Non-typhoidal Salmonella (NTS), primarily caused by Salmonella enterica serovars Enteritidis and Typhimurium, is a leading pathogen of acute infectious gastroenteritis (GE) transmitted through ingestion of contaminated food and the fecal-oral route (1-4). Globally, the annual occurrence of NTS GE and associated mortality is approximately 93,800,000 cases, of which 80,300,000 cases were foodborne, with 155,000 deaths (5). Although most cases of NTS GE clinically resolve spontaneously, the risk of invasive complications increases in infants younger than 3 months and in adults aged ≥ 65 years, as well as in patients with comorbidities or immunocompromised status, for whom antibiotic therapy may be required (6-10). Age is a factor used for early risk stratification in the emergency department (ED). Nevertheless, few authors have directly compared children and adults with NTS GE within the same cohort from the perspective of ED treatment. This study was performed to characterize the clinical features of children with stool polymerase chain reaction (PCR) confirmed NTS GE presenting to a single university hospital ED, and to compare them with those of adults in the same ED. Through this, we sought to identify age-related differences in initial presentation and ED care.

All analyses were performed using SAS ver. 9.4/SAS Studio (SAS Institute). Continuous variables were summarized as median (interquartile range) and compared using the Wilcoxon rank-sum test. Ninety‑five percent confidence intervals for the median EDLOS and the between‑group median difference were calculated using a nonparametric bootstrap method. Categorical variables were expressed as frequencies and percentages and compared using the Pearson chi-square test or Fisher exact test, as appropriate. A P < 0.05 was considered significant.

During the study period, 189 patients including 134 children visited the ED with PCR-confirmed NTS GE (Figure 2). Figure 1 shows the monthly counts of the patients, revealing an annual increase in August to September, with a spike observed in August 2021.

Baseline characteristics are summarized in Table 1. Among the children, 52.2% were younger than 5 years, while among the adults, 27.3% were aged 65 years or older. The children showed lower proportions of the comorbidities (5.2% vs. 56.4%), occurrence during the outbreak (17.9% vs. 41.8%), high-acuity (0% vs. 14.5%), and hospitalization to the ICU (0% vs. 14.5%), as well as a shorter median EDLOS (237.0 minutes [interquartile range, 188.0-336.0] vs. 360.0 minutes [335.0-569.0]; difference, 123.0 minutes [95% confidence interval, 85.0-328.0]; P < 0.001)), than the adults. All children were triaged as a Korean Triage and Acuity Scale 3-4.

The symptom profile and laboratory, imaging, and microbiological findings are summarized in Table 2. Fever and hematochezia were more common in the children (fever, 94.8% vs. 63.6%; hematochezia, 37.3% vs. 0%), whereas abdominal pain was more frequent in the adults (71.6% vs. 87.3%). The enteritis/ileus on radiography was more often observed in the adults (45.3% vs. 63.3%). The laboratory findings showed lower median values of segmented white blood cell count and neutrophil percentages and C-reactive protein concentration in the children than in the adults (segmented, 69.4 × 10³/μL [interquartile range, 58.0-76.0] vs. 79.0 × 10³/μL [69.0-87.0]; C-reactive protein, 6.3 mg/dL [3.2-9.7] vs. 7.2 mg/dL [4.0-12.9]). Microbiologically, NTS bacteremia was identified in 6 patients including 3 children: 1, < 5 years; 2, 5-17 years; and 3, 18-64 years. No invasive complications such as meningitis or osteomyelitis were identified.

Table 3 summarizes antibiotic prescriptions by age groups. Most patients received antibiotics (128 of the 134 children [95.5%] and 52 of the 55 adults [94.5%]). Ceftriaxone was more commonly used in the children (72.7% vs. 51.9%). In the children, azithromycin was prescribed to 1 patient.

This study has clinical implications as follows. First, the children’s low acuity or favorable outcome, such as a shorter EDLOS, suggests that their management should be focused on oral rehydration, electrolyte correction, and observation rather than on routine hospitalization. Second, due to the low rate of bacteremia, empirical antibiotic therapy or blood cultures may be reserved for children with suspected bacteremia or at high risk of it.

These study findings are broadly consistent with relevant pediatric NTS studies that describe fever and hematochezia as common features and emphasize the generally low risk of invasive complications in children (9,10,15). In our cohort, the ward hospitalization was more frequent in children despite their lower acuity, consistent with pediatric NTS series where short-term hospitalizations were often driven by rehydration or observation rather than the true acuity (9,10). By contrast, adults with NTS GE exhibited a higher acuity, in terms of the inflammatory markers, abnormal radiography, prolonged EDLOS, and ICU hospitalization. These findings are consistent with adult NTS studies, suggesting that comorbidities and immunosuppression are more common in adults than in children, and that these conditions are associated with bacteremia and poor prognosis (11,12,16).

The patterns of antibiotic use also deserve attention. The predominance of ceftriaxone monotherapy in the children aligns with recommendations favoring a single-agent therapy when antibiotics are indicated (9,10). However, it is recently recommended against antibiotic therapy for noninvasive NTS GE in immunocompetent children, reserving the therapy for patients suspicious of or at a high risk of bacteremia (e.g., age < 3 months, immunocompromised, severe colitis, suspected bacteremia, or extra-intestinal foci) (8-10).

It is notable that the rate of antibiotic use was 95.5% in our pediatric cohort despite the absence of ICU hospitalization and the rarity of bacteremia. This finding suggests that the antibiotic therapy, rather than the choice of agent, was not adherent to the current recommendations (8-10). This discrepancy underscores the need for antimicrobial stewardship in EDs (8).

This study has several limitations. First, the single-center retrospective study design limits external validity and leaves potential residual confounding. Second, the test-based selection of patients with GE who underwent stool PCR may have introduced selection bias, as PCR positivity can reflect carriage or inactive infection. Third, regional outbreaks in 2021 accounted for a large proportion of cases and may have overrepresented specific serotypes/exposure factors. Fourth, information on the return visits was collected only within our hospital and may have been underestimated compared to the actual figures. Finally, because multivariate adjustment was not performed, confounding factors related to comorbidities, timing of presentation, or testing practices may persist (17,18).

In summary, the children with NTS GE who visited the ED had lower acuity, shorter EDLOS, no ICU hospitalization, and were more often characterized by fever, hematochezia, and ceftriaxone monotherapy, compared with the adults with the same disease. These findings highlight the generally favorable outcome of NTS GE in children, and support conservative management with judicious antibiotic use. Further research is needed to confirm these patterns and to inform evidence-based management strategies.