PEDBASE.org - The Pediatric Database - Detailed information of ENTEROHEMORRHAGIC COLITIS

ENTEROHEMORRHAGIC COLITIS

DEFINITION:

A bacterial infection of the colon caused by Enterohemorrhagic E. coli (EHEC) resulting in a dysenteric diarrhea.

EPIDEMIOLOGY:

incidence: 1-3% of diarrhea, 15-30% of bloody diarrhea
risk factors:
- age: all ages
- season: ?
- route: direct: fecal-oral
- indirect: food (poorly-cooked meats), milk
- environ: ?
incubation period: ?

PATHOGENESIS:

1. Background

Enterohemorrhagic E. coli is a gram negative rod
- serotypes O157:H7 and O26:H11
- produce two major enterocytotoxins:

1. Verotoxin 1

shiga-like toxin I (identical to shigatoxin)

2. Verotoxin 2

shiga-like toxin II (distantly related to shiga-toxin)
these are protein synthesis-inhibiting toxins:
- cleave adenine residue from rRNA at the site where EF-1-dependent attachment of aminoacyl t-RNA occurs
likely carried on transferrable plasmids

CLINICAL FEATURES:

1. Diarrhea

initially watery -> profuse grossly bloody diarrhea
lasts up to 5-9 days
associated symptoms: crampy abdominal pain, fever is rare

2. Complications

Hemolytic Uremic Syndrome (secondary to shigatoxin)

INVESTIGATIONS:

1. Stool

culture, DNA probes, ? toxin assays

2. Biospy

1. Electron Microscopy

EHEC adheres to intestinal cells and produces a lesion similar to that produced by EPEC
pathological changes are found primarily in the colon

MANAGEMENT:

1. Supportive

oral rehydration fluid (ORF) or intravenous rehydration

Pediatric Database - ENTEROHEMORRHAGIC COLITIS

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