A unique seroepidemiological pattern of HBV, HCV and HTLV-I in Nenets and Komi in northwestern Russia.

An epidemiological study of hepatitis viruses type B (HBV) and type C (HCV) and human T-cell leukemia virus type I (HTLV-I) was carried out among 105 residents (male:female=19:86) regarded as Nenets partly mixed with Komi, in the region of Krasnoe, the Nenets Autonomous District of the Arkhangelsk Region, in northwestern Russia in 2004. Blood was drawn from apparently healthy volunteers at ages of 41.6+/-16.5 (range 14-85) years. HBsAg, HBsAb, HBcAb, HBeAb and HCV Ab were measured by microparticle enzyme-immunoassay, and HTLV-I Ab was measured by particle agglutination. Prevalences of HBsAg(+), HBsAb(+), HBcAb(+) and HBeAb(+) were 0.0%, 29.5.%, 20.0% and 7.6%, respectively. The overall HBV infection rate (positive HBsAb or HBcAb) was 34.3%, while no positive HCV or HTLV-I Abs could be detected. A serological subgroup with positive HBsAb and negative HBcAb, consisting of 15(14.3%) females, contrasted sharply to other serological subgroups in sex, age, parent's ethnicity, positive HBeAb rate, and HBcAb inhibition%. We conclude that HBV is prevalent with unique serological patterns among the Nenets, while HCV and HTLV-I infections are negligible.

An epidemiological study of HBV, HCV and HTLV-I in Sherpas of Nepal.

An epidemiological study of hepatitis viruses type B (HBV) and type C (HCV) and human T-cell leukemia virus type I (HTLV-I) was carried out among 103 residents (male:female=61:42) regarded as Sherpas, at Lukla (Solukhumbu district), Nepal in 2004. Blood was drawn from apparently healthy volunteers at ages of 28.8+12.3 (range 15-66) years. HBsAg, HBsAb, HBcAb, and HCV Ab were measured by microparticle enzyme-immunoassay, and HTLV-I Ab was measured by particle agglutination. Prevalence of HBsAg(+), HBsAb(+), HBcAb(+), and HBsAb(+) or HBcAb(+) were 1.9% 22.3%, 24.3%, and 28.2%, respectively. For HCV Ab, only a borderline reaction was observed in one sample, and for HTLV-I Ab all samples were negative. Nucleotide sequencing of the PreS1, PreS2, and S genes revealed that HBV among Sherpas to be of the A' (or Aa) genotype, which is prevalent among Nepalese but rare in native Tibetans, suggesting transmission within Nepal rather than association with ancestors' migration from Tibet as the origin. This is the first report of Himalayan Sherpas' state of infection with HBV, HCV, and HTLV-I.