The heightened HIV vulnerability associated with men who have sex with men (MSM) and find sex online in Western and East Asian countries may pose similar concerns for MSM in Southeast Asia. However, this line of research has been underexamined among Southeast Asian MSM, especially in Southeast Asian cities with a high HIV prevalence among young MSM, such as Ho Chi Minh City, Vietnam. To characterize the sexual behavioral and psychosocial correlates of online sex seeking in a sample of largely gay-identified young MSM in Ho Chi Minh City (HCMC), Vietnam. To examine the relationships between social support, outness, and last condomless anal sex, but not PrEP or ART. The analysis included specific attention paid to the use of different types of online sex platforms, which may contribute to the understanding of online sexual seeking. Patterns of online sexual seeking in a cross-sectional sample of YMSM (N=1005) were identified using latent class analysis (LCA). Multinomial logistic regressions and Poisson regressions with robust variance were used to estimate the associations between patterns of online sex seeking and other participant characteristics. We found four latent classes of MSM with distinct profiles of online platform use for sex seeking: 1) “negligible app users,” 2) “gay app users,” 3) “poly app users,” and 4) “low-cost app users.” Patterns of online sex seeking moderated the protective effects of social support and outness on last condomless anal sex, but not on PrEP or ART. When stratified by levels of social support and outness, only gay app users were associated with a protective effect on last condomless anal sex but not on PrEP or ART when social support and outness were high. Low-cost app users were marginally associated with a higher prevalence of condomless anal sex but not with PrEP or ART when the level of outness was low. Vietnamese YMSM who find sex partners online have distinct patterns of app use, with contrasting sexual and psychosocial health burdens that indicate online sex seeking as a socially patterned behavior. HIV prevention programs and tailored digital interventions should consider the different exposures to social influences associated with patterns of social networking app use as they could moderate the effectiveness of the delivered programs and interventions in reducing YMSM’s HIV vulnerability.

Background: There is scarce research on male sex workers in the context of alcohol use. While heavy alcohol use has been established as a risk factor for HIV and STI infections among men who have sex with men (MSM), men who engage in sex work with other men, particularly from the Global South, have not been included in these studies. Moreover, studies among male sex workers in Asia often do not explore migration contexts of these men. Objectives: The objective of this exploratory study is to examine the prevalence and correlates of heavy alcohol use among migrant and non-migrant male sex workers in Bangkok and Pattaya, Central Thailand. Methods: Between August and October 2015, 18-24year-old migrant and non-migrant male sex workers (n = 212) were recruited from various male sex work-identified venues (bars, clubs, massage parlors, and go-go bars) to take an interviewer-administered cross-sectional survey in Bangkok and Pattaya, Thailand. Measures were adapted from previous studies in similar populations and included structured questions across four domains, including demographic characteristics, alcohol use, stimulant use, and sexual behaviors. Multivariable logistic regression assessed the independent associations between heavy alcohol use (heavy versus not heavy) and demographic characteristics, stimulant use and sexual behavior. Results: Heavy alcohol use was prevalent among one-third of participants. Heavy alcohol use was positively associated with male sex workers who were non-migrant and Thai, currently using stimulants, having 15 or more male clients in the past month and having first consumed alcohol at age 15years or younger. Conclusions: Current HIV prevention efforts should consider subpopulations of MSM, including male sex workers and migrants, as well as other risk behaviors like alcohol, as important contexts for HIV and STI risks.

Male sex workers (MSWs) in Vietnam are at high risk for acquisition and transmission of human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs), yet are extremely disengaged from the healthcare system. This contributes to large numbers of untreated or late-treated infections and increased secondary transmission. We enrolled 995 MSWs in Hanoi and Ho Chi Minh City (HCMC) in a Sexual Health Promotion intervention that included face-to-face delivery of seven content modules, a clinical examination and testing for HIV, syphilis, gonorrhea and Chlamydia. Onsite treatment was provided for STIs, and those who tested positive for HIV were referred to local treatment centers. While 64.6% of participants had never been to a health service and fewer than half (41.2%) had ever been tested for HIV, 67.1% returned for test results. This testing identified 109 (11.0%) participants who were HIV-positive and 312 (31.4%) who tested positive for at least one other STI. Substantive differences were seen in MSWs from different cities, with those from Hanoi more likely to have ever visited a health service (57.8% vs. 24.9%) and to have taken a prior HIV test (54.1% vs. 37.9%) than those in HCMC. Sexual health promotion is a promising approach to engaging MSWs in health services.

