Virus de l'hépatite E

Abstract

Hepatitis E virus (HEV) is a non-enveloped positive-sense RNA virus, currently classified in a new family "Hepeviridae genus hepevirus" (single-stranded RNA viruses). The genome (7,2kb) contains three open reading frames (ORF) encoding for non structural (ORF1) and structural proteins (ORF2 & ORF3). HEV infection has been associated with developing countries as a major cause of epidemic acute hepatitis transmitted by faecal-oral route. But sporadic cases of hepatitis have been reported in Western countries, without a history of travel to endemic regions. Phylogenetic analysis of different geographical HEV identified four main genotypes: genotype I gathering Asian (I1) and African (I2) isolates, genotype II found in Mexico and Nigeria, genotype III discovered among US humans and US swine, and genotype IV in Taiwan. Additional genotypes were described in non HEV endemic areas (Greece, Italy, Argentina). Isolation of HEV in domestic animals supports an environmental reservoir of HEV. The current diagnosis of HEV infection includes molecular tools for the detection of the virus in stool or serum samples and serological tests for identification of anti-HEV Ig G and Ig M.