Analysis of clinical characteristics of invasive non-typhoidal Salmonella infections in children: a 5-year dual-center retrospective study

ObjectiveTo investigate the incidence, microbiological characteristics, clinical manifestations, and antibiotic resistance of invasive non-typhoidal Salmonella (iNTS) infections in children. MethodsA retrospective study was conducted from January 2018 to December 2022 at two large teaching hospitals: Zhejiang University School of Medicine Childrens Hospital (ZCH) and Childrens Hospital of Soochow University (SCH). Medical records of culture-confirmed iNTS cases were reviewed, and a standardized case report form was used to collect demographic, clinical, and microbiological data. ResultsA total of 109 cases of iNTS infection were included, with 40 cases from SCH and 69 cases from ZCH. 71 cases (65.1%) were boys.. Infants under 1 year old accounted for 30.3% of the cases. Among the cases, 38 cases (34.9%) had underlying diseases, mainly tumors (55.3%,21/38). The most common sites of infection were the bloodstream (84.4%) and bones and joints (12.8%). The most common serogroups were B (36.8%), C (44.7%) and D (38.2%). The overall resistance rate of ampicillin was 53.6%, ceftriaxone resistance rate was 17.8%, and carbapenem resistance rate was 0%. Seasonal trends indicated higher incidence rates during the summer. ConclusioniNTS infections in children primarily affect the bloodstream and bones/joints, with a significant proportion of cases in those with underlying medical conditions. Ceftriaxone remains the first-line antibiotic, but increasing resistance highlights the need for vigilant antimicrobial stewardship. Carbapenems can be considered as second-line antibiotics in severe cases. Further studies are needed to understand the molecular characteristics and improve treatment strategies for iNTS infections in pediatric patients.