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The National Academies: What You Need To Know About Infectious Disease

What You Need To Know About Infectious Disease


Salmonella bacteria can cause the infection salmonellosis. In the United States, about 1.2 million cases and about 450 deaths occur each year. Salmonella lives in the intestinal tracts of humans and other animals, including birds. The bacteria are usually transmitted to humans by eating foods contaminated with animal feces. Contaminated foods are often of animal origin, such as beef, poultry, milk, or eggs, but any food, including vegetables, may become contaminated. Because contaminated foods usually look and smell normal, it is important to be aware of public health announcements about outbreaks. Salmonella may also be found in the feces of some pets, especially birds and reptiles. People can become infected if they do not wash their hands after contact with pets or pet feces.

Most persons infected with Salmonella develop nausea, vomiting, diarrhea, fever, chills, headache, and abdominal cramps, and they may have blood in the stool. Symptoms emerge from several hours after infection to up to 2 days. Because many different kinds of illnesses can cause these symptoms, diagnosis depends on laboratory tests that can identify Salmonella in the stool of an infected person.

People usually recover from salmonellosis within a few days and often do not require treatment other than oral fluids. Persons with severe diarrhea may require rehydration with intravenous fluids. Antibiotics are not usually necessary unless the infection spreads from the intestines to the bloodstream. But antibiotics are not beneficial in uncomplicated cases. 

Because foods of animal origin may be contaminated with Salmonella, people should cook eggs, poultry, and meat thoroughly. Cross contamination of foods can be prevented by keeping uncooked meats separate from produce, cooked foods, and ready-to-eat foods. Although Salmonella can be found in the intestines and feces of all animals, the bacteria are most likely to be found in the living environment and on the bodies of reptiles and birds. For this reason, people should wash their hands immediately after handling birds and reptiles.


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What do you know about infectious disease?

True or False: Our bodies contain at least 10 times more human cells than bacterial cells.

  • Sorry, that’s incorrect.

    Our bodies contain at least 10 times more bacterial cells than human cells. 

  • Correct!

    Our bodies contain at least 10 times more bacterial cells than human cells. 

Infectious Disease Defined


Any abnormal condition  that affects all or part of an organism, resulting in symptoms such as pain or loss of function.

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