Venues, patrons, and alcohol use dynamics: the creation of a high risk sexual environment.

Venue-based HIV prevention interventions, especially in sex on premise venues, can disrupt high-risk sexual networks. However, prior to intervening, it is essential to understand the person-venue dynamics that contribute to HIV risk. As such, we conducted five ethnographic observations at each of six venues where alcohol is sold and sex occurs onsite (2 each porn theaters, sex clubs, and dance clubs) frequented by gay and other men who have sex with men (G&MSM) in the Buenos Aires metropolitan area. Alcohol use, sexual behavior, and person-venue dynamics differed markedly across venue types. In dance clubs, substantial alcohol consumption often preceded visits to the darkroom for sex which, at times, included unprotected anal and vaginal intercourse. Condoms, although available, were not easily accessible. HIV prevention messaging was generally non-existent. These venues are in critical need of interventions to reduce HIV transmission risk.

HIV testing practices among men who have sex with men in Buenos Aires, Argentina.

The objective of the study was to explore HIV-testing practices among men who have sex with men (MSM) in Buenos Aires, Argentina, in light of current international health guidelines that recommend frequent HIV testing for MSM who engage in high-risk behavior. Participants, who were recruited using respondent-driven sampling (RDS), were 500 mostly young, nongay-identified MSM of low socioeconomic status, high levels of unemployment, living mainly in the less-affluent areas surrounding Buenos Aires, and lacking health insurance. They provided blood samples for HIV testing and responded to a Computer Assisted Self Interview. Fifty-two percent had never been tested for HIV, and 20% had been tested only once; 17% were found to be HIV infected, of whom almost half were unaware of their status. Main reasons for never having tested previously were: not feeling at risk, fear of finding out results, and not knowing where to get tested. Among those previously tested, men had been tested a median of 2 times with their most recent test having occurred a median of 2.7 years prior to study enrollment. Of those who had not tested positive before entering the study, only 41% returned for their results. HIV testing was infrequent and insufficient for early detection of infection, entry into treatment, and protection of sexual partners. This was particularly the case among nongay-identified MSM. Testing campaigns should aim to help MSM become aware of their risk behavior, decrease fear of testing by explaining available treatment resources and decreasing the stigma associated with HIV, and by publicizing information about free and confidential testing locations. Rapid HIV testing should be made available to eliminate the need for a return visit and make results immediately available to individuals who are tested.

HIV, HBV, and HCV molecular epidemiology among trans (transvestites, transsexuals, and transgender) sex workers in Argentina.

Commercial sex work is frequent among male-to-female transvestites, transsexuals and transgenders in Argentina, leading to high susceptibility to HIV, HBV, and HCV among other sexually transmitted infections. In a global context of scarce data on the trans sex workers population, this study was aimed to study the genomic characterization of these viruses. Plasma presence of HIV, HBV, and HCV genomic material was evaluated in samples from 273 trans sex workers. Genomic sequences of HIV-gag, pol, and vif-vpu genes, HBV-S gene, and HCV-5'UT and NS5B genes were obtained. Molecular characterization involved phylogenetic analysis and several in silico tools. Resistance-associated mutations in HIV and HBV pol genes were also analyzed. The HIV genomic characterization in 62 trans sex workers samples showed that 54.8% of the isolates corresponded to BF intersubtype recombinants, and 38.7% to subtype B. The remaining were classified as subtypes C (4.8%) and A (1.6%). HBV and HCV co-infection prevalence among HIV positive trans sex workers yielded rates of 3.2% and 6.5% respectively. Drug resistance-associated mutations were found in 12/62 (19%) HIV pol sequences, but none among HBV. Based on phylogenetic relationships, HIV isolates characterized as subtypes BF and B appeared intermingled with those from other high-risk groups. Despite trans sex workers declared not to have received antiviral treatment, complex drug resistance-associated mutation patterns were found in several HIV isolates. Planned prevention, screening, and treatment are needed to reduce further transmission and morbidity.

HIV status disclosure among infected men who have sex with men (MSM) in Buenos Aires, Argentina.

