Disease
Fact Sheet Series:
What is E. coli 0157:H7?
Escherichia coli 0157:H7 is a
bacterium that infects the intestinal tract and may produce a toxin that
affects other parts of the body as well. E. coli 0157:H7 infections
can occur as isolated cases or as part of an outbreak; cases are seen more
frequently during the summer months.
What are the symptoms of E. coli 0157:H7
infections?
E. coli 0157:H7 infections usually cause diarrhea, which is
often bloody, and severe abdominal cramps. There is generally little or no
fever. Some individuals may become infected but display no symptoms.
How soon after exposure do symptoms appear?
The symptoms of E. coli 0157:H7 infection typically appear from
3 to 8 days, but usually about 3-4 days, following exposure.
What are the complications of E. coli 0157:H7
infections?
Two complications of E. coli infections have been reported:
hemolytic-uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP).
HUS and TTP are serious illnesses characterized by kidney failure and
destruction of the red blood cells leading to anemia, respectively. Young
children and the elderly appear to be at greatest risk of developing HUS
or TTP following infection with E. coli 0157:H7.
How does a person acquire this infection?
Infection with E. coli 0157:H7 can be acquired by eating
contaminated food or water and by contact with fecal material from
infected persons or animals. Foods that have been associated with E.
coli 0157:H7 infections are raw or undercooked beef (especially
ground beef) and unpasteurized (raw) milk. Person-to-person spread of the
bacteria is possible and has occurred in family settings, in day care
centers and in nursing homes. It is not known if infected persons who do
not have symptoms are an important factor in spreading this infection.
How is the infection and its complications treated?
Treatment with antibiotics has not been shown to be effective.
Antibiotic treatment does not alter the severity or duration of diarrhea,
or shorten the period of time someone has E. coli 0157:H7 in their
stool. More importantly, antibiotic treatment does not reduce the risk of
developing complications of E. coli 0157:H7 infection and
may, in fact, increase the risk of developing HUS. It is important to
prevent and treat dehydration. HUS and TTP require hospitalization for
transfusions and kidney dialysis.
How long can a person carry E. coli 0157:H7?
In adults, E. coli 0157:H7 infections generally resolve
within one week. In children infected with this bacteria, about one third
will carry and shed the organism in their stool for up to three weeks.
Is this a new disease?
Diarrhea caused by E. coli 0157:H7 was first recognized in
1982. HUS and TTP have been known to exist for many years but their
association with E. coli 0157:H7 infections has only recently been
identified.
Do infected people need to be isolated from school or
work?
Since the organism is passed in the feces, infected persons with
diarrhea and those who are unable to control their bowel habits
(particularly children in day care centers and individuals in nursing
homes) should be isolated until symptoms have resolved. Specific
guidelines regarding return to work or school may vary depending on
individual parameters; consultations with the local or state health
department is recommended.
How can E. coli 0157:H7 infections be prevented?
- Avoid eating raw or undercooked beef (steak tartare or rare
hamburgers, for example).
- Avoid drinking unpasteurized (raw) milk or unpasteurized milk
products.
- Avoid drinking unpasteurized fruit juices (e.g., apple juice or
apple cider).
- Always carefully wash your hands with plenty of soap and water
after bowel movements, and before and after food preparation.
Parents should stress proper handwashing habits to their children.
- Wash hands following contact with cattle and cattle fecal material
including manure used for farming or domestic gardening practices.
For more information, contact your
Local
Public Health Department
Back to Communicable Disease
Fact Sheet Series Index Page
PDF: The free Acrobat Reader®
software is needed to view and print portable document format (PDF)
files. Learn
more
Last Revised: November 04, 2008
|
