title: Genetic characterization of human T-cell lymphotropic virus type 1 in Mozambique: transcontinental lineages drive the HTLV-1 endemic.
abstract: BACKGROUND
  Human T-Cell Lymphotropic Virus Type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It has been estimated that 10-20 million people are infected worldwide, but no successful treatment is available. Recently, the epidemiology of this virus was addressed in blood donors from Maputo, showing rates from 0.9 to 1.2%. However, the origin and impact of HTLV endemic in this population is unknown.
  
  
  OBJECTIVE
  To assess the HTLV-1 molecular epidemiology in Mozambique and to investigate their relationship with HTLV-1 lineages circulating worldwide.
  
  
  METHODS
  Blood donors and HIV patients were screened for HTLV antibodies by using enzyme immunoassay, followed by Western Blot. PCR and sequencing of HTLV-1 LTR region were applied and genetic HTLV-1 subtypes were assigned by the neighbor-joining method. The mean genetic distance of Mozambican HTLV-1 lineages among the genetic clusters were determined. Human mitochondrial (mt) DNA analysis was performed and individuals classified in mtDNA haplogroups.
  
  
  RESULTS
  LTR HTLV-1 analysis demonstrated that all isolates belong to the Transcontinental subgroup of the Cosmopolitan subtype. Mozambican HTLV-1 sequences had a high inter-strain genetic distance, reflecting in three major clusters. One cluster is associated with the South Africa sequences, one is related with Middle East and India strains and the third is a specific Mozambican cluster. Interestingly, 83.3% of HIV/HTLV-1 co-infection was observed in the Mozambican cluster. The human mtDNA haplotypes revealed that all belong to the African macrohaplogroup L with frequencies representatives of the country.
  
  
  CONCLUSIONS
  The Mozambican HTLV-1 genetic diversity detected in this study reveals that although the strains belong to the most prevalent and worldwide distributed Transcontinental subgroup of the Cosmopolitan subtype, there is a high HTLV diversity that could be correlated with at least 3 different HTLV-1 introductions in the country. The significant rate of HTLV-1a/HIV-1C co-infection, particularly in the Mozambican cluster, has important implications for the controls programs of both viruses.
authors.affiliation: Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
authors.forename: Ana Carolina P
authors.initials: AC
authors.lastname: Vicente
authors.forename: Eduardo Samo
authors.initials: ES
authors.lastname: Gudo
authors.forename: Alena Mayo
authors.initials: AM
authors.lastname: Iñiguez
authors.forename: Koko
authors.initials: K
authors.lastname: Otsuki
authors.forename: Nilesh
authors.initials: N
authors.lastname: Bhatt
authors.forename: Celina M
authors.initials: CM
authors.lastname: Abreu
authors.forename: Adolfo
authors.initials: A
authors.lastname: Vubil
authors.forename: Dulce
authors.initials: D
authors.lastname: Bila
authors.forename: Orlando C
authors.initials: OC
authors.lastname: Ferreira
authors.forename: Amílcar
authors.initials: A
authors.lastname: Tanuri
authors.forename: Ilesh V
authors.initials: IV
authors.lastname: Jani
mesh_terms: D001782:Blood Donors; D015153:Blotting, Western; D016000:Cluster Analysis; D005838:Genotype; D015658:HIV Infections / Q000150:complications; D015490:HTLV-I Infections / Q000453:epidemiology* / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009073:Mozambique / Q000453:epidemiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D012367:RNA, Viral