Epidemiology and Antibiotic Resistance of Foodborne Diseases Among Children in Shanghai: A Four-Year Surveillance Study, 2021–2024

Objective: The primary objective of this study was to examine the epidemiology and antibiotic resistance of food-borne diseases in pediatric populations in Shanghai from 2021 to 2024. Methods: Data were collected from patients presenting with suspected food-borne illnesses at the intestinal clinic of the Children’s Hospital of Fudan University during the period from July 1, 2021 to June 30, 2024. Fresh stool samples from all enrolled patients were analyzed for six pathogens: Salmonella, Vibrio parahaemolyticus, Diarrheagenic Escherichia coli, Campylobacter, Shigella, and Norovirus . Detection of Salmonella, Shigella, Diarrheagenic Escherichia coli and Norovirus was performed using polymerase chain reaction (PCR) methods, while culture assays were utilized for Salmonella, Shigella, Vibrio parahaemolyticus , and Campylobacter . Antimicrobial susceptibility testing of the isolated strains (102 Salmonella and 90 Campylobacter isolates) was performed in accordance with CLSI M100 and M45 guidelines, 2024. Results: A total number of 795 cases were included in the study, revealing an overall positivity rate of 68.3% (543/795). This positivity rate indicates that at least one of the six pathogens tested was positive. The predominant pathogen identified was Diarrheagenic Escherichia coli , which accounted for 49.2% (391/795) of cases. Co-infections were identified in 20.0% (159/795) of the samples analyzed. Salmonella resistance rates were high, at 74.5% for ampicillin and 24.5% for multi-drug resistance. Campylobacter exhibited over 80% resistance to ciprofloxacin and tetracycline; 18.9% of isolates were resistant to all three tested antibiotics. Conclusion: Food-borne pathogens are widely prevalent among children with suspected food-borne illnesses in Shanghai, and the high levels of antibiotic resistance observed in Salmonella and Campylobacter highlight a critical public health concern. These findings underscore the necessity for strengthened surveillance of pediatric food-borne diseases, rational clinical use of antibiotics, and implementation of targeted preventive strategies to reduce the burden of drug-resistant infections in this vulnerable population. Keywords: food-borne diseases, Salmonella , Diarrheagenic Escherichia coli , antimicrobial susceptibility testing