Surveillance of Chemical Foodborne Disease Outbreaks in Zhejiang Province, China, 2011-2023

Foodborne diseases are a growing public health problem worldwide, and chemical foodborne disease outbreaks (FBDOs) often have serious consequences. This study aimed to explore the epidemiological characteristics of chemical FBDOs in Zhejiang Province, China, and propose targeted prevention and control measures. Descriptive statistical methods were used to analyze chemical FBDO data collected from the Foodborne Disease Outbreaks Surveillance System in Zhejiang Province from 2011 to 2023. From 2011 to 2023, 74 chemical FBDOs were reported in Zhejiang Province, resulting in 461 cases, 209 hospitalizations, and one death. In contrast to other types of FBDOs, the percentage of hospitalized cases in chemical FBDOs was the highest (45.34%) (chi-square = 1047.9, p < 0.001). Outbreaks caused by nitrite accounted for the largest percentage (56.76%), followed by lead (17.57%). Outbreaks caused by nitrite occurred mainly in households (27), followed by restaurants (6), street stalls (5), and work canteens (3). Among all nitrite-related outbreaks, 59.52% (25/42) were caused by cooking food where it was used as a common seasoning, 26.19% (11/42) by eating pickled vegetables, 7.14% (3/42) by eating cooked meat products, and 4.76% (2/42) by eating grain products. Outbreaks caused by the misuse of nitrite in cooking mainly occurred in households (68%, 17/25), street stalls (16%, 4/25), work canteens (8%, 2/25), and restaurants (8%, 2/25). Outbreaks caused by eating pickled vegetables occurred mainly in households (90.91%, 10/11), and one outbreak occurred in a work canteen. Outbreaks caused by lead (n = 13) occurred in households, and liquor was involved in 12 outbreaks where they were caused by residents consuming yellow rice wine stored in tin pots. In view of the frequent outbreaks of chemical foodborne diseases in our province from 2011 to 2023, a variety of prevention and control measures were proposed based on the research results of the temporal and regional distribution, food and food establishments involved, and the etiological agents of the chemical FBDOs. However, the effectiveness of these recommendations needs to be further verified and studied. In general, public health institutions should further strengthen the surveillance and health education of the population. Individuals should store toxic chemicals, such as nitrates, pesticides, and rodenticides correctly to avoid poisoning by ingestion. In view of the chemical FBDOs caused by food in the catering and distribution links, relevant departments should strengthen targeted supervision.