Epidemiology of Nontyphoidal Salmonella Bloodstream Infections in Children

BACKGROUND Nontyphoidal Salmonella (NTS) infections are the most common culture-confirmed foodborne illness in the United States. Although extremes of age and chronic or immunosuppressing conditions are known risk factors for NTS bloodstream infection (BSI), further predictors of BSI and BSI with focal infection in children remain poorly understood. METHODS This was a retrospective review of NTS-positive blood cultures collected from 1999 to 2018 and stool studies collected from 2009 to 2018 in children. Incidence rates and risk factors for NTS BSI with and without focal infection were determined. RESULTS Incidence rates of NTS BSI have not decreased over the last 20 years. There were 211 cases of NTS BSI with an incidence rate of 1.4 per 100 000 children per year. Twenty-one (10%) had underlying comorbidities. S. heidelberg was the most common serotype occurring in 45 (21%) cases. Compared with children with uncomplicated NTS BSI, children with NTS BSI with focal infection were more likely to have an underlying comorbidity, less diarrhea, and higher absolute neutrophil count. On multivariable analysis, the only difference in having NTS BSI in children with NTS gastroenteritis who had blood cultures obtained was a longer duration of fever (4.4 vs 2.5 days), less bloody diarrhea, and S. heidelberg isolated from stool. Laboratory studies, group of NTS, and other symptoms were not significant. CONCLUSIONS Clinicians should remain vigilant for NTS BSI in children with prolonged fevers. S. heidelberg is the most common cause of NTS BSI in children and a predictor of BSI in children with NTS gastroenteritis.