent cross-contamination. Bacteria can spread from one food product to another throughout the kitchen and can get onto cutting boards, knives, sponges, and countertops. Keep raw meat, poultry, seafood, and their juices away from other foods that are ready to eat.

Food Irradiation

Food irradiation is the treatment of food with high energy such as gamma rays, electron beams, or x rays as a means of cold pasteurization, which destroys living bacteria, to control foodborne disease. The United States relies exclusively on the use of gamma rays, which are similar to ultraviolet light and microwaves and pass through the food leaving no residue or "radioactivity."

Food irradiation is currently approved for wheat, potatoes, spices, seasonings, pork, poultry, red meats, whole fresh fruits, and dry or dehydrated products. Although irradiation destroys many bacteria, it does not sterilize food. Even if you're using food that has been irradiated by the manufacturer, you must continue to take precautions against food poisoning, through proper refrigeration and handling, to safeguard against any surviving organisms.

Other Disorders

Scientists suspect that foodborne pathogens are linked to chronic disorders and can even cause permanent tissue or organ destruction. Research suggests that when some people are infected by foodborne pathogens, the activation of their immune system can trigger an inappropriate autoimmune response, which means the immune system attacks the body's own cells. In some people, an autoimmune response leads to a chronic health condition.

Chronic disorders that may be triggered by foodborne pathogens are

arthritis
inflammatory bowel disease
kidney failure
Guillain-Barré syndrome
autoimmune disorders

Further research is needed to explain the link.

Summary

food poisoning results from eating food that is contaminated with bacteria, viruses, or parasites.
Treatment may range from replacement of lost fluids and electrolytes for mild cases of food poisoning, to hospitalization for severe conditions such as hemolytic uremic syndrome.

You can prevent food poisoning by taking the following precautions:

Wash your hands with hot, soapy water before preparing food and after using the bathroom or changing diapers.
Keep raw meat, poultry, or seafood and their juices away from ready-to-eat foods.
Cook foods properly and at a high enough temperature to kill harmful bacteria.

Reference for Food Poisoning Article

National Institutes of Health

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