Research progress in the etiology of hepatitis type E virus / 中华肝脏病杂志

Hepatitis type E virus (HEV) is a significant infectious zoonotic disease that causes hepatitis E. The disease is primarily transmitted via the fecal-oral route through contaminated water or food and is transmissible between species and genera. The causative agent for the disease is the hepatitis type E virus, which is a member of the Hepadnaviridae family and a single-stranded RNA virus. Its 7.2 kb genome mainly contains three open reading frames (ORFs): ORF1 encodes a non-structural polyprotein that mediates viral replication and transcription; ORF2 encodes a capsid protein and free antigen that induce neutralizing antibodies; ORF3 partially overlaps with ORF2 and encodes a small multifunctional protein involved in virion formation and release. HEV has a unique dual life cycle: it is excreted into feces in the form of naked virions but circulates in the blood in the form of "quasi-enveloped" particles. The two kinds of virus particles adsorb and penetrate the host cell in distinct ways, then internalize and decapsulate to replicate the genome, thereby producing more virion and releasing it outside the cell to mediate the virus's spread. This paper reviews the morphological characteristics, genome structure, encoded proteins, and function of HEV virus-like particles in order to provide a theoretical basis for basic research and comprehensive disease prevention and control.

Advances in hepatitis E epidemiology / 中华肝脏病杂志

Hepatitis E is a viral hepatitis that the hepatitis E virus (HEV) causes. In the early 1980s, the hepatitis E virus was first discovered and identified, and it is one of the important pathogens that cause acute viral hepatitis globally. HEV infection is usually self-limiting, but in some groups of populations, such as pregnant women, patients with chronic liver disease, and the elderly, the prognosis is poor and may result in acute or subacute liver failure or even death. In addition, HEV infection can occur in chronically immunocompromised populations. At present, some regions and countries are not paying enough attention to hepatitis E prevention, diagnosis, and treatment, which suggests that we should study the epidemiology of HEV infection.

Hepatitis A and E among immigrants and refugees in Central Brazil

ABSTRACT OBJECTIVE To estimate the prevalence of hepatitis A virus (HAV) and hepatitis E virus (HEV) among immigrants and refugees in Goiás, Central Brazil. METHODS Overall, 355 individuals were interviewed, and blood samples were tested for anti-HAV and anti-HEV IgG. Anti-HEV-positive samples were similarly tested for HEV RNA. RESULTS All participants were from Latin American countries, most of whom, young adult males. The overall anti-HAV IgG prevalence was 87.4% (95%CI: 83.5-90.4), of whom 94.9%, 75.6%, and 60% were from Haiti, Venezuela, and other Latin American countries, respectively (p < 0.001). Age above 19 years and more than 36 months residing in Brazil were associated with a higher prevalence of previous HAV and HEV infection, respectively. Of the children eligible for HAV vaccination according to the National Immunization Program, only eight (44%) had been vaccinated. The overall anti-HEV IgG prevalence was 6.5% (95%CI: 4.4-9.5). All anti-HEV IgG-positive individuals were Haitians, including a child born in Brazil. HEV RNA was detected in two of the anti-HEV IgG-positive samples. CONCLUSION The survey detected a high prevalence of anti-HAV and anti-HEV IgG among immigrants and refugees, and active HEV infection among some Haitian participants. Prevention measures are urgently required to interrupt enteric virus transmission in this emergent and vulnerable population.

High genetic diversity of hepatitis E virus in swine in São Paulo State, Brazil / Diversidade genética do vírus da hepatite E em suínos no estado de São Paulo, Brasil

