Food Poisoning

Microorganisms that we ingest (eat) may cause gastrointestinal upset in a variety of ways. Our stomach acid easily destroys most microorganisms that we ingest, incapacitating them. Some microorganisms will only cause illness if we ingest great numbers of them at a time. Ingestion of these great numbers can allow a large number of microorganisms to escape the acid environment, invade the small intestine and cause illness. Salmonella (SAL-moh-NEL-ah) is an example of this type of microorganism.  These bacteria reproduce in the food product before we eat it, thus providing for an ingestion of a large number of bacteria at one time. Within twenty-four to forty–eight hours after ingesting the food, Salmonella bacteria invade the lining of the small intestine and bring about symptoms.  Usually Salmonella food poisoning can be prevented by the proper refrigeration of foods and by cooking foods thoroughly. A stool culture is used to diagnose Salmonella food poisoning.

Other types of microorganism are very virulent (VIR-u-lent; difficult to kill) and are thus able to with stand the stomach acid environment. Ingesting even small numbers of these will allow passage into the small intestine and cause illness. These organisms include viruses, amoebae, and shigella, which are often spread by a fecal–oral route.

Another way that microorganisms make us ill is by producing a toxin (poisoning). The bacteria itself does not cause the harm, but the enterotoxin (intestine poison) it produces does the damage. Staphylococcal food poisoning is of this type. Staphylococcal organisms contaminate non-refrigerated food and release enterotoxins. When these enterotoxins are ingested, they quickly invade the lining of the stomach and small intestine, leading to symptoms within one to four hours. Staphylococcal food poisoning, determined by a food culture, can be prevented by proper refrigeration of food. Prognosis is good, and symptoms usually improve within twenty-four hours.

Most gastrointestinal upset caused by contaminated food can be prevented by following these measures:

• Always wash your hands before and after food preparation.
• Wash your hands before and after meals.
• Keep dishes (plates/utensils) clean and stored until ready for use.
• Cover and refrigerate food properly.
• Cook foods thoroughly, especially meats.