title: Ten year trends in community HIV viral load in Barbados: implications for treatment as prevention.
abstract: BACKGROUND
  Treatment as prevention is a paradigm in HIV medicine which describes the public health benefit of antiretroviral therapy (ART). It is based on research showing substantial reductions in the risk of HIV transmission in persons with optimally suppressed HIV-1 Viral Loads (VL). The present study describes ten year VL trends at the national HIV treatment unit and estimates VL suppression at a population level in Barbados, a Caribbean island with a population of 277,000, an estimated adult HIV prevalence of 1.2%, and served by a single treatment unit.
  
  
  METHODS
  The national HIV treatment centre of the Barbados Ministry of Health has a client VL database extending back to inception of the clinic in 2002 (n = 1,462 clients, n = 17,067 VL measurements). Optimal VL suppression was defined at a threshold value of ≤200 viral copies/mL.
  
  
  RESULTS
  Analysis of VL trends showed a statistically significant improvement in VL suppression between 2002 to 2011, from 33.6% of clients achieving the 200 copies/mL threshold in 2002 to 70.3% in 2011 (P<0.001). Taking into account the proportion of clients alive and in care and on ART, the known diagnosed HIV population in Barbados, and estimates of unknown HIV infections, this translates into an estimated 26.2% VL suppression at a population level at the end of 2010.
  
  
  CONCLUSIONS
  We have demonstrated a significant trend towards optimal VL suppression in clients utilizing the services of the national HIV treatment program in Barbados over a 10-year period. Estimates of VL suppression at a population level are similar to reports in developed countries that applied similar methodologies and this could suggest a public health benefit of ART in minimizing the risk of sexual transmission of HIV. Continued efforts are warranted to extend HIV testing to hidden populations in Barbados and linking infected persons to care earlier in their disease.
authors.affiliation: Chronic Disease Research Centre, The University of the West Indies, Bridgetown, Barbados. clive.landis@cavehill.uwi.edu
authors.forename: R Clive
authors.initials: RC
authors.lastname: Landis
authors.forename: Songee Lynn
authors.initials: SL
authors.lastname: Branch-Beckles
authors.forename: Shawna
authors.initials: S
authors.lastname: Crichlow
authors.forename: Ian R
authors.initials: IR
authors.lastname: Hambleton
authors.forename: Anton
authors.initials: A
authors.lastname: Best
mesh_terms: D000328:Adult; D001460:Barbados / Q000453:epidemiology; D016208:Databases, Factual; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission; D015497:HIV-1; D006801:Humans; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies