猪繁殖与呼吸综合征病毒变异株自然感染病例的病理分析

Pathology study on the natural infection by a variant strain of Porcine reproductive and respiratory syndrome virus

为探讨猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)变异毒株的致病特点,为其发病机制研究提供重要资料。对临床感染病例的肺脏、脾、肾、淋巴结等组织进行了显微和超微病理结构变化的观察。PRRSV变异毒株的病理损伤以间质性肺炎和全身性急性淋巴结炎为特征,伴有肝、脾、肾、心脏、胃和肠等器官的变性坏死;肺泡巨噬细胞、淋巴结及脾脏中的淋巴细胞和浆细胞均被不同程度的感染,并含有大量病毒包涵体。研究表明,PRRSV变异毒株的组织嗜性与中国典型毒株ch-1a相比已有较大的改变,其感染会引起全身性免疫抑制。

In order to explore the pathological characters and pathogenesis of PRRSV variant strain,the microstructure and ultramicrostructure of lung,spleen,kidney and lymph node of piglets infected with PRRSV were studied.The results showed that the major pathological characters of PRRSV variant strain were interstitial pneumonia and adenolymphitis,accompanied by the degeneration and necrosis of liver,spleen,kidney,heart,stomach and intestine.Alveolar macrophages,lymph nodes and lymphocytes and plasma cells in spleen were infected with different degrees,where a large number of viral inclusion bodies were found.The results indicated that the tissue tropism of PRRSV variant strain,compared with the typical strain ch-1a in China,showed great changes and the infection could cause systemic immunosuppression.