Retrospective Study Evaluating Seroprevalence of Hepatitis E Virus in Blood Donors and in Swine Veterinarians in Italy (2004)

Hepatitis E is an emerging viral disease in developed countries, with sporadic cases occasionally linked to the consumption of raw or undercooked pork, wild boar or deer meat. Cases due to transfusion or transplantation have also been reported. In developed countries, hepatitis E is considered a zoonosis and pig is the main reservoir. In the last few years, several studies conducted in Europe reported variable seroprevalence rates among the general population, ranging between 0.26% and 52.5%. A higher seroprevalence was described among workers who come in contact with pigs. The aim of this retrospective study was to evaluate the seroprevalence of anti‐HEV IgG and IgM antibodies in blood donors (170) and in pig veterinarians (83). Archival sera were collected in Italy in 2004. The observed seroprevalence was 9.64% and 8.82% in veterinarians and blood donors, respectively. Overall, only three sera from blood donors were positive for IgM, but no HEV‐RNA was detected.     

戊型肝炎病毒的研究进展

戊型肝炎病毒是一种RNA病毒,主要引起急性传染性肝炎,该病毒不仅可以感染人,而且有多种动物可以作为其自然宿主。文章从病原学、流行病学、检测方法及其疫苗的研制几个方面对其进行了综述。     

规模化猪场戊型肝炎病毒感染状况的调查与分析

为调查规模化猪场中戊型肝炎病毒(HEV)感染和流行特征,首先在4个猪场采集血样80份,用酶联免疫吸附试验(ELISA)榆测抗-HEV IgG抗体.在此基础上,作者于2007-2009年采集规模化猪场肛拭子样品415份,及规模化猪场送检的临床病猪肝脏样品135份,应用巢式PCR(RT-nPCR)方法进行HEV RNA检测,将PCR扩增产物测序,利用Neighbour-joining法进行进化分析.结果:4个猪场80份血清中HEV阳性血清56份,抗-HEV抗体阳件率高达60.0%以上.8个规模化猪场中有5个猪场的肛拭子检测到HEV,肛拭子阳性率8.43%(35/415);从临床送榆的发病猪采集的肝脏样品中HEV阳性率为15.55%(21/135);HEV RNA最早检出日龄为7 d,最晚检出日龄为84 d.遗传进化分析表明:测序的38株阳性毒株之间同源性为92%～100%,均属于HEV基因4型.其中,从肛拭子中分离的毒株(FJ445406)与猪源毒株DQ279091株处在同一分支上;而肝脏中分离的毒株(GQ202266.1)和人源毒株处在一个亚支,属于4型巾的同一亚型,表明该毒株与人源毒株亲缘关系较近.本研究表明华中地Ⅸ猪群中普遍存在HEV感染,阳性率较高.本研究为规模化猪场HEV的防控提供了依据.     

猪戊型肝炎病毒的流行病学调查

利用双抗原夹心ELISA对2009-2011年间采自广东省各地区的若干猪场的484份血清样品,进行血清流行病学调查;对69份病猪胆汁样品进行分子流行病学调查,分离得到猪源戊型肝炎病毒(swine hepatitis E virus, swHEV),并基于ORF2部分基因序列进行核苷酸序列比对、相似性分析和遗传进化树分析,以期初步了解广东各地猪群戊型肝炎(hepatitis E, HE)的感染情况和流行特点。试验结果显示,全部被检查猪的swHEV抗体平均阳性率为71.9%(348/484),分离的猪源HEV毒株均属于基因Ⅳ型,阳性率为71.0%(49/69)。调查结果表明基因Ⅳ型swHEV在广东地区普遍流行。     

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。     

猪戊型肝炎病毒结构蛋白片段的表达及其在ELISA中的初步应用

为建立一种快速的猪戊型肝炎病毒抗体检测方法，根据已克隆的戊型肝炎病毒株DQ1结构蛋白基因（ORF2）的抗原性及水溶性分析，在其序列上设计一对引物，上游引物和下游引物分别带有BamHⅠ、HindⅢ酶切位点，用PCR方法扩增，获得369bp大小的相应片段，位于ORF2128—497bp处。将扩增片段克隆到pET-32a构建了原核表达载体pET32a—D001，经测序证明该片段正确插入。将pET32a—D001转化BL21并诱导表达，SDS-PAGE结果显示表达蛋白大小为33ku，Western-blot结果表明表达的蛋白质具有生物活性，将表达蛋白作为诊断抗原，对反应条件进行优化，初步建立了ELISA诊断方法。     

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.     

圈养大熊猫戊型肝炎病毒感染调查

采用ELISA、巢式RT—PCR、免疫组织化学等多种方法对北京动物园保存的大熊猫组织材料和部分现存活个体的粪便、血清等样品进行戊型肝炎病毒抗原调查。调查发现在死亡大熊猫肝脏组织中戊肝病毒抗原阳性检出率为88．9％（8／9）,肾脏的阳性检出率为85．7％（6／7）。现活体动物的粪便、血清抗原检查没有出现阳性结果。结果说明死亡大熊猫曾感染过戊型肝炎病毒,现有个体中没有戊肝病毒感染。     

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.     

