Hepatic rupture hemorrhage syndrome in chickens caused by a novel genotype avian hepatitis E virus

Since 2016, severe outbreaks of hepatic rupture hemorrhage syndrome (HRHS) have emerged in chickens in several Chinese provinces and caused huge economic losses to the poultry industry, but the etiological characteristics and pathogenic potential of it has remained unclear. This study sequenced the partial helicase and capsid gene of the potentially novel avian hepatitis E virus (HEV) isolated from chickens with HRHS and tested the pathogenicity of it on SPF chicks, while the appearance of clinical signs, histopathological changes, viral distribution, viremia and viral shedding were monitored for 14 days post-infection (dpi). Analysis revealed that the HRHS related avian HEV belongs to a novel genotype, and infected chicks developed the typical symptoms of HRHS. Thus, this study successfully developed an experimental infection model for studying the pathogenicity and role of the novel avian HEV in HRHS. Meanwhile, the novel avian HEV mainly existed in the liver and spleen, inducing a rapid viremia and chronic viral shedding in infected chicks, and could cause 40% mortality before 14 dpi. In conclusion, this study found the novel genotype avian HEV and confirmed its role in HRHS.