Racial incidence of hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is the most common cause of acute renal failure in children and is caused by infection with verotoxin-producing Escherichia coli. There is no consensus on the relative incidence of HUS in blacks and whites. An equal racial incidence has been reported by two centers with small black populations. A series from Washington D.C. reported a low incidence in blacks. The population of Alabama is 32% black and 66% white. The Children's Hospital of Alabama admission rate has a similar racial distribution (35% black, 65% white). A record review from 1980-1992 identified 45 patients with HUS; 43 (96%) were white and only 2 (4%) were black. Based on census data for Alabama in 1980 and 1990, this gives an average annual incidence of HUS of 0.45 per 100,000 in whites and of 0.043 per 100,000 in blacks (P < 0.001, Fischer's exact test). Similar results were found in the group of patients with HUS and a history of diarrhea; whites 0.39 and blacks 0.02 (P < 0.001). However, in those with no history of diarrhea there was no significant racial difference: whites 0.05 and blacks 0.02. There were too few blacks to compare clinical course and outcome. We conclude that typical diarrhea-associated HUS is a relatively rare disease in blacks compared with whites. The reasons are unclear.