A 20-year population-based study of postdiarrheal hemolytic uremic syndrome in Utah

To determine epidemiologic features, trends in frequency, and predictors of clinical outcome of postdiarrheal hemolytic uremic syndrome (HUS) in Utah.

A 20-year population-based study of HUS with a review of the HUS registry, hospital records, transplant registry, and a survey of pediatricians and pediatric nephrologists to ensure completeness of ascertainment.

All Utah residents under 18 years of age with HUS occurring after a diarrheal prodrome between 1971 and 1990.

Incidence of HUS, severity, complications, and long-term sequelae.

There were 157 cases during 20 years; 140 (89%) occurred after a diarrheal prodrome. The mean annual incidence was 1.42/100,000 children (range 0.2 to 3.4/100,000 children/year). Periods of high incidence occurred; however, there was no overall sustained increase in incidence. Escherichia coli O157:H7 was isolated from the stool of 62% of children who had specimens submitted. There were no differences between the first and second decade in the proportion with diarrheal prodrome, bloody diarrhea, most abnormal laboratory values, hospital course, or outcome. However, admission laboratory abnormalities were more severe during the first decade suggesting a delay in diagnosis. Age < 2 years, anuria before admission, and higher white blood cell counts on admission predicted severe disease. Bad outcome (death, end-stage renal disease, or stroke) occurred in 11%; 5% died. Chronic renal sequelae, usually mild, were found on follow-up (median 6.5 years) in 51% of survivors.

HUS has been an important clinical and public health problem in Utah for 20 years. The consistency of the clinical and epidemiologic features over 2 decades suggests that a common etiologic agent has accounted for most cases of HUS in this region since 1971.