Diseases & Conditions

Escherichia coli

Escherichia coli (E. coli) are a large and diverse group of bacteria. Although most strains of E. coli are harmless, others can make you sick. Some kinds of E. coli cause disease by making a toxin called Shiga toxin. The most commonly identified type in North America is E. coli 0157:H7; however, there are many other serogroups that can cause illness. When you hear news reports about outbreaks of E. coli infections, they are usually taking about E. coli 0157.

Experts think that there may be about 70,000 infections with E. coli 0157 each year in the United States. The number is an estimate because health officials know that many infected people do not seek medical care, many do not submit a stool specimen for testing, and many labs do not test for STEC (Shiga toxin-producing E. coli).

Signs & Symptoms

The symptoms of E. coli vary for each person but often include severe stomach cramps, diarrhea (often bloody), and vomiting. If there is a fever, it is usually not very high. E. coli infections can also cause urinary tract infections, respiratory illness and pneumonia, and other illnesses. Most people get better within 5 to 7 days. Some infections are very mild, while others are severe or life-threatening.

STEC infections are usually diagnosed through lab testing of stool specimens. STEC typically disappears from the feces by the time the illness is resolved, but may be shed for several weeks, even after symptoms go away. Young children tend to carry STEC longer than adults. A few people keep shedding these bacteria for several months.

Infection

STEC live in the guts of ruminant animals, including cattle, goats, sheep, deer and elk. The major source of human illnesses is cattle. STEC that cause human illness generally do not make animals sick. Other kinds of animals, including pigs and birds, sometimes pick up STEC from the environment and may spread it.

Infections start when you swallow STEC - you can get tiny (usually invisible) amounts of human or animal feces in your mouth. Exposures that result in illness include consumption of contaminated food, consumption of unpasteurized (raw) milk, consumption of water that has not been disinfected, contact with cattle, or contact with feces of infected people. People have become infected by swallowing lake water while swimming, touching the environment in petting zoos and other animal exhibits, and by eating food prepared by people who do not wash their hands well after using the toilet.

Prevention

The Centers for Disease Control and Prevention provide these prevention tips:

1. Wash your hands thoroughly after using the bathroom or changing diapers and before preparing or eating food. Wash your hands after contact with animals or their environments (at farms, petting zoos, faris, even your backyard).
2. Cook meats thoroughly. Ground beef and meat that has been needle-tenderized should be cooked to a temperature of at least 160°F/70°C. It is best to use a thermometer, as color is not a very reliable indicator of "doneness."
3. Avoid raw milk, unpasteurized dairy products, and unpasteurized juices (i.e., fresh apple cider).
4. Avoid swallowing water when swimming or playing in lakes, ponds, streams, swimming pools and backyard "kiddie" pools.
5. Prevent cross contamination in food preparation areas by thoroughly washing hands, counter, cutting boards, and utensils after they touch raw meat.

Source: www.cdc.gov