Burden and risk factors of Shigella sonnei shigellosis among children aged 0–59 months in hyperendemic communities in Israel

Objectives: Ultraorthodox Jewish populations living in towns with good sanitary infrastructure but with conditions of crowding have been the epicenter of Shigella sonnei shigellosis outbreaks. In this study, the incidence and risk factors of S. sonnei shigellosis in children living in an ultraorthodox community were determined. Methods: Data for the years 2000–2013 for all reported culture-proven S. sonnei shigellosis cases in children aged 0–59 months in the city of Elad were compared with data for the rest of the sub-district. Environmental factors obtained through parental interviews were evaluated for 78 incident cases of S. sonnei shigellosis and 141 community controls, matched by age, sex, and neighborhood. Conditional logistic regression models were performed. Results: Cyclic epidemics of S. sonnei shigellosis occurred every 2 years. The mean annual incidence was 10.0 per 1000 children in Elad (95% confidence interval 7.9–12.6) vs. 3.8 per 1000 children (95% confidence interval 3.3–4.4) in the sub-district (p < 0.001). Concurrent diarrheal disease in family members, having the same person in the daycare center responsible for food handling and changing diapers, and more rooms and sinks in the center, were positively associated with S. sonnei shigellosis, while children's hand-washing before meals was inversely associated. Conclusions: The burden of S. sonnei shigellosis in ultraorthodox communities is high. Enhanced hygiene interventions are required for epidemic control.