Yan B Y, Lyu J J, Feng Y, Wu W L, Liu J Y, Xu A Q, Zhang L
Division of Expanded Programme Immunization, Shandong Provincial Center for Disease Control and Prevention/Shandong Provincial Key Laboratory of Infectious Disease Control and Prevention, Jinan 250014, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2020 Jun 6;54(6):696-701. doi: 10.3760/cma.j.cn112150-20200311-00315.
To understand the genotype distribution and molecular epidemiological characteristics of hepatitis E virus (HEV) isolated in Shandong Province, 2017. The cases of hepatitis E who were reported to the National Notifiable Disease Reporting System (NNDRS) from January to December 2017 in Shandong Province were chosen as the subjects in the study. Epidemiological information and blood samples were collected from 1 045 participants. Both anti-HEV IgM and anti-HEV IgG were detected using ELISA method. Viral nucleic acids were extracted only from those of anti-HEV IgM positive samples. Nested reverse transcription-polymerase chain reaction was carried out to amplify 644 bp nucleotide sequences within HEV open reading frame (ORF) 2 region. The sample sequences together with reference sequences from GenBank were subjected to phylogenetic analysis. In total, 638 (61.1%) cases were detected positive for anti-HEV IgM. The average age of male was (57.9±12.2) years, and the anti-HEV IgM positive rate was 61.5% (496/807). The average age of female was (58.1±15.0) years, and the anti-HEV IgM positive rate was 59.7% (142/238). A total of 163 HEV strains were detected, and the positive rate was 25.6% (163/638). The positive rate of the eastern, central and western region was 23.0% (71/309), 33.6% (72/214) and 17.4% (20/115), respectively. Phylogenetic tree and homology analysis indicated that all isolates belonged to genotype Ⅳ, clustering into four different subgenotype (4a, 4b, 4d and 4h). Subgenotype 4d was predominant, accounting for 85.9% (140 strains), followed by 4b (7.4%, 12 strains), 4a (3.7%, 6 strains) and 4h (3.1%, 5 strains). The 4a, 4b, and 4h subgenotype were mainly detected in the eastern region, accounting for 3/5, 11/12, and 4/6, respectively. The 4d subgenotype was mainly in the middle region, accounting for 50.0% (70/140). The homology analysis showed that the 163 sequences shared 82.7% to 100.0% nucleotide sequence identity with each other. The 140 sequences of HEV 4d strains showed high similarity with swine-origin HEV（KF176351）, cattle-origin HEV（KU904278）and sheep-origin HEV（KU904267）isolated in Shandong Province, and the nucleotide homology was 93.1%-98.3%, 92.7%-97.9% and 92.7%-97.9%, respectively. HEV genotype Ⅳ(4d subgenotype) was dominant in Shandong province. A complicated interspecies transmission might be the main source of human HEV infection in Shandong Province, China.
为了解2017年山东省分离的戊型肝炎病毒（HEV）的基因型分布及分子流行病学特征。选取2017年1月至12月山东省报告至国家法定传染病报告系统（NNDRS）的戊型肝炎病例作为研究对象。收集了1045名参与者的流行病学信息和血样。采用ELISA法检测抗HEV IgM和抗HEV IgG。仅从抗HEV IgM阳性样本中提取病毒核酸。进行巢式逆转录-聚合酶链反应以扩增HEV开放阅读框（ORF）2区域内644 bp的核苷酸序列。将样本序列与来自GenBank的参考序列进行系统发育分析。总共638例（61.1%）抗HEV IgM检测呈阳性。男性平均年龄为（57.9±12.2）岁，抗HEV IgM阳性率为61.5%（496/807）。女性平均年龄为（58.1±15.0）岁，抗HEV IgM阳性率为59.7%（142/238）。共检测到163株HEV毒株，阳性率为25.6%（163/638）。东部、中部和西部地区的阳性率分别为23.0%（71/309）、33.6%（72/214）和17.4%（20/115）。系统发育树和同源性分析表明，所有分离株均属于基因型Ⅳ，聚类为四个不同的亚基因型（4a、4b、4d和4h）。亚基因型4d占主导，占85.9%（140株），其次是4b（7.4%，12株）、4a（3.7%，6株）和4h（3.1%，5株）。4a、4b和4h亚基因型主要在东部地区检测到，分别占3/5、11/12和4/6。4d亚基因型主要在中部地区，占50.0%（70/140）。同源性分析表明，163个序列彼此之间的核苷酸序列同一性为82.7%至100.0%。140个HEV 4d毒株序列与山东省分离的猪源HEV（KF176351）、牛源HEV（KU904278）和羊源HEV（KU904267）高度相似，核苷酸同源性分别为93.1% - 98.3%、92.7% - 97.9%和92.7% - 97.9%。在中国山东省，HEV基因型Ⅳ（4d亚基因型）占主导。复杂的种间传播可能是中国山东省人类HEV感染的主要来源。