A hepatite E é uma zoonose emergente que afeta diversas espécies de mamíferos, inclusive o ser humano. É ocasionada por um vírus da espécie Orthohepevirus A que possui diversos genótipos e subgenótipos. No Brasil é descrito o genótipo HEV-3, cujo principal reservatório é o porco doméstico. Testes moleculares e sorológicos demonstram o HEV-3 em diferentes estados, tanto em animais quanto em humanos. No estado de São Paulo, existem diversos estudos sobre a epidemiologia da hepatite E em humanos, mas faltam informações sobre o HEV-3 em suínos. Assim, o objetivo deste trabalho foi verificar a ocorrência de HEV por meio da técnica de RT-PCR e posterior sequenciamento em um banco de amostras de fezes de suínos colhidas entre 2008 e 2009, na região metropolitana de Campinas. Das 89 amostras analisadas, foi possível detectar o HEV-3 em sete e, pela reconstrução filogenética, foram encontrados os subgenótipos HEV-3b, HEV-3h, e HEV-3j. Uma amostra disponível no GenBank, proveniente de São Paulo, que ainda não havia sido subgenotipada, foi agrupada ao HEV-3i. Os subgenótipos HEV-3j e HEV-3i ainda não tinham sido relatados no país. O estudo demonstra uma grande diversidade genética do HEV no estado de São Paulo e reforça o caráter zoonótico da HEV-3.(AU)

Hepatitis E virus infection increases the risk of diabetes and severity of liver disease in patients with chronic hepatitis C virus infection

OBJECTIVES: Co-infection with hepatitis A or B viruses may aggravate liver injury in patients infected with hepatitis C virus (HCV). However, few studies have assessed co-infection with hepatitis E virus (HEV) and HCV. Therefore, this study aimed to assess the prevalence and impact of HEV infection among Brazilian patients with chronic HCV infection. METHODS: This observational study included adult patients with chronic HCV infection who were naive to antiviral therapy from January 2013 to March 2016. A total of 181 patients were enrolled, and HEV serology and PCR were performed for all patients. RESULTS: Seropositivity for anti-HEV IgG was detected in 22 (12.0%) patients and anti-HEV immunoglobulin M in 3 (1.6%). HEV RNA showed inconclusive results in nine (4.9%) patients and was undetectable in the remaining patients. HEV serology positive patients had more severe liver disease, characterized by liver fibrosis ≥3 versus ≤2 (p<0.001), Aspartate Aminotransferase-to-Platelet Ratio Index of ≥1.45 (p=0.003), and Fibrosis-4 score of ≥3.25 (p=0.001). Additionally, the odds of HEV-positive patients developing diabetes mellitus were 3.65 (95% CI 1.40-9.52) times the corresponding odds of HEV-negative patients. A case-control-based histological analysis (n=11 HEV-HCV-positive patients and n=22 HCV-positive patients) showed no significant differences between the groups. CONCLUSIONS: This prevalence is higher than that reported in previous studies of the general population in Brazil. Thus, HEV infection may influence the severity of liver disease and may represent an additional risk of developing diabetes mellitus in patients with HCV infection.

Evolutionary study of potentially zoonotic hepatitis E virus genotype 3 from swine in Northeast Brazil

Hepatitis E virus (HEV), an emerging virus associated with acute hepatic disease, leads to thousands of deaths worldwide. HEV has already been reported in Brazil; however, there is a lack of epidemiological and molecular information on the genetic variability, taxonomy, and evolution of HEV. It is thus unclear whether hepatitis E is a neglected disease in Brazil or it has low relevance for public health in this country. Here, for the first time, we report the presence of HEV in Northeast Brazil. A total of 119 swine faecal samples were screened for the presence of HEV RNA using real-time polymerase chain reaction (RT-PCR) and further confirmed by conventional RT-PCR; among these, two samples were identified as positive. Molecular evolution analyses based on capsid sequences revealed that the samples had close proximities to HEV sequences belonging to genotype 3 and were genetically related to subtype 3f isolated in humans. Parsimony ancestral states analysis indicated gene flow events from HEV cross-species infection, suggesting an important role of pig hosts in viral spillover. HEV's ability for zoonotic transmission by inter-species host switching as well as its possible adaptation to new animal species remain important issues for human health.

