Food Poisoning

  • Basics

    Food poisoning is a gastrointestinal illness that results from ingesting food-borne microorganisms, their toxins, parasites, or chemicals. Every year, one in five Americans will suffer a bout of food poisoning—usually after eating something contaminated with bacteria such as an undercooked hamburger or a potato salad that has been sitting out all day at a picnic. Commonly referred to as “the stomach flu” or “the 24-hour bug,” food poisoning typically strikes within hours or days of eating the offending food. It usually starts with a wave of nausea followed by vomiting and/or diarrhea. In healthy adults, most cases are mild—albeit unpleasant—and run their course within a day or two. But in children, older adults, and people with weakened immune systems, food poisoning can be dangerous. Although it is rare, food poisoning such as botulism can be fatal.

  • Causes

    Food poisoning is usually caused by any one of a number of bacteria. Viruses, parasites, and chemicals are other causes Table 01. Many types of bacteria that live in the intestines of humans and animals can cause illness when they get into the food that we eat. Meat and poultry are sometimes contaminated during slaughter. Organisms also may be transferred to food by anyone who has not washed their hands after coming into contact with human or animal feces.

    Some bacterial organisms make toxins that damage intestinal cells and cause a loss of fluid that contains vital proteins, water, and electrolytes. Viruses and parasites can also attack the intestinal lining and wreak havoc when they enter your digestive system. Intestinal parasites like Giardia and Cryptosporidium are usually picked up by drinking contaminated water. Chemical toxins may be man-made (drugs—pharmaceutical or illegal) or occur naturally in plants or fish.

    Table 1.  Common Bacteria That Cause Food Poisoning

    Bacteria Comments
    Campylobacter These bacteria are very common in poultry. It is believed that half of all raw chicken is contaminated with it. Other sources of infection include unpasteurized milk and contaminated water.
    Clostridium botulinum This bacterium is common in soil, and can lead to a deadly illness called botulism. Food-borne botulism is rare because the organism needs specific conditions in order to produce toxins; namely a temperature above 38? Fahrenheit and a lack of oxygen. Poorly canned vegetables and fruits are a potential source for this type of food poisoning, but modern canning methods have almost done away with the problem. Honey can be a source of infant botulism.
    E. coli These bacteria are the most common cause of traveler?s diarrhea. Drinking water?even ice cubes floating in a drink?or eating peeled fruit while in a foreign country can lead to infection. Undercooked ground beef and unpasteurized milk are other havens for E. coli. There have been several recent nationwide E. coli outbreaks in which the culprit was a vegetable, rather than meat or water. An outbreak in 2006 affected more than 150 people and resulted in 3 deaths. Public health officials eventually traced the outbreak to raw spinach, but the ultimate source of contamination remains unknown. .
    Listeria monocytogenes This bacterium is usually picked up from soft cheeses, undercooked meats, and foods prepared in delicatessens.
    Salmonella These bacteria are commonly found in raw or undercooked meat, poultry, and raw eggs.
    Shigella These bacteria thrive in food that is left out for long periods.
    Staphylococcus These bacteria are usually picked up from mayonnaise-based salads (tuna salad, potato salad, egg salad) and cream-filled desserts.
    Vibrio Normal marine bacteria. Usually acquired by eating raw mollusks.

Recommended Reading

Meet the Pharmacists

I'm Shereen A. Gharbia, PharmD. Welcome to PDR Health!

Check out my latest blog post on antidepressants

Food Poisoning Related Drugs

Food Poisoning Related Conditions