Prevalences, genotypes, and risk factors for HIV transmission in South America

Sexually Transmitted Infections Risk and Interstate Sexual Networks Among Men Who Have Sex With Men in New England

ABSTRACT

By investigating relationships between sexual mobility and sexual transmitted infection (STI) risk factors among men who have sex with men, we found that STI history, number of sexual partners, and substance use are associated with increased odds of interstate sexual encounters, suggesting that interjurisdictional approaches to STI prevention are needed.

Social, Epidemiological, and Virological Characteristics from Peruvian Subjects Living with HIV-1/AIDS with Different Sexual Risk Behavior

HIV-1 genetic diversity and resistance profile might change according to the risky sexual behavior of the host. To show this, we recruited 134 individuals between the years 2015 and 2017 identified as transgender women sex workers (TWSW, n = 73) and Heterosexual Military Officers (HET-MO, n = 61). After obtaining informed consent, we collected a blood sample to perform the HIV genotyping, CD4 cell count, and viral load. We used bioinformatics approaches for detecting resistance mutations and recombination events. Epidemiological data showed that both groups reported sexually transmitted diseases and they were widespread among TWSW, especially syphilis and herpes virus (35.6%). Illegal drugs consumption was higher among TWSW (71.2%), whereas condom use was inconsistent for both HET-MO (57.4%) and TWSW (74.0%). TWSW showed the shortest time exposition to antiretroviral therapy (ART) (3.5 years) and the lowest access to ART (34.2%) that conducted treatment failure (>4 logs). HIV-1 sequences from TWSW and HET-MO were analyzed to determine the genetic diversity and antiretroviral drug resistance. Phylogeny analysis revealed 125 (93%) cases of subtype B, 01 subtype A (0.76%), 07 (5.30%) BF recombinants, and 01 (0.76%) AG recombinant. Also, TWSW showed a higher recombination index (9.5%, 7/73) than HET-MO (1.5%, 1/68). HET-MO only showed acquired resistance (26.23%, 16/61), whereas TWSW showed both acquired as transmitted resistance (9.59% for each). In conclusion, TWSW and HET-MO showed significant differences considering the epidemiological characteristics, genetic diversity, recombination events, and HIV resistance profile.

Factors associated with exchanging sex for money in men who have sex with men in Brazil

This study aimed to analyze the association between sociodemographic, programmatic and contextual factors and the receipt of money in exchange for sex among men who have sex with men (MSM). This is a multicenter, cross-sectional study conducted in ten Brazilian cities between 2008 and 2009. Adult MSM recruited through the Respondent Driven Sampling (RDS) were interviewed. Weighted Odds Ratio (ORw) was obtained through logistic regression, retaining the variables associated with the event (p < 0.05) in the final model. Of the total sample, 33.3% reported receiving money in exchange for sex in the last 12 months before the interview. The variables that were independently associated with the event were age less than or equal to 25 years, lower education, lower social classes, previous history of syphilis, using sites or services to find sexual partners in the previous month, very high risk behavior, using illicit drugs in the previous six months, self-identifying as heterosexual or bisexual, having suffered physical violence due to sexual orientation and having suicidal thoughts always or most of the time. It was observed that MSM who received money in exchange for sex had greater socioeconomic, programmatic and contextual vulnerability, potentially increasing the risk of HIV infection than the other MSM in the sample.

Increased incidences of noninfectious comorbidities among aging populations living with human immunodeficiency virus in Ecuador: a multicenter retrospective analysis

Introduction: Besides the well-known increased risk of developing HIV-related infectious comorbidities; compared with the general population, people living with HIV (PLHIV) may also have an increased risk of developing noninfectious comorbidities (NICMs). This is the first study intended to determine the NICMs rates affecting PLHIV who were under cART regimen in Ecuador. Methods: A total of 503 HIV-positive patients were evaluated during the period June 2015-November 2016 and included in a multicenter retrospective, cross-sectional study conducted in seven main government and nongovernment community-based hospitals in Ecuador. Results: The average age of the participants was 39.2±11.9 years old and the majority of them were male (67.2%). The average age at HIV diagnosis was 34.1 years old and cART in average was started 15.9 months after HIV-diagnosis. Recruited patients were receiving cART for an average of 59.2±40.2 months. Only 9.9% (n=50) of the patients did not show any NICMs. Diabetes and pre-diabetes was found in 6% (n=30) and 16.3% (n=82) patients, respectively; however, dyslipidemia and overweight/obesity was frequent, as they affected 41.4% (n=208) and 36.4% (n=183) patients, respectively. Sixty patients (11.9%) were diagnosed with depression and 28.2% (n=142) of the studied subjects were found to have other NICMs. Conclusion: Prevalence of NICMs among subjects under cART was greater than that reported among the Ecuadorian general population, therefore specific public health actions are required to make patients aware of and prevent NICMs among PLHIV in Ecuador.

Earlier Initiation of Antiretroviral Treatment Coincides With an Initial Control of the HIV-1 Sub-Subtype F1 Outbreak Among Men-Having-Sex-With-Men in Flanders, Belgium

Human immunodeficiency virus type 1 (HIV-1) non-B subtype infections occurred in Belgium since the 1980s, mainly amongst migrants and heterosexuals, whereas subtype B predominated in men-having-sex-with-men (MSM). In the last decade, the diagnosis of F1 sub-subtype in particular has increased substantially, which prompted us to perform a detailed reconstruction of its epidemiological history. To this purpose, the Belgian AIDS Reference Laboratories collected HIV-1 pol sequences from all sub-subtype F1-infected patients for whom genotypic drug resistance testing was requested as part of routine clinical follow-up. This data was complemented with HIV-1 pol sequences from countries with a high burden of F1 infections or a potential role in the global origin of sub-subtype F1. The molecular epidemiology of the Belgian subtype F1 epidemic was investigated using Bayesian phylogenetic inference and transmission dynamics were characterized based on birth-death models. F1 sequences were retained from 297 patients diagnosed and linked to care in Belgium between 1988 and 2015. Phylogenetic inference indicated that among the 297 Belgian F1 sequences, 191 belonged to a monophyletic group that mainly contained sequences from people likely infected in Belgium (OR 26.67, 95% CI 9.59–74.15), diagnosed in Flanders (OR 7.28, 95% CI 4.23–12.53), diagnosed at a recent stage of infection (OR 7.19, 95% CI 2.88-17.95) or declared to be MSM (OR 34.8, 95% CI 16.0–75.6). Together with a Spanish clade, this Belgian clade was embedded in the genetic diversity of Brazilian subtype F1 strains and most probably emerged after one or only a few migration events from Brazil to the European continent before 2002. The origin of the Belgian outbreak was dated back to 2002 (95% higher posterior density 2000–2004) and birth-death models suggested that its extensive growth had been controlled (R_e < 1) by 2012, coinciding with a time period where delay in antiretroviral treatment initiation substantially declined. In conclusion, phylogenetic reconstruction of the Belgian HIV-1 sub-subtype F1 epidemic illustrates the introduction and substantial dissemination of viral strains in a geographically restricted risk group that was most likely controlled by effective treatment as prevention.

A discrete choice experiment to investigate patient preferences for HIV testing programs in Bogotá, Colombia

BACKGROUND

To assess patients' preferences for HIV testing in Colombia.

METHODS

A discrete choice experiment was used to assess preferences of patients diagnosed with HIV, for HIV testing in two HIV clinics in Bogotá, Colombia. Patients were asked to choose repeatedly between two hypothetical HIV testing options that varied with respect to five attributes: distance to testing site, confidentiality, testing days, sample collection method, and the services if HIV positive. A random parameter model was used to analyze the data.

