Porcine circovirus (PCV) is a small, naked DNA virus with diameter of 17 nm and is a member of the Circoviridae family. Porcine circovirus type 2 (PCV2) is nowadays considered as the etiological agent of postweaning multisystemic wasting syndrome (PMWS), a recently described disease of nursery and growing pigs. Moreover, it has been demonstrated that PCV2 often co-infected pigs with other viruses including porcine reproductive and respiratory syndrome virus (PRRSV) or classical swine fever virus (CSF...