Logo of jurbhealthspringer.comThis journalToc AlertsSubmit OnlineOpen ChoiceThis journal
J Urban Health. Mar 2003; 80(1): 106–114.
PMCID: PMC3456110

Estimation of the number of injecting drug users attending an outreach syringe-exchange program and infection with human immunodeficiency virus (HIV) and hepatitis C virus: the AjUDE-Brasil project


This study estimated the number of street injecting drug user (IDU) clients of a syringe-exchange program (SEP) who were infected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). A two-sample capture-recapture method was carried out. The first capture listed all interviewed IDUs outreached for syringe exchange from April 1 to May 1, 1998; the second capture involved those outreached from May 2 to June 6, 1998. Blood spots were collected for HIV and HCV serologies. Analysis used captured probability model varying with time. We interviewed 55 IDUs in the first capture and 99 in the second; 17 participated in both samples. An estimate of 317 IDUs attending the SEP was obtained (95% confidence interval [CI] 235–467). Based on the overall seroprevalence rates for HIV (47.7%) and HCV (53.1%), it was estimated that 151 IDUs were HIV infected (95% CI 112–223) and 168 (95% CI 125–248) were HCV infected. Enumeration of IDUs associated with estimates of the total number of HIV and HCV seropositives provide a powerful tool for SEPs to help monitor the number of IDUs, to plan for provisions, and to organize the new demands on existing health facilities for HIV and HCV care.

Keywords: Capture-recapture, HIV, HCV, Injecting drug users, Syringe-exchange program

