title: Prevalence and behavioural risks for HIV and HCV infections in a population of drug users of Dakar, Senegal: the ANRS 12243 UDSEN study.
abstract: OBJECTIVE
  Data on the extent of drug use and associated HIV, hepatitis C and hepatitis B infection in West Africa are lacking. The objectives of ANRS12244 UDSEN study were to estimate the size of the heroin and/or cocaine drug user (DU) population living in the Dakar area (Senegal), and assess the prevalence and risk factors of HIV, hepatitis C virus (HCV) and hepatitis B virus (HBV), including behavioural determinants in this population, in order to set up an integrated prevention and treatment programme for DUs.
  
  
  METHODS
  A capture-recapture method was applied for population size estimation, whereas the respondent-driven sampling (RDS) method was used to recruit a sample of DUs living in the Dakar area and determine HIV, HBV and HCV prevalence. Behavioural data were gathered during face-to-face interviews, and blood samples were collected on dried blood spots for analysis in a central laboratory. Data analysis was performed using the RDS analysis tool, and risk factors were determined by logistic regression. Access to laboratory results was organized for the participants.
  
  
  RESULTS
  The size of the DU population in the Dakar area was estimated to reach 1324 (95% confidence interval (95% CI: 1281-1367)). Based on the 506 DUs included in the study, the HIV, HCV and HBV prevalence were 5.2% (95% CI: 3.8-6.3), 23.3% (95% CI: 21.2-25.2) and 7.9% (95% CI: 5.2-11.1), respectively. In people who inject drugs (PWID), prevalence levels increased to 9.4% for HIV and 38.9% for HCV (p=0.001 when compared to those who never injected). Women were more at risk of being HIV infected (prevalence: 13.04% versus 2.97% in males, p=0.001). Being PWID was a risk factor for HCV and HIV infection (odds ratio, OR: 2.7, 95% CI: 1.7-4.3, and OR: 4.3, 95% CI: 1.7-10.7, respectively), whereas older age and female sex were additional risk factors for HIV infection (10% increase per year of age, p=0.03 and OR: 4.9, 95% CI: 1.6-156, respectively). No specific determinant was associated with the risk of HBV infection.
  
  
  CONCLUSIONS
  High HIV and HCV prevalence were estimated in this population of DUs (including non-injectors) living in the Dakar area, Senegal, whereas HBV prevalence was close to that of the global Senegalese population, reflecting a risk of infection independent of drug use. Women seem to be highly vulnerable and deserve targeted interventions for decreasing exposure to HIV, while behavioural risk factors for HIV and HCV include the use of unsafe injections, reflecting the urgent need for developing harm reduction interventions and access to opioid substitution therapy services.
authors.affiliation: Institut Médecine Epidémiologie Appliquée, Université Xavier Bichat, Paris, France; anlepretre@gmail.com.
authors.forename: Annie
authors.initials: A
authors.lastname: Leprêtre
authors.affiliation: Hôpital Psychiatrique de Thiaroye, Dakar, Senegal.
authors.forename: Idrissa
authors.initials: I
authors.lastname: Ba
authors.affiliation: Sorbonne-Universités, Paris, France.|Service de Maladies Infectieuses et Tropicales, Hôpitaux Universitaires de l'Est Parisien, Hôpital Saint-Antoine, Paris, France.|Inserm UMR-S1136, Institut Pierre-Louis de Santé Publique, Paris, France; karine.lacombe@sat.aphp.fr.
authors.forename: Karine
authors.initials: K
authors.lastname: Lacombe
authors.affiliation: Centre Régional de Recherche et de Formation à la Prise en Charge Clinique (CRCF), Service des Maladies Infectieuses, Centre Hospitalier Universitaire de Fann, Dakar, Sénégal.
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Maynart
authors.affiliation: Institut Médecine Epidémiologie Appliquée, Université Xavier Bichat, Paris, France.
authors.forename: Abdalla
authors.initials: A
authors.lastname: Toufik
authors.affiliation: Centre Régional de Recherche et de Formation à la Prise en Charge Clinique (CRCF), Service des Maladies Infectieuses, Centre Hospitalier Universitaire de Fann, Dakar, Sénégal.
authors.forename: Ousseynou
authors.initials: O
authors.lastname: Ndiaye
authors.affiliation: Laboratoire de Bacterio-virologie, Hôpital Le Dantec, Dakar, Senegal.
authors.forename: Coumba Toure
authors.initials: CT
authors.lastname: Kane
authors.affiliation: Sorbonne-Universités, Paris, France.|Laboratoire de Virologie, Hôpitaux Universitaires de l'Est Parisien, Hôpital Saint-Antoine, Paris, France.
authors.forename: Joël
authors.initials: J
authors.lastname: Gozlan
authors.affiliation: Centre Régional de Recherche et de Formation à la Prise en Charge Clinique (CRCF), Service des Maladies Infectieuses, Centre Hospitalier Universitaire de Fann, Dakar, Sénégal.
authors.forename: Judicaël
authors.initials: J
authors.lastname: Tine
authors.affiliation: Centre Régional de Recherche et de Formation à la Prise en Charge Clinique (CRCF), Service des Maladies Infectieuses, Centre Hospitalier Universitaire de Fann, Dakar, Sénégal.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Ndoye
authors.affiliation: Département Santé, Expertise France, Paris, France.|Service de Maladies Infectieuses et Tropicales, Hôpitaux Universitaires de l'Est Parisien, Hôpital Saint-Antoine, Paris, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Raguin
authors.affiliation: Sorbonne-Universités, Paris, France.|Service de Maladies Infectieuses et Tropicales, Hôpitaux Universitaires de l'Est Parisien, Hôpital Saint-Antoine, Paris, France.|Inserm UMR-S1136, Institut Pierre-Louis de Santé Publique, Paris, France.
authors.forename: Pierre-Marie
authors.initials: PM
authors.lastname: Girard
mesh_terms: D000328:Adult; D055030:Drug Users; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000209:etiology; D040261:Harm Reduction; D006509:Hepatitis B / Q000453:epidemiology / Q000209:etiology; D006526:Hepatitis C / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012309:Risk-Taking; D019966:Substance-Related Disorders / Q000150:complications
keywords: Senegal; drug use; hepatitis B virus; hepatitis C virus; human immunodeficiency virus; respondent-driven sampling