HTLV-1/2 in Indigenous Peoples of the Brazilian Amazon: Seroprevalence, Molecular Characterization and Sociobehavioral Factors Related to Risk of Infection

Viruses. 2022 Dec 21;15(1):22. doi: 10.3390/v15010022.


HTLV-1/2 infection is endemic in Indigenous peoples of the Americas. Its origin is attributed to the migratory flow of Amerindian ancestral peoples. The present study aimed to investigate the seroprevalence of HTLV-1/2 infection in Indigenous peoples of the Brazilian Amazon. A total of 3350 Indigenous people belonging to 15 communities were investigated. The investigation was performed using serological (ELISA), molecular (qPCR) and confirmatory (Western blot and/or Inno-Lia) tests to detect and differentiate the infection. The seroprevalence was 8.3% for HTLV-1/2 infection, with 0.1% of individuals seropositive for HTLV-1 and 8.1% for HTLV-2. The prevalence of infection was statistically higher in women (10.1%) than in men (6.5%) (p = 0.0002). This female predominance was observed in all age groups; in females the prevalence was significant from 41 years old (p < 0.0001) and in males from 51 years old (p < 0.0001). Here, we present a prevalence of HTLV-1/2 among Indigenous peoples of the Brazilian Amazon. The endemic infection in these groups must reflect the different epidemiological profiles observed in these peoples, such as sexual transmission through rejection of condom use, breastfeeding, especially in cases of cross-breastfeeding, and the high rate of pregnancy in the villages.

Keywords: Brazilian Amazon; HTLV-1/2; Indigenous people; epidemiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brazil / epidemiology
  • Female
  • HTLV-I Infections* / epidemiology
  • HTLV-II Infections* / epidemiology
  • Human T-lymphotropic virus 1* / genetics
  • Human T-lymphotropic virus 2
  • Humans
  • Indigenous Peoples
  • Male
  • Middle Aged
  • Seroepidemiologic Studies

Grants and funding

This study received financial support from the National Council for Scientific and Technological Development (CNPq) (Process No. 442522/2019-3; 302935/2021-5 and 402412/2021-4) and the Qualified Production Support Program (PAPQ/2022) from the Federal University of Pará.