疑有禽白血病病毒混合感染的肉种鸡大肝大脾病

山东某父母代肉种鸡开产后死淘率突然升高，死亡鸡肝脏、脾脏、腺胃等内脏器官肿大，高峰期周产蛋率仅为72%，明显低于同场区未发病鸡群的83%，更显著低于其标准产蛋率（87%）。利用RT-PCR技术对肿大的脏器分别进行分子病原学诊断，禽网状内皮增生症病毒、戊型肝炎病毒和马立克氏病毒等PCR检测结果阴性，而ALV pol基因检测阳性，经测序与GenBank 已发表的ALV E 亚群毒株的核苷酸同源性高达97.5%-99.5%。血清学检测证实， ALV-AB亚群在发病前阳性率为8.3%，而发病后的抗体阳性率则攀升为70%。鸡群发病后的种蛋蛋清p27抗原检测ALV阳性率为5.3%。综上所述，鸡群可能混合感染ALV。

A big liver and spleen disease case report about suspected co-infection with ALV in broiler breeders

This paper discussed the pathogen of a parent broiler breeder in Shandong province, which just produces less eggs when the sudden death rate increased, body weight loss, low productivity, organs enlargement, and even white tumor nodules in the liver, spleen, and stomach et al. The peak of the week laying rate averages only 72%, significantly lower than the same field area unaffected reared chickens laying rate （83%）, more significantly below the standard strains laying rate （87%）. Rapid diagnosis by RT-PCR technique directly on the tumor tissue ALV pol gene-specific molecular etiological diagnosis was conducted, and the results confirm that the PCR test was positive, which was confirmed by sequencing later. Combined sequences with GenBank published ALV references, the strains with different subtypes of ALV homology between 97.5% -99.5%, relatively conservative. Phylogenetic analysis showed that the majority of virus and ALV subgroup E strains in the same branch. Other while, REV, hepatitis E virus and Marek＆#39;s disease virus and others were all negative. Serological tests confirmed that ALV-AB subset in the pathogenesis of the positive rate was 8.3%, while the positive rate of antibody after the onset of has risen to 70%. The positive rate of p27 antigen detection ALV chicken group after the onset of egg was 5.3%. In summary, the chickens may be mixed co-infection of ALV.