2011年4月份,河北省某地一些鸭场饲养的20~45日龄的樱桃谷肉鸭发生了以腹腔中充满大量清亮、茶色或啤酒样腹水为主要病变特征的疾病,即鸭腹水综合征。采集两个不同日龄的病死鸭肝脏样品,接种SPF鸭胚进行病毒分离,获得两个病毒分离物(HB01和HB02)。这两个病毒分离物对鸡、鸭和鹅的红细胞均无血凝活性。RT-PCR或PCR检测表明,HB01和HB02中鸭肝炎病毒检测为阳性,而鸭呼肠孤病毒、鸭圆环病毒、鸭黄病毒等检测均为阴性。将HB02接种5日龄SPF鸭,致死率为40%;对20日龄的鸭不致死。HB02分离物中鸭肝炎病毒的序列分析表明其与鸭肝炎病毒NA株及弱毒疫苗株C80和F64遗传距离较近。根据试验结果,推测鸭肝炎病毒可能是诱发本次鸭腹水综合症的因素之一。
In April 2011,a duck ascites syndrome was found in 20-45 day-old Cherry Valley ducks in some duck farm of Hebei province.This disease was characterized by the abdominal cavity filled with a clear,dark brown or beer-like ascites.Two virus isolates named HB01 and HB02 were isolated from duck liver samples which were from two different day-age ducks.This two virus isolates had no hemagglutinating activity with chicken,duck and goose red blood cells.RT-PCR or PCR results showed that Duck hepatitis virus type 1 could be detected in HB01 and HB02,but other eight kinds of duck virus not.Four out of ten ducks died within one week postinoculation when 5 day-old SPF ducks were challenged with HB02,while no ducks died in 20 day-old SPF ducks group.Phylogenetic and evolutionary analysis revealed that HB02 had a close relationship with NA,C80 and FC64 strains based on the alignment of the full genome sequence of different strains.According to the above results,we deduced that duck hepatitis virus(including some vaccine virus) could be one of the important factors to induce duck ascites syndrome occurred in some duck farms of Hebei Prorince this year.