Risk determinants for the development of typical haemolytic uremic syndrome in Belgium and proposition of a new virulence typing algorithm for Shiga toxin-producing Escherichia coli

Abstract

In Belgium, it is mandatory to report Shiga toxin-producing Escherichia coli (STEC) infections to the health inspection authorities. To facilitate the decision making regarding infection control measures, information about the risk factors for the development of the haemolytic uremic syndrome (HUS) can be helpful. We performed statistical analyses on a dataset of 411 Belgian STEC strains. Demographic and clinical patient characteristics as well as phenotypical and genotypical STEC strain characteristics were taken into account. Multivariate logistic regression models indicated that age categories ⩽5, 6-12 and ⩾75; the stx2 gene; and the eae gene were significant HUS development risk determinants. The stx2a subtype had the highest risk (OR 29.6, 95% CI 7.0-125.1), while all stx1 subtypes encompassed a significant lower risk (OR 0.3, 95% CI 0.1-0.5). Presence of the stx1 gene without stx2 encompassed a lower risk than the combined presence of stx1 and stx2, or stx2 solely. Based on these results, we propose a new virulence typing algorithm that will enable the National Reference Centre to provide the physicians and health inspection authorities with a risk classification for the development of HUS. We believe this will contribute to a more efficient STEC infection control management in Belgium.

Hemolytic uremic syndrome caused by Shiga toxin–producing Escherichia coli in children: incidence, risk factors, and clinical outcome

“…Among the STEC-positive children, age < 3 years was a risk for HUS, which is consistent with the recent findings in Norway [14]. Previously, age less than 5 years has been reported to be a risk for development of HUS [8,10,36]. In a recent study, females were more likely to develop HUS [36], as was also the case in our study.…”

“…Patients having both stx1 and stx2 had lower risk of developing HUS than patients with only stx2, consistent with earlier literature [1]. Several other virulence factors contribute to the pathogenicity of STEC, and one of them is eae, which encodes intimin [8]. In our material, however, eae was not found to significantly increase the risk of developing HUS.…”

“…There is controversy as to whether the STEC serotype is a risk factor for developing HUS [8,10,17,35]. In our study, the risk of developing HUS did not differ among patients with serogroup O157 when compared with non-O157 STEC cases or when patients with serogroup O26 were compared with others, but after adjustment for age and sex, serogroup O157 was found to increase the risk of HUS.…”

“…In our study, the risk of developing HUS did not differ among patients with serogroup O157 when compared with non-O157 STEC cases or when patients with serogroup O26 were compared with others, but after adjustment for age and sex, serogroup O157 was found to increase the risk of HUS. An association between the development of HUS and the presence of stx2 gene, especially subtype stx2a (with or without stx2c) and stx2d, has been described [6,8,10,39,40]. We found stx2a to be a risk factor, whereas stx1, stx1a, and stx2c were associated with a reduced risk of developing HUS.…”

Pathogenicity assessment of Shiga toxin‐producing Escherichia coli (STEC) and the public health risk posed by contamination of food with STEC

“…The human or host factor is especially important and more than any other factor, age is associated with a higher risk of severe infection with STEC. Multivariate analyses have indicated odds ratios (ORs) for the risk of HUS of 11.4 (Ethelberg et al, 2004), 16.2 (crude) and 10.4 (adjusted) in children ≤ 7 years (Persson et al, 2007), and 9.6, 11.5 and 12.6 for age categories ≤ 5, 6-12 and ≥ 75 respectively (De Rauw et al, 2018). The OR was 16.7 in children ≤ 5 years in Norway in a model including all factors analysed in a multivariate analysis (Brandal et al, 2015b).…”