In order to verify the correlation between the seropositivity and the infectivity of the meat, will be positive-known companies can be selected and monitored: there will be piglet from weaning to slaughter are serologically tested monthly. At slaughter will be taken in tissue samples from the animals sero which will then be tested by means of qPCR for the presence of tissue cysts. From the PCR positive salen the infecting T. gondiistarn will be isolated by bio-assay so that this drop can be once gegenotypeed.