In vivo drug resistance mutation dynamics from the early to chronic stage of infection in antiretroviral-therapy-naïve HIV-infected men who have sex with men.

Human immunodeficiency virus type 1 (HIV) primary drug resistance mutations (DRMs) influence the long-term therapeutic effects of antiretroviral treatment (ART). Drug-resistance genotyping based on polymerase gene sequences obtained by next-generation sequencing (NGS) was performed using samples from 10 ART-naïve HIV-infected men who have sex with men (MSM; P1-P10) from the acute/early to chronic stage of infection. Three of the 10 subjects exhibited the presence of major (abundance, ≥ 20%) viral populations carrying DRM at early/acute stage that later, at the chronic stage, dropped drastically (V106M) or remained highly abundant (E138A). Four individuals exhibited additional DRMs (M46I/L; I47A; I54M, L100V) as HIV minority populations (abundance, 2-20%) that emerged during the chronic stage but ephemerally.

High Substance Use and HIV Risk Behavior Among Young Argentine Men Who Have Sex with Men.

In the United States young men who have sex with men have higher rates of substance use, higher HIV incidence, and less frequent HIV testing than their heterosexual counterparts and older MSM. Less is known about comparable populations in Latin America. As part of an epidemiological study, MSM were recruited through Respondent Driven Sampling in the metropolitan area of Buenos Aires, Argentina and answered a computerized behavioral survey. From the total of 500 MSM enrolled, a sub-sample of 233 aged 18-25 was analyzed. The sample was concentrated among lower socioeconomic strata, and only 16% identified as gay. Nearly half reported male, female, and transvestite sexual partners. Reported substance use was widespread ranging from 61% for marijuana to 20% for pasta base (cocaine sulfate). Seventy percent of the sample had never been tested for HIV infection; 3% tested positive for HIV and 8% for syphilis during the study.

High Frequency of Illegal Drug Use Influences Condom Use Among Female Transgender Sex Workers in Argentina: Impact on HIV and Syphilis Infections.

The high prevalence of HIV and syphilis found among female transgender sex workers (FTSWs) in Argentina calls for the study of factors leading to negative health consequences. Given the particular characteristics observed in this population (high marginalization, school dropout, and low adherence to healthcare services), we explored the association of several socio-demographic characteristics with syphilis and HIV infections, and the determinants of condom use. This study revealed that FTSWs from Argentina were exposed to several risk factors decreasing thus their ability to negotiate condom use and leading to increased risk for transmission of HIV and other sexually transmitted infections (STIs). Strategies to reduce HIV and syphilis in this population should consider interventions aimed at decreasing violence and substance use which appear to be the most important determinants. Results of this study will contribute to the global information among FTSWs.

High prevalence of substance use among men who have sex with men in Buenos Aires, Argentina: implications for HIV risk behavior.

Five hundred gay and other men who have sex with men (G&MSM) from Buenos Aires, Argentina completed an assessment regarding substance use and sexual behavior. During the past 2 months, 78 % of participants consumed alcohol and 61 % drugs. Over 20 % of participants reporting alcohol, marijuana, cocaine sulfate, or tranquilizer use, did so daily. Heavy alcohol use was more likely among participants with greater mood reactivity (AOR = 1.64) and less likely among those who identified as gay (AOR = 0.38). Weekly drug use was less likely among older (AOR = 0.98), and gay-identified participants (AOR = 0.50), but more likely among participants with greater mood reactivity (AOR = 1.49). Drug use was correlated with unprotected anal and vaginal intercourse with men, women, and transvestites among non-gay identified participants (r = 0.22). Findings highlight the need to reduce substance use and sexual risk behavior in this population.

HIV knowledge and beliefs among men who have sex with men (MSM) in Buenos Aires, Argentina.

