E. coli

Escherichia coli O157:H7 is just one of the hundreds of strains of the bacterium Escherichia coli (E. coli). Most strains of E. coli are harmless and live in the intestines of healthy humans and animals. E. coli, however, produces a powerful toxin that can cause a severe infection. (The combination of letters and numbers in the name of the bacterium refers to the specific markers found on its surface and distinguishes it from other types of E. coli.)

The CDC recognizes E. coli as a foodborne illness. Infection often leads to bloody diarrhea, stomach cramps, vomiting, and fever.

Most E. coli illness has been associated with eating undercooked, contaminated ground beef. E. coli bacteria live in the intestines of healthy cattle and, although the number of organisms required to cause disease is not known, it is suspected to be very small. Meat becomes contaminated during slaughter, and organisms can be thoroughly mixed into beef when it is ground. Contaminated beef looks and smells normal. Other ways to transmit E. coli include:

Person-to-person contact in families and in child-care and other institutional-care centers can also be places where the transmission of the bacteria can occur.
Bacteria present on a cow's udders, or on equipment, may get into raw milk causing the infection.
Infection may also occur after swimming in or drinking sewage-contaminated water.
It has been confirmed that unpasteurized juices, such as apple cider, may also cause the infection.

Bacteria in diarrhea stools of infected people can be passed from one person to another if hygiene or handwashing habits are inadequate. This is particularly likely among toddlers who are not toilet trained. Family members and playmates of these children are at high risk of becoming infected.

Young children typically shed the organism in their feces for a week or two after their illness resolves.

CDC recommendations for prevention of the infection include:

Cook all ground beef or hamburger thoroughly. Make sure that the cooked meat is gray or brown throughout (not pink), any juices run clear, and the inside is hot.
Using a digital instant-read meat thermometer, the temperature of the meat should reach a minimum of 160 degrees F.
If you are served an undercooked hamburger in a restaurant, send it back.
Consume only pasteurized milk and milk products. Avoid raw milk.
Consume only pasteurized juices and ciders.
Make sure that infected people, especially children, wash their hands carefully and frequently with soap to reduce the risk of spreading the infection.
Drink municipal water that has been treated with adequate levels of chlorine, or other effective disinfectants.
Avoid swallowing lake or pool water while swimming.
Wash hands thoroughly after using the toilet.
People with diarrhea should not:
- Swim in public pools or lakes
- Bathe with others
- Prepare food for others