Enterovirulent E. Coli (EEC) (cont.)
Charles Patrick Davis, MD, PhD
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
In this Article
- Enterovirulent E. coli (EEC) facts
- What are enterovirulent E. coli (EEC)?
- What are the symptoms caused by enterovirulent E. coli (EEC)?
- A new EEC group? (update on the E. coli 0104:H4 outbreak in Germany)
- How do enterovirulent E. coli groups cause disease?
- When should one seek medical care for enterovirulent E. coli infection?
- How are enterovirulent E. coli infections diagnosed?
- How are enterovirulent E. coli infections treated?
- How is self-care at home done for enterovirulent E. coli?
- What are the complications associated with enterovirulent E. coli (EEC)?
- How are enterovirulent E. coli (EEC) infections prevented?
- What are the prognoses (outcomes) of enterovirulent E. coli infections?
- Find a local Doctor in your town
How do enterovirulent E. coli groups cause disease?
In general, all EEC groups cause disease by disruption of the normal secretory mechanisms of the intestines which leads to diarrhea. As outlined above, different groups use different methods that ultimately results in diarrhea; the type of diarrhea and the intensity of the disease are related to the mechanisms used by the bacteria.
- EHEC secrete Shiga toxins that can not only
destroy intestinal cells, but can be spread to other organ systems to cause
additional disease. E. coli 0157:H7 is the major EHEC pathogen responsible and
is considered to be one of the most virulent organisms in all of the EEC groups
because of Shiga toxin production.
- EPEC group organisms also can produce a toxin
closely related to Shigella toxin that has many of the same properties of Shiga
toxin although the serotypes cause the disease (sometimes milder) mainly in
- The ETEC group does not produce Shiga toxins or their closely related
toxins, but ETEC do produce two other exotoxins that stimulate the intestines to
secrete fluid and mucus. Yet another mechanism is used by
- EIEC organisms, these
bacteria have the ability to penetrate the epithelial cells that line areas of
the human intestines. EIEC organisms then cause many of the cells to lyse thus
disrupting the fluid adsorption and secretion capacity of the intestines.
- Both EAEC and EAggEC groups of bacteria, by attaching to intestinal cells, cause irritation or inflammation of the intestinal cells. This physiologic and immunologic response also disrupts adsorption and secretion in the intestines.
When should one seek medical care for enterovirulent E. coli infection?
Many people (the large majority) do not need to seek medical care as most of the infections are self-limiting, unless the patient is immunodepressed or is an undernourished child in a third world country. Because a number of patients are children; their progress in self-limiting the disease needs to be carefully watched as they can, in some instances, rapidly deteriorate. This is the situation for all the EEC groups. Most infected individuals, unless diagnosed, will not even know they are infected with EEC since many bacterial and viral diseases have similar symptoms of nausea, low-grade fever, and diarrhea.
Many clinicians suggest that affected individuals should seek medical care if:
- there are signs of dehydration (for example, decreased urination, dry
mucous membranes), especially in children under 5 years of age and the elderly;
- sustained fever over 101 F (37.7 C);
- presence of blood in the stool;
- known ingestion of E. coli 0157:H7 or contaminated food or fluid or close
personal contact with individuals known to have any E. coli infection caused by
a EEC group bacteria; and/or
- any complication of an E. coli EEC group infection (see complication section below).
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