title: High risk of heterosexual transmission of human T-cell lymphotropic virus type 1 infection in Brazil.
abstract: Human T-cell lymphotropic virus type 1 is transmitted primarily either through sexual intercourse or from mother to child. The current study investigated sexual transmission and compared the HTLV-1 proviral load between seroconcordant and serodiscordant couples by examining both men and women among the index partners without using subjective criteria to establish the direction of sexual transmission. Between January 2013 and May 2015, 178 HTLV-1-positive patients had spouses, 107 of which had tested partners, thus increasing the initial sample size (46 men and 61 women). Individuals co-infected with HTLV-2 or human immunodeficiency virus were not included in the analysis. From among the included participants, 26 men and 26 women were paired with each other, resulting in 26 seroconcordant couples; 12 seroconcordant couples were formed from another four men and eight women. Forty-three serodiscordant couples were formed from 16 men and 27 women. The rate of seroconcordance was 46.9%. The HTLV-1 proviral load was compared between 19 and 37 seroconcordant and serodiscondant couples, respectively, and the concordant couples showed higher proviral loads (P = 0.03). There were no differences between the groups according to age, relationship length, having a mother or sibling with HTLV-1, race, ethnicity, nationality, education, history of blood transfusion, HAM/TSP, ALT, or hepatitis C virus status. In multivariate analysis, relationship time was shown associated with ocurrence of seroconcordance status. The apparent association between high circulating levels of provirus and seroconcordance rate among couples suggests that proviral loads contribute markedly to the risk of sexual transmission, regardless of gender index.
authors.affiliation: Institute of Tropical Medicine of São Paulo, São Paulo, São Paulo, Brazil.|Department of Dermatology, Laboratory of Dermatology and Immunodeficiencies, University of São Paulo Medical School, Butantã, São Paulo, Brazil.
authors.forename: Arthur
authors.initials: A
authors.lastname: Paiva
authors.affiliation: Institute of Infectious Diseases "Emilio Ribas" (IIER), São Paulo, São Paulo, Brazil.
authors.forename: Jerusa
authors.initials: J
authors.lastname: Smid
authors.affiliation: Institute of Infectious Diseases "Emilio Ribas" (IIER), São Paulo, São Paulo, Brazil.
authors.forename: Michel E J
authors.initials: MEJ
authors.lastname: Haziot
authors.affiliation: Institute of Tropical Medicine of São Paulo, São Paulo, São Paulo, Brazil.|Department of Dermatology, Laboratory of Dermatology and Immunodeficiencies, University of São Paulo Medical School, Butantã, São Paulo, Brazil.
authors.forename: Tatiane
authors.initials: T
authors.lastname: Assone
authors.affiliation: Department of Dermatology, Laboratory of Dermatology and Immunodeficiencies, University of São Paulo Medical School, Butantã, São Paulo, Brazil.
authors.forename: Samara
authors.initials: S
authors.lastname: Pinheiro
authors.affiliation: Department of Preventive Medicine, University of São Paulo Medical School, Butantã, São Paulo, Brazil.
authors.forename: Luiz A M
authors.initials: LAM
authors.lastname: Fonseca
authors.affiliation: Institute of Infectious Diseases "Emilio Ribas" (IIER), São Paulo, São Paulo, Brazil.
authors.forename: Augusto C Penalva
authors.initials: ACP
authors.lastname: de Oliveira
authors.affiliation: Institute of Tropical Medicine of São Paulo, São Paulo, São Paulo, Brazil.|Department of Dermatology, Laboratory of Dermatology and Immunodeficiencies, University of São Paulo Medical School, Butantã, São Paulo, Brazil.
authors.forename: Jorge
authors.initials: J
authors.lastname: Casseb
mesh_terms: D000328:Adult; D015153:Blotting, Western; D001938:Brazil / Q000453:epidemiology; D060085:Coinfection / Q000453:epidemiology / Q000821:virology; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology; D015490:HTLV-I Infections / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D020010:Heterosexuality; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D015367:Human T-lymphotropic virus 2; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011533:Proviruses / Q000235:genetics; D012307:Risk Factors; D012747:Sexual Partners; D015229:Sexually Transmitted Diseases, Viral / Q000453:epidemiology* / Q000635:transmission; D018454:Spouses; D019562:Viral Load; D055815:Young Adult
chemical_list: D004279:DNA, Viral
keywords: Brazil; HTLV-1; proviral load; sexual transmission