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  • Poster presentation
  • Open Access

Human T-cell lymphotropic virus type 1 (HTLV-1) infection among couples of a cohort followed up in São Paulo, Brazil

  • 1,
  • 1,
  • 1,
  • 2,
  • 2 and
  • 1Email author
Retrovirology201512 (Suppl 1) :P34

  • Published:


  • Peripheral Blood Mononuclear Cell
  • Transmission Rate
  • Sexual Transmission
  • Horizontal Transmission
  • Proviral Load

This study proposes to investigate the vertical and sexual HTLV-1 transmission rate in a coorte followed up in São Paulo, Brazil. The latter 173 HTLV-1-infected patients were selected until july 2014 (27.2% of 636 HTLV-1-infected individuals). Data were recorded using RedCap (Research Electronic Data Capture), transported to SPSS – Statistical Package for Social Sciences (v 20) and subjected to statistical analysis. To compare results between groups, one-way analysis of variance (one-way ANOVA test) was used. The vertical transmission rate found among 73 individuals born to HTLV-1-positive mothers was 6.8%. HTLV-1 concordant couples were compared to HTLV-1 discordant couples. Those coinfected with HIV were excluded from the sample. Among 91 individuals with stable partnership and without HIV, 49% did not know about the current partner serology: 39% of wives and 54.5% of husbands have not been tested. The horizontal transmission rate of HTLV-1 among those tested couples was 55.3%. Among men 68.2% of its wives were seropositive for HTLV-1, while among women 44.0% of its husbands were seropositive. HTLV-1 concordant couples (cases, n=6) were also compared to HTLV-1 discordant couples (controls, n=14), with respect to HTLV-1 proviral load. Those without HTLV-1 proviral load were excluded. In turn, the control group was subdivided into two subgroups: discordant couples with male index partner (n=5) and discordant couples with female index partner (n=9). Because of the impossibility of defining whether sexual transmission had occurred from man to woman or woman to man, for group 1 (concordant couples) we chose to use the average of the proviral loads of both partners in this group. Serodiscordant couples showed higher mean proviral loads (670 ±515 cópias/104 peripheral blood mononuclear cell (PBMC)) compared with serodiscordant couples (282 ± 293 cópias/104 PBMC) (p=0.045), probably associated with increased genital shedding of this virus and resulting increased risk of sexual transmission.

Authors’ Affiliations

Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
Instituto de Infectologia “Emílio Ribas”, São Paulo, Brazil


© Paiva et al. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.