Quantifying human toxoplasmosis risk from pork consumption in Denmark: A conceptual framework for tissue cyst-based analysis

A quantitative risk assessment model was developed to provide a biologically representative approach to quantify the risk of human toxoplasmosis by using tissue cysts (clusters of infectious bradyzoites) as exposure units, rather than individual bradyzoites. The model with the most recent data on salting and heating, estimated the cumulative prevalence of T. gondii infection in the Danish population to be in the range of 7-15%, depending on the underlying model assumptions. Human infections occurred from consumption of undercooked pork, drycured sausages, and smoked pork. Scenario analyses demonstrated that the model was sensitive to both data on salting and to the model assumptions. Moreover, the risk of infection attributed to consumption of dry-cured sausages was highly uncertain and required careful interpretation. Supported by sensitivity analyses, Beta (1, 2) appears to be the most appropriate prior, as it best represented the prior beliefs on tissue cyst survival probability applied in the model.