High frequency of hepatitis E virus infection in swine from South Brazil and close similarity to human HEV isolates

Abstract Hepatitis E virus is responsible for acute and chronic liver infections worldwide. Swine hepatitis E virus has been isolated in Brazil, and a probable zoonotic transmission has been described, although data are still scarce. The aim of this study was to investigate the frequency of hepatitis E virus infection in pigs from a small-scale farm in the rural area of Paraná State, South Brazil. Fecal samples were collected from 170 pigs and screened for hepatitis E virus RNA using a duplex real-time RT-PCR targeting a highly conserved 70 nt long sequence within overlapping parts of ORF2 and ORF3 as well as a 113 nt sequence of ORF2. Positive samples with high viral loads were subjected to direct sequencing and phylogenetic analysis. hepatitis E virus RNA was detected in 34 (20.0%) of the 170 pigs following positive results in at least one set of screening real-time RT-PCR primers and probes. The swine hepatitis E virus strains clustered with the genotype hepatitis E virus-3b reference sequences in the phylogenetic analysis and showed close similarity to human hepatitis E virus isolates previously reported in Brazil.

High Clinical Manifestation Rate in an Imported Outbreak of Hepatitis E Genotype 1 Infection in a German Group of Travellers Returning from India

Abstract: Background. There are only few reports about travel-associated, imported tropical hepatitis E virus (HEV) genotype 1 infections within Western travellers. We describe the clinical course of a single outbreak of hepatitis E in a German travellers group returning from India and compare the results of two commercial HEV-seroassays. Material and methods. After identifying hepatitis E in an index patient returning from a journey to India all 24 members of this journey were tested for anti-HEV-IgG and IgM using two commercial seroassays (Wantai and Mikrogen), for HEV-RNA by PCR and HEV-Ag by an antigen-assay (Wantai). Results. 5/24 (21%) individuals were viraemic with viral loads between 580-4,800,000 IU/mL. Bilirubin and ALT levels in these patients ranged from 1.3-14.9 mg/dL (mean 7.3 mg/dL, SD 5.6 mg/dL) and 151-4,820 U/L (mean 1,832U/L, SD 1842U/L), respectively and showed significant correlations with viral loads (r = 0.863, p < 0.001; r = 0.890, p < 0.001). No risk factor for food-borne HEV-transmission was identified. All viraemic patients (5/5) tested positive for anti-HEV-IgG and IgM in the Wantai-assay but only 4/5 in the Mikrogen-assay. Wantai-HEV-antigen-assay was negative in all patients. Six months later all previously viraemic patients tested positive for anti-HEV-IgG and negative for IgM in both assays. However, two non-viremic individuals who initially tested Wantai-IgM-positive stayed positive indicating false positive results. Conclusions. Despite the exact number of exposed individuals could not be determined HEV genotype 1 infections have a high manifestation rate of more than 20%.The Wantai-antigen-test failed, the Wantai-IgMrapid-test and the Mikrogen-IgM-recomblot showed a better performance but still they cannot replace real-time PCR for diagnosing ongoing HEV-infections.

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.

Hepatitis E virus infection in Brazil: results of laboratory-based surveillance from 1998 to 2013

Data on hepatitis E virus (HEV) in Brazil are limited. We analyzed 15 years of HEV surveillance data in a major clinical laboratory in São Paulo, Brazil.

A Survey on the Status of Hepatitis E Virus Infection Among Slaughterhouse Workers in South Korea / 예방의학회지

OBJECTIVES: The seroprevalence of hepatitis E virus (HEV) among high-risk groups overseas is high, but studies in these groups are rare in South Korea. We conducted the present study from April to November 2012 to obtain data on the seroprevalence and associated risk factors for HEV among slaughterhouse workers in South Korea. METHODS: Slaughterhouse workers from 80 workplaces nationwide were surveyed in South Korea in 2012. The subjects comprised 1848 cases: 1434 slaughter workers and 414 residual products handlers. By visiting 80 slaughterhouses, which were mixed with 75 of which also performed residual products handling, we conducted a questionnaire survey for risk factors and obtained blood samples in order to determine the seropositivity and seroprevalence of HEV. Anti-HEV IgG and IgM were measured using HEV IgG and IgM enzyme-linked immunospecific assay kits and HEV antigen was measured by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The seropositivity of anti-HEV IgG was 33.5% (slaughter workers 32.8% and residual products handlers 36.2%), and among the seropositive individuals the seroprevalence of anti-HEV IgM was 0.5% (slaughter workers 0.5%, residual products handlers 0.7%). The response rate of HEV-antigen as measured by RT-PCR was 0.2%. Risk factors significantly related to anti-HEV IgG seropositivity were age, sex , and working duration (slaughter workers only). CONCLUSIONS: There were significant risk factors (sex, age, and working duration) for HEV identified in our study. All three positive cases for HEV-antigen by RT-PCR were related to pig slaughter but without statistical significance. To prevent HEV, an educational program and working guidelines may be needed for high risk groups.