Five hundred men who have sex with men were recruited in Buenos Aires using respondent driven sampling. Of them, 46 respondents (24 of them not gay identified) who were HIV infected were asked questions on serodisclosure. The sample was characterized by indicators of low socioeconomic status. Most of the respondents reported being in good to excellent health despite 42% of them having been diagnosed with AIDS. Only 10% of respondents had not disclosed their serostatus to at least one person. Coworkers and lovers or main sexual partners were those most likely to know the respondents' serostatus. Reactions to disclosure were for the most part supportive. Those who had not disclosed anticipated less favorable reactions than those who had disclosed. No significant differences were observed between gay and non-gay identified respondents. The progressive social environment of Argentina that includes federal laws recognizing gay marriage may contribute to create a climate favorable for serostatus disclosure.

Presence of IgG anti-gp160/120 antibodies confers higher HIV capture capacity to erythrocytes from HIV-positive individuals.

BACKGROUND: HIV binding has been demonstrated in erythrocytes from HIV-positive and HIV-negative individuals. However, the presence of immunoglobulins G anti-HIV (IgG anti-HIV) in erythrocytes from HIV-positive individuals is still to be elucidated. Moreover, the capacity of erythrocytes from HIV-positive individuals to capture an additional amount of HIV has not been studied. Indeed, it is unknown if HIV binding to erythrocytes in HIV-positive persons could have consequences on the cell-free infectious virus available. METHODOLOGY/PRINCIPAL FINDINGS: IgGs anti-HIV associated to erythrocytes were found in 77.3% (58/75) of the HIV-positive individuals studied and the IgGs anti-gp160 and anti-p24 were the most frequently found. We found a positive association between detectable plasma viral load (pVL) and presence of IgGs anti-HIV associated to erythrocyte (p<0.005), though the anti-p24/160 were present with or without detectable pVL. The HIV capture capacity was higher in erythrocytes from HIV-positive than HIV-negative individuals (p<0.0001). Furthermore, among the HIV-positive individuals the higher viral capture capacity was associated with the presence of anti-gp160/gp120 on erythrocytes. Moreover, the viral capture by erythrocytes was independent of pVL (rho=0.022, p=0.8817). Additionally, reduction of cell-free infectious virus and available viral load was observed in the presence of erythrocytes from HIV-positive individuals. CONCLUSIONS/SIGNIFICANCE: Results suggest that in HIV-positive individuals, erythrocytes are capable of capturing high amounts of HIV by the presence of IgGs anti-gp160/120 on their membranes and this may produce a reduction in the available free virus. Finally, the current measurement of pVL would underestimate the real viral quantity due to the HIV binding through specific antibodies to erythrocytes.

Use of respondent driven sampling (RDS) generates a very diverse sample of men who have sex with men (MSM) in Buenos Aires, Argentina.

BACKGROUND: Prior research focusing on men who have sex with men (MSM) conducted in Buenos Aires, Argentina, used convenience samples that included mainly gay identified men. To increase MSM sample representativeness, we used Respondent Driven Sampling (RDS) for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited sample, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior. METHODOLOGY: 500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI. CONCLUSION: In contrast with prior studies, RDS generated a very diverse sample of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as "other." Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49%) reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size.

[Prevalence of HIV infection and Treponema pallidum in Argentine female sex workers]. / Prevalencia de la infección por el VIH y de Treponema pallidum en mujeres trabajadoras sexuales de Argentina.

OBJECTIVE: Estimate the prevalence of human immunodeficiency virus (HIV) infection and Treponema pallidum in Argentine female sex workers (FSW), and describe the sociodemographic characteristics of this population group associated with HIV transmission. METHODS: A cross-sectional study and convenience sampling were conducted in FSW over 18 years of age in nine Argentine cities from October 2006 to December 2009. A total of 1 255 women participated in this study. A group of FSW was especially trained to invite other women to participate in the workshops and undergo screening for HIV and T. pallidum. RESULTS: The most noteworthy socioepidemiological characteristics of the FSW included a high percentage of sexual abuse, limited condom use with noncommercial sex partners, and a high percentage of violence. HIV prevalence was 2% (25/1 255, 95% confidence interval [95% CI]:1.2-2.8) and T. pallidum prevalence was 22.4% (245/1 094; 95% CI: 19.9-24.9). In the city of La Plata, HIV prevalence in FSW was significantly lower compared to that of other regions of the country (0.3% vs. 2.7%, P < 0.05, respectively). CONCLUSIONS: The lower HIV prevalence and the higher rate of condom use reported by the women from La Plata surveyed suggest that the presence of a health center for FSW has a direct influence on reducing risky behavior and, consequently, HIV infection. The creation of "friendly" health centers like the one already in this city contributes to providing a comprehensive response to the problems faced by these women and encourages use of the health system. It therefore helps reverse their vulnerability and higher risk of contracting HIV and other sexually transmitted infections.

