Purpose: This study evaluated the potential to improve public health outcomes (reduction of the number of Salmonella-related illnesses and outbreaks) by enumerating Salmonella in ground turkey products with the goal of focusing control measures on levels of contamination associated with outbreaks.
Methods: A risk assessment model was developed to estimate the national occurrence of Salmonella infections attributable to ground turkey, based on current human salmonellosis incidence, data on prevalence, and enumeration of Salmonella in ground turkey products, patterns of ground turkey consumption, and dose-response models for infection. Model parameters were estimated from published data. The impact of removing product contaminated at one colony forming unit (CFU) of Salmonella per gram of ground product from the fresh and frozen distribution chain was evaluated. Outbreak-specific attack rates associated with FSIS recall data were used to validate model estimates.
Results: The model estimated a median of 1,301 Salmonella infections per year. This would result in 45 Salmonella cases reported to public health officials, with an upper bound exceeding 4,000 cases. The net effect of removing lots with > one CFU/g contamination was a 21% reduction in median cases and an 82% reduction in the estimated upper bound of reported cases. At this threshold level of contamination, only two Salmonella infections and no reported cases would be expected from distribution of a single 2,000 pound lot of contaminated product. Distribution of at least 70 such lots would be required to produce a detectable cluster of reported cases.
Significance: The model demonstrated the relationship between levels of Salmonella in ground turkey products and public health outcomes, including the recognition of potential foodborne outbreaks.