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.
Humans ; Hepatitis E virus/genetics* ; Hepatitis E

China ; epidemiology ; Hepatitis E ; epidemiology ; Hepatitis E virus ; genetics ; immunology ; Humans ; Immunoglobulin E

Animals ; Genotype ; Hepatitis E ; veterinary ; virology ; Hepatitis E virus ; genetics ; Hepatitis, Viral, Animal ; virology ; Prevalence

Cell Line ; DNA, Viral ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; Humans ; Ribonucleases ; genetics ; Transfection ; Virus Replication

Humans ; Hepatitis B e Antigens ; Hepatitis B virus/genetics* ; Alanine Transaminase ; RNA ; Antiviral Agents ; DNA, Viral

Alanine Transaminase ; Hepatitis B ; Hepatitis B e Antigens ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/drug therapy* ; Humans

OBJECTIVETo determine the distribution of genotype IV among hepatitis E virus (HEV) infections in Wuhan by sequencing the open reading frame (ORF) 3 gene of HEV clinical isolates.

METHODSSerum samples were collected from 103 individuals who tested positive for the anti-HEV IgM antibody, and total HEV RNA was extracted for targeted gene sequencing analysis. Reverse transcription-nested polymerase chain reaction (PCR) was used to amplify two fragments of the ORF3 gene (5020 to 5392 nt and 5347 to 5956 nt, EF570133). The two PCR products were sequenced and the sequences were stitched with the ContigExpress program and used to determine the HEV genotype.

RESULTSBoth ORF3 gene fragments were amplified in 18 out of the 103 anti-HEV IgM-positive serum samples. These 18 HEV isolates shared 92.5% to 99.4% identity with each other at the nucleotide level. Nucleotide sequence homology analysis of the HEV genotypes I, II, III, and IV indicated the highest homology was with genotype IV; specifically, homology with genotype I was 83.5% to 86.7%, with genotype II was 83.2% to 85.2%, with genotype III was 84.6% to 87.2%, and with genotype IV was 92.0% to 96.5%.

CONCLUSIONTargeted sequencing of the HEV ORF3 gene facilitated genotyping of clinical isolates. Using this method, it was determined that nearly 20% of HEV clinical isolates from Wuhan belong to genotype IV.

Base Sequence ; Genotype ; Hepatitis E ; epidemiology ; virology ; Hepatitis E virus ; genetics ; Humans ; Open Reading Frames ; Sequence Homology, Nucleic Acid

OBJECTIVETo investigate the genotypes of hepatitis E viruses (HEV) detected in sera of patients from different regions of China.

METHODSThe partial genome (nt6461-6860, nt5994-6294) of open reading frame 2 (ORF2) of 45 HEV strains detected from 14 cities of China was amplified and sequenced using polymerase chain reaction (PCR) and direct sequencing.

RESULTSForty-one of 45 strains (91%) share the same genotype with HEV Burma strain (B), with nucleotide identities higher than 98% with the representative HEV Chinese strain. Only 4 HEV strains are significantly divergent from the 3 prototype strains of HEV, with nucleotide identities of 77%-80% with HEV Burmese/Chinese strain, 74%-76% with Mexican strain and 74%-77% with the newly discovered HEV US/swine strain, respectively. Phylogenetic analysis suggests that these 4 strains may represent 2 different subtypes that belong to a novel genotype of HEV, which is significantly divergent from the prototype Mexico, Burmese and US/swine strains.

CONCLUSIONAmong patients with hepatitis E in China, most are infected by the Chinese prototype HEV, and only a small part by the new genotype HEV.

Base Sequence ; Genotype ; Hepatitis E ; virology ; Hepatitis E virus ; classification ; genetics ; Humans ; Open Reading Frames ; Phylogeny ; RNA, Viral ; blood ; chemistry

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.
Animals ; Genotype ; Hepatitis E/*epidemiology/mortality/*transmission/virology ; Hepatitis E virus/genetics/*physiology ; Humans ; Zoonoses/epidemiology/mortality/*transmission/virology

Animals ; China ; epidemiology ; Disease Reservoirs ; Hepatitis E ; epidemiology ; transmission ; Hepatitis E virus ; genetics ; isolation & purification ; Humans ; Rodentia ; virology ; Swine ; virology