猪戊型肝炎病毒分子生物学与流行病学研究进展

戊型肝炎病毒(Hepatitis E virus,HEV)是20世纪80年代发现的又一新型肝炎病毒,近年来对戊型肝炎病毒病原学、流行病学、实验室诊断、基因结构等方面研究取得了重大进展,本文就HEV的形态、基因分型、分子生物学特性、戊型肝炎(Hepatitis E,HE)的流行病学特点作一简要概述。     

戊型肝炎疫苗研究进展

戊型肝炎病毒(hepatitis E virus,HEV)是一种经肠道传播的非甲非乙型肝炎病毒,1989年在东京国际会议上正式命名,是引起戊型肝炎的病原.戊型肝炎(hepatitis E,HE)以水源性暴发流行和急性散发为特点.有统计结果表明,在发展中国家,50%以上的非甲非乙型肝炎主要由戊型肝炎病毒引起(Lewis等,2006).     

一种新的人兽共患病——猪戊型肝炎研究进展

猪戊型肝炎病毒(Hepatitis E virus,HEV)是导致猪戊型肝炎(HE)的病原体,现在很多国家和地区,如美国、日本、欧洲、中国、中国台湾、印度等都检测出了猪戊型肝炎病毒的抗体,少数国家和地区还有人感染猪戊型肝炎病毒的报道,越来越多的证据表明猪HE是一种人兽共患的传染病。     

戊型肝炎病毒感染检测方法的研究进展

建立针对戊型肝炎病毒(HEV)感染的具有较高敏感性、特异性和稳定性的检验方法,对戊型肝炎(HE)患者和患畜的早期诊断和治疗,以及控制食源性戊肝病毒感染具有重要意义。本文针对目前检测HE病毒及其特异性抗体的不同方法和特点作了综述。     

动物戊型肝炎病毒研究进展

<正>戊型肝炎是一种由戊型肝炎病毒引起的,既往称肠道传播的非甲非乙型肝炎。1983年前苏联学者Balayan等首次用免疫电镜技术从一名志愿受试者粪便中观察到戊型肝炎病毒颗粒。1989年在东京召开的国际会议上,正式将此型肝炎及相关病毒分别命名为戊型肝炎(hepatitis E,HE)和戊型肝炎病毒(hepatitis E virus,HEV)。     

猪戊型肝炎研究进展

戊型肝炎(HE)是由戊型肝炎病毒(Hepatitis Evirus,HEV)引起的一种急性病毒性肝炎,是一种人畜共患传染病。我国各大猪场感染戊型肝炎几率较高,且流行情况复杂,本文对该病的流行情况、     

戊型肝炎病毒研究进展

戊型肝炎(hepatitis E,HE)是由戊型肝炎病毒(hepatitis Evirus,HEV)引起的一种经肠道传播的非甲-非乙型肝炎(ET-NANBH)。戊型肝炎是一种人兽共患病,已成为我国的一个重要公共卫生问题。猪、牛、羊、鸡、狗等动物可能作为戊型肝炎的贮存宿主,在人类病毒性肝炎流行病学中具有重要的地位。本文从戊肝的病原学、基因型、病毒分子生物学、诊断方法、感染动物、流行病学等多方面探讨戊型肝炎的危害及研究现状。     

戊型肝炎病毒动物模型的研究进展

戊型肝炎(HE)是由戊型肝炎病毒(HEV)引起的一种急性的自限性病毒性疾病,主要以粪口途径传播,在全球范围内呈暴发流行或散发传播,目前已被世界卫生组织认定为一个重要的公共卫生疾病。随着对戊型肝炎深入研究,越来越多的HEV动物宿主被证实,这促进了更多动物模型的建立。常见的实验动物模型有非人灵长类动物、猪、兔、啮齿类动物等。HEV动物模型在研究HEV传播、致病机制等方面具有非常重要的意义。本文就近年来HEV动物模型的研究进展进行综述。     

戊型肝炎研究进展

戊型肝炎(hepatitis E,HE)是由戊型肝炎病毒(hepatitis E virus,HEV)引起的一种病毒性人兽共患传染病.自1997年在美国首次从家猪体内发现HEV以来,已确定该病毒能够感染人类以及猪、鹿、兔、骆驼、大鼠等多种动物.HEV通常会导致肝衰竭、慢性肝炎以及肝外神经和肾脏疾病.该病主要通过粪口途径...     

动物感染戊型肝炎病毒的研究进展

70年代末,发现一种类似甲型肝炎的非甲非乙肝炎.1990年Reyes等首先应用分子克隆技术获得该病毒的基因克隆.1998年在东京召开的国际会议上,正式将此型肝炎及相关病毒分别命名为戊型肝炎(hepatitis E,HE)和戊型肝炎病毒(hepatitis E virus,HEV).     

Identification and characterization of viral polypeptides from type-II avian adenoviruses.

