title: Molecular characterization of HIV-1 infection in Northwest Spain (2009-2013): Investigation of the subtype F outbreak.
abstract: BACKGROUND
  HIV-1 subtype B is the predominant one in European regions several, while other subtypes and recombinants are also circulating with high prevalence. A sub-epidemic of subtype F with specific characteristics and low response to treatment has been recently identified in Galicia. In this study we investigated the characteristics of the HIV-1 subtype F sub-epidemic in A Coruña and Santiago de Compostela in Northwest Spain.
  
  
  METHODS
  420 newly HIV-1 diagnosed patients during 2009-2013 were enrolled in this study. HIV-1 subtyping was carried out using automated subtyping tools and phylogenetic analysis. Molecular epidemiology investigation of subtypes B and F was performed by means of phylogenetic analysis using fast maximum likelihood. Phylodynamic analysis was performed using Bayesian method as implemented in BEAST v1.8.
  
  
  RESULTS
  Subtype B found to be the predominant (61.2% and 70.4%) followed by subtype F (25.6% and 12.0%) in both areas (A Coruña and Santiago de Compostela, respectively). The latter found to mainly spread among men having sex with men (MSM). The vast majority of subtype F lineages from both areas clustered monophyletically, while subtype B sequences clustered in several tree branches. The exponential growth of subtype F sub-epidemic dated back in 2008 by means of phylodynamic analysis. Most of new infections during 2009-2013 occurred within the subtype F transmission cluster.
  
  
  CONCLUSIONS
  Subtype F circulates at high prevalence in A Coruña and Santiago de Compostela in Northwest Spain, suggesting that the HIV-1 epidemic in this region has distinct characteristics to the rest of Spain. Subtype F has being spreading among MSM and is currently the most actively spreading network. The single cluster spread of this local sub-epidemic might provide an explanation for the distinct characteristics and the low response to antiretroviral treatment.
authors.affiliation: National Retrovirus Reference Center, Department of Hygiene, Epidemiology and Medical Statistics, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece. Electronic address: dparask@med.uoa.gr.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Paraskevis
authors.affiliation: National Retrovirus Reference Center, Department of Hygiene, Epidemiology and Medical Statistics, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Kostaki
authors.affiliation: National Retrovirus Reference Center, Department of Hygiene, Epidemiology and Medical Statistics, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece; Institute of Infection & Global Health (IGH), University of Liverpool, Liverpool, UK.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Beloukas
authors.affiliation: Service of Microbiology, INIBIC-Complejo Hospitalario Universitario de A Coruña, A Coruña, Spain.
authors.forename: Angelina
authors.initials: A
authors.lastname: Cañizares
authors.affiliation: Service of Microbiology, Hospital Conxo-CHUS, and Department of Microbiology, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Aguilera
authors.affiliation: Service of Microbiology, Hospital Conxo-CHUS, and Department of Microbiology, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Rodríguez
authors.affiliation: Division of Clinical Virology, INIBIC-Complejo Hospitalario Universitario de A Coruña, Universidade da Coruña, A Coruña, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Grandal
authors.affiliation: Division of Clinical Virology, INIBIC-Complejo Hospitalario Universitario de A Coruña, Universidade da Coruña, A Coruña, Spain.
authors.forename: Berta
authors.initials: B
authors.lastname: Pernas
authors.affiliation: Division of Clinical Virology, INIBIC-Complejo Hospitalario Universitario de A Coruña, Universidade da Coruña, A Coruña, Spain.
authors.forename: Angeles
authors.initials: A
authors.lastname: Castro-Iglesias
authors.affiliation: Division of Clinical Virology, INIBIC-Complejo Hospitalario Universitario de A Coruña, Universidade da Coruña, A Coruña, Spain.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Mena
authors.affiliation: Division of Clinical Virology, INIBIC-Complejo Hospitalario Universitario de A Coruña, Universidade da Coruña, A Coruña, Spain.
authors.forename: José D
authors.initials: JD
authors.lastname: Pedreira
authors.affiliation: Division of Clinical Virology, INIBIC-Complejo Hospitalario Universitario de A Coruña, Universidade da Coruña, A Coruña, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Poveda
mesh_terms: D000328:Adult; D004196:Disease Outbreaks; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D013030:Spain / Q000453:epidemiology
keywords: Galicia; HIV-1; Local sub-epidemic; Molecular epidemiology; Spain; Subtype F