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.     

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。     

动物戊型肝炎病毒(HEV)RT-nPCR检测方法的建立及应用

根据戊型肝炎病毒(HEV)的4个基因亚型,寻找其保守序列ORF2,成功设计了一套以Ⅰ、Ⅳ型为主兼顾Ⅱ、Ⅲ型的通用简并引物,摸索条件,建立检测动物戊型肝炎病毒反转录套式聚合酶链反应(RT-nPCR)的方法,扩增片段为507 bp。该方法检测所需时间为5 h,灵敏度可达10 pg,特异性强、重复性好;经优化研制了动物戊型肝炎病毒RT-nPCR检测试剂盒,保存期半年以上,该试剂盒可用于动物粪便、胆汁HEV RNA的检测。     

Seroprevalence of Hepatitis E virus infection in the Irish pig population

Background

Hepatitis E is an acute viral disease of humans, occurring in explosive outbreaks in the developing world and as sporadic cases in returning travellers. Increasing recognition of indigenous transmission in Western countries suggests a zoonotic source of infection, most likely pigs. To determine if hepatitis E virus is present in Irish pigs, sera from 330 animals were examined for antibodies using a commercially available ELISA.

Findings

Antibodies were detected in 89 pigs (27%) in 13 herds (81%).

Conclusions

Hepatitis E virus is present in most Irish pig herds and in many animals within these herds.     

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。     

Seroepidemiology of Hepatitis E in Selected Population Groups in Croatia: A Prospective Pilot Study

Hepatitis E has become an emerging infection in many European countries. We analysed the prevalence of hepatitis E virus (HEV) infection in selected population groups in Croatia. Overall HEV IgG seropositivity was 5.6%, while 1.9% participants showed IgM antibodies suggestive of recent infection. No IgM‐positive sample was positive for HEV RNA. HEV IgG antibodies were most prevalent in alcohol abusers (8.9%) and war veterans (8.6%), compared with 6.1% among injecting drug users and 2.7% in healthcare professionals. No individual with high‐risk sexual behaviour tested HEV seropositive. HEV IgG positivity increased significantly with age from 1.8% to 2.3% in individuals younger than 40 years to 11.3% in individuals older than 50 years (P = 0.023). The mean age of HEV‐positive participants was significantly higher than that of HEV‐negative participants (50.9 ± 11.8 years versus 41.2 ± 11.8 years, P = 0.008). Seroprevalence rates were significantly higher in residents of suburban and rural areas compared with residents of urban areas (14.5% versus 2.5%, P = 0.003). Additionally, an increasing prevalence of HEV IgG antibodies was observed from 1.8% in participants living in families with two household members to 12.1% in those living with more than four members (P = 0.046). Gender, marital status, educational level, sexual orientation, source of drinking water, history of blood transfusions, surgical procedures, tattooing and travelling were not associated with HEV seroprevalence. Logistic regression showed that living in suburban/rural areas was the main risk factor for HEV seropositivity (OR = 6.67; 95%CI = 1.89–25.0; AOR = 7.14, 95%CI = 1.89–25.0).     

Hepatitis E Virus Antibody Prevalence in Wildlife in Poland

Hepatitis E is an important public health problem mostly in developing but occasionally also in industrialized countries. Domestic and wildlife animals are considered reservoirs of the hepatitis E virus (HEV). Since no information on the prevalence of autochthonous HEV infections in human and animal in Poland is available, the aim of the study was to investigate the HEV seroprevalence of different wildlife species as potential virus reservoirs in the country. No HEV antibodies were found in any of the sera collected from the red deer (Cervus elaphus), European bison (Bison bonasus), roe deer (Capreolus capreolus), elk (Alces alces), fallow deer (Dama dama), sika deer (Cervus nippon), Tatra chamois (Rupicapra rupicapra tatrica) or brown bear (Ursus arctos). HEV‐specific antibodies were detected in 44.4% (95% CI 38.3–50.7) serum samples originated only from wild boars. The percentage of seropositive wild boars differed significantly between the provinces and was positively correlated with the wild boar density and rurality of the area. This study showed that HEV circulates among wild boar population in Poland, and this species should be considered as an important reservoir of the virus.     

