Objectives: The objectives of this study were to better estimate the age-specific risks of hemolytic uremic syndrome (HUS) and hemolytic anemia after Escherichia coli O157:H7 infection among a representative cohort of both referred and nonreferred children with documented illness from the province of Alberta and to compare this with the rates in children evaluated at referral centers in the rest of Canada. Study design: Children with H US or E. coli O157:H7 gastroenteritis were eligible if they were <15 years of age. Hemoglobin, blood smear, urinalysis, and serum creatinine were obtained 8 to 10 days after the onset of diarrhea to ascertain for hemolysis, anemia, thrombocytopenia, and renal injury. Subjects were monitored for 1 month. Results: From June 1991 to March 1994, HUS was diagnosed in 205 children. Of these 77% had evidence or E. coli O157:H7 infection. A further 582 children had E. coli O157:H7 gastroenteritis, of whom 18 had hemolytic anemia. The risk of HUS after E. coli O157:H7 infection in Alberta was 8.1% (95% confidence interval, 5.3 to 11.6) compared with 31.4% in referral centers in the rest of Canada. In Alberta the highest age-specific risk f HUS/hemolytic anemia was 12.9% in those <5 years of age. Conclusions: These data will help guide clinical care and provide a basis for estimating the sample sizes required in future treatment trials for the secondary prevention of 11 US.
Bibliographical noteFunding Information:
Supported by a grant (6606-4519-54) from the National Health Research and Development Program, Health and Welfare Canada and in part by a Career Scientist Award to Dr. Rowe from the Ministry of Health of Ontario. Funding for the Canadian Pediatric Kidney Disease Research Centre was provided by the Foundation of the Children's Hospital of Eastern Ontario.