Five hundred men who have sex with men (MSM), recruited through respondent driven sampling in Buenos Aires, Argentina, were interviewed in order to assess knowledge and beliefs about HIV infection. The mean proportion of HIV correct knowledge answers was 62 %; however participants whose sexual partners in the prior year included women (MSM&W) had lower frequencies of correct answers than participants with no women partners. Men with previous HIV testing experience and those who were HIV positive had higher HIV knowledge. In relation to HIV beliefs, less than half of participants responded correctly to each of the scenarios presented. Accurate answers for all items were more likely among those who only have sex with men. Men have basic HIV knowledge but also many misconceptions about transmission and prevention. Furthermore, MSM&W have less information than those who are exclusively MSM, probably related to the fact that information campaigns specifically targeted gay identified men.

HIV/STI co-infections, syphilis incidence, and hepatitis B vaccination: the Buenos Aires cohort of men who have sex with men.

In a previous cohort study among 327 men who have sex with men (MSM) in Buenos Aires, an HIV incidence rate of 3.9 per 100 persons-year was reported. Using data from this study, we determined: (a) HIV/STI co-infections; (b) clinical manifestations of incident HIV infections; (c) syphilis incidence and its associated risk factors; and (d) adherence and immune response to hepatitis B virus (HBV) vaccine. During the cohort study, 12 incident HIV infections were found. Within this group, HIV infection alone was most frequent (42%), followed by co-infection of HIV/HBV (33%), and triple co-infection of HIV/HBV/syphilis (25%). The most frequent clinical manifestations among incident HIV cases were: pharyngitis, fever, lymphadenopathy, asthenia, and myalgia. Seven new syphilis infections were detected yielding an incidence rate of 2.4 (95% CI=1.07 - 4.73) per 100 persons-year. Sex work was the only significant risk factor associated with syphilis seroconversion (hazard rate=10.93, p-value=0.033). Only 7% of cohort participants reported having received HBV vaccine. Ninety-percent of the 204 cohort members who agreed to be vaccinated completed the HBV vaccination schedule with an immune response rate of 85%. Our findings suggest the need to increase the access to serologic testing for STI and HBV immunization, as well as the developing of effective HIV/STI behavioral and educational prevention programs among MSM in Buenos Aires.

Longitudinal characterization of HIV-1 pol-gene in treatment-naïve men-who-have-sex-with-men from acute to chronic infection stages.

HIV-1 is characterized by its ability to mutate and recombine even at polymerase (pol) gene. However, pol-gene diversity is limited due to functional constraints. The aim of this study was to characterize longitudinally, by next-generation sequencing (NGS), HIV-1 variants based on pol-gene sequences, at intra- and inter-host level, from acute/early to chronic stages of infection, in the absence of antiretroviral therapy. Ten men who have sex with men (MSM) were recruited during primary infection and yearly followed for five years. Even after a maximum of a five-year follow-up period, the phylogenetic analysis of HIV-1 pol-gene sequences showed a host-defined structured pattern, with a predominance of purifying selection forces during the follow-up. MSM had been acutely infected by different HIV-1 variants mainly ascribed to pure subtype B, or BF recombinant variants and showed different genetic mosaicism patterns that last until the chronic stage, representing a major challenge for prevention strategies.

Human immunodeficiency virus and tuberculosis in Argentina: prevalence, genotypes and risk factors.