河南省猪场戊型肝炎病毒流行病学调查

为了解河南地区猪戊型肝炎感染情况,同时掌握该地区猪感染戊型肝炎病毒的基因型,对来自河南新乡、平顶山、南阳等地区不同商品猪场血清、肝脏、粪样品,采用ELISA技术检测猪血清中抗HEV特异性抗体水平,并使用套式RT-PCR检测肝脏和粪便中猪戊型肝炎病毒核酸。结果显示530份样品中HEV抗体阳性率0.6%,HEV RNA均为阴性,推测目前河南省猪戊型肝炎病毒感染率较低。     

攀西地区山羊戊型肝炎血清流行病学调查

为了解攀西地区山羊戊型肝炎的感染情况及流行特点,本研究利用双抗原夹心ELISA方法对凉山州和攀枝花地区采集的180份山羊血清进行戊型肝炎病毒(HEV)抗体检测.结果显示,攀西地区山羊HEV抗体总阳性率为26.11％ (47/180),其中规模化羊场阳性率为19.26％(26/135),散养羊群阳性率为46.67％(21/45),差异极显著(p＜0.01).按年龄划分,3岁以上、1～3岁、1岁以下阳性率分别为39.22％、23.29％、17.86％,3岁以上与1岁以下山羊HEV抗体阳性率差异极显著(p＜0.01).按性别划分,公山羊和母山羊的阳性率分别为33.74％(28/83)和30.59％(16/85),差异不显著.凉山州(30.93％)与攀枝花市(20.48％)山羊抗体阳性率差异不显著.检测结果表明,HEV在攀西地区山羊群中普遍流行.     

免疫组化法检测大鼠肝脏组织中的乙型肝炎病毒和戊型肝炎病毒

为探讨SD大鼠乙型肝炎病毒(HBV)和戊型肝炎病毒(HEV)的感染情况,本试验采集了53例SD大鼠肝脏,采用免疫组织化学染色、HE染色和Mallory三染色法对上述肝脏样品中的HBsAg、HBcAg和HEV进行了检测,同时对其病理形态学变化进行了观察。结果如下:在53例肝脏样品中有47例呈HBsAg阳性反应,阳性率为88.68%;有38例呈HBcAg阳性反应,阳性率为71.70%;HBV的双阳性率为66.15%,总阳性率为96.23%;而HEV的阳性率为100%。镜下HBsAg阳性反应物在肝细胞胞核、胞浆和胞膜上均有分布,而HBcAg阳性反应物主要分布于肝细胞胞核和胞浆内;HEV阳性反应物分布在肝细胞胞核、胞浆和小叶间胆管上皮中。组织病理学观察结果显示,在上述免疫组化阳性反应肝脏样品的HE染色切片中,均有不同程度的病理变化,主要表现为肝细胞固缩、变性、坏死、中央静脉淤血、淋巴细胞浸润、小叶间胆管增生。Mallory三色染色结果证明有22%的肝脏样品有纤维结缔组织增生。     

Seroprevalence of hepatitis E virus in dogs in Switzerland

Hepatitis E virus (HEV) is the causative agent of an acute and in most cases self‐limiting hepatitis. Of the four major HEV genotypes that infect humans, genotype 3 and 4 are zoonotic and have been identified in humans but predominantly in pigs and wild boar, which are considered the main reservoirs. However, the known host range of zoonotic HEV may be increasing to comprise additional species, including companion animals. Several studies have identified contact with dogs as a risk factor for HEV infection in humans, yet information on the occurrence of HEV in Swiss dogs is lacking. To examine a possible risk of exposure, this study was designed to assess the seroprevalence of HEV in 84 Swiss dogs. Serum and plasma samples collected from four veterinary clinics were screened for HEV‐specific antibodies by HEV‐antibody ELISA test kit. In addition, information of 22 dogs regarding the country of origin, the type of dog feed and any history of hunting was recorded. Samples from seropositive animals were also screened for the presence of HEV RNA by quantitative real‐time RT‐PCR (qRT‐PCR). Overall, 38% (32 of 84) of the dogs tested seropositive for anti‐HEV, indicating exposure to HEV. Among the 22 dogs for which information was available, HEV‐specific antibodies were detected in three of five dogs that were born abroad, in one of two dogs that were fed a raw meat‐based diet, and in one hunting dog. No viral RNA could be detected in any of the serum and plasma samples; thus, the genotype of the strains remained undetermined. This study provides further evidence for canine exposure and susceptibility to HEV and highlights the need to further assess the risks of HEV transmission to humans with contact to dogs.     