Emerging animal viruses: real threats or simple bystanders? / Vírus emergentes de animais: verdadeiras ameaças ou meros espectadores?

The list of animal viruses has been frequently added of new members raising permanent concerns to virologists and veterinarians. The pathogenic potential and association with disease have been clearly demonstrated for some, but not for all of these emerging viruses. This review describes recent discoveries of animal viruses and their potential relevance for veterinary practice. Dogs were considered refractory to influenza viruses until 2004, when an influenza A virus subtype H3N8 was transmitted from horses and produced severe respiratory disease in racing greyhounds in Florida/USA. The novel virus, named canine influenza virus (CIV), is considered now a separate virus lineage and has spread among urban canine population in the USA. A new pestivirus (Flaviviridae), tentatively called HoBi-like pestivirus, was identified in 2004 in commercial fetal bovine serum from Brazil. Hobi-like viruses are genetically and antigenically related to bovine viral diarrhea virus (BVDV) and induce similar clinical manifestations. These novel viruses seem to be widespread in Brazilian herds and have also been detected in Southeast Asia and Europe. In 2011, a novel mosquito-borne orthobunyavirus, named Schmallenberg virus (SBV), was associated with fever, drop in milk production, abortion and newborn malformation in cattle and sheep in Germany. Subsequently, the virus disseminated over several European countries and currently represents a real treat for animal health. [...] Finally, the long time and intensive search for animal relatives of human hepatitis C virus (HCV) has led to the identification of novel hepaciviruses in dogs (canine hepacivirus [CHV]), horses (non-primate hepaciviruses [NPHV] or Theiler's disease associated virus [TDAV]) and rodents. For these, a clear and definitive association with disease is still lacking and only time and investigation will tell whether they are real disease agents or simple spectators.

O número de vírus animais cresce continuamente, causando preocupação permanente a virologistas e veterinários. O potencial patogênico e associação com doença tem sido claramente demonstrado para alguns - mas não para todos - vírus emergentes. Esse artigo apresenta uma breve revisão das recentes descobertas de vírus animais e a sua potencial relevância para saúde animal. Cães eram considerados refratários aos vírus da influenza até 2004, quando um vírus influenza A subtipo H3N8 foi transmitido de equinos e causou doença respiratória severa em cães galgos na Flórida/EUA. O novo vírus, denominado vírus da influenza canina (CIV), agora considerado uma linhagem distinta do vírus da influenza equina, disseminou-se na população canina urbana dos EUA. Um novo Pestivirus (Flaviviridae) - provisoriamente denominado pestivírus Hobi-like - foi identificado em 2004 em soro fetal bovino importado do Brasil. Os vírus Hobi-like são genética e antigenicamente relacionados com o vírus da diarreia viral bovina (BVDV) e induzem manifestações clínicas semelhantes. A sua origem e distribuição são desconhecidas, mas estão aparentemente disseminados no rebanho brasileiro e já foram identificados no sudeste asiático e na Europa. Em 2011, um novo buniavírus transmitido por mosquitos, denominado vírus Schmallemberg (SBV), foi associado com febre, redução da produção de leite, abortos e malformações fetais em bovinos e ovinos da Alemanha. [...] Finalmente, a longa e intensiva busca por vírus animais relacionados ao vírus da hepatite C humana (HCV) tem levado a identificação de "novos" pestivírus em cães (canine hepacivirus [CHV]), equinos (hepacivirus de não-primatas [NPHV] ou vírus associado à doença de Theiler [TDAV]) e em roedores. Para estes, uma associação clara e definitiva com doença ainda não foi demonstrada e apenas tempo e investigação irão dizer se são patógenos reais ou apenas espectadores.

