7Drolet R,Larochelle R,Morin M,et al.Detection ratesof porcine reproductive and respiratory syndrome vi-rus,porcine circovirus type 2,and swine influenza virusin porcine proliferative a.
8Li Y,Wang X,Bo K,et al.Emergence of a highly path-ogenic porcine reproductive and respiratory syndromevirus in the mid-eastern region of China[J].Vet J,2007,174(3):577-584.
9Opriessnig T,Meng X J,Halbur P G.Porcine circovir-us type2associated disease:update on current terminol-ogy,clinical manifestations,pathogenesis,diagnosis,and intervention strategies[J.
10Krakowka S,Ellis J A,Mc Neilly F,et al.Activation ofthe immune system is the pivotal event in the produc-tion of wasting disease in pigs infected with porcinecircovirus-2(PCV-2)[J].Vet.