The objective of this study was to determine the prevalence and genetic variability of human immunodeficiency virus type 1 (HIV-1) and other sexually transmitted infections (STIs) among 205 patients with clinical diagnosis of tuberculosis (TB) in Buenos Aires in 2001. Infections with hepatitis B virus (HBV), HIV-1, hepatitis C virus (HCV), Treponema pallidum and human T-cell lymphotropic virus types I/II were diagnosed in 37/187 (19.8 %), 35/205 (17.1 %), 22/187 (11.8 %), 13/187 (7.0 %) and 4/181 (2.2 %) patients, respectively. Almost one in three participants (33.1 %) presented at least one infection in addition to TB. Multiresistance to TB drugs (isoniazid plus rifampicin) was detected in the isolates recovered from three patients. Injecting drug use was detected as the main risk factor for HIV, HBV and HCV infections. Of ten patients who died, eight were infected with HIV. HIV genetic characterization showed the presence of two different subtypes. Env subtype F was found in 13/24 samples (54.2 %) and subtype B in 11/24 samples (45.8 %) by heteroduplex mobility assay. Sequencing of the protease/RT region was performed in ten samples: three were characterized as subtype B and seven as B/F recombinants by bootscanning analysis. Phylogenetic analysis of four full-length sequences showed that three were the circulating recombinant form CRF12_BF. The results of this study suggest an urgent need to detect HIV infection in high-risk groups to prevent future HIV transmission as well as morbidity and mortality associated with TB by providing highly active antiretroviral therapy (HAART) and/or TB treatment. Collaboration between TB and HIV programmes seems to be the best approach to decrease the incidence of these diseases, especially in high-prevalence HIV settings.

High genetic variability of HIV-1 in female sex workers from Argentina.

BACKGROUND: A cross-sectional study on 625 Female Sex Workers (FSWs) was conducted between 2000 and 2002 in 6 cities in Argentina. This study describes the genetic diversity and the resistance profile of the HIV-infected subjects. RESULTS: Seventeen samples from HIV positive FSWs were genotyped by env HMA, showing the presence of 9 subtype F, 6 subtype B and 2 subtype C. Sequence analysis of the protease/RT region on 16 of these showed that 10 were BF recombinants, three were subtype B, two were subtype C, and one sample presented a dual infection with subtype B and a BF recombinant. Full-length genomes of five of the protease/RT BF recombinants were also sequenced, showing that three of them were CRF12_BF. One FSW had a dual HIV-1 infection with subtype B and a BF recombinant. The B sections of the BF recombinant clustered closely with the pure B sequence isolated from the same patient. Major resistance mutations to antiretroviral drugs were found in 3 of 16 (18.8%) strains. CONCLUSION: The genetic diversity of HIV strains among FSWs in Argentina was extensive; about three-quarters of the samples were infected with diverse BF recombinants, near twenty percent had primary ART resistance and one sample presented a dual infection. Heterosexual transmission of genetically diverse, drug resistant strains among FSWs and their clients represents an important and underestimated threat, in Argentina.

Buenos Aires cohort of men who have sex with men: prevalence, incidence, risk factors, and molecular genotyping of HIV type 1.

The prevalence, incidence, risk factors, and molecular genotyping of HIV-1 infection among men who have sex with men (MSM) were assessed through a prospective cohort study. The study was conducted in Buenos Aires from February 2003 to December 2004. Sociodemographic, sexual risk behavior data, and blood samples for HIV testing were collected at baseline and at 6 and 12 months. Cox regression analysis was applied to determine risk factors associated with HIV seroconversion. HIV-positive samples were analyzed by partial (pro/RT) and full-length genome sequencing. Of 811 HIV-negative participants evaluated at baseline, 327 volunteers that fulfilled the inclusion criteria were enrolled. Retention rates at 6 and 12 months were 97.2% and 91.5%, respectively. Twelve MSM seroconverted for HIV infection [incidence rate = 3.9 (95% CI = 2.0-6.7) per 100 person-years]. HIV seroconversion was associated with a greater number of different sexual contacts in the preceding 6 months (> or =10, hazard ratio = 3.3, 95% CI: 1.1-10.4). By partial pro/RT genotyping analysis, 83% HIV-positive samples were subtype B and 17% samples were BF recombinants, most of these being unique recombinant forms. This study describes for the first time the recruitment and follow-up of a cohort of MSM in Argentina. Retention rates and HIV incidence rate were high. These data should be considered as a promising potential population for HIV vaccine trials.

Genomic characterization and molecular evolution analysis of subtype B and BF recombinant HIV-1 strains among Argentinean men who have sex with men reveal a complex scenario.

