title: Silent dissemination of HTLV-1 in an endemic area of Argentina. Epidemiological and molecular evidence of intrafamilial transmission.
abstract: BACKGROUND
  Molecular and epidemiological studies of transmission routes and risk factors for infection by HTLV-1 are extremely important in order to implement control measures, especially because of the high prevalence of HTLV-1 in several regions of the world. San Salvador de Jujuy, Northwest Argentina, is a highly endemic area for HTLV-1 and foci of tropical spastic paraparesis/HTLV-1-associated myelopathy.
  
  
  OBJECTIVE
  To gain further insight into the role of intrafamilial transmission of HTLV-1 in a highly endemic region in Argentina.
  
  
  METHODS
  Cross-sectional study in Northwest Argentina. Epidemiological data and blood samples were collected from 28 HTLV-1 infected subjects (index cases) and 92 close relatives/cohabitants. HTLV-1 infection was diagnosed by detection of antibodies and proviral DNA. The LTR region was sequenced and analyzed for genetic distances (VESPA software), in addition to determination and identification of polymorphisms to define HTLV-1 family signatures.
  
  
  RESULTS
  Fifty seven of the 120 subjects enrolled had antibodies against HTLV-1 and were typified as HTLV-1 by PCR. The prevalence rate of HTLV-1 infection in family members of infected index cases was 31.52% (29/92). The infection was significantly associated with gender, age and prolonged lactation. Identity of LTR sequences and presence of polymorphisms revealed high prevalence of mother-to-child and interspousal transmission of HTLV-1 among these families.
  
  
  CONCLUSIONS
  There is an ongoing and silent transmission of HTLV-1 through vertical and sexual routes within family clusters in Northwest Argentina. This evidence highlights that HTLV-1 infection should be considered as a matter of public health in Argentina, in order to introduce preventive measures as prenatal screening and breastfeeding control.
authors.affiliation: Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: María C
authors.identifier: http://orcid.org/0000-0002-6349-6264
authors.initials: MC
authors.lastname: Frutos
authors.affiliation: Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Rene
authors.initials: R
authors.lastname: Gastaldello
authors.affiliation: Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Marcos
authors.initials: M
authors.lastname: Balangero
authors.affiliation: Departamento de Enfermedades Infecciones, Hospital San Roque, San Salvador de Jujuy, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Remondegui
authors.affiliation: Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Sebastián
authors.initials: S
authors.lastname: Blanco
authors.affiliation: Laboratorio de Genética Molecular de Microorganismos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Koko
authors.initials: K
authors.lastname: Otsuki
authors.affiliation: Laboratorio de Genética Molecular de Microorganismos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Paulo Vicente
authors.affiliation: Departamento de Matemática. Facultad de Ciencias Exactas, Físicas y Naturales- Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: David
authors.initials: D
authors.lastname: Elías
authors.affiliation: Departamento de Matemática. Facultad de Ciencias Exactas, Físicas y Naturales- Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Mangeaud
authors.affiliation: Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Silvia
authors.initials: S
authors.lastname: Nates
authors.affiliation: Instituto de Virología "Dr. J. M. Vanella", Facultad de Ciencias Médicas-Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Sandra
authors.initials: S
authors.lastname: Gallego
mesh_terms: D001118:Argentina / Q000453:epidemiology; D019353:Endemic Diseases; D005260:Female; D020022:Genetic Predisposition to Disease; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D015493:Paraparesis, Tropical Spastic / Q000453:epidemiology* / Q000635:transmission; D010375:Pedigree; D011247:Pregnancy; D015229:Sexually Transmitted Diseases, Viral / Q000453:epidemiology / Q000635:transmission