title: Design and baseline findings of a large-scale rapid response to an HIV outbreak in people who inject drugs in Athens, Greece: the ARISTOTLE programme.
abstract: OBJECTIVE
  To (i) describe an intervention implemented in response to the HIV-1 outbreak among people who inject drugs (PWIDs) in Greece (ARISTOTLE programme), (ii) assess its success in identifying and testing this population and (iii) describe socio-demographic characteristics, risk behaviours and access to treatment/prevention, estimate HIV prevalence and identify risk factors, as assessed at the first participation of PWIDs.
  
  
  METHODS
  A 'seek, test, treat, retain' intervention employing five rounds of respondent-driven sampling.
  
  
  METHODS
  Athens, Greece (2012-13).
  
  
  METHODS
  A total of 3320 individuals who had injected drugs in the past 12 months.
  
  
  METHODS
  ARISTOTLE is an intervention that involves reaching out to high-risk, hard-to-reach PWIDs ('seek'), engaging them in HIV testing and providing information and materials to prevent HIV ('test') and initiating and maintaining anti-retroviral and opioid substitution treatment for those testing positive ('treat' and 'retain').
  
  
  METHODS
  Blood samples were collected for HIV testing and personal interviews were conducted.
  
  
  RESULTS
  ARISTOTLE recruited 3320 PWIDs during the course of 13.5 months. More than half (54%) participated in multiple rounds, resulting in 7113 visits. HIV prevalence was 15.1%. At their first contact with the programme, 12.5% were on opioid substitution treatment programmes and the median number of free syringes they had received in the preceding month was 0. In the multivariable analysis, apart from injection-related variables, homelessness was a risk factor for HIV infection in male PWIDs [odds ratio (OR) yes versus no = 1.89, 95% confidence interval (CI) = 1.41, 2.52] while, in female PWIDS, the number of sexual partners (OR for > 5 versus one partner in the past year = 4.12, 95% CI = 1.93, 8.77) and history of imprisonment (OR yes versus no = 2.76, 95% CI = 1.43, 5.31) were associated with HIV.
  
  
  CONCLUSIONS
  In Athens, Greece, the ARISTOTLE intervention for identifying HIV-positive people among people who inject drugs (PWID) facilitated rapid identification of a hidden population experiencing an outbreak and provided HIV testing, counselling and linkage to care. According to ARISTOTLE data, the 2011 HIV outbreak in Athens resulted in 15% HIV infection among PWID. Risk factors for HIV among PWID included homelessness in men and history of imprisonment and number of sexual partners in women.
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors.forename: Angelos
authors.initials: A
authors.lastname: Hatzakis
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors.forename: Vana
authors.initials: V
authors.lastname: Sypsa
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Medical School, University of Athens, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Paraskevis
authors.affiliation: IAS/NIDA Fellow, Hellenic Center for Diseases Prevention and Control, Athens, Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Nikolopoulos
authors.affiliation: Hellenic Centre for Diseases Control and Prevention, Athens, Greece.
authors.forename: Chrissa
authors.initials: C
authors.lastname: Tsiara
authors.affiliation: Organization Against Drugs, Athens, Greece.
authors.forename: Katerina
authors.initials: K
authors.lastname: Micha
authors.affiliation: Organization Against Drugs, Athens, Greece.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Panopoulos
authors.affiliation: Medical School, University of Athens, Athens, Greece.
authors.forename: Meni
authors.initials: M
authors.lastname: Malliori
authors.affiliation: Department of Propedeutic Medicine, Medical School, University of Athens, Athens, Greece.
authors.forename: Mina
authors.initials: M
authors.lastname: Psichogiou
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm, Sweden.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Pharris
authors.affiliation: European Monitoring Centre for Drugs and Drug Addiction, Lisbon, Portugal.
authors.forename: Lucas
authors.initials: L
authors.lastname: Wiessing
authors.affiliation: Consultant Public Health, Utrecht, the Netherlands.
authors.forename: Marita
authors.initials: M
authors.lastname: van de Laar
authors.affiliation: World Health Organization Regional Office for Europe, Copenhagen, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Donoghoe
authors.affiliation: Cornell University, Ithaca, NY, USA.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Heckathorn
authors.affiliation: National Development and Research Institutes, New York, USA.
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Friedman
authors.affiliation: Beth Israel Medical Center, New York, USA.
authors.forename: Don C
authors.initials: DC
authors.lastname: Des Jarlais
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D023241:Antiretroviral Therapy, Highly Active; D015897:Comorbidity; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D006115:Greece; D015658:HIV Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012309:Risk-Taking; D012960:Socioenvironmental Therapy; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D055815:Young Adult
keywords: HIV outbreak; PWIDs; intervention; prevalence; respondent-driven sampling; risk factors