Little is known about the age of onset of sexual and drug risk and their association with complex patterns of recent drug use among male sex workers (MSW) in a developing country, such as Vietnam. The aim of this study was to determine whether latent class analysis (LCA) would aid in the detection of current individual and polydrug use combinations to predict how different trajectories of sexual and drug initiation contribute to different patterns of current illicit drug use. Data were collected from a cross-sectional survey administered to young MSWs between 2010 and 2011 in Vietnam (N = 710). LCA clustered participants into recent drug use groups, incorporating both the specific types and overall count of different drugs used. Men reported drug use within a 1 month period from an 11-item drug use list. LCA identified three distinct drug use classes: (1) alcohol use, (2) alcohol and tobacco use, and (3) high polydrug use. The current drug use classes are associated with sex worker status, housing stability, income level, educational attainment, marital status, sexual identity, and sexual preferences. High levels of drug use are strongly associated with being a recent sex worker, not having recent stable housing, higher than median income, more than a high school education, less likely to be currently in school and more likely to have non-homosexual preferences and heterosexual partners. An event history analysis approach (time-event displays) examined the timing of the age of onset of drug and sexual risks. Early ages of drug and sexual initiation are seen for all three classes. High current drug users show earlier onset of these risks, which are significantly delayed for moderate and low current drug users. LCA incorporating an overall count of different drugs detected three distinct current drug use classes. The data illustrates that the complexity of drug factors that must be accounted for, both in advancing our epidemiological understanding of the complexity of drug use and the use of drug and sexual risk initiation data to predict current drug use subtypes among high-risk populations.

Young male sex workers (YMSW) in Vietnam have high rates of HIV and STIs, yet have poor access to healthcare due low knowledge, stigma, and economic constraints. In the process of implementing a Sexual Health Promotion intervention to engage YMSW in Ho Chi Minh City in healthcare, we identified a unique sex work venue, known as a "Shared House," in which YMSW provide sex under the direction of a manager who negotiates the terms of the transaction directly with the client. Survey data reveal that compared with YMSW recruited in other locations, those interviewed in Shared Houses reported lower levels of substance use, less contact with the police, and fewer nights spent sleeping in pubic places. However, observational data and informal interviews with YMSW in Shared Houses revealed that the majority were trafficked through third-party brokers who connect youth with Shared House managers for the explicit purpose of sex work. These YMSW had little or no control over their sex work transactions and very low levels of knowledge regarding transmission of HIV and STIs. Further research is needed in these and other venues in which young men are trafficked for sex work.

Background Urban centres in Vietnam have high rates of HIV infection, especially among men who have sex with men (MSM). A subgroup of MSM, young male sex workers (YMSW), are at especially high risk due to concurrent sex with multiple male and female partners, low levels of knowledge regarding HIV and sexually transmissible infection (STI) transmission, and limited engagement with health services, including STI and HIV screening and treatment. METHODS A targeted intervention (SHEATH) derived from Harm Reduction and Sexual Health Promotion intervention technology was implemented in an out-of-treatment population of YMSW in Hanoi and Ho Chi Minh City (n=919). RESULTS YMSW reported high levels of satisfaction with each of the seven core modules within the intervention and for the intervention as a whole. The intervention conferred significant benefit in relation to improved knowledge of STI and HIV transmission (P<0.001). Although only 36% of participants had seen a healthcare provider in the past year, following the intervention 81% intended to see one in the next 6 months. Similarly, although 71% of participants did not disclose that they were MSM the last time they visited a healthcare provider, following the intervention 71% intended to do so at their next visit. High rates of STIs (>10%) and HIV (9.5%) were also found. CONCLUSION The data show that the SHEATH intervention can be implemented in this population and setting, is met with high rates of acceptability, and positively impacts STI and HIV knowledge and multiple health services outcomes (including knowledge of HIV status and disposition towards habituation of HIV screening).

OBJECTIVE:The aim of this manuscript is to describe the prevalence, genotypic distribution of penile HPV infection and the behavioral risk factors associated with penile HPV infection (any HPV type, high-oncogenic-risk [HR] types, low-oncogenic-risk [LR] types, and of multiple HPV types) in a group of sexually active males who went to an STI clinic in San Juan, Puerto Rico.METHODS:After providing informed consent, the participants, underwent a detailed behavioral interview and a clinical examination. Frequency distributions and descriptive statistics were used to characterize the study samples. Prevalence estimates and 95% confidence intervals (CI) were calculated for any type of HPV, HR types, LR types, or multiple types. Logistic regression analyses was performed to determine factors associated with each of the HPV types.RESULTS:Two hundred and six participants were enrolled in this study. The mean age of the participants was 37.8±13.1 years. Close to 80% of the sample were infected with at least one HPV type; 73.5% were infected with one or more LR-HPV types; 32.4%, with one or more HR-HPV types; and 46.0%, with multiple HPV types. The most prevalent HR types were HPV-35, -31, and -16; the most prevalent LR types were HPV 6/11, and -84. After adjusting for age, having a high number of lifetime female sexual partners was highly associated with having multiple types of HPV infection (estimated OR=2.86; 95% CI=1.41, 5.80).CONCLUSION:HPV infection is common among sexually active males frequenting this STI clinic. HPV types not covered by the current quadrivalent HPV vaccine were identified. Multiple HPV types in the penis are significantly related to the lifetime number of female sexual partners. The high prevalence of HPV at this particular STI clinic evidences that males need to be targeted in primary care settings if the available vaccine is to be effectively promoted. In addition, opportunities for secondary prevention of HPV in STI settings are recommended, because of the burden of anal and penile cancer documented in the island.

