Abstract
Background
Haemolytic Uraemic Syndrome (HUS) is a serious complication of Shiga toxin-producing Escherichia coli (STEC) infection and the key reason why intensive health protection against STEC is required. However, although many potential risk factors have been identified, accurate estimation of risk of HUS from STEC remains challenging. Therefore, we aimed to develop a practical composite score to promptly estimate the risk of developing HUS from STEC.
Methods
This was a retrospective cohort study where data for all confirmed STEC infections in Ireland during 2013–15 were subjected to statistical analysis with respect to predicting HUS. Multivariable logistic regression was used to develop a composite risk score, segregating risk of HUS into ‘very low risk’ (0–0.4%), ‘low risk’ (0.5–0.9%), ‘medium risk’ (1.0–4.4%), ‘high risk’ (4.5–9.9%) and ‘very high risk’ (10.0% and over).
Results
There were 1397 STEC notifications with complete information regarding HUS, of whom 5.1% developed HUS. Young age, vomiting, bloody diarrhoea, Shiga toxin 2, infection during April to November, and infection in Eastern and North-Eastern regions of Ireland, were all statistically significant independent predictors of HUS. Demonstration of a risk gradient provided internal validity to the risk score: 0.2% in the cohort with ‘very low risk’ (1/430), 1.1% with ‘low risk’ (2/182), 2.3% with ‘medium risk’ (8/345), 3.1% with ‘high risk’ (3/98) and 22.2% with ‘very high risk’ (43/194) scores, respectively, developed HUS.
Conclusion
We have developed a composite risk score which may be of practical value, once externally validated, in prompt estimation of risk of HUS from STEC infection.
Shiga toxin-producing Escherichia coli O26:H11 associated with a cluster of haemolytic uraemic syndrome cases in South Africa, 2017