RESULTS

A total of 249 questionnaires were eligible for data analysis. Respondents showed a preference for testing on weekdays, nobody being aware, a sample taken from the arm, and receiving medications through a referral. The respondents showed a high negative preference for many people being aware, followed by testing during the weekend and home testing. Subgroup analyses by gender and prior testing history did not reveal significant differences.

CONCLUSION

This study suggests that patients' preferences for HIV testing focused especially on confidentiality, availability during weekdays, and using a sample from the arm. This information could be useful to improve uptake of HIV testing in Bogotá, Colombia.

Molecular Epidemiology of HIV-1 Virus in Puerto Rico: Novel Cases of HIV-1 Subtype C, D, and CRF-24BG

HIV-1 subtype B virus is the most prevalent subtype in Puerto Rico (PR), accounting for about 90% of infection in the island. Recently, other subtypes and circulating recombinant forms (CRFs), including F(12_BF), A (01_BF), and CRF-39 BF-like, have been identified. The purpose of this study is to assess the distribution of drug resistance mutations and subtypes in PR. A total of 846 nucleotide sequences from the period comprising 2013 through 2017 were obtained from our "HIV Genotyping" test file. Phylogenetic and molecular epidemiology analyses were performed to evaluate the evolutionary dynamics and prevalence of drug resistance mutations. According to our results, we detected a decrease in the prevalence of protease inhibitor, nucleoside reverse transcriptase inhibitor (NRTI), and non-NRTI (NNRTI) resistance mutations over time. In addition, we also detected recombinant forms and, for the first time, identified subtypes C, D, and CRF-24BG in PR. Recent studies suggest that non-subtypes B are associated with a high risk of treatment failure and disease progression. The constant monitoring of viral evolution and drug resistance mutation dynamics is important to establish appropriate efforts for controlling viral expansion.

MSM in Bogotá are living with HIV for extended periods without diagnosis or treatment

We examined recency of infection in serum samples obtained from 69 newly identified HIV-positive cases in a sample of 1000 men who have sex with men (MSM) in Bogotá. HIV antibody avidity assays were performed using the Architect HIV Ag/AB combo. Avidity indices ranged from 0.62 to 1.22, with a cut-off score below 0.80 indicative of recent infection. Two samples were classified as recent, six fell within the gray zone (0.75 to 0.85), and the remaining 61 were considered established infections. Results provided evidence of widespread, long-term, undiagnosed HIV infection, as well as an estimate of one-year incidence at .25 in the population of MSM in Bogotá. This incidence rate is approximately 8.5 times the rate estimated for the general adult population in Colombia. The large proportion of newly diagnosed cases found among individuals with established infections indicates that many MSM in Bogotá are living with HIV for extended periods without being diagnosed and treated. Greater efforts to detect and treat undiagnosed infections are crucial to decrease HIV incidence and increase maximum effectiveness of medical intervention. Given the over-representation of MSM and transgender women in the HIV epidemic in Colombia, such efforts should specifically target this population.

Risk Factors Associated With HIV Among Men Who Have Sex With Men (MSM) in Ecuador

The Joint United Nations Program on HIV/AIDS estimates that between 0.3% and 0.7% of adults aged 15 to 49 years were living with HIV in Ecuador in 2013. However, very little is known about the HIV prevalence rate among men who have sex with men (MSM) in that country. A cross-sectional survey was conducted to investigate the knowledge, attitudes, and practices regarding HIV/AIDS as well as to estimate the prevalence of HIV among MSM in one of the cities with high HIV prevalence rates in Ecuador. In this study, questionnaires were administered to 307 adult MSM. An HIV prevalence of 10% was observed. Knowledge about HIV was high; 91% of participants could identify how HIV is transmitted. Although consistent condom use for anal sex was relatively high (89%) among participants who reported having pay-for-service clients, only 64% reported using a condom during oral sex with a client. Participants who had multiple male sexual partners (i.e., their stable male partners plus other partner[s]) had 3.7 times higher odds of testing positive for HIV compared with those who did not. They also had reduced odds of condom use. Participants who were forced to have anal receptive sex had 3 times higher odds of testing positive for HIV. Despite the finding that participants exhibited high knowledge about HIV/AIDS, a high prevalence rate of HIV was observed, which warrants targeted behavioral interventions. These data are consistent with MSM being one of the highest at-risk population groups for HIV in this region of Ecuador.

Transactional Sex and the HIV Epidemic Among Men Who have Sex with Men (MSM): Results From a Systematic Review and Meta-analysis

Engagement in transactional sex has been hypothesized to increase risk of HIV among MSM, however conflicting evidence exists. We conducted a systematic review and meta-analysis comparing HIV prevalence among MSM who engaged in transactional sex to those who did not (33 studies in 17 countries; n = 78,112 MSM). Overall, transactional sex was associated with a significant elevation in HIV prevalence (OR 1.34, 95 % CI 1.11-1.62). Latin America (OR 2.28, 95 % CI 1.87-2.78) and Sub-Saharan Africa (OR 1.72, 95 % CI 1.02-2.91) were the only regions where this elevation was noted. Further research is needed to understand factors associated with sex work and subsequent HIV risk in Latin America and Sub-Saharan Africa.

HIV, STI and Behavioral Risk Among Men Who have Sex with Men in a Setting of Elevated HIV Prevalence Along Ecuador's Pacific Coast

We assessed HIV and STI prevalence, risk behaviors and factors associated with HIV infection in men who have sex with men (MSM) in Guayaquil, Ecuador. Respondent-driven sampling was used to recruit 400 MSM in 2011-2012. Participants completed a computer-assisted self-interview and provided blood samples. Statistical analysis accounted for differential probability of selection and for recruitment patterns. HIV prevalence was 11.3 %, HSV-2 30.2 %, active syphilis 6.9 % and hepatitis B 1.2 %. In the previous 12 months, 84 % of MSM reported casual male sex partners and 25 % sex work. Only 48 % of MSM consistently used condoms with male partners and 54 % had ever been tested for HIV. Of 17 % of MSM reporting a female partner, consistent condom use was 6 %. HIV infection was associated with age 25 or older, active syphilis and homosexual self-identification. Findings suggest continuing HIV risk and a need to strengthen prevention and testing among MSM.

HIV Prevalence and Awareness of Positive Serostatus Among Men Who Have Sex With Men and Transgender Women in Bogotá, Colombia

OBJECTIVES

We estimated HIV prevalence among men who have sex with men (MSM) and transgender women in Bogotá, Colombia, and explored differences between HIV-positive individuals who are aware and unaware of their serostatus.

METHODS

In this cross-sectional 2011 study, we used respondent-driven sampling (RDS) to recruit 1000 MSM and transgender women, who completed a computerized questionnaire and received an HIV test.

RESULTS

The RDS-adjusted prevalence was 12.1% (95% confidence interval [CI] = 8.7, 15.8), comparable to a previous RDS-derived estimate. Among HIV-positive participants, 39.7% (95% CI = 25.0, 54.8) were aware of their serostatus and 60.3% (95% CI = 45.2, 75.5) were unaware before this study. HIV-positive-unaware individuals were more likely to report inadequate insurance coverage, exchange sex (i.e., sexual intercourse in exchange for money, goods, or services), and substance use than other participants. HIV-positive-aware participants were least likely to have had condomless anal intercourse in the previous 3 months. Regardless of awareness, HIV-positive participants reported more violence and forced relocation experiences than HIV-negative participants.

CONCLUSIONS

There is an urgent need to increase HIV detection among MSM and transgender women in Bogotá. HIV-positive-unaware group characteristics suggest an important role for structural, social, and individual interventions.

