Department of Veterinary Microbiology, University of Ibadan, 200223 Ibadan, Nigeria.
Department of Infectious Diseases, Division of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Robert Koch Institute, 13353 Berlin, Germany.
Viruses. 2021 May 21;13(6):954. doi: 10.3390/v13060954.
Avian hepatitis E virus (aHEV) is the major etiological agent of hepatitis-splenomegaly syndrome (HSS), big liver and spleen disease (BLSD), and hepatic rupture hemorrhage syndrome (HRHS) in chickens. Infections with aHEV cause a significant decrease in egg production and increased mortality in chickens worldwide. However, studies on the prevalence of aHEV in Nigeria are scarce. In this study, serum ( = 88) and fecal samples ( = 110) obtained from apparently healthy layer chickens from three states in southwestern Nigeria were analyzed by nested reverse transcription-polymerase chain reaction (nRT-PCR) targeting the helicase and capsid gene for the presence of aHEV. Avian HEV was detected in 12.5% ( = 11/88) of serum samples and 9.1% ( = 10/110) of fecal samples tested. Phylogenetic analysis showed that five of the twelve identified aHEV sequences belonged to genotype 2. The remaining seven sequences were only distantly related to other known aHEV isolates. After amplification of the near-complete ORF2 fragment (1618 bp) and part of the ORF1 (582 bp) of isolate YF40_aHEV_NG phylogenetic analysis revealed a nucleotide sequence identity between 79.0 and 82.6% and 80.1 and 83.5%, respectively, to other known aHEV strains, indicating that the Nigerian isolate YF40_aHEV_NG belongs to a novel aHEV genotype. This is the first report of co-circulation of aHEV genotypes in chickens in Nigeria.
禽戊型肝炎病毒（aHEV）是引起鸡肝炎-脾肿大综合征（HSS）、大肝大脾病（BLSD）和肝破裂出血综合征（HRHS）的主要病原体。禽戊型肝炎病毒感染会导致全球范围内的鸡产蛋量显著下降和死亡率增加。然而，关于尼日利亚禽戊型肝炎病毒流行情况的研究却很少。在这项研究中，通过巢式逆转录聚合酶链反应（nRT-PCR）针对螺旋酶和衣壳基因，对来自尼日利亚西南部三个州的 88 份血清样本和 110 份粪便样本进行了分析，以检测 aHEV 的存在。在检测的 88 份血清样本中有 12.5%（11/88）和 110 份粪便样本中有 9.1%（10/110）检测到禽戊型肝炎病毒。系统进化分析表明，在 12 个鉴定的 aHEV 序列中，有 5 个属于基因型 2。其余 7 个序列与其他已知的 aHEV 分离株仅存在较远的关系。在扩增到近全长 ORF2 片段（1618 bp）和 ORF1 的一部分（582 bp）后，对分离株 YF40_aHEV_NG 的系统进化分析显示，其核苷酸序列的同一性分别为 79.0%至 82.6%和 80.1%至 83.5%，与其他已知的 aHEV 株，表明尼日利亚分离株 YF40_aHEV_NG 属于一种新型的 aHEV 基因型。这是尼日利亚首次报告禽戊型肝炎病毒基因型的共同流行。
