Information on E. coli O157:H7

What is E. coli infection?
There are many strains of E. coli bacteria that normally live in the intestines of humans and animals. Most of them do not cause symptoms in humans. However, one particular strain which does not normally live in the intestines of humans, E. coli O157:H7 can cause serious illness. Symptoms can range from mild, non-bloody diarrhea to severe diarrhea which is virtually all blood. Diarrhea is often accompanied by abdominal cramps (typically severe), nausea and vomiting. Less than 1/3 of patients have a fever. Complications such as kidney damage may also occur.

What should someone do if they have these symptoms?
See a doctor!

How is E. coli O157:H7 spread?
The bacteria can be spread in several ways.

• The bacteria live in the intestines of cattle. Beef carcasses can become contaminated with the bacteria during the slaughtering process. A person can become infected with E. coli O157:H7 if he/she eats raw or undercooked beef, especially ground beef.
• Drinking unpasteurized (raw) milk, eating unwashed fresh vegetables and fruits, unpasteurized fruit juices, or any food product eaten raw which may be contaminated by feces or manure used for fertilizer.
• Cross-contaminating cutting boards or other food preparation surfaces. Do not place ready-to-eat foods on counters, cutting boards or plates that have been in contact with raw meats. Wash all surfaces with hot, soapy water.
• E. coli O157:H7 bacteria are in the intestines of an infected person. When an infected person has a bowel movement, his/her hands can become contaminated while wiping. If the infected person does not wash his/her hands thoroughly after using the bathroom, he/she can spread E. coli O157:H7 to others through handling or sharing their food and drink. It is also spread when a person does not wash his/her hands after changing the diaper of an infected child.
• Cattle or humans with O157:H7 infections can contaminate streams, lakes, irrigation ditches or swimming pools with feces. Other people who swallow the water can become infected.
• Petting zoos and livestock shows have also been associated with E. coli O157:H7 outbreaks.

When do the first signs of illness occur?
Two to eight days after being infected. (Average is 3-4 days).

How long is someone contagious?
Adults: when symptoms are present. Children: when symptoms are present and up to several weeks after symptoms have stopped.

How can infection with E. coli O157:H7 be prevented?
Infection can be very serious, even fatal, and often results in hospitalization, so preventing E. coli O157:H7 infection is very important. Infection can be prevented by:

• Thoroughly cooking meat especially ground beef (until there is no pink and the juices run clear)
• Thoroughly washing fresh fruits and vegetables in potable (clean) water
• Washing hands thoroughly with soap and water after having a bowel movement, diapering children, and before eating or preparing food (Be sure to wash hands after handling raw meat as well!)
• Sanitizing all surfaces (including plates, knives, spatulas, cutting boards, faucets, etc.) which come in contact with raw meat and wash hands after handling raw meat.
• Not swallowing water from streams, lakes, irrigation ditches or swimming pools.
• Washing hands after contact with pets, birds or livestock.

Are there any work or child care restrictions?
Yes!

• Infected adults working as food handlers, as child care providers, or health care workers may not perform their regular duties until their diarrhea has stopped. The health department may require workers to submit a stool specimen for testing to determine they are no longer infected with E. coli O157:H7 before returning to work.
• Incontinent children or children in diapers who are infected may not attend child care until their diarrhea has stopped. The health department may require a stool specimen for testing to determine a child is no longer infected before the child returns to child care.
• Since children can shed E. coli O157:H7 in their stool for several weeks, child care operators and staff must adhere to very strict hygiene standards for thorough hand washing after changing diapers and before handling food.

How is E. coli O157:H7 treated?
Antibiotics are generally not recommended for uncomplicated cases of E. coli O157:H7 infection. It is important that symptomatic people drink fluids frequently to avoid dehydration.