Advances in hepatitis E – I: virology, pathogenesis and diagnosis

Abstract

This article reviews the current knowledge about structure, genomic organization, taxonomy, genetic epidemiology, host specificity and replication of the human HEV and of various closely-related viruses that infect other animals. In addition, the models available for the study of HEV infection, the available information on the pathogenesis of this infection and the techniques available for its diagnosis are also reviewed. Expert commentary: A circulating, enveloped form of the human HEV has been recently recognized. Originally believed to naturally infect only humans and possibly primates, HEV-like viruses are now known to infect several vertebrate animals. Based on this, phylogenetic classification of these viruses has recently been revised. In vitro replicons and infection systems have been developed, which have improved our understanding about the virus and the pathogenesis of infection with it. Recent development of mouse models with chimeric livers that contain human hepatocytes provides another avenue for further advancement of this knowledge.

The First Case Report of Acute Symptomatic HEV Genotype 4 Infection in an HIV-positive Patient in Japan

“…Apart from asymptomatic and acute hepatitis manifestations, HEV infection may manifest as a chronic infection in immunosuppressed patients, including those with HIV infection (13). In most cases, chronic HEV infection is associated with genotype 3 (14). Conversely, genotype 4 rarely presents as a chronic infection, although one case of chronic infection was described in a patient with acute lymphoblastic leukemia (13,15).…”

Disparities in detection of antibodies against hepatitis E virus in US blood donor samples using commercial assays

“…The assays used have been validated for clinical purposes in symptomatic persons but not for epidemiologic studies in asymptomatic individuals. In addition, the performance of antibody assays is much better in patients with acute infection than in those with past infection . Also, specimens initially positive by the Wantai assays were not retested as recommended in the manufacturer's instructions; however, one would expect a high correlation between initially reactive and repeatedly reactive samples in a commercial assay that has been widely used for anti‐HEV studies worldwide.…”

Hepatitis E and pregnancy: current state

“…HEV Ag appears in blood simultaneously with HEV‐RNA, but it decreases quickly as seroconversion occurs. This test could be used in areas where PCR technology is not available but, for the time being, detection of HEV‐RNA cannot be replaced because of the lower sensitivity of this EIA …”

“…HEV Ag appears in blood simultaneously with HEV-RNA, but it decreases quickly as seroconversion occurs. This test could be used in areas where PCR technology is not available but, for the time being, detection of HEV-RNA cannot be replaced because of the lower sensitivity of this EIA 74. 6.2 | Indirect testsThe method of choice for detection anti-HEV IgG and anti-HEV IgM is EIA including antigens of the viral capsid (ORF2) protein and some of the tests, from ORF3 protein.…”