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.     

人与家畜戊型肝炎病毒感染的流行病学关联性调查

为探讨人群戊型肝炎病毒(HEV)感染与家畜HEV感染的流行病学关联性,揭示戊型肝炎发病的危险因素,以134例戊型肝炎患者为病例组进行1∶2配对病例对照研究,对收集与家畜相关的卫生行为资料采用多因素COX回归分析戊型肝炎发病的危险因素,同时采集研究现场的家养猪、鸡粪便、猪胆囊、猪肝、环境水样等进行HEV核酸检测,并对病例和猪肝阳性样本进行基因分析。多因素COX回归分析结果显示,猪类接触史(OR=7.21,95%CI:1.65~31.45)、生食瓜果蔬菜史(OR=2.95,95%CI:1.19~7.36)有统计学意义,研究现场的猪粪、猪胆囊、猪肝HEV核酸阳性检出率分别为10.2%、23.5%、30.8%,其余样本均为阴性。人和猪感染的HEV以基因4型为主,核苷酸同源性89.9%~99.3%。结果表明生猪接触史、生食瓜果蔬菜史是戊型肝炎的危险因素,猪胆囊、猪肝的HEV含量高,猪能通过猪粪排出HEV,本地区人源和猪源HEV同源性高,猪是本地人群HEV的重要宿主动物;应结合戊型肝炎的流行特点开展相关防控工作,加强戊型肝炎防控的健康教育和重点人群的保护。     

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。     

Familial Hepatitis E Outbreak Linked to Wild Boar Meat Consumption

An HIV‐infected patient was diagnosed with acute hepatitis E infection in our hospital. An epidemiological inquiry was performed to collect demographic, food and animal exposure variables in order to identify the potential route of transmission. The patient reported that his family traditionally hunted wild boar for food. All family members were analysed for hepatitis E virus infection. Additionally, route of transmission by wild boar meat consumption and prevalence of HEV infection among wild boar from the same hunting area were investigated. In all‐family members (n = 8), HEV‐RNA was amplified. Two wild boar meat slices consumed was analysed, showing the presence of HEV. The virus isolated was consistent with genotype 3, revealing 100% homology between family members and meat. Additionally, we tested nine wild boar hunted in the same hunting area. All of them were RNA‐HEV positive, isolating the same HEV genotype 3 viral strain. We demonstrated by phylogenetic analysis zoonotic transmission of HEV by wild boar meat consumption. The prevalence of HEV infection among wild boar found in our study suggests that this species is an important route of transmission to human.     

新型鸭肝炎病毒实验感染雏鸭的组织病理学

以“新型鸭肝炎病毒”实验感染雏鸭，对感染雏鸭的组织病理变化进行了观察。结果表明，接毒后24－48h为感染鸭死亡高峰，试验发病的死亡率为80％；感染雏鸭肝、脾、胰、肾的组织病理变化分别表现为出血性、坏死性肝炎，坏死性脾炎，胰局灶性坏死及肾小叶的异嗜性粒细胞浸润。肝、肾组织的脂肪染色结果表明，肝脏有脂肪蓄积，而肾脏未见有脂肪蓄积。     

鸭病毒性肝炎和急性霍乱混感的诊治

通过观察患病麻鸭的生活环境、临床症状、剖检变化、实验室检查，确诊为鸭病毒性肝炎和霍乱，并提出了有效的治疗办法，分析了发病原因及传播途径，以利于提高鸭养殖业的经济效益。     