Prevalencia de la infección por el VIH y de Treponema pallidum en mujeres trabajadoras sexuales de Argentina / Prevalence of HIV infection and Treponema pallidum in Argentine female sex workers

OBJETIVO: Estimar la prevalencia de infección por el virus de la inmunodeficiencia humana (VIH) y de Treponema pallidum en mujeres trabajadoras sexuales (MTS) de Argentina, y describir las características sociodemográficas de este grupo de población asociadas a la transmisión del VIH. MÉTODOS: Entre octubre de 2006 y diciembre de 2009 se realizó un estudio de corte transversal y un muestreo por conveniencia en MTS mayores de 18 años de nueve ciudades de Argentina. Un total de 1 255 mujeres participaron en este estudio. Se capacitó especialmente a un grupo de MTS para convocar a las otras mujeres a participar en talleres y a realizarse el diagnóstico del VIH y T. pallidum. RESULTADOS: Las características socio-epidemiológicas más destacadas de las MTS incluyeron un alto porcentaje de abuso sexual, escaso uso de preservativos con parejas sexuales no comerciales y un alto porcentaje de situaciones de violencia. La prevalencia del VIH fue de 2 por ciento (25/1 255, intervalo de confianza de 95 por ciento [IC95 por ciento]:1,2-2,8) y la de T. pallidum, de 22,4 por ciento (245/ 1 094, IC95 por ciento: 19,9-24,9). En las MTS de la ciudad de La Plata, la prevalencia del VIH fue significativamente más baja comparada con las participantes del resto del país (0,3 por ciento vs 2,7 por ciento, P < 0,05, respectivamente). CONCLUSIONES: La menor prevalencia del VIH y la mayor tasa de uso de preservativos informadas por las mujeres encuestadas de La Plata sugieren que la presencia de un lugar de atención sanitaria para MTS influye directamente en la disminución de sus conductas de riesgo y, por ende, en la infección por el VIH. La creación de centros de salud "amigables", como el que ya hay en dicha ciudad, contribuye a dar una respuesta integral al problema que enfrentan estas mujeres; asimismo, favorece su acercamiento al sistema de salud y contribuye así a revertir su situación de mayor vulnerabilidad y mayor riesgo frente al VIH y otras infecciones de transmisión sexual.

OBJECTIVE: Estimate the prevalence of human immunodeficiency virus (HIV) infection and Treponema pallidum in Argentine female sex workers (FSW), and describe the sociodemographic characteristics of this population group associated with HIV transmission. METHODS: A cross-sectional study and convenience sampling were conducted in FSW over 18 years of age in nine Argentine cities from October 2006 to December 2009. A total of 1 255 women participated in this study. A group of FSW was especially trained to invite other women to participate in the workshops and undergo screening for HIV and T. pallidum. RESULTS: The most noteworthy socioepidemiological characteristics of the FSW included a high percentage of sexual abuse, limited condom use with noncommercial sex partners, and a high percentage of violence. HIV prevalence was 2 percent (25/1 255, 95 percent confidence interval [95 percent CI]:1.2-2.8) and T. pallidum prevalence was 22.4 percent (245/1 094; 95 percent CI: 19.9-24.9). In the city of La Plata, HIV prevalence in FSW was significantly lower compared to that of other regions of the country (0.3 percent vs. 2.7 percent, P < 0.05, respectively). CONCLUSIONS: The lower HIV prevalence and the higher rate of condom use reported by the women from La Plata surveyed suggest that the presence of a health center for FSW has a direct influence on reducing risky behavior and, consequently, HIV infection. The creation of "friendly" health centers like the one already in this city contributes to providing a comprehensive response to the problems faced by these women and encourages use of the health system. It therefore helps reverse their vulnerability and higher risk of contracting HIV and other sexually transmitted infections.

