PHYLOGENETIC ANALYSIS OF HEPATITIS-E VIRUS ISOLATES FROM EGYPT

Hepatitis E virus (HEV) genome was detected by reverse transcriptase-p olymerase chain reaction (RT-PCR) in fecal samples of two sporadic cas es of hepatitis E in Cairo Egypt. Sequence of the complete putative st ructural region [open reading frame (ORF)-2] and complete region of un known function (ORF-3) was determined for the two HEV isolates. Phylog enetic analysis of the nucleotide sequences was performed using neighb or joining or maximum parsimony methods of tree reconstruction. Direct correspondence between the HEV evolutionary trees and geographic orig in of the HEV isolates was observed. Three genotypes of HEV were ident ified: genotype I (Asia-Africa), genotype II (US), and genotype III (M exico). Genotype I was further divided into two subgenotypes (Asia and Africa). In the Asian subgenotype, three smaller genetic clusters wer e observed (China-like sequences, Burma-like sequences, and sequence f rom a fulminant case of HEV). The segregation of all these genetic clu sters was supported by the high level of bootstrap probabilities. Four regions of the HEV genome were used for phylogenetic analysis. In all four regions, Egyptian HEV isolates were grouped in a separate Africa n clade. J. Med. Virol. 57:68-74, 1999. Published 1999 Wiley-Liss, Inc .