Hemolytic uremic syndrome in Belgium: Incidence and association with verocytotoxin-producing Escherichia coli infection

Abstract

Objective: To evaluate the incidence of hemolytic uremic syndrome (HUS) in Belgium and to determine the role of verocytotoxin-producing Escherichia coli 0157:H7 and other serotypes (non-0157 VTEC). Methods: Twenty-two centers, including the seven university hospitals, registered prospectively all cases of HUS; they collected clinical samples for isolation of VTEC strains and serum for detection of specific O-lipopolysaccharide antibodies. Results: Forty-seven cases of HUS (including five incomplete cases) were recorded. Three cases were seen in nonresidents. The incidence of complete HUS in Belgian residents was 4.3 cases/100,000 in children < 5 years old, 1.8 cases/100,000 when all children < 15 years were considered, and 0.42/100,000 when patients of all ages were taken into account. By combining bacteriologic and serologic results, evidence of VTEC infection was obtained in 64% of the patients, mainly but not exclusively in children with prodromal diarrhea. The 13 VTEC isolates belonged to serotypes 0157:H7 (nine isolates), 026:H11, 0121:H-, 0145:H- and 0172:H- (one each) and all produced VT2 (+VT2vh-a in three 0157 strains) and were positive for the eaeA gene. Conclusions: The incidence rate found in this study and the high mortality and morbidity linked with this syndrome warrant further registration of pediatric and post-diarrheic adult HUS cases and also examination of stools for both 0157 and non-0157 VTEC strains. For effective prevention of this disease, further study of the serotypes and accessory virulence factors associated with HUS is needed.