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

The National Academies

What You Need To Know About Infectious Disease


Salmonella is the name of the bacteria that can cause the infection salmonellosis. Every year, approximately 40,000 cases of salmonellosis are reported in the United States. Because many milder cases are not diagnosed or reported, the actual number of infections may be 30 or more times greater. Salmonella live 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 those with diarrhea. People can become infected if they do not wash their hands after contact with pets or pet feces.

Most persons infected with Salmonella develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. 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 in 5 to 7 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. Some Salmonella bacteria have become resistant to antibiotics, largely as a result of the use of antibiotics to promote the growth of cattle and other animals raised for food.

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?

The human papillomavirus (HPV) causes about what percentage of cervical cancer cases?

  • Sorry, that’s incorrect.

    The human papillomavirus (HPV) causes more than 90% of cervical cancer cases.

  • Sorry, that’s incorrect.

    The human papillomavirus (HPV) causes more than 90% of cervical cancer cases.

  • Correct!

    The human papillomavirus (HPV) causes more than 90% of cervical cancer cases.

Infectious Disease Defined


An organism in which a parasite that is pathogenic for some other organism lives and reproduces without harming its host.

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