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

The National Academies

What You Need To Know About Infectious Disease

E. Coli

Escherichia coli is a bacterium found in the human gut. Most strains of E. coli are harmless; however, several can cause severe illness. Shiga-toxin producing E. coli (called STEC for short) are bacteria that make a toxin that causes disease. STEC live in the guts of many animals that are typically not adversely affected by the bacteria. If humans drink water or eat fruits and vegetables contaminated with microscopic amounts of feces from these animals, they can become ill. Other means of transmission include eating contaminated or undercooked meat, drinking raw milk, working closely with cattle (the major source for human illness), or contact with human feces.

The symptoms of an STEC infection usually begin about 3 to 4 days after ingestion of the bacteria and include cramps, diarrhea (often bloody), vomiting, and fever. Most people recover within 5 to 10 days; however, a small percentage of infections lead to complications and fatal diseases. One of these diseases, hemolytic uremic syndrome (HUS), develops about 7 days after the initial symptoms and may result in acute kidney failure. Patients developing HUS often feel tired, urinate less, and lose facial coloring.

There is no special treatment for E. coli infections other than staying well hydrated. Patients should not take antidiarrheals because diarrhea is important for removing the bacteria from the intestine. Antibiotics should also be avoided; they have not been found to be beneficial and may increase the risk of developing HUS.

Because E. coli is spread through animal and human feces, care should be taken to avoid consumption of products that may be contaminated. An easy way to prevent E. coli infections is by washing your hands with soap after using the bathroom and before working with or eating foods. E. coli can live in environments with temperatures up to 158°F (70°C); therefore, meats should be thoroughly cooked, and milk and juices should be pasteurized before consumption. After preparation of raw meat, wash your knives and cutting boards to prevent contamination of other foods that touch the same utensils. Drinking water sources should be protected from animal waste and drinking water that has not been tested for contaminants should be avoided.


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What do you know about infectious disease?

Which are larger?

  • Correct!

    Bacteria are 10 to 100 times larger than viruses.

  • Sorry, that’s incorrect.

    Bacteria are 10 to 100 times larger than viruses.

Infectious Disease Defined


An event that occurs when the incidence of new cases of a certain disease, over a given period of time, substantially exceeds what is expected in a specific population.

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