Hepatitis-E-Virus

摘要: First indications of hepatitis E as a distinct disease, which differs from A, were found in 1980 when sensitive and specific detection systems for A virus (HAV) first became available epidemics examined India. Epidemiologic studies up to that time pointed the fact these infections with clinically very similar course caused by HAV pathogens transmitted faecal-oral route. The experimental proof second route, was later called (HEV), provided 1983 transmission Balayan et al. [1]. In experiments, HAVimmune voluntary individuals infected stool suspensions patients A-like disease occurred Tashkent, Uzbekistan. Spherical virus-like particles, 27–30 nm diameter, could be isolated stools experimentally persons, formed band CsCl gradient at density 1.35 g/cm3. These particles detected immuno-electron microscopy (IEM) both pre-clinical (as 27th day post infection (dpi)) post-clinical phase (45 dpi, onset approximately 36 dpi) (fig. 1). Up 1990, IEM inoculation monkeys only diagnostic methods HEV their differentiation HAV. 1991, Reyes [2] succeeded cloning genome. This opened new paths development serological molecular infections. categorised part Caliciviridae family, based on its morphological properties. Sequence analysis, however, revealed genome structure is significantly this family. Therefore, today classified so far representative hepevirus genus family Hepeviridae. small non-enveloped, single-stranded icosaedric diameter 32–34 nm. capsid probably consists one single protein. positive-sense size 7.2 kbp. It flanked non-encoding regions, polyadenylated 3' end, bears m7G-cap 5' end. itself encodes three overlapping open reading frames (ORF 1–3). Hepeviruses have feature ORF 2 length kbp located end especially characteristic makes calicivirus, sequence encoding 1 5 nonstructural proteins involved RNA replication: RNA-dependent polymerase, guanylyl methyl transferases, helicase papain-like protease. 3 372 bp overlaps 331 1. immunogeneic phosphoprotein not more than 123 amino acids. Based phylogenetic analyses, isolates now are into four different genotypes world-wide distributions [3]. For genotype Burma isolate represents prototype, Mexican isolate, USA 4 Chinese isolate. then further grouped genetic subtypes. Serologically, seems behave uniform manner, neutralisation cell culture protection shown [4]. Various provide evidence replicates hepatocyte humans macaques. purpose, cultures suspensions. such vitro studies, Emerson [5] able show half infectiveness inactivated after heat treatment 45–50 °C h almost entire 56 °C. addition, authors Clinical Information · Klinische