The prevalence of HBsAg subtypes and HBV genotypes in native population groups of Siberia

The prevalence of HBsAg and its subtypes and hepatitis B virus (HBV) genotypes in native population groups of five Siberian regions—the Republic of Altai, Kemerovo oblast, Irkutsk oblast, Yamalo-Nenet autonomous oblast (the YaNAO), and Kransnoyarsk krai (a total of 5657 samples)—was studied. Statistically significant differences were found in these groups for the studied HBV markers and types. HBsAg was the most prevalent in Altaians in Republic of Altai (13.4% of samples); Dolgans and Nganasans in Krasnoyarsk krai (13.2%); Teleuts in Kemerovo oblast (10.2%); and Buryats in Irkutsk oblast (5.4–8.2%). HBsAg prevalence was minor in Khants, Komi, Nenets and Selkups in YaNAO (0.7–1.7%). The study of the partial HBsAg-gene sequences of 143 HBV isolates from different groups of the five Siberian regions revealed that 130 (90.9%) belonged to genotype D (subtypes ayw2 and ayw3), 10 (7%) to genotype C (subtype adrq+), and 3 (2.1%) to genotype A (subtype adw2). Of the 130 genotype D isolates, 120 belonged to subgenotypes D1 (34.3%), D2 (22.4%), and D3 (27.3%), while the genotype was not determined in 10 (7%) isolates. Subgenotype D1 (HBsAg subtype ayw2) was prevalent among Kazakhs in the Republic of Altai (85.7% of the strains), Teleuts in Kemerovo oblast (60.0%), Russians in Irkutsk oblast (87.5%), and Dolgans and Nganasans in Krasnoyarsk krai (68.8%). Subgenotype D2 (subtype ayw3) was prevalent among Khants and Komi (75%) and Nentsi (57.1%) from the YaNAO. Subgenotype D3 (subtype ayw2) was prevalent in Altaians in the Republic of Altai (76.2%) and Buryats from Irkutsk oblast (50%). Significant prevalence of genotype C (subgenotype C1, 18.8%) was first found in the Far North of Siberia (Taimyr Peninsula, Krasnoyarsk krai). On the basis of the obtained data, we suggested that there exist several epidemiologically different sources of HBV expansion in native Siberian population groups.