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
Suspect: A case of postdiarrheal 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
EHEC serotype from a clinically compatible case
Confirmed: A case that meets the laboratory criteria for
diagnosis.
Comment
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.