Evaluating the Relative Impact of Swine Deep Tissue Lymph Nodes on Human Salmonellosis Due to Consumption of Ground Pork Based on Quantitative Simulation Modeling

Introduction: The consumption of pork products is considered one of the major causes for human salmonellosis throughout the world, among which wholesale fresh ground pork (WFGP) has drawn increasing attention. The inclusion of deep tissue or nonvisceral lymph nodes (DTLNs) contaminated with Salmonella, probably occurring during WFGP processing, may pose risks to public health.

Purpose: This study assessed the relative contribution of DTLNs to human salmonellosis in the United States and investigated the critical control points for reducing the risk.

Methods: A stochastic simulation model was established to quantify the level of risk.

Results: The model predicted an average of 170 cases of salmonellosis with 95% confidence interval from 117 to 223 per 100,000 consumers, annually, due to ground pork consumption. The scenario analysis showed interventions relating DTLNs, such as complete removal of DTLNs during processing, could be associated with a slight reduction in the average number of Salmonella in WFGP (7.4 to 6.3 CFU/serving), but a significant decrease in the prevalence of Salmonella.

Significance : These observations indicate the removal of DTLNs at processing plants might not be as effective as other interventions in reducing the risk.