The polypeptides of serologically related viruses of hemorrhagic enteritis (HE) in turkeys, marble spleen disease (MSD) in pheasants, and splenomegaly in chickens (SMC) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and analyzed by protein immunoblotting with polyclonal antibodies to HE virus (HEV). The viral polypeptides II, III, IV, V, VI, and VII were detected on SDS-PAGE with the size range from 18 to 97 kDa in HEV. Viral polypeptides II, III, V, VI, and VII were detected in MSD virus and virus of SMC. Protein immunoblotting of viral proteins with anti-HEV serum revealed antigenic differences between the 3 viruses of avian adenovirus type-II examined. The differences were that the polypeptides II, III, IV, V, VI, and VII were identified in HEV and the polypeptides II, V, VI, and VII were identified in MSD virus and virus of SMC. The bands of penton base (polypeptide III) and fiber (polypeptide IV) were seen in HEV only by protein immunoblotting.     

Detection of hepatitis E virus RNA in saliva for diagnosis of acute infection

Diagnosis of acute hepatitis E virus (HEV) infection is established by detection of anti‐HEV IgM antibodies by ELISA or by amplification of serum viral RNA. Here, we evaluate the diagnostic value of testing HEV RNA in saliva to identify patients with acute HEV infection. Prospective proof‐of‐concept study including patients with acute hepatitis. Whole blood and neat saliva samples were obtained from all patients. Saliva samples were processed and analysed for HEV RNA by RT‐PCR within 2 hr after collection. A total of 34 patients with acute hepatitis and 12 healthy donors were included in the study. HEV RNA in serum was confirmed by RT‐PCR in eight of these patients (23.5%; 95% CI: 12.2%–40.2%). HEV was isolated in the saliva of eight of 34 patients (23.5%; 95% CI: 12.2%–40.2%). All patients with HEV RNA amplified in saliva had detectable HEV RNA in serum. HEV was isolated neither in the saliva of any of the 26 patients without detectable HEV RNA in serum nor in healthy donors. Our study suggests that acute HEV infection could be diagnosed by assessing viral load in saliva.     

Natural and experimental hepatitis E virus genotype 3 - infection in European wild boar is transmissible to domestic pigs

Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but sporadic and autochthonous cases do also occur in industrialised countries. In Europe, food-borne zoonotic transmission of genotype 3 (gt3) has been associated with domestic pig and wild boar. However, little is known about the course of HEV infection in European wild boar and their role in HEV transmission to domestic pigs. To investigate the transmissibility and pathogenesis of wild boar-derived HEVgt3, we inoculated four wild boar and four miniature pigs intravenously. Using quantitative real-time RT-PCR viral RNA was detected in serum, faeces and in liver, spleen and lymph nodes. The antibody response evolved after fourteen days post inoculation. Histopathological findings included mild to moderate lymphoplasmacytic hepatitis which was more prominent in wild boar than in miniature pigs. By immunohistochemical methods, viral antigens were detected mainly in Kupffer cells and liver sinusoidal endothelial cells, partially associated with hepatic lesions, but also in spleen and lymph nodes. While clinical symptoms were subtle and gross pathology was inconspicuous, increased liver enzyme levels in serum indicated hepatocellular injury. As the faecal-oral route is supposed to be the most likely transmission route, we included four contact animals to prove horizontal transmission. Interestingly, HEVgt3-infection was also detected in wild boar and miniature pigs kept in contact to intravenously inoculated wild boar. Given the high virus loads and long duration of viral shedding, wild boar has to be considered as an important HEV reservoir and transmission host in Europe.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0121-8) contains supplementary material, which is available to authorized users.     

Seroprevalence of Hepatitis E Virus in Domestic Pigs and Wild Boars in Switzerland

Hepatitis E is considered an emerging human viral disease in industrialized countries. Studies from Switzerland report a human seroprevalence of hepatitis E virus (HEV) of 2.6–21%, a range lower than in adjacent European countries. The aim of this study was to determine whether HEV seroprevalence in domestic pigs and wild boars is also lower in Switzerland and whether it is increasing and thus indicating that this zoonotic viral infection is emerging. Serum samples collected from 2,001 pigs in 2006 and 2011 and from 303 wild boars from 2008 to 2012 were analysed by ELISA for the presence of HEV‐specific antibodies. Overall HEV seroprevalence was 58.1% in domestic pigs and 12.5% in wild boars. Prevalence in domestic pigs was significantly higher in 2006 than in 2011. In conclusion, HEV seroprevalence in domestic pigs and wild boars in Switzerland is comparable with the seroprevalence in other countries and not increasing. Therefore, prevalence of HEV in humans must be related to other factors than prevalence in pigs or wild boars.     

