Molecular epidemiology of hepatitis B virus in Pakistan: link with Southern Asia

ABSTRACT

Viruses and their genotypes reflect the relationship of their hosts. How these strains evolve, is one question and how they cross the borders is another. Since the HBV genotypes have been described by Okamoto and colleagues in 1988, Hepatitis B virus is expressed by a classification of different HBV strains into genetic genotypes and sub genotypes. A degree of 8% divergence between the groups has since then become the definition for HBV genotype. Now HBV is known by its geographic genotype and sub-genotype distribution. They also exhibit combination of both separately or in the form of a hybrid and hybrid of HBV genotypes is a common event in countries where movement of people is frequent across the borders, thus, providing a mixture of variation within individuals and in the population in general. It is seen that if travelling is by road then the different genotypes are prevalent around the borders, but if travelling is by air then they exist in general population as a less prevalent genotype. This review highlights the genotypic link between Pakistan and its South Asian neighbors