Currently, data on HIV-1 circulating strains among men who have sex with men (MSM) in Argentina is scarce. In South America, the distribution and the prevalence of BF recombinants are dissimilar and exhibit an underappreciated heterogeneity of recombinant structures. Here, we studied for the first time the genetic diversity of HIV-1 BF recombinants and their evolution over time through in-depth phylogenetic analysis and multiple recombination detection methods involving 337 HIV-1 nucleotide sequences (25 near full-length (NFL) and 312 partial pol gene) obtained from Argentinean MSM. The recombination profiles were studied using multiple in silico tools to characterize the genetic mosaicism, and phylogenetic approaches to infer their relationships. The evolutionary history of BF recombinants and subtype B sequences was reconstructed by a Bayesian coalescent-based method. By phylogenetic inference, 81/312 pol sequences clustered within BF clade. Of them, 46 sequences showed a genetic mosaic with CRF12_BF-like patterns, including plausible second-generation recombinants. Other CRFs_BF like (CRF17, 28, 29, 39, 42, 44, 47) and probable URFs_BF were less frequently found. Phylogenetic and recombination analyses on NFL sequences allowed a meticulous definition of new BF mosaics of genomic patterns. The Bayesian analyses pointed out quite consistent onset dates for the CRFs_BF clade based on B and F gene datasets (~1986 and ~1991 respectively). These results indicate that the CRFs_BF variants have been circulating among Argentinean MSM for about 30 years. This study reveals, through growing evidence showing the importance of MSM in the dynamics of the HIV-1 epidemic in Argentina, the coexistence of CRF12_BF-like and high diversity of strains exhibiting several BF mosaic patterns, including non-reported URFs that may reflect active clusters as potential intervention targets to hinder HIV-1 transmission.

High acceptability of rapid HIV self-testing among a diverse sample of MSM from Buenos Aires, Argentina.

INTRODUCTION: The objective of this study was to explore the acceptability of rapid HIV self-testing (RHST) among men who have sex with men (MSM). METHODS: During 2006-2009, a sample of 500 MSM was recruited through Respondent Driven Sampling for an HIV prevalence/incidence study. Attitude toward RHST was explored among HIV negative MSM. Data were weighted prior to analyses. RESULTS: Participants reported they were likely to buy RHST (74%), test themselves more frequently than they currently do (77%), and that the procedure would simplify testing (70%). Furthermore, 71% reported they would probably use it alone, 66% would use it with a steady partner, and 56% with a friend/partner. While a majority acknowledged that RHST use would deprive them of receiving counseling (61%), 74% declared they would go for help if they tested positive; 57% would use an RHST in order to avoid condoms. Probability of use surpassed 70% among gay and non-gay identified MSM as well as those with and without a previous HIV test. Those likely to buy RHST were older (p = 0.025) and more likely to identify as gay (p = 0.036). A total of 17% said they would think about killing themselves and 9% would attempt suicide if they tested positive. These MSM were more likely to be younger (p<0.001), with lower mood level (p<0.001) and greater feelings of loneliness (p = 0.026). CONCLUSIONS: The high acceptability of RHST found among MSM should encourage the authorities to consider the possibility of offering it for self-testing, as it can improve early diagnosis and prevention of future transmissions. However, further research is needed to understand how to best disseminate RHST among MSM who wish to use it and to offer support and linkage to care for those who test HIV-positive.

First report of an HIV-1 triple recombinant of subtypes B, C and F in Buenos Aires, Argentina.

We describe the genetic diversity of currently transmitted strains of HIV-1 in men who have sex with men (MSM) in Buenos Aires, Argentina between 2000 and 2004. Nearly full-length sequence analysis of 10 samples showed that 6 were subtype B, 3 were BF recombinant and 1 was a triple recombinant of subtypes B, C and F. The 3 BF recombinants were 3 different unique recombinant forms. Full genome analysis of one strain that was subtype F when sequenced in pol was found to be a triple recombinant. Gag and pol were predominantly subtype F, while gp120 was subtype B; there were regions of subtype C interspersed throughout. The young man infected with this strain reported multiple sexual partners and sero-converted between May and November of 2004. This study reported for the first time the full genome analysis of a triple recombinant between subtypes B, C and F, that combines in one virus the three most common subtypes in South America.

