Enterohemorrhagic Escherichia Coli (EHEC)
2001 Case Definition
2001 Case Definition
Clinical Description
An infection of variable severity characterized by diarrhea (often bloody) and abdominal cramps. Illness may be complicated by hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP); asymptomatic infections also may occur.
Laboratory Criteria For Diagnosis
- Isolation of Escherichia coli O157:H7 from a specimen, OR
- Isolation of shiga toxin-producing E. coli from a clinical specimen*
Case Classification
Suspected
A case of post-diarrheal HUS or TTP (see HUS case definition)
Probable
- A case with isolation of E. coli O157 from a clinical specimen, pending confirmation of H7 or shiga toxin production, OR
- A clinically compatible case that is epidemiologically linked to a confirmed or probable case, OR
- Identification of shiga toxin in a specimen from a clinically compatible case, OR
- Definitive evidence of an elevated antibody titer to a known Enterohemorrhagic E. coli (EHEC) serotype from a clinically compatible case
Confirmed
A case that meets the laboratory criteria for diagnosis.
Comments
*Laboratory-confirmed isolates are reported via the Public Health Laboratory Information System (PHLIS), which is managed by the Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, CDC. Both probable and confirmed cases are reported to the National Notifiable Diseases Surveillance System (NNDSS), but only confirmed cases are reported to PHLIS. Confirmation is based primarily on laboratory findings.