Phylogenetic analysis of hepatitis D viruses indicating a new genotype I subgroup among African isolates.

Genetic analysis was performed on 13 hepatitis D virus (HDV) isolates from Ethiopia, Somalia, Jordan, Kuwait, Bulgaria, Moldavia, and Sweden. The complete nucleotide sequence and genomic organization are described for the first time for two African HDV isolates. Phylogenetic analysis showed all the African isolates to be intrarelated and to form a novel group within HDV genotype I; the suggested designation for this group is IC. The genetic distance to previously described type I isolates was about 0.15. The HDV genotype I isolates (total of 22 examined) phylogenetically formed three clusters, each of them corresponding to certain geographic regions; the "western" group consisted of six HDV isolates from western Europe and the United States plus one from Kuwait; the "eastern" group consisted of two isolates from Moldavia and one each from Bulgaria, Nauru, mainland China, and Taiwan; and the "African-Middle East" group consisted of six HDV isolates from Ethiopia and one from Somalia, Jordan, and Lebanon.