First report on sexually transmitted infections among trans (male to female transvestites, transsexuals, or transgender) and male sex workers in Argentina: high HIV, HPV, HBV, and syphilis prevalence.

OBJECTIVES: Due to the scarce data on the prevalence of sexually transmitted infections (STIs) among male-to-female trans-sex workers (TSW) and male sex workers (MSW) in Argentina, the present study aimed to estimate the incidence of human immunodeficiency virus (HIV), and the prevalence of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and Treponema pallidum. Human papillomavirus (HPV) and Chlamydia trachomatis infections were tested among TSW. METHODS: Two hundred and seventy-three TSW and 114 MSW were recruited by nongovernmental organizations. HIV incidence was estimated by STARHS (serologic testing algorithm for recent HIV seroconversion). HPV and C. trachomatis infections were tested in anal cells from TSW. RESULTS: TSW showed significantly higher prevalences of HIV (34.1 vs. 11.4%), HBV (40.2 vs. 22.0%), and T. pallidum (50.4 vs. 20.4%) than MSW. TSW tested positive for HPV in 111/114 cases and for C. trachomatis in 4/80 cases. Investigation of HBV, HCV, HIV, and T. pallidum co-infections showed that 72% of TSW and 39% of MSW had at least one STI. T. pallidum was the most frequent mono-infection. The estimated HIV incidence was 10.7 per 100 person-years (95% confidence interval (CI) 3.8-17.7) for TSW and 2.3 per 100 person-years (95% CI 0-6.7) for MSW. CONCLUSIONS: The high prevalence of STIs and the high incidence of HIV demonstrate the great vulnerability of these high-risk populations and indicate the urgent need for preventive strategies on intervention and facilitation of access to healthcare programs.

Human papilloma virus genotype diversity of anal infection among trans (male to female transvestites, transsexuals or transgender) sex workers in Argentina.

BACKGROUND: Reports on the prevalence and genotypes of HPV among trans (male to female transvestites, transsexuals or transgender) sex workers (TSW) are scarce in the literature. OBJECTIVES: The aim of the study was to determine the infecting HPV genotypes among TSW in Argentina. STUDY DESIGN: 119 TSW were recruited. Anal cells were self collected with a cytobrush. HPV DNA detection was carried out by PCR and genotyping was performed by RLB. RESULTS: HPV prevalence was 97.4%. 103/111 HPV positive samples were genotyped. High risk genotypes were detected in 82.5%. Two or more coinfecting HPV genotypes were found in 70.9%. One case showed up to 10 different coinfecting types. The number of genotypes was not related to condom usage. Infection rates were similar for HIV positive (100%) and HIV negative (95.8%) participants. However, 18.8% of HIV negative had 4-9 different genotypes, while among HIV positive this percentage raised to 46.2% (p=0.006). Prevalence of high risk genotypes and the frequency of each high risk type were similar between HIV positive and HIV negative groups. According to the participants' answers HIV status showed no association with condom usage. CONCLUSIONS: The high HPV prevalence, the coinfection with multiple genotypes and the high frequency of high risk genotypes detected, together with a situation of extreme social marginalization, discrimination and stigmatization make this population to be of extreme vulnerability.

Presence of p24-antigen associated to erythrocyte in HIV-positive individuals even in patients with undetectable plasma viral load.

