Quantitative risk assessment of nontyphoidal Salmonella in retail pork in China

Nontyphoidal Salmonella (NTS), a major global cause of diarrheal disease, is principally carried by contaminated food, particularly products of animal origin such as poultry and pork. In China, NTS is the primary causative agent of pork-related foodborne illness. This study integrates the largest nationwide surveillance and behavior dataset in China into a unified QMRA framework, providing contextualized risk estimates and revealing a 34.3% contamination rate, with variations across regions and types of pork products. A study on pork consumption behavior helps establish a quantitative risk assessment model from retail to consumption, considering various scenarios such as purchasing, transportation, preparation and consumption. Exposure assessment models simulate NTS growth, reduction, and cross-contamination from retail pork to ready-to-eat food during kitchen preparation. The model predicts average NTS contamination concentrations after different storage methods and cross-contamination scenarios. A Beta-Poisson model estimates the probability of NTS disease daily, resulting in an annual incidence of 2526 cases per million residents. The results of sensitivity analysis indicate that the NTS transfer rate from pork to the cutting board is the most significant factor influencing the probability of NTS contamination with a correlation coefficient of 0.52, followed by the initial contamination level of NTS (r = 0.49). Scenario simulations revealed that intervention involving both producers and consumers, including enhanced retail production standards, and improved consumer cooking practice, could substantially reduce NTS disease risk. These findings provide evidence-based guidance for strengthening pork safety management and consumer food safety education in China.