Selection pressure in CD8⁺ T-cell epitopes in the pol gene of HIV-1 infected individuals in Colombia. A bioinformatic approach

One of the main characteristics of the human immunodeficiency virus is its genetic variability and rapid adaptation to changing environmental conditions. This variability, resulting from the lack of proofreading activity of the viral reverse transcriptase, generates mutations that could be fixed either by random genetic drift or by positive selection. Among the forces driving positive selection are antiretroviral therapy and CD8+ T-cells, the most important immune mechanism involved in viral control. Here, we describe mutations induced by these selective forces acting on the pol gene of HIV in a group of infected individuals. We used Maximum Likelihood analyses of the ratio of non-synonymous to synonymous mutations per site (dN/dS) to study the extent of positive selection in the protease and the reverse transcriptase, using 614 viral sequences from Colombian patients. We also performed computational approaches, docking and algorithmic analyses, to assess whether the positively selected mutations affected binding to the HLA molecules. We found 19 positively-selected codons in drug resistance-associated sites and 22 located within CD8+ T-cell epitopes. A high percentage of mutations in these epitopes has not been previously reported. According to the docking analyses only one of those mutations affected HLA binding. However, algorithmic methods predicted a decrease in the affinity for the HLA molecule in seven mutated peptides. The bioinformatics strategies described here are useful to identify putative positively selected mutations associated with immune escape but should be complemented with an experimental approach to define the impact of these mutations on the functional profile of the CD8+ T-cells.

Transactional sex among men who have sex with men in Latin America: economic, sociodemographic, and psychosocial factors

OBJECTIVES

We assessed factors associated with engagement in transactional sex among men who have sex with men recruited from one of the largest Internet sites for men seeking social or sexual interactions with other men in Latin America.

METHODS

We constructed multilevel logistic regression models to analyze factors associated with engagement in transactional sex in 17 Latin American countries in 2012.

RESULTS

Of 24 051 respondents, 1732 (7.2%) reported being paid for sexual intercourse in the past 12 months. In a multivariable model, higher country-level unemployment was associated with increased odds of transactional sex (adjusted odds ratio [AOR] = 1.07 per 1% increase in unemployment; 95% confidence interval [CI] = 1.00, 1.13). Individual or interpersonal factors associated with increased odds of engagement in transactional sex included self-reported HIV (AOR = 1.33; 95% CI = 1.04, 1.69) or sexually transmitted infection (AOR = 1.33; 95% CI = 1.11, 1.59), childhood sexual abuse history (AOR = 1.75; 95% CI = 1.48, 2.06), intimate partner violence (past 5 years, AOR = 1.68; 95% CI = 1.45, 1.95), and sexual compulsivity (AOR = 1.77; 95% CI = 1.49, 2.11).

CONCLUSIONS

Structural-level economic interventions and those that address individual and interpersonal factors may improve HIV prevention efforts among men who have sex with men who engage in transactional sex.

Male sex workers: practices, contexts, and vulnerabilities for HIV acquisition and transmission

Male sex workers who sell or exchange sex for money or goods encompass a very diverse population across and within countries worldwide. Information characterising their practices, contexts where they live, and their needs is limited, because these individuals are generally included as a subset of larger studies focused on gay men and other men who have sex with men (MSM) or even female sex workers. Male sex workers, irrespective of their sexual orientation, mostly offer sex to men and rarely identify as sex workers, using local or international terms instead. Growing evidence indicates a sustained or increasing burden of HIV among some male sex workers within the context of the slowing global HIV pandemic. Several synergistic facilitators could be potentiating HIV acquisition and transmission among male sex workers, including biological, behavioural, and structural determinants. Criminalisation and intersectional stigmas of same-sex practices, commercial sex, and HIV all augment risk for HIV and sexually transmitted infections among male sex workers and reduce the likelihood of these people accessing essential services. These contexts, taken together with complex sexual networks among male sex workers, define this group as a key population underserved by current HIV prevention, treatment, and care services. Dedicated efforts are needed to make those services available for the sake of both public health and human rights. Evidence-based and human rights-affirming services dedicated specifically to male sex workers are needed to improve health outcomes for these men and the people within their sexual networks.

Transactional sex and prevalence of STIs: a cross-sectional study of MSM and transwomen screened for an HIV prevention trial

Few studies have characterised the degree of engagement in transactional sex among men and transgender women who have sex with men and explored its association with sexually transmitted infections and human immunodeficiency virus in Ecuador. We screened 642 men who have sex with men and transgender women for a pre-exposure prophylaxis clinical trial (iPrEx) in Guayaquil, Ecuador, 2007-2009. We analysed the association of degree of engagement in transactional sex and prevalence of sexually transmitted infections including human immunodeficiency virus using chi-square and analysis of variance tests. Although just 6.2% of those who screened self-identified as sex workers, 52.1% reported having engaged in transactional sex. Compared to those who had never been paid for sex, those who had been paid were more likely to have a sexually transmitted infection (56.6% vs. 45.0%, p = 0.007) and trended towards a higher human immunodeficiency virus prevalence (16.6% vs. 10.4%, p = 0.082) at screening. Transgender women compared to other men who have sex with men were more likely to have sexually transmitted infections diagnosed at screening (75.6% vs. 50.0%, p = 0.001). Transactional sex is practiced widely but occasionally among the men who have sex with men and transgender women in Guayaquil who screened for the iPrEx study; however, engaging in transactional sex may not lead to a sex worker self-identification. Both transactional sex and being a transgender woman are associated with sexually transmitted infections prevalence.

Sampling methodologies for epidemiologic surveillance of men who have sex with men and transgender women in Latin America: an empiric comparison of convenience sampling, time space sampling, and respondent driven sampling

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June-August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through TSS, and 127 through RDS. The TSS sample included the largest proportion of TW (30.7 %) and the lowest percentage of subjects who had previously participated in HIV/STI research (14.9 %). The prevalence of newly diagnosed HIV infection, according to participants' self-reported previous HIV diagnosis, was highest among TSS recruits (17.9 %) compared with RDS (12.6 %) and CS (10.2 %). TSS identified diverse populations of MSM/TW with higher prevalences of HIV/STIs not accessed by other methods.

HIV testing among MSM in Bogotá, Colombia: the role of structural and individual characteristics

This study used mixed methods to examine characteristics related to HIV testing among men who have sex with men (MSM) in Bogotá, Colombia. A sample of 890 MSM responded to a computerized quantitative survey. Follow-up qualitative data included 20 in-depth interviews with MSM and 12 key informant interviews. Hierarchical logistic set regression indicated that sequential sets of variables reflecting demographic characteristics, insurance coverage, risk appraisal, and social context each added to the explanation of HIV testing. Follow-up logistic regression showed that individuals who were older, had higher income, paid for their own insurance, had had a sexually transmitted infection, knew more people living with HIV, and had greater social support were more likely to have been tested for HIV at least once. Qualitative findings provided details of personal and structural barriers to testing, as well as inter-relationships among these factors. Recommendations to increase HIV testing among Colombian MSM are offered.

Global burden of HIV among men who engage in transactional sex: a systematic review and meta-analysis

BACKGROUND

Men who engage in transactional sex, the exchange of sex for money, goods, or other items of value, are thought to be at increased risk of HIV, but there have been no systematic attempts to characterize HIV burden in this population. We undertook a systematic review and meta-analysis to quantify the burden in this population compared with that of men in the general population to better inform future HIV prevention efforts.

METHODS

We searched seven electronic databases, national surveillance reports, and conference abstracts for studies of men who engage in transactional sex published between 2004-2013. Random effects meta-analysis was used to determine pooled HIV prevalence and prevalence ratios (PR) for the difference in HIV prevalence among men who engage in transactional sex as compared to general population men.

