Gastroenteritis, Escherichia coli

Key Features

• E coli causes gastroenteritis by a variety of mechanisms

• Enterotoxigenic E coli (ETEC) is an important cause of traveler's diarrhea

Clinical Findings

• Enterotoxigenic E coli (ETEC)

  • Elaborates either a heat-stable or a heat-labile toxin that mediates diarrhea

• Enteroinvasive E coli (EIEC)

  • Invades cells, causing bloody diarrhea and dysentery similar to infection with Shigella species

• Shiga-toxin producing E coli (STEC)

  • Can result in asymptomatic carriage stage, nonbloody diarrhea, hemorrhagic colitis, hemolytic-uremic syndrome, and thrombotic thrombocytopenic purpura

  • Serotype O157:H7 is responsible for most cases in the United States; recently in Europe, serotype O104:H4 has been reported to cause severe disease

  • Older individuals and young children are most severely affected

  • Hemolytic-uremic syndrome is more common in young children

Diagnosis

• Both ETEC and EIEC can be detected on stool-based multiplex-PCR

• Hemolytic-uremic syndrome or thrombotic thrombocytopenic purpura occurring in association with a diarrheal illness suggests the diagnosis and should prompt evaluation for STEC

• Recommendations from the CDC

  • All stools submitted for routine testing from patients with acute community-acquired diarrhea should be simultaneously cultured for E coli O157:H7 and tested with an assay that detects Shiga toxins to detect non-O157 STEC, such as E coli O145

Treatment

• Primarily supportive; disease is self-limited

• Ciprofloxacin 500 mg orally twice daily for ETEC and EIEC infections

  • Shortens the clinical course

  • However, usually not required

• Antimicrobial therapy for STEC infection

  • Does not alter the course of the disease

  • May increase the risk of hemolytic-uremic syndrome

• Confirmed infections should be reported to public health officials