Worldwide prevalence of HDV among HBV carriers in 2015. Eight genotypes have been identified worldwide by comparative phylogenetic analysis. Genotype 1 is the most frequent and has variable pathogenicity, Genotypes 2 and 4 are found in East Asia causing relatively mild disease. Genotype 3 is found in South America in association with severe<unk> . Genotypes 5, 6, 7, 8 have been found only in Africa. The<unk>  occurs worldwide. Although the figures are disputed, a recent systematic review suggests that up to 60 million individuals could be infected. The major victims are the carriers of the<unk>  B surface antigen (HBsAg), who become superinfected by the HDV, and intravenous drug users who are the group at highest risk. The infection usually results in liver damage<unk>  D); this is most often a chronic and severe<unk>  rapidly conducive to cirrhosis. __TOC__
Epidemiology of Hepatitis D
HCV genotypes
Epidemiology of HIV/AIDS
HIV disease progression rates
Epidemiology of syphilis
CDC classification system for HIV infection
Epidemiology of binge drinking
Structure and genome of HIV