[Molecular epidemiology of hepatitis A virus].

The genome of hepatitis A virus (HAV) is a linear plus-strand RNA molecule of 7,500 nucleotides and it shares common strategies of construction and function of the picornavirus family. Since it has a unique nucleotide sequence homology, HAV has been classified in the genus of hepatovirus, newly added to the family. Nucleotide sequence of the putative VP1/2A junction area was found variable and a 168 nucleotide portion of the region has been compared with many HAV sequences obtained from all over the world. It was found that HAV strains could be identified and classified into 7 genotypes or 9 subgenotypes. Analyses of the nucleotide sequence homology of this particular region is useful, not only in the study of epidemiology of hepatitis A, but also in the study of the molecular epidemiology of HAV.