Design, implementation, and evaluation at entry of a prospective cohort study of homosexual and bisexual HIV-1-negative men in Belo Horizonte, Brazil: Project Horizonte

Loss to follow-up in a cohort of HIV-negative men who have sex with men: Project Horizonte

OBJECTIVE

The objective of this study is to estimate the attrition rates and evaluate factors associated with loss to follow-up between 1994 and 2011 in an open cohort of HIV-negative men who have sex with men.

METHODS

The Project Horizonte is an open cohort study that aimed to assess the incidence of HIV infection, evaluate the impact of educational interventions, and identify potential volunteers for HIV vaccine trials. The rates of losses to follow-up were estimated for three periods (1994–1999, 2000–2005, and 2006–2011). The variables analyzed were collected in a psychosocial questionnaire. Volunteers who dropped out were compared with the ones who remained in the study using a Cox regression model.

RESULTS

A total of 1,197 volunteers were recruited. The median follow-up time in the study (n = 626) was 4.2 years. The median follow-up time for the volunteers who dropped out of the study (n = 571) was 1.46 years. The overall rate of loss to follow-up was 11.6/100 person-years. Attrition rates by period were: 12.60 (1994–1999), 11.80 (2000–2005), and 9.00 (2006–2011) per 100 person-years. Factors associated with losses to follow-up were: age group of 21–30 years old, monthly per capita income of more than six or less than one Brazilian minimum wage, having more than two dependents, report of bisexual practice, and inconsistent use of condoms for receptive anal sex.

CONCLUSIONS

A slight decrease of the loss to follow-up was observed over time. Higher attrition rates happened in the first three years of follow-up. It is possible that the link of the volunteers were not yet well established. Those who reported inconsistent condom use in receptive anal sex were more likely to leave the study, suggesting an underestimation of the incidence of HIV infection in a cohort population. For greater effectiveness, retention strategies must be reassessed considering the connection between the characteristics of homosexual and bisexual behavior and the motivations to engage in health research.

Risk factors associated with HIV infection among male homosexuals and bisexuals followed in an open cohort study: Project Horizonte, Brazil (1994-2010)

BACKGROUND

There has recently been an increase in HIV infection rates among men who have sex with men (MSM). This study aimed at investigating risk factors associated with incident HIV infection in a MSM cohort-Project Horizonte, Belo Horizonte, Minas Gerais, Brazil.

METHODOLOGY

This is a nested case-control study in an ongoing open cohort of homosexual and bisexual men, carried out in 1994-2010, during which 1,085 volunteers were enrolled. Each HIV seroconverted volunteer (case) was compared with three randomly selected HIV negative controls, matched by admission date and age (±3 years). During follow-up, 93 volunteers seroconverted and were compared with 279 controls.

PRINCIPAL FINDINGS

The risk factors associated with HIV seroconversion were: contact with partner's blood during sexual relations (OR 3.7; 95% CI 1.2-11.6), attendance at gay saunas in search for sexual partners (OR 2.6; 95% CI 1.3-5.4), occasional intake of alcohol when flirting and engaging in sexual activity (OR 2.5; 95% CI 1.3-5.1), inconsistent use of condoms in receptive anal sex (OR 2.4; 95% CI 1.1-5.4), little interest to look up information about AIDS (OR 2.6; 95% CI 1.0-6.7) particularly in newspapers (OR 3.4; 95% CI 1.4-8.1).

CONCLUSIONS

This study shows that MSM are still engaging in risk behavior, such as unprotected anal intercourse, despite taking part in a cohort study on various preventive measures. New preventive strategies in touch with the epidemic's development and the specificities of this particular population are needed.