Hepatitis E Virus Antibodies in Finnish Veterinarians

We investigated hepatitis E virus (HEV) infections in Finnish veterinarians engaged in different practice specialties and evaluated the effect of different background factors on HEV exposure by examining total HEV antibodies in samples collected from the participants of the 2009 National Veterinary Congress in Helsinki, Finland. Finnish veterinarians commonly have total HEV antibodies with seroprevalence of 10.2%. Of the non‐veterinarians, 5.8% were seropositive. Increasing age was associated with HEV seropositivity, and, surprisingly, the highest HEV seroprevalence (17.8%) among veterinarians was detected among small animal practitioners. Although no positive correlation between swine contacts and HEV seropositivity was found, 22.7% of veterinarians who had had needle stick by a needle that had previously been injected into a pig versus 9.0% of those who had not were seropositive, even though the finding was statistically non‐significant (P = 0.07). Our results suggest that, although contact with swine is a known risk factor for HEV infection, the sources of HEV infections are probably numerous, including travelling abroad and possibly also other reservoirs of HEV than pigs.     

Epidemiological Study of Hepatitis E Virus Infection in Pigs in Zhejiang Province

<正>The study was aimed at establishing an indirect ELISA for epidemiological investigation of hepatitis E viral(HEV) infection in pigs from the major pig-producing regions of Zhejiang Province. The gene fragment covering the immunogenic epitopes of HEV ORF2 was synthesized and expressed in Escherichia coli.Western blot analysis revealed that the purified protein reacted to HEV positive sera,but not to positive sera from some other common viruses that infect pigs.An indirect ELISA system was then developed using truncated HEV ORF2 protein as the coating antigen and had diagnostic accuracy of 91.5% as compared with a diagnostic kit for HEV antibodies.A total of 1 330 serum samples were collected from 46 pig farms in Zhejiang Province from 2005-2008 and tested for sero-prevalence of HEV using the indirect ELISA.The average HEV-positive rate was 55.7%(741/1 330).The positive rate of 2005 and 2006 was 62.7%(175/279) and 61.4%(301/490) respectively,much higher than those of 2007(43.0%,59/137) and 2008(48.6%,206/424).Pigs aged 66-100 days had a statistically higher positive rate(58.2%,110/189) when compared to that of pigs aged 30-65 days(39.7%,73/184) or 101-160 days(44.1%,83/188).Only three herds in the study were HEV antibody-negative,indicating high sero-prevalence of HEV in the pig populations in Zhejiang Province.     

Seroprevalence of Hepatitis E Virus in Humans and Geographically Matched Food Animals in Egypt

The aim of current study was to investigate the epidemiology of Hepatitis E virus (HEV) in humans and geographically matched food animals as a novel zoonotic assessment in Egypt. Blood samples were collected from patients who had a history of jaundice and attended to fever and general hospitals. Animal blood samples were collected from cows, buffaloes, sheep and goats convenient to HEV seropositive humans. Enzyme Immuno Assay (EIA) protocol was used to determine IgG anti‐HEV. Sex and pregnancy were investigated as potential risk factors for HEV infection. Of 134 examined humans, 51 (38.1%) were positive for IgG anti‐HEV. The males showed 26.8% seropositivity while the recorded female seropositivity was 50.8%, with a significant difference at P = 0.005, Odds Ratio (OR) = 0.35 at 95% confidence interval (CI): 0.17–0.73. There was a significant difference at P = 0.02 between seropositivity in pregnant (25%) and non‐pregnant women (59.6%); OR was 0.23 (95% CI: 0.06–0.81). Anorexia was the most common symptom whereas paraesthesia and back pain were the least within icteric seropositive HEV humans. Hepatitis E virus seropositivity was recorded in 21.6%, 14%, 4.4% and 9.4% from examined cows, buffaloes, sheep and goats, respectively. The infected food animals were convenient to positive HEV humans who may declare the epidemiological picture of potential zoonotic HEV.     

河南信阳地区肉种鸭病毒性肝炎防疫状况调查

为了解信阳地区肉种鸭病毒性肝炎防疫情况,应用ELISA方法对信阳地区33家规模化鸭场的1127份血样进行了调查分析。结果显示,鸭肝炎抗体平均合格率为67.0%,低于国家70%的群体合格标准,其中潢川县最高,为74.8%,光山县最低,为53.0%。今后,要加强对肉种鸭病毒性肝炎的免疫,以提高对整个鸭群的保护力。