Background: HIV research in Vietnam has focused primarily on its large heroin injector population. Data on men who have sex with men [MSM], particularly the large and growing population of men who exchange sex for money or other material rewards, male sex workers [MSWs], is very limited.Methods: Data derive from a cross-sectional study of MSW, age 16-35, recruited using community sampling methods in three cities in 2010-2011, including Hanoi, Ho Chi Minh City [HCMC], and Nha Trang City (n = 710). Assessments included demographic characteristics, substance use, sexual risk, and use of health services. A series of "event" questions were used to assess the influence of alcohol and drugs on sexual risk.Results: Both tobacco and alcohol are initiated at a young age and most participants currently use both substances overall across all three cities. While alcohol and tobacco use precede the initiation of sex work, stimulant and opiate use are initiated following the initiation of sex work. There was substantial overlap between substance use and sexual risk, and this overlap was strongest in sexual events involving male and female elective partners rather than sex work clients.Conclusion: Although rates of HIV infection in this group are low, this may be an artifact of the young age of the sample. High rates of drug use, including alcohol, tobacco and illicit drugs, coupled with high rates of ulcerative STIs such as HPV, suggest the potential for rapid amplification of STI/HIV risk among MSW and their complex sex partnering networks. (C) 2014 Elsevier B.V. All rights reserved.

This paper examines young women's initiation to heroin use in the context of an intimate relationship based on data from a small-scale ethno-epidemiology of heroin use in Ireland, 2007-2009. The epidemiological sample included 120 young people, and life history interviews were conducted with a sub-sample of 40 youth aged 16-25 years. A detailed analysis of the "risk environment" of young women's heroin initiation highlights a complex interplay between women's agency and intimate partner influence. It is argued that dichotomous representations of women as victims or emancipated consumers do not adequately capture the complexity of women's initiation journeys. The study's limitations are noted and implications for drug use prevention and harm reduction strategies are discussed.

ABSTRACT. Objectives: This study assessed depression and anxiety symptoms and their association with high-risk sexual and drug behaviors among male sex workers in 3 Vietnamese cities. Methods: Male sex workers ages 16 to 35 years old completed an interview that included the Center for Epidemiological Studies Depression Scale to assess depressive symptoms and the Beck Anxiety Inventory to assess anxiety symptoms, as well as questions assessing drug and sexual risk practices. Results: A majority of participants reported depressive symptomatology, although fewer reported symptoms of anxiety. Risky sexual and drug use practices predicted both types of symptoms. Conclusions: Mental distress is associated with drug and sexual risk among male sex workers.

UNLABELLED:Background This paper examines sexual practices, partner concurrency and sexually transmissible infections (STI)/HIV infection among male sex workers (MSWs) in Vietnam.METHODS:Six hundred and fifty-four MSWs, aged 16-35 years, were recruited in Hanoi, Nha Trang and Ho Chi Minh City between 2009 and 2011. Survey measures included demographic characteristics, drug use, types of sexual partners and sexual practices. Subjects were screened for STIs, including HIV.RESULTS:MSWs in Ho Chi Minh City (33%) were more likely than those from the other two sites to be current users of one or more types of illegal drugs (P<0.001). MSWs with both male and female elective partners (compared with other partnership types) were more likely to have anal sex with male client partners (P<0.001), elective male partners (P=0.045) and elective female partners (P=0.025). At last sex with a male client partner, only 30% used a condom during anal intercourse. At last sex with an elective female partner, only 31% used a condom during vaginal sex and only 3% during anal sex. Although rates of HIV are low (4%), other STIs are high, including chlamydia (17%), gonorrhoea (29%) and human papillomavirus (33%). Most (57.3%) have never been tested for HIV and only 17% have ever disclosed to a healthcare provider that they have sex with men.CONCLUSIONS:Complex patterns of sexual concurrency, coupled with high rates of STIs, signal the urgent need for health services interventions among MSWs, both to improve individual health outcomes and to reduce secondary STI/HIV transmission among sexual partner networks.

