上海交大罕见肝炎病毒感染与传播机制研究取得进展

　　

生物通报道，上海交通大学农业与生物学院人兽共患病与比较医学华修国团队在戊型肝炎的感染与传播机制上的研究取得新进展，相关成果Hepatitis E Virus Infection in Central China Reveals No Evidence of Cross-Species Transmission between Human and Swine in This Area公布在PLoS One上。

 

戊型肝炎（HE）过去称为肠道传播的非甲非乙型肝炎。1989年Reyes氏等应用分子克隆技术，获得本病毒的基因克隆，并正式命名为戊型肝炎病（HEV）。其基因组为单股正联RNA，全长7.6kb,核苷酸链自5'端起按功能依次分为5'非编码区，ORF1，ORF3，ORF2，和3'非编码区。ORF1编码螺旋酶和RNA复制酶，ORF2编码衣壳蛋白，ORF3功能尚待研究。在电子显微镜下HEV的形态和生物学特性类似萼状病毒，因此将HEV归为萼状病毒。

　　

戊型肝炎病毒是一种人兽共患病病原体，对人畜健康和公共卫生构成潜在威胁。目前世界上已有多个国家和地区报道戊型肝炎病毒（HEV）在人群和猪群之间跨种感染传播。

 

上海交大华修国带领的研究小组通过对我国中部部分地区普通人群和猪群的多个HEV毒株基因组部分测序和系统进化分析，发现该地区人源和猪源HEV毒株在遗传关系上分别属于不同基因亚型，其人群戊型肝炎感染源并非来源于猪群，进而揭示了HEV存在着跨种间传播以外的特异种间传播方式。

 

本研究揭示了特定地域、环境、气候、人群、生活习性等因素均可能导致戊型肝炎病毒感染与传播方式多样性存在，这一研究成果可为进一步深入研究HEV分子流行病学、生态学及综合防控提供科学依据。

（生物通 小茜）

生物通推荐原文检索

Hepatitis E Virus Infection in Central China Reveals No Evidence of Cross-Species Transmission between Human and Swine in This Area

【Abstract】

Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Swine stands out as the major reservoir for HEV infection in humans, as suggested by the close genetic relationship of swine and human virus. Since 2000, Genotype 4 HEV has become the dominant cause of hepatitis E disease in China. Recent reports showed that genotype 4 HEV is freely transmitted between humans and swine in eastern and southern China. However, the infection status of HEV in human and swine populations in central China is still unclear. This study was conducted in a rural area of central China, where there are many commercial swine farms. A total of 1476 serum and 554 fecal specimens were collected from the general human and swine populations in this area, respectively. The seroepidemiological study was conducted by enzyme-linked immunosorbent assay. Conserved genomic sequences of open reading frame 2 were detected using reverse transcription-PCR. The results indicated that the overall viral burden of the general human subjects was 0.95% (14/1476), while 7.0% (39/554) of the swine excreted HEV in stool. The positive rate of anti-HEV IgG and IgM in the serum samples was 7.9% (117/1476) and 1.6% (24/1476), respectively. Phylogenetic analysis based on the 150 nt partial sequence of the capsid protein gene showed that the 53 swine and human HEV isolates in the current study all belonged to genotype 4, clustering into three major groups. However, the HEV isolates prevalent in the human and swine populations were classified into known distinct subgenotypes, which suggested that no cross-species transmission between swine and humans had taken place in this area. This result was confirmed by cloning and phylogenetic analysis of the complete capsid protein gene sequence of three representative HEV strains in the three major groups. The cross reactivity between anti-HEV IgG from human sera and the two representative strains from swine in central China was confirmed by Dot-blot assay. In conclusion, although all the HEV strains prevalent in central China belonged to genotype 4, there is no evidence of cross-species transmission between human and swine in this area.

 

华修国、男、1956年7月生，中共党员、博士、教授、博士生导师，享受国务院特殊津贴；教育部高等农林教育教学指导委员会委员、中国兽医内科学会理事、中国兽医外科学会常务理事、中国养犬学会常务理事、中国藏獒学会名誉会长、中国医用胶学会副理事长、上海畜牧兽医学会理事、上海农学会副秘书长、上海交通大学动物医学研究所所长；传染病与预防兽医学重点学科、预防兽医学硕士点、预防兽医学与畜产品安全博士点学科带头人;长期从事人兽共患病、比较医学、模式动物与基因调控、小型猪动物模型等方面的教学、科研工作。 

 

    主持“十一五”国家863生物医药领域重点项目《新发人畜共患附红细胞体病防控共性关键技术的研究》；国家自然基金《红细胞免疫异常与附红细胞体感染与发病发生的研究》；科技部“十五”重点攻关项目《中国小型猪资源开发与利用》；国家科技支撑计划子课题《华东地区影响奶业生产的共性关键技术—奶牛热应激综合症和奶牛乳房炎.子宫内膜炎防治技术的研究》以及上海市科委《附红细胞体病分子流行病学和综合防治技术研究》,《猪戊型肝炎阻断技术研究》等国家和省部级重大重点科研项目10余项。