BACKGROUND: HIV adherence to erythrocytes has been demonstrated in vitro, and it has been suggested that erythrocytes may be carriers of the virus. However, the association between HIV particles or viral proteins and erythrocytes in HIV-infected individuals is still to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: HIV-positive participants (n =112) were classified into two groups according to values of three plasma viral loads (pVL) determined during the 12-month period prior to the study. The first group included 71 individuals with detectable pVL, whereas the second group included 41 individuals with undetectable pVL. Plasma viral load, erythrocyte-associated p24-antigen and p24-antigen in plasma were determined at the moment of the study. A total of 51 out of the 71 patients with detectable pVL showed erythrocyte-associated p24-antigen whereas 13 showed p24-antigen in plasma. Twenty-two out of the 51 patients with erythrocyte-associated p24-antigen showed pVL<10,000 copies/ml and undetectable p24-antigen in plasma. The data indicates that the amount of erythrocyte-associated p24-antigen was not related to p24-antigen in plasma or pVL levels in this group. Among the 41 patients with prior undetectable pVL, eight presented detectable pVL and erythrocyte-associated p24-antigen at the moment of the study. The other 33 showed undetectable pVL and five of these presented erythrocyte-associated p24-antigen. A positive relationship was found between the presence of erythrocyte-associated p24-antigen and the detectable pVL at the moment of the study (p<0.00001). Even more, in another series of assays, a detectable viral load associated to erythrocytes was determined and it was always accompanied by erythrocyte-associated p24-antigen detection. CONCLUSIONS/SIGNIFICANCE: This study demonstrates the presence of erythrocyte-associated p24-antigen in HIV-infected individuals. Since erythrocyte-associated p24-antigen is not always related to pVL or p24-antigen in plasma, erythrocyte-associated p24-antigen showed viral expression not represented in plasma. Therefore, the determination of erythrocyte-associated p24-antigen may contribute to better understand the kinetics and/or evolution of HIV infection.

Prevención del VIH/Sida en los circuitos de levante HSH: una asignatura pendiente / Prevenção do HIV/AIDS nos circuitos de levante HSH: uma assinatura pendente / Prevention of HIV / AIDS in MSM uprising circuits: a pending signature

A partir de un relevamiento de tipo etnográfico, este artículo describe prácticas sexuales y lugares de encuentro de HSH (Hombres que tienen Sexo con Hombres) en la ciudad de Buenos Aires. Tales espacios, así como las características que asumen en ellos los encuentros sexuales, delinean obstáculos específicos en la adopción de comportamientos preventivos, y generan nuevos desafíos para las actividades de prevención. Se plantean además dificultades y debates conceptuales que la categoría HSH presenta, y sus consecuencias en el abordaje preventivo y teórico-metodológico para las ciencias sociales. Se proponen asimismo nuevos interrogantes acerca de los alcances y las limitaciones del modelo preventivo del VIH/Sida para HSH...

A partir de um levantamento de tipo etnográfico, este artigo descreve práticas sexuais e lugares de encontro de HSH (Homens que fazem Sexo com Homens) na cidade de Buenos Aires. Tais espaços, assim como as características que neles assumem os encontros sexuais, delineiam obstáculos específicos na adoção de comportamentos preventivos, e geram novos desafios para as atividades de prevenção. Estabelecem-se, além disso, dificuldades e debates conceituais que a categoria HSH apresenta, e suas consequências na abordagem preventiva e teórico-metodológica para as ciências sociais. São propostas também novas interrogações a respeito dos alcances e das limitações do modelo preventivo do HIV/AIDS para o HSH...

Based on findings from an ethnographic study, we describe cruising sites and sexual behavior among men who have sex with men (MSM) in the city of Buenos Aires. These dynamics present specific obstacles to adopting HIV preventive behaviors, thus generating new concerns about the effectiveness of prevention approaches. We also introduce the difficulties and debates around the use of "MSM" as an analytical category, and their consequences as related to prevention and social science theory and methods. New concerns are raised regarding the reach and limitations of the current HIV/AIDS prevention model for MSM...

PREVENCIÓN DEL VIH/SIDA EN LOS CIRCUITOS DE LEVANTE HSH: UNA ASIGNATURA PENDIENTE.

A partir de un relevamiento de tipo etnográfico, se describen lugares de encuentro de HSH en la Ciudad de Buenos Aires y sus prácticas sexuales. El reconocimiento de tales espacios, así como las características que asumen en ellos los encuentros sexuales entre los HSH, plantean obstáculos específicos en la adopción de comportamientos preventivos y, asimismo, generan nuevos desafíos para las actividades de prevención. Se plantean las dificultades y debates conceptuales que la misma categoría presenta, y sus consecuencias en el abordaje preventivo y teórico-metodológico para las ciencias sociales. Además, se proponen nuevos interrogantes acerca de los alcances y las limitaciones del modelo preventivo del VIH/Sida para HSH.

Centrifugation improves the detection of HIV-1 p24 antigen in plasma from children born to mothers infected with HIV-1.