Full Text

The Full Text of this article is available as a PDF (73K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Garfein RS, Vlahov D, Galai N, Doherty MC, Nelson KE. Viral infections in short-term injection drug users: the prevalence of the hepatitis C, hepatitis B, human immunodeficiency virus, and human T-lymphotropic viruses. Am J Public Health. 1996;86:655–661. doi: 10.2105/AJPH.86.5.655. [PMC free article] [PubMed] [Cross Ref]
2. Crofts N. Going where the epidemic is. Epidemiology and control of hepatitis C among injecting drug users. Aust Fam Physician. 2001;30:420–425. [PubMed]
3. Oliveira MLA, Bastos FI, Telles PR, et al. Prevalence and risk factors for HBV, HCV and HDV infections among injecting drug users from Rio de Janeiro, Brazil. Brazilian J Med Biol Res. 1999;32:1107–1114. [PubMed]
4. Thomas DL, Astemborski J, Rai RM, et al. Natural history of hepatitis C virus infection. JAMA. 2000;284:450–456. doi: 10.1001/jama.284.4.450. [PubMed] [Cross Ref]
5. Caiaffa WT, Bastos FI. Usuários de drogas injetáveis e infecção pelo virus da imunodeficiência humana: epidemiologia e perspectivas de intervenção. Rev Bras Epidemiol. 1998;1:190–202. doi: 10.1590/S1415-790X1998000200009. [Cross Ref]
6. Bastos FI, Strathdee SA. Evaluating effectiveness of syringe exchange programmes: current issues and future prospects. Soc Sci Med. 2000;51:1771–1782. doi: 10.1016/S0277-9536(00)00109-X. [PubMed] [Cross Ref]
7. Brazil,Boletim Epidemiológico de AIDS XIV. January–March 2001; Brasília, Brazil: Ministry of Health, Secretariat for Health Policies, National STD/AIDS Coordinating Office.
8. Teixeira P, Vitoria M, Barreira D, Dhalia C, Castilho E. Aids epidemics in Brazil: present situation, national response and future trends. Actualizaciones em AIDS. 2001;9:1–9.
9. Strathdee SA, Ameijden E, Mesquita F, et al. Can HIV epidemics among injection drug users be prevented? AIDS. 1998;12:S71–S79. doi: 10.1097/00002030-199808000-00003. [PubMed] [Cross Ref]
10. Strathdee SA, Patrick DM, Currie S, et al. Needle exchange is not enough: lessons from the Vancouver Injection Drug Use Study. AIDS. 1997;11:F59–F59. doi: 10.1097/00002030-199708000-00001. [PubMed] [Cross Ref]
11. Bruneau J, Lamothe F, Franco E, et al. High rates of HIV infection among injection drug users participating in needle exchange programs in Montreal: results of a cohort study. Am J Epidemiol. 1997;146:994–1002. [PubMed]
12. Lurie P. Dr. Lurie replies [letter] Am J Epidemiol. 1998;148:715–715. doi: 10.1093/aje/148.7.715. [Cross Ref]
13. Lurie P, Drucker E. An opportunity lost: HIV infections associated with lack of a national needle-exchange programme in the USA. Lancet. 1997;349:604–608. doi: 10.1016/S0140-6736(96)05439-6. [PubMed] [Cross Ref]
14. Taylor A, Goldberg D, Hutchinson S, Cameron S, Fox R. High risk injecting behaviour among injectors from Glasgow: cross sectional community wide surveys 1990–1999. J Epidemiol Community Health. 2001;55:766–767. doi: 10.1136/jech.55.10.766. [PMC free article] [PubMed] [Cross Ref]
15. Domingo-Salvany A, Hartnoll RL, Maguire A, et al. Analytical considerations in the use of capture-recapture to estimate prevalence: case studies of the estimation of opiate use in the metropolitan area of Barcelona, Spain. Am J Epidemiol. 1998;148:732–740. [PubMed]
16. Davies AG, Cormack RM, Richardson AM. Estimation of injecting drug users in the city of Edinburgh, Scotland, and number infected with human immunodeficiency virus. Int J Epidemiol. 1999;28:117–121. doi: 10.1093/ije/28.1.117. [PubMed] [Cross Ref]
17. Mastro TD, Kitayaporn D, Weniger BG, et al. Estimating the number of HIV-infected injection drug users in Bangkok: a capture-recapture method. Am J Public Health. 1994;84:1094–1099. [PMC free article] [PubMed]
18. Frischer M, Leyland A, Cormack R, et al. Estimating the population prevalence of injection drug use and infection with human immunodeficiency virus among injection drug users in Glasgow, Scotland. Am J Epidemiol. 1993;138:170–181. [PubMed]
19. Hay G, McKeganey N. Estimating the prevalence of drug misuse in Dundee, Scotland: an application of capture-recapture methods. J Epidemiol Community Health. 1996;50:469–472. doi: 10.1136/jech.50.4.469. [PMC free article] [PubMed] [Cross Ref]
20. McKeganey N, Barnard M, Leyland A, Coote I, Follet E. Female streetworking prostitution and HIV infection in Glasgow. BMJ. 1992;305(6857):801–804. doi: 10.1136/bmj.305.6857.801. [PMC free article] [PubMed] [Cross Ref]
21. Otis DL, Burnham KP, White GC, Anderson DR. Statistical inference from capture data on closed animal populations. Wildlife Monogr. 1978;62:1–135.
22. Abeni DD, Brancato G, Perucci CA. Capture-recapture to estimate the size of the population with human immunodeficiency virus type 1 infection. Epidemiology. 1994;5:410–414. doi: 10.1097/00001648-199407000-00006. [PubMed] [Cross Ref]
23. Caiaffa WT. Projeto AjUDE-BRASIL. Avaliação Epidemiológica dos Usuários de Drogas Injetáveis dos Projetos de Redução de Danos Apoiados pela CN-DST/AIDS/Brasil. Brasília, Brazil: Ministry of Health, Secretariat for Health Policies, National STD/AIDS Coordinating Office; 2001. Available at: www.aids.gov.br/final/biblioteca/avaliacao6/ajud1.htm. Accessed December 23, 2002.
24. Silva RC. Mingoti SA.Capture-Recapture Program in Turbo Pascal. Departamento de Estatística da UFMG. Belo Horizonte; 1998.
25. Darroch JN. The multiple-recapture census I: estimation of a closed population. Biometrika. 1958;45:343–359. doi: 10.2307/2333183. [Cross Ref]
26. Rexstad E, Burnham K. User's Guide for Interactive Program Capture. Fort Collins, CO: Colorado Cooperative Fish and Wildlife Research Unit, Colorado State University; 1991.
27. Proietti ABC, Proietti FA, Gonçalves VE, et al. Blood collection on filter paper; a practical approach for sample collection for studies of seroprevalence among Injecting drug users. In:Thirteenth International AIDS Conference, 2000, Durban. 2000;2:348–348.
28. Proietti FA, Caiaffa WT, Proietti ABC, et al. Seroprevalence correlates of HIV and HCV infection among injection drug users attending an outreach syringe exchange program (SEP) in five cities in Brazil. In:Thirteenth International AIDS Conference, 2000, Durban. 2000;2:6.
29. Jarlais DC, Paone D, Milliken J, et al. Audio-computer interviewing to measure risk behaviour for HIV among injecting drug users: a quasi-randomised trial. Lancet. 1999;15(353):1657–1661. doi: 10.1016/S0140-6736(98)07026-3. [PubMed] [Cross Ref]
30. Darke S. Self-report among injecting drug users: a review. Drug Alcohol Depend. 1998;51:253–263. doi: 10.1016/S0376-8716(98)00028-3. [PubMed] [Cross Ref]
31. McElrath K, Chitwood DD, Griffin DK, Comerford M. The consistency of self-reported HIV risk behavior among injection drug users. Am J Public Health. 1994;12:1965–1970. [PMC free article] [PubMed]
32. Anthony JC, Vlahov D, Celentano D, et al. Self-reported interview data for a study on HIV-1 infection among intravenous drug users: description of methods and preliminary evidence on validity. J Drug Issues. 1991;21:739–757.
33. Jarlais DC, Dehne K, Casabona J. HIV surveillance among injecting drug users. AIDS. 2001;15(suppl 3):S13–S22. doi: 10.1097/00002030-200104003-00003. [PubMed] [Cross Ref]
34. Stein MD, Maksad J, Clarke J. Hepatitis C disease among injection drug users: knowledge, perceived risk and willingness to receive treatment. Drug Alcohol Depend. 2001;61:211–215. doi: 10.1016/S0376-8716(00)00144-7. [PubMed] [Cross Ref]

Articles from Journal of Urban Health : Bulletin of the New York Academy of Medicine are provided here courtesy of New York Academy of Medicine


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • MedGen
    Related information in MedGen
  • PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...