FINDINGS

Of 66 studies included representing 31,924 men who had engaged in transactional sex in 28 countries, pooled biological assay-confirmed HIV prevalence was 10.5% (95% CI = 9.4 to 11.5%). The highest pooled HIV prevalence was in Sub-Saharan Africa (31.5%, 95% CI = 21.6 to 41.5%), followed by Latin America (19.3%, 95% CI = 15.5 to 23.1%), North America (16.6%, 95% CI = 3.7 to 29.5%), and Europe (12.2%, 95% CI = 6.0 to 17.2%). Men who engaged in transactional sex had an elevated burden of HIV compared to the general male population (PR = 20.7, 95% CI = 16.8 to 25.5).

CONCLUSIONS

The global burden of HIV is disproportionately high among men who engage in transactional sex compared with the general male population. There is an urgent need to include this population in systematic surveillance as well as to scale-up access to quality HIV prevention programs.

Prevalence of HIV-1 subtypes among men who have sex with men in China: a systematic review

The distribution of prevalent HIV-1 strains are still complex in China. Men who have sex with men (MSM) play an important bridging role in spreading HIV. The aim of our study was to quantitatively evaluate the prevalence of HIV-1 subtypes among the MSM population in China from published studies. Relevant studies were searched by selection criteria from CNKI, CBM, Pubmed, etc. We computed the estimates of the pooled proportion of HIV-1 subtypes. Heterogeneity between studies was investigated and measured using Cochran's Q statistic and the I (2) statistic. All analyses were conducted by the R statistical package version 2.13.1. A meta-analysis was performed, which included 19 articles. For comprehensive analysis of env, gag and pol genes, the pooled estimates for the prevalence of subtype B was 28.25% (95% CI: 18.10-39.66%), CRF01_AE was 53.46% (95% CI: 46.11-60.74%), CRF07_BC was 18.66% (95% CI: 13.06-25.01%) and CRF08_BC was 5.85% (95% CI: 2.73-10.07%), respectively. In subgroup analysis, the proportion of subtype B decreased, while the proportion of CRF01_AE and CRF07_BC showed an increasing tendency. Beijing, Guangdong and Henan provinces had high proportions of subtype CRF01_AE while Guangdong and Hebei provinces had the highest proportions of subtype B and CRF07_BC, respectively. A high genetic variability of HIV-1 presents a serious challenge for HIV prevention and treatment strategies among MSM in China.

HIV Risk Perception, Sexual Behavior, and HIV Prevalence among Men-Who-Have-Sex-with-Men at a Community-Based Voluntary Counseling and Testing Center in Kuala Lumpur, Malaysia

We describe the HIV risk perception, sexual behavior, and HIV prevalence among 423 men-who-have-sex-with-men (MSM) clients who received voluntary counseling and testing (VCT) services at a community-based center in Kuala Lumpur, Malaysia. The mean age was 29 years old. One hundred one (23.9%) clients rated themselves as low risk, 118 (27.9%) as medium risk, 36 (8.5%) as high risk, and 168 (39.7%) were unsure of their risk. Twenty-four (9.4%) clients tested HIV positive (4 (4%) low risk, 9 (7.6%) medium risk, 11 (30.6%) high risk, and 13 (7.7%) unsure risk). We found a positive correlation between risk perception and HIV infection in this study. Clients with high HIV risk perception have 17x the odds of testing HIV positive compared to low risk clients. High HIV risk perception was significantly associated with multiple sex partners, multiple types of sex partners, alcohol use before intercourse, unprotected sex beyond 6 months, and inconsistent condom use during anal sex compared to low risk clients. There were no statistically significant differences between medium risk and unsure risk clients compared to low risk clients. Strategies should be targeted towards change in sexual practices among those who are perceived to be at high risk.

Similar replicative fitness is shared by the subtype B and unique BF recombinant HIV-1 isolates that dominate the epidemic in Argentina

The HIV-1 epidemic in South America is dominated by pure subtypes (mostly B and C) and more than 7 BF and BC recombinant forms. In Argentina, circulating recombinant forms (CRFs) comprised of subtypes B and F make up more than 50% of HIV infections. For this study, 28 HIV-1 primary isolates were obtained from patients in Buenos Aires, Argentina and initially classified into subtype B (n = 9, 32.1%), C (n = 1, 3.6%), and CRFs (n = 18, 64.3%) using partial pol and vpu-env sequences, which proved to be inconsistent and inaccurate for these phylogenetic analyses. Near full length genome sequences of these primary HIV-1 isolates revealed that nearly all intersubtype BF recombination sites were unique and countered previous "CRF" B/F classifications. The majority of these Argentinean HIV-1 isolates were CCR5-using but 4 had a dual/mixed tropism as predicted by both phenotypic and genotypic assays. Comparison of the replicative fitness of these BF primary HIV-1 isolates to circulating B, F, and C HIV-1 using pairwise competitions in peripheral blood mononuclear cells (PBMCs) indicated a similarity in fitness of these BF recombinants to subtypes B and F HIV-1 (of the same co-receptor usage) whereas subtype C HIV-1 was significantly less fit than all as previously reported. These results suggest that the multitude of BF HIV-1 strains present within the Argentinean population do not appear to have gained replicative fitness following recent B and F recombination events.

A continuing HIV epidemic and differential patterns of HIV-STI risk among MSM in Quito, Ecuador: an urgent need to scale up HIV testing and prevention

This study characterized the HIV epidemic among men who have sex with men (MSM) in Quito, Ecuador and contrasted risk patterns with other STI's. 416 MSM ages 15 years and older were recruited using respondent-driven sampling in 2010-2011. Biological testing and a self-interview survey assessed HIV and STI infections and risk behaviors. Analysis incorporated recruiter-level variables and clustering adjustments to control for recruitment patterns. We identify high levels of HIV (11 %), HSV-2 (14 %) and active syphilis (5.5 %) infections, low levels of lifetime HIV testing (57 %), limited knowledge of HIV and STI's (<48 %) and limited consistent condom use independent of partner type (<40 %). Sex work was associated with all infections while associations with residential location, how casual partners are met and other variables, varied. Scale-up of behavioral prevention and HIV testing is urgently needed. Interventions should target male sex workers and exploit differential patterns of HIV-STI risk to stay ahead of the epidemic.

Local and global spatio-temporal dynamics of HIV-1 subtype F1

Previous studies have attempted to explore the origin of the F1 subtype, but the precise origin of the Romanian and South American F1 variants remains controversial. As the F1 subtype is the most frequent non-B variant among Europeans residing in Italy, the aim of this study was to estimate its phylogeography in order to reconstruct its origin and route of dispersion. The phylogeographical analyses, which were made using the Bayesian Markov Chain Monte Carlo approach and BEAST software, revealed two significant clades: the first included all of the Romanian strains together with a few Italian and four African isolates; the second encompassed all of the South American sequences and the large majority of Italian variants. By putting the African reference sequences into two discrete groups based on specific countries, phylogeographic analysis indicated that the F1 epidemic originated in Cameroon/Democratic Republic of Congo in the early 1940s, and was exported to South America 10 years later. Subsequently, the F1 virus spread to Angola and, from there, was exported to Romania in the early 1960s. It reached Italy in the 1970s from South America and Romania. The South American and Romanian variants of F1 have different African countries of origin and different temporal spreads. The South American variant seems to be characterized by multiple introduction events, whereas the Romanian strain probably spread as a result of a single entry. Two different pathways from South America and Romania led the F1 variant to Italy in the 1970s.

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.

Armed conflict, homonegativity and forced internal displacement: implications for HIV among Colombian gay, bisexual and transgender individuals

Colombia has endured six decades of civil unrest, population displacement and violence. We examined the relationships between contextual conditions, displacement and HIV among gay, bisexual and transgender individuals in Bogotá, Colombia. A total of 19 key informants provided information about internal displacement of sexual minorities. Life-history interviews were conducted with 42 participants aged 18 to 48 years and included questions about displacement experiences, sexual behaviour, life prior to displacement and participants' economic and social situation in Bogotá. The interplay of a variety of factors - including internal conflict and violence, homonegativity and 'social cleansing', gender and sexual identity and poverty - strongly shaped the varied experiences of displacement. Migration, sexual violence, exchange sex and low rates of HIV testing were risk factors that increased vulnerability for HIV in this displaced sample. Although displacement and HIV in Colombia are major problems, both are understudied.