四川地区藏猪戊型肝炎病毒的检测和遗传演化分析

旨在调查四川地区藏猪戊型肝炎病毒（hepatitis E virus,HEV）的流行情况和遗传演化,作者用RT-PCR法对2018—2020年采集自四川省甘孜藏族自治州和阿坝藏族自治州的22个藏猪场332份藏猪粪便样本进行HEV检测,并对阳性样本进行基因分型。RT-PCR检测结果表明HEV核酸阳性率为20.48%（68/332,95% CI=16.3%~25.2%）,22个规模藏猪场中HEV猪场阳性率为77.27%（17/22,95% CI=54.6%~92.2%）,健康样本阳性率为2.86%（3/105,95% CI=0.6%~8.1%）,腹泻样本阳性率为28.63%（65/227,95% CI=22.8%~35.0%）,系统进化分析显示所有阳性株均为G4型。为了进一步研究该地区流行毒株的演化过程,以贝叶斯进化分析软件进行分歧时间估算,结果表明,藏猪流行毒株的分歧时间最早为1999年,最晚为2016年。并分别从每年的样本中挑选1份阳性样本得到全基因组序列,核酸序列相似性为89.5%~93.1%。通过对3条全基因组重组分析发现SWU/301/2019存在重组现象,SWU/301/2019重组区域位于ORF1的3 746—4 655 bp。本研究首次对四川地区藏猪源HEV进行调查,结果表明四川藏猪中存在一定程度的HEV感染,为四川地区对藏猪感染HEV的防治以及深入研究四川藏猪源HEV遗传变异及生物学特性提供了参考依据。     

猪戊型肝炎研究进展

猪戊型肝炎是一种新发现的传染病,其病原戊型肝炎病毒(HEV)是一种无囊膜的RNA病毒,基因组全长为7.2 kb~7.4 kb。研究发现,世界上许多国家的猪群中普遍存在较高的HEV抗体,也检测到猪戊型肝炎病毒,与猪接触的职业人群的血清抗HEV抗体均高于非职业人群,有些国家从猪群中分离到的HEV核苷酸序列与当地居民感染的HEV具有高度的同源性。据此认为猪戊型肝炎是一种人兽共患病,猪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,对于公共卫生、异种器官移植和食品安全等构成潜在威胁。     

Hepatitis E virus as an emerging zoonotic pathogen

Hepatitis E outbreaks are a serious public health concern in developing countries. The disease causes acute infections, primarily in young adults. The mortality rate is approximately 2%; however, it can exceed 20% in pregnant women in some regions in India. The causative agent, hepatitis E virus (HEV), has been isolated from several animal species, including pigs. HEV genotypes 3 and 4 have been isolated from both humans and animals, and are recognized as zoonotic pathogens. Seroprevalence studies in animals and humans indirectly suggest that HEV infections occur worldwide. The virus is primarily transmitted to humans via undercooked animal meats in developed countries. Moreover, transfusion- and transplantation-mediated HEV infections have recently been reported. This review summarizes the general characteristics of hepatitis E, HEV infection status in animals and humans, the zoonotic transmission modes of HEV, and HEV vaccine development status.     

2015年-2016年度南宁部分地区猪戊型肝炎病毒基因型分析

为了解广西猪群中戊型肝炎病毒(HEV)基因型,利用套式RT-PCR用对南宁周边猪场采集到的104份新鲜猪粪便进行HEV检测、分离并成功扩增和克隆了11株阳性毒株的ORF2基因部分保守片段.序列测定结果表明,11株HEV ORF2序列自身核苷酸同源性为97.7%~100%,推导编码的氨基酸同源性为97.9%~100%;与4型HEV代表毒株Ch-S-1、Ch-T11、swGX40等的核苷酸同源性为84.6%~90.6%,而与其他各型之间的同源性较低.系统发育进化树结果表明,11株HEV广西株为基因4型,其中,10株HEV为4a亚型,1株毒株为4e亚型.结果表明,广西猪群中流行的HEV均为基因4型,且以4a亚型为优势流行毒株.     

猪源戊型肝炎病毒ORF2部分基因的原核表达及其鉴定

本试验旨在表达猪源戊型肝炎病毒(sHEV)ORF2部分基因片段,纯化表达产物并进行抗原性分析。以sHEV的cDNA为模板,PCR扩增ORF2基因片段,构建重组质粒pET32a-dORF2,转化表达菌BL21,IPTG诱导,SDS-PAGE凝胶电泳和Western blotting进行检测。试验结果表明,获得60 ku的目的蛋白,该蛋白具有良好的抗原性,主要以可溶性形式存在。     

戊型肝炎病毒研究动态

戊型肝炎病毒(hepatitis E virus,HEV)是引起戊型肝炎(hepatitis E,HE)的病原体,主要经粪口途径传播,呈全球分布,戊型肝炎病毒不仅可以感染人类,而且可以跨物种在多种动物中传播。作为一种新的人畜共患病,本文从病原学、流行病学、疫苗研制以及检测方法等方面进行了综述。