Transmitted human immunodeficiency virus-1 drug resistance in a cohort of men who have sex with men in Belo Horizonte, Brazil--1996-2012

The presence of transmitted human immunodeficiency virus (HIV)-1 drug-resistance (TDR) at the time of antiretroviral therapy initiation is associated with failure to achieve viral load (VL) suppression. Here, we report TDR surveillance in a specific population of men who have sex with men (MSM) in Belo Horizonte, Brazil. In this study, the rate of TDR was evaluated in 64 HIV-infected individuals from a cohort of MSM between 1996-June 2012. Fifty-four percent had a documented recent HIV infection, with a seroconversion time of less than 12 months. The median CD4+T lymphocyte count and VL were 531 cells/mm3 and 17,746 copies/mL, respectively. Considering the surveillance drug resistance mutation criteria, nine (14.1%) patients presented TDR, of which three (4.7%), five (7.8%) and four (6.2%) had protease inhibitors, resistant against nucleos(t)ide transcriptase inhibitors and against non-nucleoside reverse-transcriptase inhibitors mutations, respectively. Two of the patients had multi-drug-resistant HIV-1. The most prevalent viral subtype was B (44, 68.8%), followed by subtype F (11, 17.2%). This study shows that TDR may vary according to the population studied and it may be higher in clusters of MSM.

Barriers of enrolment in HIV vaccine trials: a review of HIV vaccine preparedness studies

Barriers to participation in an HIV vaccine trial have been examined in many HIV vaccine preparedness studies (VPS). These barriers can be understood in terms of the locus of the barrier (personal vs. social) and the nature of the barrier (risk vs. cost). Another type of barrier is perceived misconceptions. In this systematic review, we categorize barriers, and compare these barriers between the Organization for Economic Co-operation and Development (OECD) countries and the non-OECD countries. In the OECD countries, we retrieved 25 studies reporting personal risks (PR), 9 studies reporting social risks (SR), 10 studies reporting personal costs (PC), and 16 studies reporting misconceptions. In the non-OECD countries, we retrieved 27 studies reporting PR, 19 studies reporting SR, 18 studies reporting PC, 1 study reporting social costs (SC), and 13 studies reporting misconceptions. Important PR were "adverse effects" and "vaccine-induced seropositivity", "distrust of institutions", and "temptation to have unsafe sex" in men who have sex with men (MSM). "Discrimination" was a common SR. "Time commitment" was an important PC, and "family commitments" were a SC in one non-OECD country. "HIV infection from the vaccine" was a common misconception. Both the OECD and the non-OECD countries have similar barriers, and people's decisions to participate in a clinical trial involve multiple barriers. However, these barriers apply to hypothetical HIV vaccine trials, and barriers for actual vaccine trials need further assessment.

So different, yet so similar: meta-analysis and policy modeling of willingness to participate in clinical trials among Brazilians and Indians

BACKGROUND

With the global expansion of clinical trials and the expectations of the rise of the emerging economies known as BRICs (Brazil, Russia, India and China), the understanding of factors that affect the willingness to participate in clinical trials of patients from those countries assumes a central role in the future of health research.

METHODS

We conducted a systematic review and meta-analysis (SRMA) of willingness to participate in clinical trials among Brazilian patients and then we compared it with Indian patients (with results of another SRMA previously conducted by our group) through a system dynamics model.

RESULTS

Five studies were included in the SRMA of Brazilian patients. Our main findings are 1) the major motivation for Brazilian patients to participate in clinical trials is altruism, 2) monetary reimbursement is the least important factor motivating Brazilian patients, 3) the major barrier for Brazilian patients to not participate in clinical trials is the fear of side effects, and 4) Brazilian patients are more likely willing to participate in clinical trials than Indians.

CONCLUSION

Our study provides important insights for investigators and sponsors for planning trials in Brazil (and India) in the future. Ignoring these results may lead to unnecessary fund/time spending. More studies are needed to validate our results and for better understanding of this poorly studied theme.

