A 20-YEAR POPULATION-BASED STUDY OF POSTDIARRHEAL HEMOLYTIC-UREMIC SYNDROME IN UTAH

Objective. To determine epidemiologic features, trends in frequency, a nd predictors of clinical outcome of postdiarrheal hemolytic uremic sy ndrome (HUS) in Utah. Design. A 20-year population-based study of HUS with a review of the HUS registry, hospital records, transplant regist ry, and a survey of pediatricians and pediatric nephrologists to ensur e completeness of ascertainment. Population. All Utah residents under 18 years of age with HUS occurring after a diarrheal prodrome between 1971 and 1990. Outcome measures. Incidence of HUS, severity, complicat ions, and long-term sequelae. Results. There were 157 eases 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 over all sustained increase in incidence. Escherichia coli O157:H7 was isol ated from the stool of 62% of children who had specimens submitted. Th ere were no differences between the first and second decade in the pro portion with diarrheal prodrome, bloody diarrhea, most abnormal labora tory values, hospital course, or outcome. However, admission laborator y 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 out come (death, end-stage renal disease, or stroke) occurred in 11%; 5% d ied. Chronic renal sequelae, usually mild, were found on follow-up (me dian 6.5 years) in 51% of survivors. Conclusions. HUS has been an impo rtant clinical and public health problem in Utah for 20 years. The con sistency of the clinical and epidemiologic features over 2 decades sug gests that a common etiologic agent has accounted for most cases of HU S in this region since 1971.