Characterization of full-length hepatitis C virus genotype 4 sequences.

Over 85% of the world's nearly 170 million hepatitis C virus (HCV)-infected subjects exist in regions of Africa, Southeast Asia and Middle Eastern countries where genotypes 4-6 are very common. In particular, HCV genotype 4 is highly prevalent in Egypt with more than 19% of the population infected and chronic HCV representing one of the top five leading causes of death, due in part to ineffective interferon alpha treatment against this genotype. Despite this, very little work has been carried out to characterize the sequence diversity of genotype 4, which will be critical to the development of effective vaccines and antiviral therapies against this genotype. As a result of the paucity of sequence data available for HCV genotype 4, for which only one full genome sequence is currently available, we were interested in characterizing additional genotype 4 sequences and to provide reagents for amplification of this genotype. Here we describe seven unique HCV genotype 4a full genomes, in addition to a single genotype 4d genome, and characterize their sequence diversity in relation to other more closely characterized HCV genotypes.