The United States National Prospective Hemolytic Uremic Syndrome Study: Microbiologic, Serologic, Clinical, and Epidemiologic Findings

The frequency of Shiga toxin‐producing Escherichia coli (STEC) serotypes associated with postdiarrheal hemolytic uremic syndrome (HUS) cases among children and adults in the United States and the proportion with IgM or IgG lipopolysaccharide antibodies to E. coli O157 were determined by use of a nationwide sample from January 1987 through December 1991. Among 83 patients, STEC were isolated from 30 (43%) of 70 whose stool cultures yielded bacterial growth (25 E. coli O157 isolates and 5 non-O157 STEC isolates). Fifty-three (80%) of 66 patients with serum samples had positive O157 lipopolysaccharide antibody titers. Of the 83 patients, 60 (72%) had evidence of STEC infection, including 6 of 8 adults whose illnesses also met criteria for thrombotic thrombocytopenic purpura. Data from a subset of patients suggest that E. coli O157 was the cause of >80% of the STEC infections. All 3 women who were postpartum had evidence of E. coli O157 infection. STEC infection should be considered the likely cause for all persons with postdiarrheal HUS. Hemolytic uremic syndrome (HUS) is characterized by acute renal failure, thrombocytopenia, and microangiopathic hemolytic anemia. HUS typically develops after a prodromal diarrheal illness but may occur without diarrhea and is the major cause of acute renal failure in children. Increasing interest has focused on the infectious etiology of postdiarrheal HUS. Shiga toxin‐ producing Escherichia coli (STEC) and Shigella dysenteriae type 1 both have been clearly associated with HUS [1, 2]. Current evidence suggests that STEC cause all or almost all cases of postdiarrheal HUS in developed countries. Several studies have suggested that E. coli O157:H7 is the major cause of postdiarrheal HUS in North America [3, 4]. Some adults diagnosed with thrombotic thrombocytopenic purpura (TTP)—a syndrome characterized by symptoms similar to those of HUS but with the addition of fever and neurologic symptoms—also have