Hemolytic uremic syndrome (HUS) is a potentially fatal disease and develops when infected with the Escherichia coli O157 strain producing the Shiga toxin (STEC O157).

American researchers have analyzed the risk factors for HUS, the dependence of the frequency of HUS according to age and the deaths of patients infected with the E. coli STEC O157 strain.

Data on the isolation of the STEC O157 strain, as well as cases of HUS development for the period 2000-2006. were received from 8 participating centers of foodNet (Foodborne Diseases Active Surveillance Network). For each STEC O157 infection and HUS development, demographic data and clinical results were recorded. The study determined the frequency of infections caused by the STEC O157 strain, in which HUS appeared.

A total of 3,464 cases of STEC O157 infection were identified, of which 218 patients (6.3%) developed HUS. The highest incidence of HUS was observed in children under 5 years of age (15.3%). In patients of other age groups, HUS developed less frequently (5-9 years - 7.9%, 10-17 years - 3.4%, 18-59 years - 1.2%, 60 and over - 3.8%). According to the results of a multivariate analysis, the age of less than 5 years and the female sex were associated with an increased risk of developing HUS infected with the STEC O157 strain.

A fatal outcome was observed in 21 patients (0.6%) with an infection caused by the STEC O157 strain, including 10 (4.6%) with advanced HUS. Deaths were recorded in 12 of 390 patients (3.1%) over the age of 60, including 5 in 15 (33.3%) with HUS and 7 in 375 (1.9%) without. Among children under the age of 5, a fatal outcome occurred in 4 children (3.0%) with HUS and in 2 (0.3%) without.

Thus, children under 5 years of age and women are more susceptible to the development of hemolytic uremic syndrome in the presence of an infection caused by the STEC O157 strain. Regardless of the development of HUS, among patients in an older group with infection caused by the STEC O157 strain, the highest mortality rate was recorded. The results confirm the need to start active maintenance treatment early in young children and elderly patients if they are diagnosed with an infection caused by the Escherichia coli O157 strain producing the Shiga toxin.