POSTDIARRHEAL HEMOLYTIC UREMIC SYNDROME IN PERSONS AGED 65 AND OLDER IN FOODNET SITES, 2000–2006

METHODS Reports to the Foodborne Diseases Active Surveillance Network (FoodNet) of postdiarrheal HUS in persons aged 65 and older from 2000 through 2006 were reviewed. Surveillance was conducted in Connecticut, Georgia, Maryland, Minnesota, Oregon, and Tennessee and selected counties in California and New York. Cases were identified through passive and active surveillance and by reviewing hospital discharge data for International Classification of Diseases, Clinical Modification, Ninth Revision (ICD-9CM) discharge diagnosis codes for HUS, acute renal failure, thrombotic thrombocytopenic purpura (TTP), or diarrhea caused by E. coli. Cases were validated using medical record review. Information on age, sex, hospitalization, death, and STEC O157 culture was collected. A case of postdiarrheal HUS was an illness that a physician diagnosed as HUS or TTP with diarrhea that began in the 21 days before HUS or TTP diagnosis. Confirmed cases met the following criteria: anemia (hemoglobin (Hb)o 12.0 g/dL in women or o13 g/dL in men or hematocrit (Hct)o36% in women oro39% in men), platelet count less than 150,000/mm, acute renal impairment (serum creatinine level 1.5 mg/dL), and microangiopathic changes consistent with hemolysis on peripheral blood smear. Probable cases met all criteria, except microangiopathic changes were not recorded. All others were considered suspect cases.