HDV is classified into three genotypes, I, II, and III, based on genetic sequences.
Genotype I is found more frequently in the United States, Europe, Asia, Southern Pacific, and Mediterranean Basin.
Genotype II has been associated with outbreaks in Asia, including Japan and Taiwan.
Genotype III is found in South America.
FIGURE HDV Genotypes found around the world
See Clinical Outcomes for a treatment on the significance of HDV genotypes.