Objective To analyze the epidemiological status, serotypes, and drug resistance characteristics of Vibrio parahaemolyticus in foodborne disease surveillance in Wenzhou from 2016 to 2024, and to provide scientific evidence and data support for the prevention and control of Vibrio parahaemolyticus infections.

Methods A total of 45 980 stool or anal swab samples were collected from patients with vomiting and diarrhea as the main symptoms and a history of consuming suspicious food at medical institutions at all levels in Wenzhou from 2016 to 2024. Isolation, identification, and drug susceptibility testing were performed. Case information was collected through the National Foodborne Disease Surveillance Reporting System. The Cochran-Mantel-Haenszel (CMH) chi-square test was used to analyze the detection rates among groups.

Results Among the 45 980 suspected samples, 2 821 were positive for Vibrio parahaemolyticus, with an overall detection rate of 6.14%. A comparison of detection rates across different population groups revealed that the highest rates were found among adults aged 20‒39 (8.57%, 1 603/18 697) and among farmers and workers (7.93%, 994/12 537). A comparison of detection rates across different seasons revealed that the detection rates were higher from June to October (5.12%, 9.04%, 15.04%, 14.68%, and 7.80%, respectively), peaking in August. Analyses of the sampling results for suspect foodstuffs revealed that aquatic products and their derivatives accounted for the highest proportion (42.86%). Regarding the setting of food consumption, the household accounted for 44.53% (1 257/2 821). From 2016 to 2020, the predominant serotype was O3:K6 (28.82%, 813/2 821), followed by O10:K4 (28.25%, 797/2 821) and O4:KUT (23.61%, 666/2 821). In terms of drug resistance, the resistance rate to cefazolin was the highest at 84.15% (393/467), and the multi-drug resistance rate was 6.21% (29/467).

Conclusion From 2016 to 2024, patients with suspected foodborne illnesses in Wenzhou City experienced a peak in Vibrio parahaemolyticus infections during the summer and autumn months (June to October). Young adults aged 20‒39, as well as farmers and manual workers, were the key target groups for the prevention and control of Vibrio parahaemolyticus infections. The predominant serotype of Vibrio parahaemolyticus shifted from O3:K6 to O10:K4. Vibrio parahaemolyticus exhibited a high level of resistance to cefazolin. It is essential to strengthen surveillance of the epidemiological trends of the predominant serotype, monitor changes in the antibiotic resistance of Vibrio parahaemolyticus, enhance health education for key populations, and intensify regulatory inspections of high-risk foods such as aquatic products and their derivatives.