Higher cross-subtype IFN-γ ELISpot responses to Gag and Nef peptides in Brazilian HIV-1 subtype B- and F1- than in C-infected subjects

HIV-1 diversity has been considered a huge challenge for the HIV-1 vaccine development. To overcome it, immunogens based on centralized sequences, as consensus, have been tested. In Brazil, the co-circulation of three subtypes offers a suitable scenario to test T cell cross-subtype responses to consensus sequences. Furthermore, we included peptides based on closest viral isolates (CVI) from each subtype analyzed to compare with T cell responses detected against the consensus sequences. The study included 32 subjects infected with HIV-1 subtype B (n=13),C (n=11), and F1 (n=8). Gag and Nef-specific T cell responses were evaluated by IFN-γ-ELISpot assay. Peptides based on CVI sequences were similar to consensus in both reducing genetic distance and detecting T cell responses. A high cross-subtype response between B and F1 in both regions was observed in HIV-1 subtype B and F1-infected subjects. We also found no significant difference in responses to subtype B and C consensus peptides among subtype B-infected subjects. In contrast, the magnitude of T cell responses to consensus C peptides in the Gag region was higher than to consensus B peptides among HIV-1 subtype C-infected subjects. Regarding Nef, subtype C-infected subjects showed higher values to consensus C than to consensus F1 peptides. Moreover, subtype F1-infected subjects presented lower responses to subtype C peptides than to subtype F1 and B. A similar level of responses was detected with group M based peptides in subtype B and F1 infected subjects. However, among subtype C infected subjects, this set of peptides detected lower levels of response than consensus C. Overall, the level of cross-subtype response between subtypes B and F1 was higher than between subtype C and B or C and F1. Our data suggests that the barrier of genetic diversity in HIV-1 group M for vaccine design may be dependent on the subtypes involved.

Popular perceptions of circumcision among Colombian men who have sex with men

Male circumcision has received increased attention for its potential to reduce sexual transmission of HIV. Research on the acceptability of circumcision as a means of HIV prevention among men who have sex with men is limited. Men who have sex with men in Bogotá, Colombia, either participated in a focus group in which they shared information regarding their perceptions of circumcision or completed a survey that assessed circumcision experiences, attitudes, beliefs and willingness. Few participants reported they were circumcised, yet most participants reported knowing something about the procedure. Overall, attitudes towards circumcision were mixed: although circumcision was viewed as safe, it was also viewed as unnatural and cruel to babies. Beliefs that circumcision could improve sexual functioning and protect against STIs and HIV were not widely endorsed by survey participants, although focus-group participants discussed the potential impacts of circumcision on the availability of sexual partners and sexual performance. Some focus-group participants and many survey participants reported a hypothetical willingness to get circumcised if strong evidence of its effectiveness could be provided, barriers removed and recovery time minimised.

The increasing prevalence of HIV-1 subtype C in Southern Brazil and its dispersion through the continent

The HIV-1 has evolved swiftly and the scenario of HIV-1 genetic diversity is constantly changing. In South America, recombinant forms of subtypes B, F1, and BF1 have historically driven the HIV-1 epidemic. In recent years, however, infection with subtype C has gained prominence as its prevalence increased in Southern Brazil as well as neighboring countries. Current studies point to a single introduction of closely related strains as the beginning of the Brazilian subtype C epidemic. However, the place of origin of these strains, date, and route of introduction are under continuous debate as well as the clinical outcomes of the emergence of subtype C. Therefore, this paper reviews the history of the HIV-1 subtype C in Brazil, particularly in the Southern region, covering its demographic and evolutionary history and the possible implications to the Brazilian AIDS epidemic as well as to neighboring countries.

HIV-1 subtype F1 epidemiological networks among Italian heterosexual males are associated with introduction events from South America

About 40% of the Italian HIV-1 epidemic due to non-B variants is sustained by F1 clade, which circulates at high prevalence in South America and Eastern Europe. Aim of this study was to define clade F1 origin, population dynamics and epidemiological networks through phylogenetic approaches. We analyzed pol sequences of 343 patients carrying F1 subtype stored in the ARCA database from 1998 to 2009. Citizenship of patients was as follows: 72.6% Italians, 9.3% South Americans and 7.3% Rumanians. Heterosexuals, Homo-bisexuals, Intravenous Drug Users accounted for 58.1%, 24.0% and 8.8% of patients, respectively. Phylogenetic analysis indicated that 70% of sequences clustered in 27 transmission networks. Two distinct groups were identified; the first clade, encompassing 56 sequences, included all Rumanian patients. The second group involved the remaining clusters and included 10 South American Homo-bisexuals in 9 distinct clusters. Heterosexual modality of infection was significantly associated with the probability to be detected in transmission networks. Heterosexuals were prevalent either among Italians (67.2%) or Rumanians (50%); by contrast, Homo-bisexuals accounted for 71.4% of South Americans. Among patients with resistant strains the proportion of clustering sequences was 57.1%, involving 14 clusters (51.8%). Resistance in clusters tended to be higher in South Americans (28.6%) compared to Italian (17.7%) and Rumanian patients (14.3%). A striking proportion of epidemiological networks could be identified in heterosexuals carrying F1 subtype residing in Italy. Italian Heterosexual males predominated within epidemiological clusters while foreign patients were mainly Heterosexual Rumanians, both males and females, and South American Homo-bisexuals. Tree topology suggested that F1 variant from South America gave rise to the Italian F1 epidemic through multiple introduction events. The contact tracing also revealed an unexpected burden of resistance in epidemiological clusters underlying the need of public interventions to limit the spread of non-B subtypes and transmitted drug resistance.

Heterosexual transmission of human immunodeficiency virus type 1 subtype C in southern Brazil

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1) subtype B predominates in Brazil, but in the southern region subtype C is the most frequent, followed by subtypes B, F1 and recombinant forms. In southern Brazil, these subtypes co-circulate in subjects with homogeneous demographic and clinical features, enabling a better understanding of the role of HIV-1 subtypes on the characteristics of infection.

OBJECTIVES

To evaluate the prevalence of different HIV-1 subtypes in subjects with recent diagnosis for HIV infection in the extreme south of Brazil, and to study their association with demographic, behavioral, clinical and laboratorial characteristics.

STUDY DESIGN

We have determined the genetic sequence of viral protease and reverse transcriptase (polymerase, connection and RNase H domains) isolated from studied subjects. Viral subtype was inferred by comparison with reference HIV sequences, and recombination was determined with Simplot analysis. The association of HIV-1 subtypes with studied characteristics was evaluated by chi-square, Fisher's exact, Student's t and Kruskal-Wallis tests.

RESULTS

Two hundred and forty-five HIV isolates were molecularly characterized, and the association with variables was studied for 233 (95.1%) patients. Of those, 46.8% followed AIDS defining criteria. HIV-1C was responsible for 56.3% of infections, and was associated with heterosexual transmission (p=0.001) and with higher CD4(+) T-cell counts (p=0.02).

CONCLUSIONS

The molecular epidemiology of HIV-1 in the southernmost Brazil is currently steady with predominance of HIV-1C. This is the first study showing a robust association of the infection by this subtype and heterosexual transmission in the state of Rio Grande do Sul, Brazil.

