1526. Epidemiology of and Risk Factors for Nontyphoidal Salmonella Bacteremia in Children: A 20-Year Retrospective Cohort

Abstract

Abstract Background Nontyphoidal Salmonella (NTS) infections are the most common culture-confirmed foodborne illness in the United States. One to five percent of enteric infections due to NTS result in bloodstream infection (BSI). Host risk factors for NTS BSI include extremes of age and chronic or immunosuppressing conditions. Methods This was a retrospective review of the electronic health records (EHRs) of all blood cultures collected from January 1, 1999 to December 31, 2018 at Kaiser Permanente Northern California (KPNC) positive for Salmonella spp. The speciation and group of all Salmonella spp. were extracted from the microbiology records. Using KPNC population data, the incidence rate of NTS BSI by age and year of infection was calculated. Using a test for trend, the trend in rates of NTS BSI was determined. Risk factors for complicated NTS BSI using clinical and laboratory data were calculated. Results From 1999 to 2018, there were 212 cases of NTS BSI and 104 cases of Salmonella typhi and paratyphi BSI. The average number of cases per year was 10.6 (range 3–25). There were 14,952,802 evaluable children over the 20 years, with an average of 747,640 per year. The incident rate of NTS bacteremia was 1.4 per 100,000 children per year. The trend to increasing cases was not statistically significant (Figure 1). The distribution of NTS BSI cases were 114 (54%) Group B, 33 (15.5%) Group C, 31 (14.5%) Group D, 19 (9%) Groups E or G and 15 (7%) other/nonspecified. The predominant NTS pathogen was Salmonella heidelberg occurring in 37 (17.5%) cases. Forty-five percent of children were female. (Table 1) Forty-two percent of children were less than 3 years old with a steady rate after age 3. Two (0.9%) children had an underlying immunodeficiency, three (1.4%) additional with a malignancy and 16 (7.5%) with underlying non-immunosuppressing comorbidities. Conclusion Despite improvements in food safety, the rates of NTS bacteremia have not decreased over the last two decades. The rate of NTS was 1.4 per 100,000 children per year with the highest proportion in children less than 3 years. Two percent had underlying immunosuppressing comorbidities. Although only 10% had underlying comorbidities, this was substantially higher than the population at KPNC. Disclosures All authors: No reported disclosures.