Vacation in Egypt associated with Shiga toxin-producing Escherichia coli infection in children and adolescents, northern Italy, 2023

Abstract

Background: Haemolytic uremic syndrome (HUS) is a severe complication of infection with Shiga toxin-producing Escherichia coli (STEC). Although the reservoirs of STEC are known, the source of the infection of sporadic cases is often unknown. In 2023, we observed several cases of bloody diarrhoea with STEC infection in children and adolescents returning from vacations. Aim: We aimed to explore the association between travel and bloody diarrhoea with STEC infection in children and adolescents. Methods: We included all children and adolescents with bloody diarrhoea with STEC infection identified in 2023 by the ItalKid-HUS Network surveillance system in northern Italy. We interviewed children’s families and sent a questionnaire on recent travels abroad. The exposure time was between 3 days after arrival abroad and 5 days after return home. A self-controlled case series (SCCS) design was used in the analysis. Results: Of the 43 cases, 11 developed HUS. Twenty-three cases did not travel abroad, while 20 had travelled to several destinations. The incidence rate ratio (IRR) associated with travel to Egypt was 88.6 (95% confidence interval (CI): 17.0–462). Serotype analysis excluded the possibility of a single strain causing the infections. We did not find the source of the infections. Conclusion: There is an elevated risk of acquiring STEC infection with bloody diarrhoea and HUS associated with travel to Egypt. Specific investigations to identify the source are needed to implement effective preventive measures.