Prevalence of HIV and other sexually transmitted infections among female commercial sex workers in Argentina.

Sexually transmitted infections (STIs) have shown to enhance the transmission of human immunodeficiency virus (HIV) and to be more common among female commercial sex workers (FSWs). A cross-sectional study was conducted among 625 FSWs in six cities of Argentina in 2000-2002. The seroprevalence of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphotropic virus type I/II, and syphilis was 3.2%, 14.4%, 4.3%, 1.6%, and 45.7%, respectively. Syphilis was associated with older age (>/= 30 years, adjusted odds ratio [AOR] = 2.6 to 4.9), >/= 10 years in sex work (AOR = 2.2), use of illegal drugs (AOR = 2.1), and a prior history of an STI (AOR = 3.0). HBV and syphilis was the most common co-infection in 44 (7.5%) subjects. FSWs in Argentina are exposed to HIV and other STIs due to high-risk sexual and illegal drug use behavior. Renewed efforts are necessary to intervene effectively in this high-risk population.

[Summary of the LINKS Study: Factors associated with HIV infection among men who have sex with men in Buenos Aires, Argentina]. / Reseña del estudio "LINKS": Factores asociados a la infección por VIH en hombres que tienen sexo con hombres de Buenos Aires, Argentina.

This article summarizes published findings from Project LINKS. A total of 500 men who have sex with men were recruited through Respondent Driven Sampling into this study on factors associated with HIV infection. Among participants, 24.5 % identified as gay, 36.2 % as bisexual, 21.9 % as heterosexual, and 17.4 % as "other"; 33 % reported having sex with men, women, and transgender women during the prior two months. Prevalence of HIV, Hepatitis B, and syphilis was 17.3 %, 22.9 %, and 20.5 %, respectively; rates were significantly higher among participants who only had male sex partners. Over two-thirds of participants reported unprotected anal or vaginal intercourse during the prior two months, and 52 %had never been tested for HIV. Twenty-five percent reported heavy drinking, and 34 % reported poly-drug use during the past two months. Eighteen percent of participants reported a sexual experience prior to the age of thirteen with a partner who was at least four years older. Acceptability of microbicides and HIV home testing was high.

High seroprevalence of bloodborne viruses among street-recruited injection drug users from Buenos Aires, Argentina.

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.

Molecular Epidemiology of HIV Type 1 in Ecuador, Peru, Bolivia, Uruguay, and Argentina.

Surveillance for HIV infection among people at increased risk was conducted in five countries in South America. Seroprevalence studies were conducted in more than 36,000 people in Ecuador, Peru, Boliva, Uruguay, and Argentina, along with genetic analysis of the HIV-1 strains. In all countries, the prevalence of HIV-1 among men who have sex with men (MSM) was high (3-30%), whereas the prevalence among female commercial sex workers (FCSMs) was low (0.3-6%). By envelope heteroduplex mobility assay, subtype B predominated in MSM communities and in FCSWs in Ecuador, Bolivia, and Peru. A new genetic screening assay, the multiregion hybridization assay for subtypes B and F (MHA-bf), was developed to improve large-scale genetic screening in South America. MHA-bf can screen four regions of the genome for subtype B or subtype F, and thus can detect most recombinants. The sensitivity of MHA-bf when applied to a panel of pure subtypes and CRF12_BF was 100%, and 88% of unique recombinants were also detected as recombinant. Using MHA-bf, more than 80% of samples from Ecuador, Peru, and Bolivia were classified as pure subtype B, whereas in Uruguay and Argentina this proportion was only 30 to 40%. BF recombinants were the most prevalent form of HIV-1 in Uruguay and Argentina. Subtype B is the most common subtype in countries lacking injecting drug use (IDU) epidemics, whereas BF recombinants are more common in countries where extensive IDU epidemics have been documented, suggesting the ontogeny of recombinant strains in particular risk groups in South America.