戊型肝炎病毒流行病学研究进展

戊型肝炎（HE）是由肝炎病毒科（hepeviridae）肝炎病毒属（hepevirus）戊型肝炎病毒（hepatitis E virus,HEV）所引起的一种人兽共患传染病,主要经粪—口途径传播。对食源性戊型肝炎病毒感染的预防与控制、异种器官移植及猪源细胞的使用有重要意义。作者就该病近年的流行病概况、传播途径、动物宿主及人工感染试验进行了综述。     

The high prevalence of hepatitis E virus infection in wild boars in Ibaraki Prefecture,Japan

Hepatitis E virus (HEV) is known as a causative agent of zoonosis and food poisoning. Pigs and some species of wild animals, including wild boar, are known to be a reservoir of HEV. In this study, we investigated the situation regarding HEV infection in wild boars in Ibaraki Prefecture, Japan. Serum, liver and feces samples from 68 animals were collected, and the presence or absence of HEV genomic RNA and HEV antibodies were analyzed. The viral genome was detected in samples from 7 (10.3%) animals, with all HEVs classified as genotype 3, subtype 3b. HEV antibodies were detected in samples from 28 (41%) animals. This report demonstrates for the first time the high prevalence of HEV infection in wild boars in Ibaraki Prefecture.     

Virus isolated and immunofluorescence in different organs of pigs infected with hemagglutinating encephalomyelitis virus

Hemagglutinating encephalomyelitis virus (HEV; also designated vomiting and wasting disease virus) was inoculated oronasally in 26 colostrum-deprived pigs. Anorexia and vomition were seen after an incubation period of 4 to 6 days. In pigs killed during the incubation period or within 2 days after the onset of the clinical signs, HEV could be isolated regularly from the tonsils and the respiratory tract, irregularly from the digestive tract, rarely from the blood, and never from lymph nodes and spleen. The brainstem almost always contained virus after clinical signs appeared, but was only one positive during the incubation period. Olfactory bulb, cerebrum, cerebellum, and vagal nerve were also frequently virus positive in pigs which were ill when killed. The results of the examination by immunofluorescent antibody technique indicated that HEV multiplies in the epithelium lining the respiratory tract and the tonsillar crypts, in neuroepithelium of the nasal mucosa, and in neurons of the digestive tract. The neuronotropism of HEV was also shown by the presence of fluorescence in the perikaryon of neurons in the brainstem and in the trigeminal ganglion without the involvement of other cell types. The presence of viral antigens in the perikaryon of trigeminal sensory ganglion cells in pigs killed during the incubation period was considered as positive evidence for viral spread via nerves.     

Preliminary testing in turkeys of the safety and efficacy of a putative haemorrhagic enteritis virus vaccine

Haemorrhagic enteritis virus (HEV) causes clinical haemorrhagic enteritis in young poults and/or subclinical immunosuppression which is often associated with colibacillosis. This disease is controlled with live vaccines worldwide, however, importation of HEV vaccines or cells that support HEV propagation are not permitted in Australia. A major experiment in isolators was conducted to test the safety and efficacy of a putative HEV vaccine. The study had a factorial design with four factors namely vaccination age (28 and 42 days of age), vaccine dose (0, 10⁵, 10⁶, 10⁷ genomic copies of HEV vaccine), challenge with HEV (yes, no) and vaccination‐challenge interval (7, 21 or 42 days). A total of 315 poults were used providing 6‐8 birds per treatment combination. Turkey growth rate, mortality, pathological findings, anti‐HEV antibodies and viral load were examined. Vaccination lead to significant increases in anti HEV antibody over the following 2‐4 weeks. Overall, vaccination with 10⁶ and 10⁷ was protective against increase in relative splenic weight and splenic viral load in challenged birds. Clinical haemorrhagic enteritis was not induced by any treatment but there was an increased incidence of airsacculitis in groups receiving either HEV vaccine or challenge virus compared to the negative control birds (25.8‐29.3% vs. 9.4%, P < 0.05). Growth rate, mortality and relative bursal weight were unaffected by vaccination. This laboratory level study indicates that the putative vaccine is safe and likely to be efficacious, but may cause elevated levels of airsacculitis. These findings require confirmation in larger scale field trials.     

Hepatitis E in southern Vietnam: Seroepidemiology in humans and molecular epidemiology in pigs

Viral pathogens account for a significant proportion of the burden of emerging infectious diseases in humans. The Wellcome Trust‐Vietnamese Initiative on Zoonotic Infections (WT‐VIZIONS) is aiming to understand the circulation of viral zoonotic pathogens in animals that pose a potential risk to human health. Evidence suggests that human exposure and infections with hepatitis E virus (HEV) genotypes (GT) 3 and 4 results from zoonotic transmission. Hypothesising that HEV GT3 and GT4 are circulating in the Vietnamese pig population and can be transmitted to humans, we aimed to estimate the seroprevalence of HEV exposure in a population of farmers and the general population. We additionally performed sequence analysis of HEV in pig populations in the same region to address knowledge gaps regarding HEV circulation and to evaluate if pigs were a potential source of HEV exposure. We found a high prevalence of HEV GT3 viral RNA in pigs (19.1% in faecal samples and 8.2% in rectal swabs) and a high HEV seroprevalence in pig farmers (16.0%) and a hospital‐attending population (31.7%) in southern Vietnam. The hospital population was recruited as a general‐population proxy even though this particular population subgroup may introduce bias. The detection of HEV RNA in pigs indicates that HEV may be a zoonotic disease risk in this location, although a larger sample size is required to infer an association between HEV positivity in pigs and seroprevalence in humans.