Development of a novel enzyme-linked immunosorbent assay to detect anti-IgG against swine hepatitis E virus

Swine hepatitis E virus (HEV) is widespread throughout pigs in both developing and industrialized countries. This virus is an important zoonotic agent and a public concern worldwide. Infected pigs are asymptomatic, so diagnosing swine HEV relies on detection of the virus or antibodies against the virus. However, several obstacles need to be overcome for effective and practical serological diagnosis. In this study, we developed an enzyme-linked immunosorbent assay (ELISA) that used a purified recombinant capsid protein of swine HEV. The potential clinical use of this assay was evaluated by comparing it with a commercial kit (Genelabs Technologies, Diagnostics, Singapore). Results of the ELISA were highly correlated with those of the commercial kit with a sensitivity of 97% and specificity of 95%. ROC (receiving operator characteristic) analysis of the ELISA data produced a value of 0.987 (95% CI, 0.977~0.998, p < 0.01). The cut-off value for the ELISA was also determined using negative pig sera. In summary, the HEV-specific ELISA developed in the present study appears to be both practical and economical.

Hepatitis E virus in liver and bile samples from slaughtered pigs of Brazil

The objective of this study was to detect and identify hepatitis E virus (HEV) strains in liver and bile samples from slaughtered pigs in the state of Paraná, Brazil. Liver and bile samples were collected from 118 asymptomatic adult pigs at a slaughterhouse in a major Brazilian pork production area. The samples were assayed using a nested reverse transcription-polymerase chain reaction protocol with primer sets targeting open reading frames (ORF)1 and 2 of the HEV genome. HEV RNA was detected in two (1.7%) liver samples and one (0.84%) bile sample using both primers sets. The HEV strains were classified as genotype 3b on the basis of their nucleotide sequences. These data suggest that healthy pigs may be a source of HEV infection for consumers of pig liver and slaughterhouse workers in Brazil.

Prolonged jaundice attributed to super infection of hepatitis E virus in a case of resolving leptospirosis.

India is endemic for both Leptospira and hepatitis E virus (HEV). The clinical presentations of these diseases have overlapping features. We report a case of superinfection of HEV in a patient with resolving leptospirosis with underlying Hodgkin lymphoma. The diagnosis of HEV in our case was established by HEV-RNA PCR as our patient was immunosuppressed. The present study highlights the need for molecular diagnosis in the case of HEV infection with strong clinical suspicion and negative serological results.

Molecular analysis of swine hepatitis E virus from north India.

Background & objectives: Hepatitis E is the main cause of enterically transmitted non-A, non-B hepatitis in developing countries. In the developed countries such as the USA, Japan and Taiwan, the viruses infecting humans and swine share the same genotype with a high sequence similarity. Genotype 1 circulates in humans whereas genotype 4 in pigs in India. The present study was designed to investigate the presence of anti-HEV antibodies and HEV-RNA in swine population from north India, to investigate the genotype prevalent in it, and to compare it with other swine and human HEV strains from India. Methods: A total of 67 serum samples were collected from pigs of age period (1-6 months) from Indian Veterinary Research Institute (IVRI), Izatnagar, Bareily and subjected to anti-HEV IgG and HEV RNA detection. A phylogenetic tree was constructed using the neighbor-joining method and evaluated using the interior branch test method with MEGA 4 software. Results: Anti-HEV IgG and HEV RNA was found in 38.8 and 4.5 per cent of swine samples studied respectively. The above samples were observed to be of genotype 4e. The three new sequences had nucleotide similarity with other swine sequences in genotype 4 ranging from 80-98 per cent. Interpretation & conclusions: The three sequences observed in the present study showed nucleotide similarity with other swine sequences from southern and western India. The present study suggests that genotype 4 ‘e’ is prevalent in the north India.

