E. COLI, SHIGA TOXIN-PRODUCING (INCLUDES O157:H7)

Question 1

An infection of variable severity characterized by diarrhea (often bloody) and abdominal cramps. The illness may be complicated by hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura (TTP). Asymptomatic infections may also occur.

Answer 1

E. COLI, SHIGA TOXIN-PRODUCING

Question 2

Characterized by the acute onset of microangiopathic hemolytic anemia, renal
(i.e., kidney) injury, and low platelet count

Answer 2

Hemolytic uremic syndrome (HUS)

Question 3

Characterized by these features but can include central nervous system (CNS) involvement and fever and may have a more gradual onset.

Answer 3

Thrombotic thrombocytopenic purpura (TTP)

Question 4

Laboratory criteria for diagnosis

Answer 4

• Isolation of Escherichia coli O157:H7 from a clinical specimen (Escherichia coli O157:H7 isolates may be assumed to be Shiga toxin-producing), or
• Isolation of other E. coli from a clinical specimen with demonstration of toxin production or the presence of Shiga toxin genes.

Note: Strains of E. coli O157:H7 designated “NM” have lost the flagella “H” antigen and become nonmotile.

Question 5

A case with isolation of E. coli O157 from a clinical specimen, without confirmation of H antigen or Shiga
toxin production;

• A clinically compatible case that is epidemiologically linked to a confirmed or probable case; or
• Identification of an elevated antibody titer to a known Shiga toxin-producing E. coli serotype from a clinically compatible case.

Answer 5

Probable

Question 6

A case of post diarrheal HUS or TTP (see HUS case definition), or identification of Shiga toxin in a
specimen from a clinically compatible case without the isolation of the Shiga toxin-producing E. coli.

Answer 6

Suspected