胰腺型鸭1型甲肝病毒人工感染雏半番鸭的组织病理学观察

Histopathological Changes in Mule Ducks Infected with Pancreatitis-type Duck Hepatitis A Virus Type 1

为明确胰腺型鸭1型甲肝病毒(DHAV-1)感染雏半番鸭的组织病理变化特征,以胰腺型DHAV-1感染10d半番鸭,结果显示雏半番鸭感染后眼观病变为胰腺出血、发黄,而肝脏未见明显出血;采集样品后制备组织切片,镜检观察发现,胰腺上皮细胞大面积坏死,细胞呈颗粒状变性和坏死,组织结构疏松,坏死区域看不到血管结构;肝小叶间小静脉血管周围富集的淋巴细胞和肝细胞形成规则的腺管状结构,肝细胞呈局灶性变性,嗜碱性细胞增多和炎性细胞浸润;脾脏有坏死灶,白髓淋巴细胞明显减少,异嗜性白细胞浸润,脾小体结构模糊不清。以上结果表明,雏半番鸭感染胰腺型DHAV-1后病变以胰腺出血、发黄为特征,胰腺上皮细胞大面积坏死,细胞呈颗粒状变性和坏死。

Ecchymotic haemorrhage in enlarged livers always serve as an important diagnostic marker for duck viral hepatitis. Recently, a novel duck hepatitis, characterized by yellowed or hemorrhagic panereatitis, has emerged in some duck farms and the causative agent, named as pancreatitis-type DHAV-1 has been isolated. To elucidate the pathological characteristics of the novel duck hepatitis in mule ducks, ten-day-old mule ducks were infected with pancreatitis-type DHAV-1 and the pathologic characteristics of disease were observed. The results showed that gross lesion of yellowed or hemorrhagic panereatitis, without overt change in liver, was observed in infected ducks. Microscopy showed large areas of necrosis in the epithelium, granular degeneration and necrosis in pancreatic cells with no vascular structure were found in necrotic pancreatic areas. In liver, a regular glandular structure around the hepatic venules was formed with lymphocytes and hepatocytes along with focal degeneration, with increase of basophils and infiltration of inflammatory cells found in livers. Focal necrosis was presented in spleen where the white pulp lymphocytes number decreased significantly, and the heterophil infiltration contributed the blurred splenic corpuscle. Based on the above, the results suggested that the gross lesions of pancreatic-type DHAV-1 infection in ducklings were characterized by yellowed or hemorrhagic pancreatitis, and the histopathological leisons by large areas of necrosis of the pancreatic epithelium along with granular degeneration and necrosis in pancreatic cells.