E. coli O157:H7 is one
of hundreds of strains of the bacterium Escherichia coli. Although most
strains are harmless and live in the intestines of healthy humans and
animals, this strain produces a powerful toxin and can cause severe
What are the symptoms of
E. coli 0157:H7?
O157:H7 infection often causes severe bloody diarrhea and abdominal
cramps but sometimes the infection causes non-bloody diarrhea or no
symptoms. Usually little or no fever is present, and the illness
resolves in 5 to 10 days.
In some persons,
particularly children under 5 years of age and the elderly, the
infection can also cause complications that lead to kidney failure;
however, only about 2 to 7 percent of infections lead to this
How is E. coli 0157:H7
O157:H7 infections can typically be traced back to cattle. Meat can
become contaminated during slaughter, and organisms can be thoroughly
mixed into beef when it is ground. Bacteria present on the cow's udders
or on equipment may get into raw milk.
especially ground beef that has not been cooked sufficiently to kill
O157:H7 can cause infection. Contaminated meat looks and smells normal.
Although the number of organisms required to cause disease is not known,
it is suspected to be very small.
known sources of infection are consumption of sprouts, lettuce, salami,
unpasteurized milk and juice, and swimming in or drinking
coli 0157:H7 can be passed from person-to-person if a person has
the infection—even if
they don’t have any symptoms—and proper
hand washing procedures are not followed. This is particularly a problem
for children in diapers.
How can I keep from
getting E. coli 0157:H7?
Ways to prevent infection with E. coli O157:H7
ground beef and hamburger patties thoroughly. Ground beef should be
cooked until a thermometer inserted into several parts of the patty,
including the thickest part, reads at least 160º F.
kitchen, keep raw meat separate from ready-to-eat foods. Wash hands,
counters, and utensils with hot soapy water after they touch raw meat.
Never place cooked hamburgers or ground beef on the unwashed plate that
held raw patties. Wash meat thermometers in between tests of patties
that require further cooking.
pasteurized milk, juice or cider.
fruits and vegetables thoroughly, especially those that will not be
swallowing lake or pool water while swimming.
has diarrhea, especially a child, make sure he/she washes his/her hands
carefully with soap after bowel movements to reduce the risk of
spreading infection. Hands should also be washed carefully after
changing soiled diapers.
a diarrheal illness should avoid swimming in public pools or lakes,
sharing baths with others, and preparing food for others.
If I’ve been exposed to
E. coli 0157:H7, how long will it take for symptoms to develop?
occur within 2-3 days following exposure, but may occur as soon as 1 day
following exposure or up to one week following exposure.
What treatments are
available for E. coli 0157:H7? How serious is the disease?
Most persons with E.
coli O157:H7 recover without antibiotics or other specific treatment in
5-10 days. There is no evidence that antibiotics improve the course of
disease, and it is thought that treatment with some antibiotics may
precipitate kidney complications. Antidiarrheal agents, such as Imodium,
should also be avoided.
Generally, if people are
hospitalized, it is due to dehydration, electrolyte depletion or for
What does the Health
Department doing to prevent the spread of E. coli 0157:H7?
The Health Department’s
Epidemiology Services staff investigates all cases of E. coli 0157:H7 to
determine the source of the illness. Physicians’ offices and
laboratories are required to report all cases of E. coli to the Health
The Health Department’s
Environmental Health and Safety staff works with local food
operators and food service establishments to ensure that the food safety
standards are met.
Where can I get more
information on E. coli 0157:H7?
For more information
online, you can visit the Centers for Disease Control at
http://www.cdc.gov/ecoli/, or the Food and Drug Administration at
Or, for more information
on the Health Department’s programs, please call 859.341.4264.