HIV, syphilis infection, and risky sexual behaviors among male university students who have sex with men in Beijing, China: a cross-sectional study

Young male university students who have sex with men are at high risk of HIV and sexually transmitted infections (STIs). We conducted a cross-sectional survey to assess the prevalence of risky sexual behaviors, HIV, and syphilis among male university students who have sex with men in Beijing, China; and to identify risk factors for unprotected anal intercourse (UAI). Among 157 study participants, HIV and syphilis prevalence were 2.5% and 7.0%, respectively. We found a high prevalence of UAI in our study population. Multiple logistic regression analysis revealed two significant predictors of UAI: believing it is not necessary to use a condom with a regular sex partner and not feeling anxious about being gay. Not using a condom during first sexual experience with a man was a marginally significant predictor of UAI. Male university students who have sex with men are especially vulnerable to HIV and STIs. Intensified education and HIV testing programs are needed to reduce risk in this population.

High burden of transmitted HIV-1 drug resistance in Italian patients carrying F1 subtype

BACKGROUND

Transmitted drug resistance (TDR) is mainly restricted to individuals carrying B subtype, with low prevalence among non-B subtypes when grouped together. Subtype F1 is the most frequent non-B variant found in subjects living in Italy, allowing a specific assessment of TDR associated with this clade.

METHODS

We analysed pol sequences of HIV-1-positive individuals carrying the F1 variant included in the Antiretroviral Resistance Cohort Analysis database in the 1998-2009 period. Mutations were analysed with the Surveillance Drug Resistance Mutation and the International AIDS Society lists for naive and treated patients, respectively.

RESULTS

Among 343 HIV-1-infected patients carrying an F1 subtype, resistance was evaluated in a subset of 221 patients whose treatment status was known (169 drug naive and 52 drug experienced). The prevalence of TDR was 15.4% (11.8% for nucleoside/nucleotide reverse transcriptase inhibitors, 6.5% for non-nucleoside reverse transcriptase inhibitors and 7.1% for protease inhibitors). Among the 169 naive patients, 75.1%, 10.1% and 7.1% were Italians, South Americans and Romanians, respectively. Heterosexuals were prevalent among Italians and Romanians, while men who have sex with men were predominant among South Americans. The overall frequency of TDR declined from 21.4% to 7.1% in the 1998-2009 period. Although no statistical difference was detected, the frequency of TDR was higher in South Americans (23.5%) compared with Italian and Romanian naive patients (15% and 8.3%, respectively).

DISCUSSION

Our study shows a remarkable frequency of TDR in the F1 subtype-infected population. The high prevalence of TDR detected in South American subjects is linked to the homosexual route of infection. However, TDR was considerably high also in Italian subjects harbouring the F1 subtype, deserving careful monitoring.

Distribution of human immunodeficiency virus type 1 subtypes in the State of Amazonas, Brazil, and subtype C identification

Few studies have reported the molecular epidemiological characterization of HIV-1 in the Northern region of Brazil. The present study reports the molecular and epidemiological characterization of 31 HIV-1 isolates from blood donors from the State of Amazonas who donated blood between April 2006 and March 2007. Serum/plasma samples from all donors were screened for HIV antibodies by ELISA and the results confirmed by Western blot analysis. Genomic DNA was extracted from the buffy coat using the Super Quik-Gene-DNA Isolation kit. Nested PCR was performed on the env, gag, and pol regions of HIV-1 using the Gene Amp PCR System 9700. Sequencing reactions were performed using the inner PCR primers and the DYEnamic™ ET Dye Terminator Kit, and phylogenetic analysis was performed using the gag, pol, and env gene sequences. We collected samples from 31 blood donors who tested positive for HIV-1 in confirmatory experiments. The male:female ratio of blood donors was 3.4:1, and the mean age was 32.4 years (range: 19 to 61 years). Phylogenetic analysis showed that subtype B is the most prevalent among Northern Brazilian HIV-1-seropositive blood donors. One HIV-1 subtype C and one circulating recombinant form (CRF_BF) of HIV-1 were identified in the State of Amazonas. This is the first study showing the occurrence of a possible “homogenous” subtype C in this region of Brazil. This finding could contribute to a better characterization of the HIV-1 strains that circulate in the country. Key words: HIV-1; Subtypes; Phylogenetic analysis; Blood donors; Molecular and epidemiological characterization

Diversity of commercial sex among men and male-born trans people in three Peruvian cities

In Peru, commercial sex involving men and male-born travestis, transgenders and transsexuals (CSMT) is usually represented as a dangerous practice carried out on the streets by people experiencing economic hardship and social exclusion. However, in reality little is known about the complexities of this practice in Peru. This paper presents findings from an ethnographic study of the characteristics, patterns and sociocultural aspects of CSMT in three Peruvian cities. The study included participant observation in sex work venues and interviews with 42 sex workers and 25 key informants. We found that CSMT in Peru takes many forms (some not previously described in the country) and is practised in different places by people from various socioeconomic levels. In many cases, the practice appears linked to ideals of social mobility, migratory experiences and other economic activities. In addition, the increasing use of the Internet and mobile phones has changed patterns of sex work in Peru. We review the implications of these findings for future research and public health interventions.

Acceptability of pre-exposure prophylaxis as an HIV prevention strategy: barriers and facilitators to pre-exposure prophylaxis uptake among at-risk Peruvian populations

This study examined pre-exposure prophylaxis (PrEP) acceptability among female sex workers, male-to-female transgendered persons and men who have sex with men in Lima, Peru. Focus groups explored social issues associated with PrEP acceptability and conjoint analysis assessed preferences among eight hypothetical PrEP scenarios with varying attribute profiles and their relative impact on acceptability. Conjoint analysis revealed that PrEP acceptability ranged from 19.8 to 82.5 out of a possible score of 100 across the eight hypothetical PrEP scenarios. Out-of-pocket cost had the greatest impact on PrEP acceptability (25.2, P < 0.001), followed by efficacy (21.4, P < 0.001) and potential side-effects (14.7, P < 0.001). Focus group data supported these findings, and also revealed that potential sexual risk disinhibition, stigma and discrimination associated with PrEP use, and mistrust of health-care professionals were also concerns. These issues will require careful attention when planning for PrEP roll-out.

Levels of spending and resource allocation to HIV programs and services in Latin America and the Caribbean

Background

An estimated 1.86 million people are living with HIV in Latin America and the Caribbean (LAC). The region is comprised of mainly middle-income countries with steady economic growth while simultaneously there are enormous social inequalities and several concentrated AIDS epidemics. This paper describes HIV spending patterns in LAC countries including analysis of the levels and patterns of domestic HIV spending from both public and international sources.

Methods and Findings

We conducted an extensive analysis of the most recently available data from LAC countries using the National AIDS Spending Assessment tool. The LAC countries spent a total of US$ 1.59 billion on HIV programs and services during the latest reported year. Countries providing detailed information on spending showed that high percentages are allocated to treatment and care (75.1%) and prevention (15.0%). Domestic sources accounted for 93.6 percent of overall spending and 79 percent of domestic funds were directed to treatment and care. International funds represented 5.4 percent of total HIV funding in the region, but they supplied the majority of the effort to reach most-at-risk-populations (MARPs). However, prevalence rates among men who have sex with men (MSM) still reached over 25 percent in some countries.

Conclusions

Although countries in the region have increasingly sustained their response from domestic sources, still there are future challenges: 1) The growing number of new HIV infections and more people-living-with-HIV (PLWH) eligible to receive antiretroviral treatment (ART); 2) Increasing ART coverage along with high prices of antiretroviral drugs; and 3) The funding for prevention activities among MARPs rely almost exclusively on external donors. These threats call for strengthened actions by civil society and governments to protect and advance gains against HIV in LAC.

