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.

Lack of HTLV-I carriers in the Sami, an ethnic group living in the Arctic area in Norway.

The Sami is an ethnic group with ill-defined genetic origins, living in the northern areas of the Scandinavian Peninsula and Russia. Distinct from other European populations in culture and language, they are generally deemed to be remote from the Caucasian lineage. In order to ascertain whether the Sami are genetically linked to Asiatic Mongoloids, we investigated serological markers of human T-cell leukemia virus type I (HTLV-I) infection. Particle agglutination tests for serum HTLV-I antibody were performed for 400 Sami living in Finnmark, the northernmost county of Norway, and in 380 Caucasians (or Norse) in the same region, using serum samples collected for the purpose of studying cardiovascular disease among Northland people in 1974-75. One sample from a Sami showed a tentatively positive reaction, and 4 sera from Sami and 4 from Norse individuals exhibited non-specific agglutination. However, none of the 9 sera showed a positive result in western blotting for HTLV-I proteins, namely, gp46, p53, p24, and p19. Since HTLV-I is distributed most prevalently among northern and southwestern Japanese in Asia and Andeans in South America, the absence of HTLV-I in the Sami might suggest their genetic remoteness from these ethnic groups.