Injection drug use is the main mechanism of human immunodeficiency virus (HIV) transmission in Argentina (40% of reported AIDS cases in Argentina). This study was conducted among street-recruited injection drug users (IDUs) from Buenos Aires, with the aim of estimating seroprevalence and coinfection of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-lymphotropic viruses (HTLVs). A total of 174 volunteers participated in this study; 137 were men (78.7% of volunteers). The average age of the participants was 30 years. Only 64 of participants (37%) had no viral infection, whereas 110 (63%) were infected with > or =1 viruses. Seroprevalences were 44.3% for HIV, 54.6% for HCV, 42.5% for HBV, 2.3% for HTLV-I, and 14.5% for HTLV-II. Among the 77 HIV-infected persons, only 6.5% (5 persons) were not coinfected with other viruses; 88.3% (68) were coinfected with HCV and 68.8% (53) were coinfected with HBV. We demonstrated the existence of multiple viral infections with a high rate of prevalence in IDUs in Buenos Aires, Argentina.

The presence of recombinant intersubtypes of HIV-1 in Argentina has been reported since the mid-1990s. In this study, sequences of a region of the gag, pol, and vpu genes of HIV-1 were analyzed in samples of 21 injection drug users (IDUs) residing in the suburbs of the city of Buenos Aires. Genomic characterization and identification of recombination sites were made comparing the 3 regions with reference isolation sequences of subtypes B, F, C, A, and B/F recombinants: CRF12_BF and non-CRF12_BF sequences. Subtype assignment of the analyzed segments was phylogenetically confirmed. All the samples turned out to be BF recombinants in at least 1 of the 3 studied genes. Twelve samples (57%) had the same pattern as the Argentinean CRF12_BF, whereas in the rest, the pattern differed in at least 1 of the 3 genes. The relation of these fragments to the CRF12_BF was phylogenetically verified. These results indicate the predominance of BF recombinants and the presence of a high percentage of sequences closely related to the CRF12_BF in the IDU population in Argentina and suggest a possible association between viral variants and the transmission route.

Non-injecting cocaine users from South America are vulnerable to multiple infections and HCV infection appears to occur through the sharing of straws. HCV infection is associated with intimate relationships with IDUs or HIV-seropositive partners, supporting the hypothesis that HCV risk may be due primarily to risk-taking behaviour associated with drugs in this population.

The aim of this study was to estimate the seroprevalence rates of human immunodeficiency virus (HIV), hepatitis B virus (HBV, core antibody), hepatitis C virus (HCV), and syphilis infections and analyze associated risk factors among 504 non-injecting cocaine users (NICU) in Buenos Aires, Argentina. Participants were interviewed in face-to-face sessions through a short structured questionnaire. Using venipuncture, 10mL of blood was collected. Seroprevalence rates were: HIV (6.3%), HBV (9%), HCV (7.5%), and VDRL (4.2%). The risk of being infected with HIV, HBV, and HCV was significantly associated with having had a sex partner who was either a drug injector or who was known to be HIV positive. HIV and HCV infections were associated with former imprisonment, and HCV was associated with having been tattooed. Because of the rising number of NICU and the multiple infections detected, it is essential to implement prevention strategies focused on this population.

To study drug use in the context of poverty, it is necessary to undertake a complex analysis of various perspectives to understand the dense interweaving of socioeconomic, political, and cultural factors involved in the problem. The analysis of this social scenario was our starting point in planning holistic actions for the prevention of human immunodeficiency virus/acquired immunodeficiency syndrome and other illnesses related to drug use. Merely copying successful models from developed countries, which are designed for other contexts and populations, would result in insufficient and ineffective actions. The Asociación Civil Cristiana Recuperación Atención de Drogadependientes (ACCRAD), also known as "El Retoño" ("sprout"), is a nongovernmental organization that has been working since 1985 to consolidate a model of analysis and intervention that considers this complex framework and seeks to meet the needs of drug users from the poorest sectors of society. Our research on the use of drugs and its relationship to poverty, together with the documentation of harm-reduction interventions, has been carried out since 1997.