HIV prevalence among female sex workers, drug users and men who have sex with men in Brazil: a systematic review and meta-analysis

Background

The Brazilian response towards AIDS epidemic is well known, but the absence of a systematic review of vulnerable populations ─ men who have sex with men (MSM), female sex workers (FSW), and drug users (DU) remains a main gap in the available literature. Our goal was to conduct a systematic review and meta-analysis of studies assessing HIV prevalence among MSM, FSW and DU, calculating a combined pooled prevalence and summarizing factors associated the pooled prevalence for each group.

Methods

Nine electronic databases (MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE, AMED, CINAHL, TOXNET, SciELO, and ISI-Web of Science) were searched for peer-reviewed papers published in English, French, Spanish or Portuguese, from 1999 to 2009. To be included in the review, studies had to measure HIV prevalence and/or incidence as the primary outcome among at least one specific population under analysis.

Results

The studies targeting the three populations analyzed mostly young participants aged 30 years or less. Among FSW, eight studies were selected (3,625 participants), consistently identifying higher condom use with sexual clients than with occasional and stable partners. The combined HIV prevalence for FSW was 6.2 (95% CI: 4.4-8.3). Ten studies targeting MSM were identified (6,475 participants). Unprotected anal intercourse was commonly reported on those studies, but with great variability according to the nature of the relationship - stable vs. occasional sex partners - and sexual practice - receptive vs. insertive anal sex. Pooled HIV prevalence for MSM was 13.6 (95% CI: 8.2-20.2). Twenty nine studies targeting DU were identified (13,063 participants). Those studies consistently identified injection drug use and syringe/needle sharing as key predictors of HIV-infection, as well as engagement in sex work and male-to-male sex. The combined HIV prevalence across studies targeting DU was 23.1 (95% CI: 16.7-30.2).

Conclusions

FSW, MSM and DU from Brazil have a much risk of acquiring HIV infection compared to the general population, among which HIV prevalence has been relatively low (~0.6%). Those vulnerable populations should be targeted by focused prevention strategies that provide accurate information, counseling and testing, as well as concrete means to foster behavior change (e.g. access to condoms, drug abuse treatment, and clean syringes in the case of active injecting drug users), tailored to gender and culture-specific needs. Programs that provide these services need to be implemented on public health services throughout the country, in order to decrease the vulnerability of those populations to HIV infection.

HIV vulnerability of men who have sex with men in developing countries: Horizons studies, 2001-2008

While male-to-male sexual behavior has been recognized as a primary risk factor for human immunodeficiency virus (HIV), research targeting men who have sex with men (MSM) in less-developed countries has been limited due to high levels of stigma and discrimination. In response, the Population Council's Horizons Program began implementing research activities in Africa and South America beginning in 2001, with the objectives of gathering information on MSM sexual risk behaviors, evaluating HIV-prevention programs, and informing HIV policy makers. The results of this nearly decade-long program are presented in this article as a summary of the Horizons MSM studies in Africa (Senegal and Kenya) and Latin America (Brazil and Paraguay), and include research methodologies, study findings, and interventions evaluated. We also discuss future directions and approaches for HIV research among MSM in developing countries.

The epidemiological contribution to the preparation of field trials for HIV and STI vaccines: objectives and methods of feasibility studies

Feasibility studies are an important component of preparations for efficacy field trials of vaccine candidates, but represent a neglected area in clinical trial literature. These studies are designed to identify cohorts of higher-risk individuals with sufficiently high incidence to support a vaccine trial; to determine the readiness of these individuals to participate in a trial; to develop cost-effective recruitment and retention strategies, educational methods that ensure ethical informed consent, and instruments that accurately assess risk behaviours; to measure incidence rates over time and the effect of risk reduction interventions on incidence; to contribute estimates of incidence and loss to follow-up rates to sample size calculations; to assess the level of acceptability of a future efficacious vaccine in the target population and, in the case of several viruses, to identify circulating subtypes. Feasibility study methods have been largely developed in the context of HIV, but may also be used in the preparation of preventive intervention trials for other STI.