Non-typhoidal salmonella infections among children in a tertiary hospital in ningbo, zhejiang, china, 2012–2019

Abstract

Background Non-typhoidal Salmonella (NTS), a common cause of diarrheal enterocolitis, may also cause severe invasive diseases. Limited information on NTS infections in children is available in China. Methods We performed a retrospective study of children admitted to the Ningbo Women and Chil-dren’s Hospital with culture-confirmed NTS infections between January 2012 and December 2019. Clinical and microbiological information were collected. We compared demographic, clinical and antibiotic resistance variables of invasive NTS (iNTS) infections and non-inva-sive NTS (non-iNTS) infections, and explored associations between hospitalizations for pediatric NTS infections and temperature and rainfall. Results A total of 166 pediatric hospitalizations due to NTS infection were identified during the 8-year study period. Most of the 166 children were <5 years old (93.4%). The primary serotype was Salmonella Typhimurium (62.6%). Of 166 children with NTS infections, 11 had invasive infection. Compared to 155 children with non-iNTS infections, we found that iNTS infections were more likely to occur in infants ≤6 months or children with an underlying medical condi-tion of leukemia at admission, but iNTS infections less often presented with a symptom of diarrhea (P <0.05 in all cases). The resistance rates of non-iNTS isolates to ceftazidime, cef-triaxone, cefepime, and aztreonam were significantly higher than those of iNTS isolates (P <0.05 in all cases). In addition, compared with iNTS isolates, non-iNTS isolates were significantly associated with resistance to ≤4 CLSI (Clinical and Laboratory Standard Institute) classes (P = 0.041, OR: 0.089, 95% CI: 0.009–0.901) and ≤2 first-line treatment agents (P = 0.040, OR: 0.159, 95% CI: 0.028–0.916). On the other hand, we found that seasonal NTS hospitalizations were positively associated with average seasonal temperature (r = 0.961, P = 0.039) and average monthly rainfall (r = 0.921, P <0.001). Conclusion Non-iNTS accounts for the majority of infections in this study; infants ≤6 months and children with underlying medical conditions of leukemia are more likely to have invasive infec-tion. The rates of antibiotic resistance in the iNTS isolates are generally lower than those in the non-iNTS isolates. On the other hand, high temperatures and heavy rainfall are positively associated with NTS hospitalizations among children in Ningbo.