title: Molecular and epidemiological characterization of HIV-1 infection networks involving transmitted drug resistance mutations in Northern Greece.
abstract: OBJECTIVE
  To determine the contribution of transmission clusters to transmitted drug resistance (TDR) in newly diagnosed antiretroviral-naive HIV-1-infected patients in Northern Greece during 2000-07.
  
  
  METHODS
  The prevalence of TDR was estimated in 369 individuals who were diagnosed with HIV-1 infection in the period 2000-07 at the National AIDS Reference Laboratory of Northern Greece. Phylogenetic analysis was performed using a maximum likelihood method on partial pol sequences. TDR was defined in accordance with the surveillance drug resistance mutation list (2009 update).
  
  
  RESULTS
  The overall prevalence of TDR in our population was 12.5% [46/369, 95% confidence interval (CI) 9.1%-15.8%], comprising 7.6% (28/369) resistant to nucleoside reverse transcriptase inhibitors, 5.4% (20/369) resistant to non-nucleoside reverse transcriptase inhibitors and 3.3% (12/369) resistant to protease inhibitors. Dual class resistance was identified in 3.8% (14/369). Infection with subtype A was the sole predictor associated with TDR in multivariate analysis (odds ratio 2.15, 95% CI 1.10-4.19, P = 0.025). Phylogenetic analyses revealed three statistically robust transmission clusters involving drug-resistant strains, including one cluster of 12 patients, 10 of whom were infected with a strain carrying both T215 revertants and Y181C mutations.
  
  
  CONCLUSIONS
  Our findings underline the substantial impact of transmission networks on TDR in our population.
authors.affiliation: National AIDS Reference Centre of Northern Greece, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece. mollyskoura@gmail.com
authors.forename: Lemonia
authors.initials: L
authors.lastname: Skoura
authors.forename: Simeon
authors.initials: S
authors.lastname: Metallidis
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Buckton
authors.forename: Jean L
authors.initials: JL
authors.lastname: Mbisa
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Pilalas
authors.forename: Evagelia
authors.initials: E
authors.lastname: Papadimitriou
authors.forename: Androniki
authors.initials: A
authors.lastname: Papoutsi
authors.forename: Anna-Bettina
authors.initials: AB
authors.lastname: Haidich
authors.forename: Theofilos
authors.initials: T
authors.lastname: Chrysanthidis
authors.forename: Olga
authors.initials: O
authors.lastname: Tsachouridou
authors.forename: Zoe A
authors.initials: ZA
authors.lastname: Antoniadou
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kollaras
authors.forename: Pavlos
authors.initials: P
authors.lastname: Nikolaidis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Malisiovas
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D016000:Cluster Analysis; D024882:Drug Resistance, Viral; D005260:Female; D005838:Genotype; D006115:Greece / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009154:Mutation; D010802:Phylogeny; D015995:Prevalence
chemical_list: D019380:Anti-HIV Agents