Design of a Risk based Control System for Toxoplasma gondii in a pork supply chain

Toxoplasma gondii is recognized as one of the major foodborne pathogens. The European Food Safety Authority (EFSA) concluded that T. gondii is one of the public health hazards in pigs to be covered within a modern meat inspection and advised to include serological testing of pigs and audits of pig farms to control T. gondii. A project is presented that develops a framework where this idea is practically implemented in a pork supply chain. The aim of the program is to reduce the contribution from the pork chain to the human toxoplasmosis disease burden. In the pilot at least one blood sample per batch at delivery at the slaughterhouse is tested with a Toxoplasma Elisa. With this screening 20 (1%) high risk herds were identified. These high risk farms and their controls, 2 per high risk farm, were followed up. More samples of risk farms and their controls were collected to get a better estimate of the within herd prevalence and to follow the development of serology over time. Additional MC-PCR was performed on hearts of pigs from these herds to confirm presence of infection, tissue cysts. Also farm assessments were done to verify the presence of risk factors at the identified farms. In the first farm where hearts were tested by PCR the presence of toxoplasma tissue cysts was shown. The results give insight in how risk based approaches with food chain information (FCI) for animals sent to slaughter could work, by substantiating how risk herds can be practically identified and which interventions are feasible. The results are discussed in the perspective of human health risks.