Detection of HIV proteins and/or nucleic acids is necessary for the diagnosis of perinatal HIV infection. Despite its low sensitivity, detection of p24 antigen in plasma is a simple and economic method for the diagnosis of HIV in exposed children. The aim of this study was to improve the sensitivity of detection of p24 using centrifugation of plasma. Forty-seven selected stored samples from 37 children (23 infected, 14 uninfected, median age of 137 days) were examined. Plasma samples (volume 0.3-1.5 ml) were defrosted, centrifuged at 23,500 x g at 4 degrees C for 60 min and determination of p24 was carried out in the resuspended pellet (0.12 ml). In 32 plasma samples from infected children, p24 was found originally in 6 (18.7%) and resulted positive in 24 (75%) pellets. When only one sample per child was considered, sensitivity was significantly higher in pellets, 3/23 uncentrifuged plasma samples and 15/23 pellets (McNemar Test, p<0.001). Specificity was 100%. The absorbance/cut-off ratio was always higher in the pellets from positive children (p=0.028). Plasma samples with volumes of 1 ml or more achieved a higher sensitivity (91.7% vs. 36.4%, p=0.009). Centrifugation of plasma samples prior to determination of p24 in pediatric patients resulted in a significant increase in sensitivity.

HIV seroincidence estimates among at-risk populations in Buenos Aires and Montevideo: use of the serologic testing algorithm for recent HIV seroconversion.

Using the serological testing algorithm for recent HIV seroconversion, we estimated annualized incidences (per 100 person-years) of HIV-1 infection in different at-risk groups in Buenos Aires and Montevideo, during a 5-year period between 1998 and 2003. HIV-positive serum samples from 9 serosurveys conducted among men who have sex with men, patients attending clinics for a sexually transmitted infections consult (STIs), female commercial sex workers, injecting drug users (IDUs), noninjecting cocaine users (NICUs), asymptomatic women screened for HIV infection, and patients with tuberculosis were used. HIV incidences were as follows: 6.7 for men who have sex with men, 2.0 for STIs, 1.3 for female commercial sex workers, 0.0 for Argentinean IDUs, 10.3 for Uruguayan IDUs, 3.1 for Argentinean NICUs, 4.4 for Uruguayan NICUs, and 2.4 for patients with tuberculosis. Among asymptomatic women screened for HIV infection, incidence rose from 0.4 in 1998 to 4.6 in 1999 and to a high of 10.2 in the year 2000. Unexpectedly, high HIV incidences were detected among at-risk groups in Buenos Aires and Montevideo. This pattern shows an emerging HIV epidemic among heterosexuals stemming from core HIV-infected at-risk groups. There is an urgent need for development and implementation of specific prevention strategies to address this burgeoning epidemic.

High human immunodeficiency virus type 1 seroprevalence in men who have sex with men in Buenos Aires, Argentina: risk factors for infection.

OBJECTIVE: To determine human immunodeficiency virus (HIV) seroprevalence in a sample of men who have sex with men (MSM) in Buenos Aires City and to identify risk factors associated with HIV type 1 infection. METHODS: Participants were invited to receive HIV counselling and testing at "NEXO" (a gay non-governmental organization) by means of informative leaflets distributed in gay nightclubs, porno cinemas, gymnasiums, and in the streets. During the encounter, the study was explained by a trained social worker and individuals were invited to volunteer for the study. Diagnosis of HIV was performed using two screening tests and Western Blot assay was used as confirmatory. RESULTS: Human immunodeficiency virus was detected in 96 (13.8%; 95% CI: 11.4-16.7) of 694 MSM. Fourteen (14.6%) of the 96 HIV-positive MSM were already aware of their HIV serostatus. In univariate analysis, HIV-1 infection (odds ratio [OR] >1.5) was found to be associated with older age (30-39 years), being unemployed, a previous sexually transmitted disease (STD) history, and having an HIV-positive partner. Cocaine consumption and irregular use of condoms with occasional partners were also found to be risk factors. In multivariate logistic regression analysis, being unemployed (OR = 3.42; 95% CI: 1.17-9.99) and having an HIV-positive partner (OR = 2.67; 95% CI: 1.09-6.52) remained significant risk factors. DISCUSSION: The high HIV-1 prevalence observed suggests an urgent need for implementation of effective prevention campaigns. This represents the first cross-sectional epidemiological study of HIV among the high-risk group of MSM in Argentina.