Study On Epidemiology And Pathology Of PCV2 Of Newborn Piglets In Hunan Province

Porcine Circovirus type II is one of the most important pathogens related to Porcine Circovirus associated diseases (PCVAD). PCV2 can exist for a long time in natural environment. This pathogen can spread through maternal-neonatal transmission, semen, secretion and feces. Subclinically infected animals can transmit virus to health animals. In order to investigate the pathology and epidemiology of PCV2 in newborn piglet in Hunan province. Main research and findings include the following:1.The epidemiology of PCV2 in Hunan provinceIn this study,158 tissue sample have been collected from different area in Hunan province. Detection of PCV2 for tissues sample by PCR, the result showed that 36% (57/158) piglets were infected with PCV2. Full length gene of PCV2 has been amplified,1 strain of PCV2a and 56 strains of PCV2b have been sequenced, PCV2b is the predominant genotype in Hunan province.2.Pathology of PCV2 in newborn pigletTwo negative for PCV2 sows have been challenged with KJ867555, which divided from clinical materials. The histopathological result in newborn piglets showed that moderate to severe lymphocyte depletion, macrophage infiltration, hemorrhage has been found in lymph node; the ratio of red pulp was expanded, contrast to white pulp shrunk; alveolar walls are enlarged and hemorrhage of lung; congestion amd lymphocyte infiltration in hepatic cord; apoptosis of renal tubular epithelial cell nucleus; cardiac muscle fiber was broken and lymphocyte infiltration.3.Distribution of PCV2 in different tissuesThe IHC result showed that positive signal mainly in the cytoplasm in plasmcytes, macrophages or monocytes in immune organ that positive rate was higher than other tissues. Positive signals of PCV2 distributed in epithelial cell in renal and lung. Pathological change in different tissues corresponds to which were virus infection and reproduction..Conclusion:PCV2b is the predominant strain in Hunan province. Pathology of PCV2 in newborn piglet and finish swine herds is similarly.