Southern Brazil HIV type 1 C expansion into the state of São Paulo, Brazil

Abstract HIV diversity reflects multifactorial evolutionary forces, but monitoring subtype prevalence may provide clues to understanding the epidemic. In the Americas HIV-1 C is present at significant levels only in the southern states of Brazil. We describe in this study the presence of the HIV-1 C pol genome in 11.6% (95 CI 6-21%) of antiretroviral-naive individuals from São Paulo, the major city of South America, and 6.8% (95 CI 4-12%) from the second metropolitan area of the State of São Paulo, Brazil. Moreover, a significant growth trend of this subtype was documented among cases failing therapy in the area. Sequences were obtained by direct nested PCR from cDNA retrotranscribed from plasma RNA. Phylogenetic and amino acid signatures support an expansion from variants previously identified in southern Brazil. The evaluation of additional genomic regions (partial gag, envelope, and/or integrase) in samples with HIV-1 C at pol showed extensive recombination with clade B, observed in 47% of ARV-naive cases. The spread of HIV-1 C locally and to other areas of South America should be monitored as it may influence the dynamics of the epidemic.

Molecular characterization of the human immunodeficiency virus type 1 among children in Lima, Peru

In Peru, there is a lack of information on molecular analysis in pediatric human immunodeficiency virus (HIV) infection. At present, the mother-to-child transmission rate is estimated at approximately 2-4%. The objective of this study was to assess the molecular epidemiology of HIV-1 in infected children. Children with suspected or confirmed pulmonary tuberculosis were evaluated at two public hospitals between 2002 and 2007. Whole blood samples were obtained from 90 HIV-positive children, who were confirmed to be positive by enzyme-linked immunosorbent assay and Western blot. The specimens were subjected to envelope heteroduplex mobility assay (env HMA) followed by gag and pol gene region sequence analysis. Subtype B was found in 88 (98%) of 90 children and 2 (2%) children were subtype BF recombinants. This is the first report of recombinant HIV strains in HIV-infected children in Peru. Understanding the origin, diversity, and spread of HIV strains worldwide will be necessary for the development of an effective vaccine that targets pediatric populations throughout the world.

[HIV infection in immigrants in Spain: Epidemiological characteristics and clinical presentation in the CoRIS Cohort (2004-2006)]

INTRODUCTION

A growing number of immigrants are using the public health services for HIV in Spain. We describe the sociodemographic, epidemiological, and clinical characteristics of a cohort of naïve HIV-infected subjects (CoRIS cohort) according to their place of origin.

METHODS

CoRIS is an open, hospital-based cohort of naïve, HIV-infected persons attended in 19 hospitals from 9 of the 19 autonomous regions in Spain. We describe the characteristics of the cohort members by place of origin, and compare them with the Spanish cases identified from January 2004 to October 2006, using the chi-square and Fisher exact tests.

RESULTS

Of 2507 patients, 76.3% were men and median age was 36 years. By origin, 71.5% were Spanish, 16.0% Latin Americans (LA), 5.8% sub-Saharan Africans (SSA), 3.7% Western Europeans (WE), 1.7% Eastern Europeans (EE) and 1.4% North Africans (NA). Compared to Spaniards, there were significant differences by origin in sex, age, and transmission category. Median CD4 count at cohort entry was 352 cell/microL, with no differences according to origin. Median viral load was 48 962 copies/mL and was significantly lower for SSA. Over 11.4 months of follow-up, 57.9% initiated HAART with no differences by origin. Hepatitis C prevalence was 29.9% in Spaniards, 7.3% in Latin Americans, 11.7% in SSA, and 45.7% in EE (P<0.05). Overall, 13.4% were Mantoux-positive (28.6% in SSA and 30.8% in NA). Tuberculosis was more common among cases from EE (9.5%) and SSA (8.3%) compared to Spaniards (4.8%) (P<0.05).

CONCLUSIONS

Almost one third of naïve HIV-infected patients in CoRIS are foreign-born. Their sociodemographic, epidemiological and clinical characteristics reflect the epidemic in their places of origin. However, their immunological status at cohort entry and initiation of HAART is no different from that of Spaniards.

Close phylogenetic relationship between Angolan and Romanian HIV-1 subtype F1 isolates

BACKGROUND

Here, we investigated the phylogenetic relationships of the HIV-1 subtype F1 circulating in Angola with subtype F1 strains sampled worldwide and reconstructed the evolutionary history of this subtype in Central Africa.

METHODS

Forty-six HIV-1-positive samples were collected in Angola in 2006 and subtyped at the env-gp41 region. Partial env-gp120 and pol-RT sequences and near full-length genomes from those env-gp41 subtype F1 samples were further generated. Phylogenetic analyses of partial and full-length subtype F1 strains isolated worldwide were carried out. The onset date of the subtype F1 epidemic in Central Africa was estimated using a Bayesian Markov chain Monte Carlo approach.

RESULTS

Nine Angolan samples were classified as subtype F1 based on the analysis of the env-gp41 region. All nine Angolan sequences were also classified as subtype F1 in both env-gp120 and pol-RT genomic regions, and near full-length genome analysis of four of these samples confirmed their classification as "pure" subtype F1. Phylogenetic analyses of subtype F1 strains isolated worldwide revealed that isolates from the Democratic Republic of Congo (DRC) were the earliest branching lineages within the subtype F1 phylogeny. Most strains from Angola segregated in a monophyletic group together with Romanian sequences; whereas South American F1 sequences emerged as an independent cluster. The origin of the subtype F1 epidemic in Central African was estimated at 1958 (1934-1971).

CONCLUSION

"Pure" subtype F1 strains are common in Angola and seem to be the result of a single founder event. Subtype F1 sequences from Angola are closely related to those described in Romania, and only distantly related to the subtype F1 lineage circulating in South America. Original diversification of subtype F1 probably occurred within the DRC around the late 1950s.

AIDS in Latin America: assessing the current status of the epidemic and the ongoing response

BACKGROUND

This article provides a summary of the current status of the HIV/AIDS epidemic in Latin America, as well as an outline of the diverse responses to it.

METHODS

A search of international databases (Pubmed and ISI-Web of Science), regional databases (Scielo and Lilacs), regional and national documents and UNAIDS reports. Data are presented according to subregion.

RESULTS

In Mexico HIV remains concentrated among urban men who have sex with men (MSM), and has been growing among injecting drug users (IDU) and in rural areas in relation to migration. An increasing proportion of women among those affected is observed in all countries in Central America, the most affected region, as well as increasing the impact on other vulnerable groups, such as indigenous populations. The Andean Countries have urban epidemics concentrated among MSM. In Peru, non-traditional vulnerable populations were identified. In the Southern Cone heterosexual transmission became more relevant, probably in connection with IDU epidemics and is increasingly affecting lower income groups. Incidence rates have been declining since 2002 in Brazil, the first country to guarantee free, universal access to antiretrovirals, where one-third of drug-naïve patients are still initiating treatment at an advanced stage. Generally, access to treatment has improved as a result of support from the Global Fund and other initiatives, but there are concerns regarding coverage, equity and sustainability.

CONCLUSIONS

HIV is still concentrated among MSM in Latin America. Non-traditional vulnerable groups such as migrants and lower income populations, usually considered part of the general population, deserve attention. Programmes confronting sexual exclusion are still needed. Access to treatment has improved over time, but inequalities persist.

