title: Controlling HIV among people who inject drugs in Eastern Europe and Central Asia: insights from modeling.
abstract: BACKGROUND
  Although there is evidence of the effectiveness of needle and syringe programme (NSP), opioid substitution therapy (OST) and antiretroviral therapy (ART) in reducing HIV prevalence, most Central and Eastern European sub-regions still have low or no coverage of most or all of these interventions.
  
  
  METHODS
  We conducted a modelling analysis to consider the potential impact on HIV incidence and prevalence of OST, NSP and ART in three illustrative epidemic scenarios: Russia (St. Petersburg); Estonia (Tallinn) and Tajikistan (Dushanbe). For each intervention, we consider the coverage needed of each intervention separately or in combination to: (1) achieve a 30% or 50% relative reduction in HIV incidence or prevalence over 10 years; and (2) reduce HIV incidence to below 1% or HIV prevalence below 10% after 20 years. A sensitivity analysis for St. Petersburg considered the implications of greater on no risk heterogeneity, none or more sexual HIV transmission, like-with-like mixing, different injecting cessation rates and assuming a lower HIV acute phase cofactor.
  
  
  RESULTS
  For St. Petersburg, when OST, NSP and ART are combined, only 14% coverage of each intervention is required to achieve a 30% reduction in HIV incidence over 10 years. Similar findings are obtained for Tallinn and Dushanbe. In order to achieve the same reductions in HIV prevalence over 10 years, over double the coverage level is required relative to what was needed to achieve the same reduction in HIV incidence in that setting. To either reduce HIV incidence to less than 1% or HIV prevalence to less than 10% over 20 years, with all interventions combined, projections suggest that very high coverage levels of 74–85% are generally required for the higher prevalence settings of Tallinn and St. Petersburg, whereas lower coverage levels (23–34%) are needed in Dushanbe. Coverage requirements are robust to increased sexual HIV transmission, risk heterogeneity and like-with-like mixing, as well as to assuming a lower HIV acute phase cofactor or different injecting cessation rate.
  
  
  CONCLUSIONS
  The projections suggest that high but achievable coverage levels of NSP can result in large decreases (30%) in HIV incidence in settings with high HIV prevalence among PWID. Required coverage levels are much lower when interventions are combined or in lower prevalence settings. However, even when all three interventions are combined, the targets of reducing HIV incidence to less than 1% or prevalence to less than 10% in 20 years may be hard to achieve except in lower prevalence settings.
authors.affiliation: School of Social and Community Medicine, University of Bristol, UK. peter.vickerman@bristol.ac.uk
authors.forename: Peter
authors.initials: P
authors.lastname: Vickerman
authors.forename: Lucy
authors.initials: L
authors.lastname: Platt
authors.forename: Emma
authors.initials: E
authors.lastname: Jolley
authors.forename: Tim
authors.initials: T
authors.lastname: Rhodes
authors.forename: Michel D
authors.initials: MD
authors.lastname: Kazatchkine
authors.forename: Alisher
authors.initials: A
authors.lastname: Latypov
mesh_terms: D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D001209:Asia, Central / Q000453:epidemiology; D005061:Europe, Eastern / Q000453:epidemiology; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D015233:Models, Statistical; D018671:Needle-Exchange Programs; D058850:Opiate Substitution Treatment; D015995:Prevalence; D015819:Substance Abuse, Intravenous / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D044966:Anti-Retroviral Agents