Search

The HIV risk factor information collected by cross-sectional studies and analyses provided a better view of the status of the HIV epidemic in South America. HIV prevalences were highest among men who have sex with men and were found to be associated with multiple partners, no injection drug use, and sexually transmitted infections.

Research in Argentina has been conducted on mother-to-child HIV-1 transmission prevention. Results demonstrate the importance of development strategies for prevention of transmission via more generalized education, counseling and testing of young women.

There are two different HIV epidemics in Argentina, according to researchers who used the envelope heteroduplex mobility assay to test 134 HIV-infected women, 41 of their male sexual partners, and 95 HIV-infected gay men. The gay men were predominantly infected with env subtype B, whereas the heterosexual men and women were predominantly infected with env subtype F.

Objective: The aims of this study were to investigate the frequency of male circumcision among men who have sex with men (MSM) in Buenos Aires, Argentina; the association between circumcision and sexually transmitted infections (STIs); and, among those uncircumcised, the willingness to be circumcised. Methods: A cross-sectional study was conducted among 500 MSM recruited through the respondent-driven sampling (RDS) technique. Participants underwent a consent process, responded to a Web-based survey that included questions on demographic information, sexual behaviour, and circumcision and provided biological samples. HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum, and human papiloma virus (HPV) diagnoses were performed using standard methodologies. For all analyses, data were weighted based on participants' network size. Results: Only 64 (13%) of the 500 MSM in our study reported being circumcised. Among uncircumcised men (n =418), 302 (70.4%) said that they would not be willing to get circumcised even if the procedure could reduce the risk of HIV infection. When considering all participants, circumcision status was not significantly associated with HIV, HBV, HCV, T pallidum or HPV infections. However, when we restricted the sample to men who do not practice receptive anal intercourse (RAI) and compared circumcised to uncircumcised men, the former (N = 33) had no cases of HIV infection, while 34 of 231 (14.8%) uncircumcised men were HIV positive (p= 0.020). Regarding HPV, uncircumcised men had a significantly larger number of different HPV types compared with circumcised men (mean 1.83 vs. 1.09, p B0.001) and a higher frequency of high-risk-HPV genotypes (47.6% vs. 12.5%, p= 0.012). Conclusions: Consistent with international evidence, male circumcision appears to have a partial protective effect among MSM. The efficacy of circumcision in reducing risk of HIV infection among MSM appears to be correlated with sexual practices. Given the lack of motivation among MSM with regard to circumcision, proper awareness on the risks and benefits of circumcision needs to be created, if circumcision has to be introduced as a prevention strategy. Keywords: men who have sex with men; circumcision; respondent-driven sampling; HPV; HIV; Buenos Aires., Introduction Although male circumcision has been associated with religious practices and ethnicity, in the 20th century the procedure was introduced for health reasons. An estimated 30% of males are circumcised [...]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: In Trinidad and the wider Caribbean, subtype B Human Immunodeficiency Virus-type 1 (HIV-1B) overwhelmingly accounts for HIV infection among heterosexuals; this contrasts with the association of HIV-1B with homosexual transmission and injecting drug use globally. The HIV envelope contains genetic determinants of cell tropism and evasion from immune attack. In this study we investigate the genetic properties of the env V1-C4 of HIV-1B soon after transmission to Trinidadian heterosexuals. This will reveal distinctive genetic features of the strains that cause the HIV-1B epidemic in Trinidad and generate insights to better understand their properties. Methodology/Principal Findings: Quasispecies sampling was performed on the env V1-C4 of HIV-1B strains soon after transmission to heterosexual Trinidadians in a cohort of seroconverters. Phylogenetic relationships were determined for these quasispecies and the length and number of asparagine (N) linked glycosylation sites (NLGS) in their variable loops compared to that for HIV-1B globally. Signature amino acids within the constant domains of the env V1-C4 were identified for heterosexually transmitted HIV-1B from Trinidad relative to HIV-1B globally. HIV-1B obtained from Trinidadian heterosexuals soon after seroconversion had significantly longer V2 loops with one more glycosylation site, shorter V3 loops and no significant difference in V1 or V4 when compared to HIV-1B obtained soon after seroconversion from infected individuals in the rest of the world. HIV-1B soon after seroconversion and during chronic infection of Trinidadians was not significantly different, suggesting that distinctly long V2 loops are characteristic of HIV-1B in Trinidad. A threonine deletion at position 319 (T319-) along with the substitutions R315K and S440R were found to be distinctly associated with HIV-1B from Trinidad compared to HIV-1B globally. Conclusions: This finding of distinctive genetic features that are characteristic of HIV-1B strains from Trinidad is consistent with the Trinidad epidemic being established by a founder strain or closely related founder strains of HIV-1B. [ABSTRACT FROM AUTHOR]

The article focuses on the study that determines the erythrocyte-associated p24 antigen in HIV-infected patients with undetectable plasma viral load for more than one year. HIV-1 linked to erythrocytes was detected through reverse transcriptase-polymerase chain reaction techniques in patients. The observation is useful to know if the virus keeps on replicating at the moment of deciding whether to interrupt or diminish treatment.