Epidemiologia, diagnóstico e caracterização molecular do vírus da hepatite E no Brasil / Epidemiology, diagnosis and molecular characterization of hepatitis E virus in Brazil

Vírus da hepatite E (HEV) detectados em amostras de origem animal vêm sendo associados a casos humanos esporádicos de hepatite E aguda em regiões não endêmicas. No Brasil, a alta prevalência de anticorpos anti-HEV em suínos foi demonstrada em granjas comerciais sugerindo a grande disseminação deste vírus em rebanhos suinícolos. A fim de se comprovar a circulação do HEV no país três investigações foram conduzidas a partir de amostras obtidas de suínos, do ambiente, e de humanos. No primeiro estudo, foi realizado o acompanhamento sorológico de 26 animais desde o nascimento até a idade do abate em uma granja comercial e de 47 animais de uma fazenda modelo nos estados do Rio de Janeiro e Mato Grosso, respectivamente. Amostras de fezes foram coletadas de pocilgas de animais de diferentes faixas etárias. Ao fim deste estudo, a maioria dos animais era sororeativa para anti-HEV. Pela técnica de reação em cadeia da polimerase (PCR), o genoma parcial do HEV foi detectado e as amostras classificadas no genótipo 3, o mesmo que circula em outras populações suínas tanto de regiões endêmicas quanto não-endêmicas. Posteriormente, para se avaliar a incidência de animais com infecção corrente durante o abate, um estudo foi conduzido em três abatedouros fiscalizados pelo Serviço de Inspeção Estadual do Rio de Janeiro (SIE). Pela técnica de PCR em tempo real, o HEV foi detectado em 9,6por cento das amostras obtidas de animais. Foram realizadas coletas de efluentes não tratados dos abatedouros estudados e o genoma do HEV foi detectado em três pontos de coleta de um abatedouro. A quantificação média observada foi de 101 a 105 cópias/mL para as amostras animais de bile e de 102 cópias/mL para as amostras ambientais. A detecção do genoma parcial pela técnica de nested RT-PCR foi realizada, para caracterização molecular das amostras. Estas foram classificadas no genótipo 3 subtipo 3b do HEV, agrupando-se com as amostras caracterizadas do estudo anterior sugerindo a circulação endêmica do HEV no Rio de Janeiro. Em um estudo retrospectivo realizado com pacientes agudos de hepatite não A-C atendidos no Grupo de Atendimento para Hepatites Virais do IOC/Fiocruz foi identificado o primeiro caso humano confirmado de hepatite E do Brasil. Esta amostra agrupou-se no genótipo 3 subtipo 3b, também relacionada às amostras obtidas de suínos da granja e dos abatedouros. De acordo as informações epidemiológicas do paciente, o consumo de carne de porco pode ter sido a fonte de infecção. Os estudos apresentados foram os primeiros que constataram a circulação do HEV em suínos, amostras ambientais e em humanos no Brasil.

Revisión actualizada sobre el virus de la hepatitis E / Update on information regarding hepatitis E virus

La hepatitis E ha sido considerada desde su primera descripción como una enfermedad con un patrón epidemiológico vinculado con el consumo de agua y alimentos contaminados, de modo similar a la hepatitis A, y con una prevalencia superior en zonas geográficas con condiciones sociosanitarias deficientes. La introducción de técnicas moleculares aportó los datos necesarios para demostrar que en los países desarrollados la infección por el virus de la hepatitis E es frecuente, tiene carácter autóctono y un patrón epidemiológico distinto, asociada al contacto con animales domésticos, especialmente el cerdo. La consideración de la hepatitis E en los países desarrollados como una zoonosis supone un giro conceptual interesante que hace necesario revisar esta entidad clínica desde una perspectiva distinta de la que se venía utilizando. Esta revisión resume el conocimiento actual en la biología, la estructura y la transmisión del virus, así como el diagnóstico de la infección, y describe el estado actual en áreas con una incidencia baja de hepatitis aguda E y el papel de los animales como vectores potenciales del virus