Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu city, Sichuan, China.
Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan, China.
Transbound Emerg Dis. 2018 Feb;65(1):10-15. doi: 10.1111/tbed.12741. Epub 2017 Oct 27.
Duck hepatitis A virus (DHAV) is the most common aetiologic agent of duck virus hepatitis (DVH), causing substantial economic losses in the duck industry worldwide. In China, officially approved DHAV-1 live-attenuated vaccines have been used widely to vaccinate breeder ducks since 2013. However, following the reports of DVH outbreaks, it has become necessary to assess the epidemiological situation of this virus in China. We conducted molecular epidemiological analyses of 32 DHAV field isolates while analysing the samples from ducks suspected of having hepatitis collected from commercial duck farms in China between May 2010 and December 2015. Considerable changes were observed in the epidemiology of DHAV-1 and DHAV-3 in China over time. A higher number of DHAV-1 strains were isolated during 2010-2012, coinciding with the widespread use of officially approved DHAV-1 live vaccine strains beginning in 2013. In contrast, a higher rate of DHAV-3 causing DHAV infections was observed between 2013 and 2015. Phylogenetic analyses based on the full-length VP1 gene were performed on these field isolates and using reference strains available in GenBank. DHAV-1 field isolates were evaluated in two groups: one group closely related to prototype strains and circulating in China between 2010 and 2012 and another group exhibiting genetic and serological differences from prototype strains. All DHAV-3 strains isolated in this study were grouped as monophyletic, which has become the predominant viral type, particularly in Shandong and Sichuan provinces, since 2013. In conclusion, these data provide updated information on the genetic and serological diversity of DHAV-1 and DHAV-3, and our findings may serve as a foundation for the prevention of, and vaccine development for, DHAV in China.
鸭甲型肝炎病毒（DHAV）是鸭病毒性肝炎（DVH）最常见的病原体，在全球养鸭业造成了巨大的经济损失。在中国，自 2013 年以来，已正式批准使用 DHAV-1 活疫苗对种鸭进行免疫接种。然而，随着 DVH 爆发的报道，有必要评估该病毒在中国的流行情况。我们对 2010 年 5 月至 2015 年 12 月期间从中国商业鸭场收集的疑似肝炎鸭样本进行了 32 株 DHAV 田间分离株的分子流行病学分析。随着时间的推移，DHAV-1 和 DHAV-3 在我国的流行病学发生了很大变化。2010-2012 年分离到的 DHAV-1 株较多，这与 2013 年开始广泛使用正式批准的 DHAV-1 活疫苗株相吻合。相比之下，2013 年至 2015 年期间，DHAV-3 引起的 DHAV 感染率较高。对这些田间分离株和 GenBank 中可用的参考株进行了基于全长 VP1 基因的系统进化分析。DHAV-1 田间分离株分为两组：一组与原型株密切相关，2010 年至 2012 年在中国流行，另一组与原型株在遗传和血清学上存在差异。本研究分离的所有 DHAV-3 株均聚为一类，自 2013 年以来，特别是在山东和四川，已成为主要的病毒类型。总之，这些数据提供了 DHAV-1 和 DHAV-3 的遗传和血清学多样性的最新信息，我们的研究结果可能为中国 DHAV 的预防和疫苗开发提供基础。
