雏鸭混合感染基因A型和基因C型鸭甲肝病毒研究

研究了2013年四川地区某鸭场暴发的基因A型鸭甲肝病毒(DHAV-A)和基因C型鸭甲肝病毒(DHAV-C)的混合感染病例.疾病发生于20~25日龄雏鸭,发病率25%~30%,死亡率为20%~30%,临死前出现明显的神经症状,病死雏鸭肝脏肿大,出血.利用双重RT-PCR从病死雏鸭的肝脏组织中同时检测出DHAV-A和DHAV-C.这是四川省养鸭密集区第一次发现雏鸭混合感染DHAV-A和DHAV-C的情况.此外,对2009~2012年四川省各养鸭密集区鸭甲肝炎流行情况做了调查.一共从四川省养鸭密集区采集312份疑似鸭肝炎样本中检测出120份鸭甲型肝病毒性肝炎.其中基因C型鸭肝炎阳性率为75%,基因A型鸭肝炎仅为25%,未发现基因A型和基因C型混合感染情况.结果说明2009~2012年我省鸭病毒性肝炎以基因C型鸭甲肝病毒为优势病原.2013年,开始出现DHAV-A和DHAV-C混合感染病例.因此如何采取有效措施应对其危害,这应该引起养鸭界及相关部门的高度重视.

Diagnosis of simultaneously infection of duck hepatitis A virus genotype A and duck hepatitis A virus genotype C in duckling

Duck virus hepatitis （DHV） is a fatal and rapidly spreading disease in young duckling. The major pathologic change in infected ducklings is hepatitis. Case of simultaneous infection of DHAV-A and DHAV-C outbreak in ducklings were reported. Twenty to twenty five day old ducklings showed about 25 to 30% morbidity and 20 to 30% mortality. The dying ducklings showed neurological symptoms and the liver of died ducklings swelling and hemorrhagic tbcus. The fragments of DHAV-A and DHAV-C were specific amplified by duplex RT-PCR. This is the first report on the presence of simultaneous infection of these two hepatitis virus in the ducklings in Sichuan province. In addition, the epidemiological survey of duck hepatitis A virus was investigated covering Sichuan duck concentration areas between 2009 and 2012 . 120 duck hepatitis A viral hepatitis were collected from 312 clinical samples, and DHAV-C positive rate of 75%, DHAV-A was only 25%. The results illustrated the dominant pathogen was DHAV-C in Sichuan province. The presence of simultaneous infection of these two hepatitis virus were first reported in the ducklings in Sichuan province in 2013. Therefbre, close attention should be paid to how to take effective measures to deal with the harm.