Risk Factors for Multiple Infections with Salmonella, Shigella, and Campylobacter in Single Individuals Identified in Israel between 1999 and 2020: A Case-Case Control Study

Background: Salmonella, Shigella, and Campylobacter are highly prevalent among children. Reports on risk factors of patients infected with all three pathogens, not simultaneously, are scarce. Objectives: To identify risk factors for multiple infection with Salmonella, Shigella, and Campylobacter in the same child. Methods: Using the Israel Sentinel Laboratory-Based Surveillance Network, we conducted a retrospective observational case-case-control study among children aged 0-9 years. A case was defined as a child infected with Salmonella, Shigella, and Campylobacter at different occasions between January 1999 and December 2020. A control was defined as a child infected with a single pathogen once, during the same period. Logistic regression models were applied to determine the association between multiple infections and demographic characteristics. Results: We identified 109 cases (0.1%) infected with Salmonella, Shigella, and Campylobacter, and 86,511 controls (99.9%) infected with only one bacteria type. In a multivariable analysis, we showed that being Jewish (odds ratio [OR] 2.4, 95% confidence interval [95%CI] 1.3-4.4), having residency in Jerusalem (OR 3.2, 95%C11.3-7.7), or in the southern district (OR 3.7,95%C11.5-8.8) were independent risk factors for multiple infection. Conclusions: Although very rare, non-simultaneous infection with multiple bacteria does occur in Israel. National and local authorities should promote programs to encourage proper hygiene practices, which are culture-adjusted.