Molecular Epidemiology of Human T-Lymphotropic Virus Type II Infection in Amerindian and Urban Populations of the Amazon Region of Brazil

Document Type

Article

Authors

Antonio C. R. Vallinoto, Laboratório de Virologia, Centro de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
Marluísa O. G. Ishak, Laboratório de Virologia, Centro de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
Vânia N. Azevedo, Laboratório de Virologia, Centro de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
Ana Carolina P. Vicente, Laboratório de Genética Molecular e de Microrganismo, FIOCRUZ, Rio de Janeiro, Brazil.
Koko Otsuki, Laboratório de Genética Molecular e de Microrganismo, FIOCRUZ, Rio de Janeiro, Brazil.
William W. Hall, Laboratory of Medical Virology, University College, Dublin, Ireland.
Ricardo Ishak, Laboratório de Virologia, Centro de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.

Abstract

Molecular characterization of human T-cell lymphotropic virus II (HTLV-II) isolates in North America and Europe has shown the existence of two principal subtypes of the virus, HTLV-IIa and HTLV-IIb. Subsequent studies on HTLV-II isolates from Brazil have suggested the existence of a unique variant phylogenetically related to HTLV-IIa but phenotypically similar to HTLV-IIb with respect to the transactivatory protein, Tax. This variant has been designated HTLV-IIc. To better clarify the variability and distribution of HTLV-II in Brazil, the viruses present in two population groups from the Amazon region were tested for the presence of HTLV-II using serological and molecular assays. The groups consisted of blood donors from three Amerindian communities and of HIV-1/HTLV-II coinfected patients residing in Belém, an urban area. Nucleotide sequences and phylogenetic analysis confirmed the presence of HTLV-IIc subtype among Amerindian populations and, for the first time, the presence of the same virus among urban groups in Belém. The isolated occurrence of the HTLV-IIc subtype among Amerindian populations in the Amazon region could be attributed to (1) the different migratory pathways and founder effect, or (2) the local origin of a proto-HTLVII carried by Amerindian ancestors who migrated to the Amazon circa 11,000 to 13,000 years ago. These results suggest that not only is HTLV-IIc unique to this region, but that its presence in urban areas of Brazil has resulted from admixture processes during the colonization of the country.

Recommended Citation

Vallinoto, Antonio C. R.; Ishak, Marluísa O. G.; Azevedo, Vânia N.; Vicente, Ana Carolina P.; Otsuki, Koko; Hall, William W.; and Ishak, Ricardo (2002) "Molecular Epidemiology of Human T-Lymphotropic Virus Type II Infection in Amerindian and Urban Populations of the Amazon Region of Brazil," Human Biology: Vol. 74: Iss. 5, Article 1.
Available at: https://digitalcommons.wayne.edu/humbiol/vol74/iss5/1