College of Animal Science and Technology, Shandong Agricultural University, Sino-German Cooperative Research Centre for Zoonosis of Animal Origin Shandong Province, Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, 61 Daizong Road, Taian, 271000, Shandong Province, China.
Taian Daiyue District Administrative Examination and Approval Service Bureau, Taian, 271018, Shandong Province, China.
BMC Vet Res. 2022 Jan 25;18(1):56. doi: 10.1186/s12917-021-03079-2.
Avian hepatitis E virus (HEV) is the pathogenic agent of big liver and spleen disease (BLS) and of hepatitis-splenomegaly syndrome (HSS) in chickens, which have caused economic losses to the poultry industry in China. In this study, 18 samples of BLS chickens were collected to reveal the molecular epidemiological characteristics of avian HEV in the province of Shandong, China.
Gross and microscopic lesions of clinical samples were observed; then, virology detection and genetic analysis of avian HEV were performed. The results showed that there was significant swelling and rupture in the liver and that the spleen was enlarged. Microscopic lesions demonstrated obvious hemorrhage in the liver, with infiltration of heterophilic granulocytes, lymphocytes, and macrophages, as well as the reduction of lymphocytes in the spleen. Eleven of the 18 samples were positive for avian HEV, with a positive rate of 61.11%. More importantly, all avian HEV-positive samples were mixed infections: among these, the mixed infections of avian HEV and chicken infectious anemia virus (CIAV) and avian HEV and fowl adenovirus (FAdV) were the most common. Furthermore, the genetic evolution analysis showed that all avian HEV strains obtained here did not belong to the reported 4 genotypes, thus constituting a potential novel genotype.
These results of this study further enrich the epidemiological data on avian HEV in Shandong, prove the genetic diversity of avian HEV in China, and uncover the complex mixed infections of avian HEV clinical samples.
禽戊型肝炎病毒（HEV）是导致鸡大肝大脾病（BLS）和肝炎脾肿大综合征（HSS）的病原体，这两种疾病在中国的家禽业造成了经济损失。在本研究中，收集了 18 份 BLS 鸡样本，以揭示中国山东省禽 HEV 的分子流行病学特征。
观察了临床样本的大体和显微镜病变；然后，对禽 HEV 进行了病毒学检测和遗传分析。结果表明，肝脏明显肿胀和破裂，脾脏肿大。显微镜病变显示肝脏明显出血，有嗜中性粒细胞、淋巴细胞和巨噬细胞浸润，脾脏淋巴细胞减少。18 份样本中有 11 份为禽 HEV 阳性，阳性率为 61.11%。更重要的是，所有禽 HEV 阳性样本均为混合感染：其中，禽 HEV 与鸡传染性贫血病毒（CIAV）和禽 HEV 与禽腺病毒（FAdV）的混合感染最为常见。此外，遗传进化分析表明，本研究获得的所有禽 HEV 株均不属于已报道的 4 种基因型，因此构成了一种潜在的新型基因型。
本研究结果进一步丰富了山东禽 HEV 的流行病学数据，证明了中国禽 HEV 的遗传多样性，并揭示了禽 HEV 临床样本的复杂混合感染。
