UNASSIGNED: The hepatitis E virus (HEV) is a zoonotic disease, and infection with HEV in humans primarily causes acute infections and can progress to chronic manifestation in immunocompromised individuals. Over the past decade, guidelines for diagnosing and treating HEV infection have been developed. This study aimed to systematically assess the quality of current guidelines for diagnosing and treating HEV infection, and we analyzed the differences in guideline quality and primary recommendations and explored possible reasons for these differences.
UNASSIGNED: Guidelines published between 2013 and 2022 were searched, and studies were identified using selection criteria. The study assessed the quality of the included guidelines using the Appraisal of Guidelines for Research and Evaluation tool, extracted the primary recommendations in the guidelines, determined the highest level of evidence supporting the recommendations, and reclassified the evidence using the Oxford Centre for Evidence-Based Medicine grading system.
UNASSIGNED: Seven guidelines were included in the final analysis. The quality of the guidelines varied widely. The discrepancies may have been caused by the lack of external experts, the failure to consider influencing factors in guideline application, and the lack of consideration of the public\'s opinion. Analysis of the heterogeneity in primary recommendations revealed differences in algorithms for managing chronic HEV infection, the dosage of ribavirin, and a low level of evidence supporting the primary recommendations.
UNASSIGNED: Guideline quality and primary recommendations vary considerably. Refinement by guideline developers and researchers would facilitate updating and applying guidelines for diagnosing and treating HEV infection.

Hepatitis E virus (HEV) infection is one of the main causes of acute hepatitis in both developed and developing countries. This infectious disease has a high prevalence and incidence in Europe. HEV infection has a greater clinical impact in vulnerable populations, such as immunosuppressed patients, pregnant women and patients with underlying liver disease. Therefore, the Study Group for Viral Hepatitis (Grupo de Estudio de Hepatitis Víricas, GEHEP) of the Spanish Society of Infectious Diseases and Clinical Microbiology (Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica, SEIMC) believed it very important to prepare a consensus document to help in decision-making regarding diagnosis, clinical and therapeutic management, and prevention of HEV infection.

Infection with hepatitis E virus (HEV) is a significant cause of morbidity and mortality, representing an important global health problem. Our understanding of HEV has changed completely over the past decade. Previously, HEV was thought to be limited to certain developing countries. We now know that HEV is endemic in most high-income countries and is largely a zoonotic infection. Given the paradigm shift in our understanding of zoonotic HEV and that locally acquired HEV is now the commonest cause of acute viral hepatitis in many European countries, the focus of these Clinical Practice Guidelines will be on HEV genotype 3 (and 4).

Xenotransplantation of porcine cells, tissues, and organs may be associated with the transmission of porcine microorganisms to the human recipient. A previous, 2009, version of this consensus statement focused on strategies to prevent transmission of porcine endogenous retroviruses (PERVs). This version addresses potential transmission of all porcine microorganisms including monitoring of the recipient and provides suggested approaches to the monitoring and prevention of disease transmission. Prior analyses assumed that most microorganisms other than the endogenous retroviruses could be eliminated from donor animals under appropriate conditions which have been called \"designated pathogen-free\" (DPF) source animal production. PERVs integrated as proviruses in the genome of all pigs cannot be eliminated in that manner and represent a unique risk. Certain microorganisms are by nature difficult to eliminate even under DPF conditions; any such clinically relevant microorganisms should be included in pig screening programs. With the use of porcine islets in clinical trials, special consideration has to be given to the presence of microorganisms in the isolated islet tissue to be used and also to the potential use of encapsulation. It is proposed that microorganisms absent in the donor animals by sensitive microbiological examination do not need to be monitored in the transplant recipient; this will reduce costs and screening requirements. Valid detection assays for donor and manufacturing-derived microorganisms must be established. Special consideration is needed to preempt potential unknown pathogens which may pose a risk to the recipient. This statement summarizes the main achievements in the field since 2009 and focus on issues and solutions with microorganisms other than PERV.

High-throughput sequencing of bile and feces from two pigs experimentally infected with human hepatitis E virus (HEV) of genotype 3f revealed the same full-length consensus sequence as in the human sample. Twenty-nine percent of polymorphic sites found in HEV from the human sample were conserved throughout the infection of the heterologous host. The interspecies transmission of HEV quasispecies is the result of a genomic negative-selection pressure on random mutations which can be deleterious to the viral population. HEV intrahost nucleotide diversity was found to be in the lower range of other human RNA viruses but correlated with values found for zoonotic viruses. HEV transmission between humans and pigs does not seem to be modulated by host-specific mutations, suggesting that adaptation is mainly regulated by ecological drivers.

Hepatitis is transmitted by a number of infectious agents. The epidemiological characterization of waterborne or enterically transmitted non-A, non-B hepatitis (ET-NANBH) is unique when compared with other known hepatitides. We have reported on the molecular cloning of a cDNA clone derived from the etiologic agent associated with ET-NANBH, the hepatitis E virus (HEV). The complete sequence of these first molecular clones, isolated from an HEV-infected human after passage in Macaca fascicularis (cynomolgus macaques), illustrates a distant relationship to other known positive-strand RNA viruses of plants and animals. The translated major open reading frame (ORF-1) from these clones indicates that this portion of the genome encodes a polyprotein with consensus sequences found in RNA-dependent RNA polymerase and ATP/GTP binding domains. The latter activity has been associated with putative helicases of positive-strand RNA viruses. These viral-encoded enzymatic activities identify this region and ORF-1 as containing at least two different nonstructural genes involved in HEV replication. Molecular clones obtained from two other geographically distinct HEV isolates demonstrated sequence heterogeneity in this nonstructural gene region. Further study will be required to elucidate the pathogenic significance (if any) of this observed divergence in the nonstructural region.