CHARACTERIZATION OF HEPATITIS-E VIRUS (HEV) FROM ALGERIA AND CHAD BY PARTIAL GENOME SEQUENCE

The purpose of this study was to analyze partial nucleotide sequences and derived peptide sequences of hepatitis E virus (HEV) from two outb reaks of hepatitis E in Africa (Chad 1983-1984; Algeria 1978-1980). A portion of ORF3 and the major portion of ORF2 were amplified by Revers e Transcriptase-Polymerase Chain Reaction (RT-PCR). The PCR products w ere sequenced directly or after cloning into the pCRII vector. Sequenc es were th en com pa red to the corresponding regions of reported full length HEV sequences. In the ORF2 and ORF3 regions, the homology betw een the Algerian and the Chad isolates at the nucleic acid level was 9 2 and 95%, respectively. At the peptide level the homology was 98% in both regions. In these regions, both strains are more related to Asian strains at the nucleic acid level (89 to 95%) and at the amino acid l evel (95 to 100%) than to the Mexico strain. At the peptide level the differences are less apparent. Both African isolates have amino acid c hanges in common with some reference strains although the Chad isolate has three unique changes. These African strains of HEV, based on the ORF2 and ORF3 phylogenetic trees, appear to be a distinct phylogenetic group, separate from the Mexican and Asian strains. (C) 1997 Wiley-Li ss, Inc.