Food-Borne Diseases: Salmonella


The Salmonella bacterium was first isolated from a pig's intestine by American veterinarian Dr. Daniel Salmon. It's a common bacterium that causes a variety of intestinal infections, including typhoid fever, although the strain that causes typhoid is very rare in the United States. There are many varieties of Salmonella, and some are now becoming resistant to the antibiotics we use to treat them. Salmonella can be found in raw eggs and a variety of foods. Like other food-borne organisms, it gets into the body when we eat.

Salmonella is one of the most common causes of enteric, or intestinal, infections. There are 40,000 cases diagnosed each year, and many mild cases probably go unnoticed.

Disease Diction

An enteric infection is one that affects the intestines.

Salmonella's Symptoms

The incubation period for a Salmonella infection is 6 hours to 10 days. Symptoms usually show up in 6 to 48 hours. They include diarrhea, fever, and stomach cramps. Sometimes they start with nausea and vomiting.

Babies, the elderly, and those with compromised immune systems are most susceptible to infection.

Salmonella is rarely fatal, and like the other food-borne diseases we've discussed in this section, it's diagnosed with laboratory analysis of a stool sample.

Antibiotics are not recommended unless the infection has spread from the intestines, because such medication can prolong rather than reduce the period of bacterial shedding in the intestine. Individuals usually feel better within five to seven days.

Be a Clean Chef

Proper handling of eggs and other foods is key to preventing Salmonella infection. Since the organism spreads rapidly, it's also important to report cases quickly. You should be sure all foods are kept separate to prevent cross-contamination. All foods should be cooked thoroughly. Raw eggs should not be eaten.

As with the other food-borne organisms, drink pasteurized milk and purified water and be sure to wash hands, surfaces, utensils, and cutting boards after every use.

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Excerpted from The Complete Idiot's Guide to Dangerous Diseases and Epidemics © 2002 by David Perlin, Ph.D., and Ann Cohen. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.