Human immunodeficiency virus type 1 and other viral co-infections among young heterosexual men and women in Argentina.

Infections with hepatitis C virus, (HCV), hepatitis B virus (HBV), and human T lymphotropic type I/II (HTLV-I/II) virus are commonly found in patients infected with human immunodeficiency virus type 1 (HIV-1). We conducted a seroepidemiologic study among 174 HIV-positive heterosexuals in Buenos Aires, Argentina in 1999. Evidence of exposure to HCV, HBV, and HTLV-I/II was found in 32%, 17%, and 5%, respectively. A higher prevalence of HBV infection was observed among males (33%) compared with females (12%; P < 0.05). Among women, a prior history of a sexually transmitted infection, injecting drug use (IDU), having had more than five lifetime sex partners, and having exchanged sex-for-goods were significantly associated with HCV infection, whereas an IDU history, syringe sharing, and having exchanged sex-for-goods were found to be associated with HBV infection. Among men, an IDU history and syringe/needle sharing were significantly associated with HCV infection. The IDU-related and sexual transmission of hepatitis viruses constitute a significant problem among young, HIV-infected, heterosexuals in Argentina.

Childhood sexual experiences with an older partner among men who have sex with men in Buenos Aires, Argentina.

This study sought to describe childhood sexual experiences with older partners (CSEOP) among men who have sex with men (MSM) in Buenos Aires, Argentina. MSM were recruited through respondent driven sampling. They responded to a computer administered self-interview with questions on CSEOP, operationalized as manual, oral, genital, or anal contact prior to age 13 with a partner at least 4 years older. Of the 500 respondents, only 25% identified as gay. Eighteen percent of the respondents reported CSEOP, the majority of whom did not feel they were hurt by the experience and did not consider it to be childhood sexual abuse (CSA). Over two-thirds of MSM who reported CSEOP said that their older partner was a female. Only 4% of those with a female partner felt their experience was CSA compared to 44% of those who had a male partner. Among all men reporting CSEOP, those who felt sexually abused were more likely to have been physically forced or threatened, physically hurt, and emotionally hurt than those who did not feel sexually abused. Having CSEOP, being hurt by the experiences, and perceiving the experiences as sexual abuse were not associated with current HIV sexual risk or substance use behavior. In this sample of MSM in Argentina, a substantial minority reported CSEOP. Those who felt they had been sexually abused were much more likely to have had an older male partner than an older female partner, and were more likely to report having been physically forced and threatened by their older partner.

Violence as a barrier for HIV prevention among female sex workers in Argentina.

BACKGROUND: Violence against female sex workers (FSWs) has been increasingly reported as an important determinant of HIV infection risk. This study explores the frequency of different violent experiences (sexual abuse, rejection, beating and imprisonment) among FSWs in Argentina and its association with condom use and HIV and T. pallidum prevalence. METHODS: A convenience sample of 1255 FSWs was included in a cross-sectional study conducted between October 2006 and November 2009. RESULTS: Sexual abuse was reported by 24.1% (219/907) of women. A total of 34.7% (42/1234) reported rejection experiences, 21.9% (267/1215) reported having been beaten and 45.4% (561/1236) stated having been arrested because of their sex work activity. There was a higher frequency of inconsistent condom use with clients among FSWs who had experienced sexual abuse, rejection, and police detention. A higher frequency of HIV and T. pallidum infection was detected among FSWs who reported having been arrested by the police. CONCLUSION: The study shows for the first time the frequency of different violent situations among FSWs in Argentina. The association between violence against sex workers, condom use and STI prevalence demonstrated here calls for measures to reduce stigma and violence against FSWs. Such violent experiences may increase vulnerability to STI through coerced unprotected sex.