Polymorphism, recombination, and mutations in HIV type 1 gag-infecting Peruvian male sex workers

HIV genetic diversity in female sex workers (FSW) has been previously described in Peru; however this information is not yet available for male sex workers (MSW). Therefore, purified peripheral blood mononuclear cell DNA from 147 HIV-infected subjects identified as MSW and FSW was used to amplify a 460-bp fragment corresponding to the p24-p7 region of the gag gene. The PCR product was digested with restriction enzymes to identify genetic polymorphism. Later, a random group of samples (n = 19) was sequenced to perform phylogenetic analysis, intragenic recombination analysis, and deleterious mutations leading to a nonfunctional protein in conservative regions of the Gag protein. RFLP analysis revealed 11 genetic variants for AluI and five for MspI. A group of nonsex workers (NSW) used for comparison showed different RFLP genetic variant distributions. Of interest, nine cases of mixed genetic variants were observed for MSW, one case for FSW, and none for NSW. Phylogenetic analysis revealed that all HIV-1 species were subtype B. Intragenic recombination analysis showed a B/C recombination case from an FSW (boostrap = 1000; p value < 0.05). Of interest, deleterious mutations were observed in three cases of conservative D2 zinc domains for Gag 3/19 and one case of the high homology region (1/19). This study shows that gag of HIV circulating from MSW has high genetic polymorphism involving deleterious mutations in conserved domains from the p24-p7 gag region.

Epidemiology of male same-sex behaviour and associated sexual health indicators in low- and middle-income countries: 2003-2007 estimates

OBJECTIVES

To conduct a systematic review of published and unpublished data from research and public health information systems on the prevalence of male-to-male sex in the total male population; as well as among men who have sex with men (MSM), data on prevalence of heterosexual activity and heterosexual unions; prevalence of condom use with male and female partners; and prevalence of HIV infection and other sexually transmitted infections (STIs).

METHODS

Key indicators were defined (a) among men in the general population: prevalence of sex with a man ever and last year; (b) among MSM: prevalence of heterosexual experiences ever and last year; proportion of male-female transgenders; proportion of sex workers; prevalence of HIV and other STIs, condom use in last sexual encounter; consistent condom use with men last year; never used a condom with a man. With help from key informants, study searches were conducted in Pubmed, LILLACS, institutional databases, conference records and other sources. Methodology and quality of information were assessed, and the best data available for 2003-7 were selected. Indicator estimates from each study were used to propose regional estimate ranges.

RESULTS

A total of 83 new entries were entered into the database in addition to the previous 561, totalling 644. Of these, 107 showing 2003-7 data were selected. Many new studies came from sub-Saharan Africa, portraying hidden HIV epidemics among MSM. The most frequently reported estimate was HIV infection, with high estimate ranges in most of the regions, except for Middle East and North Africa and Eastern Europe. The next most frequently reported was lifetime frequency of heterosexual sex, showing that roughly 50% of MSM ever had sex with a woman. The small number of newer studies reporting prevalence of "sex with a man in last 12 months" between 2003 and 2007, did not warrant enough new evidence to revise our 2005 size estimates for MSM populations.

CONCLUSIONS

A considerable number of new studies with estimates of relevance to understanding sexual behaviour and HIV among MSM were identified, with an encouraging amount of new data coming from sub-Saharan Africa. However, limitations in the quality, utility and comparability of available information persist. At least three measures could be promoted for use in surveillance and academic studies: standardised indicators for MSM studies; standardised operational definitions of, and instructions to describe, variables; and standardised research designs and data gathering strategies. A prerequisite for this all is intense advocacy to ensure a social climate in which research into such matters is prioritised, resources are made available as needed and the human rights of MSM are respected.

Epidemiological and molecular characteristics of HIV-1 infection among female commercial sex workers, men who have sex with men and people living with AIDS in Paraguay

An HIV seroprevalence and molecular study was conducted among 935 subjects: 723 female commercial sex workers, 92 men who have sex with men and 120 HIV-positive volunteers. The reported injection drug use rates were 0.7% in female commercial sex workers and 3% in men who have sex with men. Sexually transmitted infections were reported in 265 (37%) of the female commercial sex workers and 38 (41%) of the men who have sex with men. A total of 20 (2.8%) female commercial sex workers and 12 (13%) men who have sex with men became HIV infected during the study period. A history of sexually transmitted infection increased the risk of subsequent HIV infection twofold (adjusted odds ratio of 2.5) among the female commercial sex workers, while cocaine use had an adjusted odds ratios of 6.61 among men who have sex with men. From 130 samples, and based on heteroduplex mobility assaying for the env gene, with sequencing of part of pol and/or full genomes, subtype B was the predominant subtype identified (66%); followed by subtype F (22%) and subtype C (4%). Recombinant CRF12-BF strains were identified in 6% and CRF17_BF was identified in 2%.

High rates of sex with men among high-risk, heterosexually-identified men in low-income, coastal Peru

In this paper we describe sex with men, including the frequency of sex and unprotected sex, among high-risk, heterosexually-identified men in urban, low-income, coastal Peru. During 2001--2002, a random community-based sample of these men was administered an epidemiologic survey collecting sexual risk behavior data. Among the 924 high-risk heterosexually-identified men, 131 (14.2%) reported at least one male partner in the past 6 months. Of these, 113 (86.3%) reported male and female partners and among those with partners of both sexes, 84.2% and 57.0% of sex acts with female and male partners, respectively, were unprotected, (RR 1.48, 95% CI = 1.31-1.68). We observed a high rate of recent bisexual behavior compared to past studies showing frequent, unprotected sex with male and female partners. This population has substantial potential to act as a bridge population between and their male and female partners and should be addressed by prevention programs.

Evidence for different susceptibility to tipranavir and darunavir in patients infected with distinct HIV-1 subtypes

BACKGROUND

Tipranavir (TPV) and darunavir (DRV) are potent against protease inhibitor (PI)-resistant viruses. Efficacy of these compounds when confronting distinct HIV subtypes is not known.

METHODS

All clinical specimens from HIV-positive patients sent to our institution for drug resistance testing between 1999 and 2006 were analysed. The prevalence of TPV and DRV resistance mutations was assessed based on the latest International AIDS Society-USA panel list. Phenotypic susceptibility to DRV and TPV was examined in a subset of these samples using the PhenoSense assay.

RESULTS

A total of 1364 genotypes were analysed, including 1178 from individuals infected with clade B (285 drug naive) and 186 with non-B subtypes (137 drug naive). The mean number (+/-SD) of DRV resistance-associated mutations was higher in clade B than non-B (0.4 +/- 0.9 versus 0.06 +/- 0.3; P < 0.001), and more frequent among PI-experienced than drug-naive patients (0.6 +/- 1.02 versus 0.02 +/- 0.21; P < 0.001). In contrast, the mean number of TPV resistance-associated mutations was higher in non-B than B subtypes (2.7 +/- 1 versus 1.2 +/- 1.6; P < 0.001), regardless of PI experience. Susceptibility to TPV and DRV was examined in 29 drug-naive patients infected with non-B subtypes (1A, 3C, 2CRF01_AE, 9CRF02_AG, 1CRF12_BF, 3CRF14_BG, 3F and 7G). All showed susceptibility to DRV and 93% to TPV. Interestingly, two subtype F specimens showed reduced TPV susceptibility, with fold-changes of 2.7 and 2.1, respectively.

CONCLUSIONS

Non-B subtypes show a greater number of TPV resistance-associated mutations than B viruses, regardless of PI exposure. While HIV clade has no influence on DRV susceptibility, some F subtypes may show reduced TPV susceptibility.

Immigration status and HIV-risk related behaviors among female sex workers in South America

This study compares immigrant (i.e., foreigner) with non-immigrant (i.e., local/native) HIV-related risk behaviors among female sex workers (FSW) in South America. A total of 1,845 FSW were enrolled in Argentina, Bolivia, Ecuador, and Uruguay. According to their nationality, 10.1% of participants were immigrant FSW. Immigrant FSW were more likely to be younger in Argentina; to work in a disco/bar in Bolivia; to be single and use illegal drugs in Ecuador; and to work in a brothel, consume alcohol, and have sex with foreign clients in Uruguay. HIV-related sexual and drug use behaviors were more common among immigrant FSW in Bolivia, Ecuador, and Uruguay. Country-specific HIV/STI prevention and control programs should be developed for immigrant FSW populations in South America.