Male sex workers (MSW) in Vietnam have complex sexual partner profiles, including both male and female client partners and both male and female elective partners. Although sex practices vary across partner types, both active and receptive oral sex is common with all partner types. As a consequence of this complexity, MSWs are at high risk for becoming infected with oral STIs as well as for transmitting STIs to sex partners. Between 2009 and 2011, a community sample of MSWs, age 16–35 years, was recruited for …

Puerto Rico (PR) has a large and rapidly growing population of people living with HIV. However, relatively little behavioral or clinical research has been done in this population. As treatment for HIV increasingly moves into a chronic condition model, it is becoming increasingly important to understand the needs of this population so critical social and behavioral interventions can be developed, thus enabling the individual and community-level benefits of antiretroviral (ARV) treatment to be fully realized. To date, however, there has been very little research on the mental health needs of people living with HIV in PR, a fact that constrains intervention development and implementation. This paper describes data from a public sexually transmitted infection (STI) and HIV clinic study in the San Juan metropolitan area between April 2010 and December 2012 (n = 1185), roughly a third (36%) of whom are living with HIV. Descriptive statistics, chi-square, t-tests, and binary logistic regressions were used to assess associations between HIV status and a history of suicide attempt. The overall prevalence of a history of suicide attempt was 20.4%. No statistically significant relationship was found between a history of suicide attempt and being HIV positive, although people with HIV infection did evidence a higher prevalence of attempts than HIV-negative subjects (23.4% vs. 19.0%). Factors associated with having a history of suicide attempt within the overall sample included gender, current employment status, a lifetime history of drug use, and a lifetime history of sex work. Similar patterns were seen in the HIV-positive subsample. There was a nonsignificant trend toward increased risk for a post-diagnosis suicide attempt. These findings suggest that additional research on mental health risks among populations at risk for HIV in PR is needed.

OBJECTIVE:This report describes the HIV-related health care practices and associated support service needs of a sample of HIV-positive incarcerated men in Puerto Rico.METHODS:Data are derived from a random sample of HIV-positive incarcerated men (n = 37) in Puerto Rico who completed a brief survey. Analysis included descriptive statistics to examine lifetime prevalence of substance use, selected health care practices, receipt of services, and hepatitis C virus (HCV) infection.RESULTS:Most men (97.3%) reported history of alcohol or drug use, prior incarceration, and drug use as the main risk factors for HIV infection (73.0%). In all, 83.8% of the men reported having had their first HIV screening test in a correctional facility, 55.6% reported intermittent HIV therapy, and most (83.8%) had also been diagnosed with HCV.CONCLUSIONS:Correctional facilities can be important settings for engaging high-risk populations in health care, capturing and enrolling unidentified HIV/HCV infections for clinical care, and engaging in substance abuse treatment. In order for these public health outcomes to be achieved, it is important to consider strategies to optimize care inside prison and in the community.

Epidemiological data in Vietnam shows high HIV prevalence rates among injection drug users, especially in urban centres. However, there are limited data on specific practices used to prepare and inject drugs or on sexual practices among Vietnamese injectors. A street-based cross-sectional interview was conducted with 862 heroin injectors in Hanoi, Vietnam, to collect such data. Variability was seen in both injection and sexual risk, with 12.9% of current injectors reporting at least one unsafe method of drug sharing and 57.1% reporting unsafe sex in the past 30 days. These risks were strongly associated with those who engaged in unsafe injection significantly more likely to engage in unsafe sex (69.4% vs. 55.3%) and those engaging in unsafe sex significantly more likely to engage in unsafe injection (15.7% vs. 9.2%). These findings highlight the overlap of injection and sexual risk practices among Vietnamese heroin users and suggest the need for strong, broadly targeted HIV prevention activities among this population.

Background MSM populations in Vietnam are faced with a rapidly growing HIV epidemic, yet little is known about STIs epidemic in this diverse population. This study describes prevalence of Gonorrhea, HPV among male sex workers, and key correlates in three major cities. Method Cross-sectional surveys from 2009 to 2011 used Time-Location-Sampling to recruit eligible participants. Eligibility criteria included being biological male at birth; self-report of having sex with a male partner in exchange for material rewards within the last 90 days; and age from 16 to 35. Blood samples were taken for HIV testing; pharyngeal, anal and urethral swabs for gonorrhoea and HPV. Results Of 710 participants, 4.2% was HIV positive. Testing for gonorrhoea and HPV showed high prevalence of 28.8% and 33.2% respectively. Pharyngeal test for gonorrhoea (23.7%) and anal test for HPV (26.1%) were highest among swapping sites. The rates of infection were particularly higher in Ho Chi Minh City (largest economic city) as compared to Hanoi (political capital) and Nha Trang (major beach city). Odds ratio controlling for cities showed that testing positive for gonorrhoea was associated with engaging in oral sex past 30 days (ORM-H = 4.33; CI = 1.3 – 14.4); having receptive anal sex with more than three clients past 30 days (ORM-H = 2.03; CI = 1.18 – 3.51). HPV infection was associated with engaging in sex work for more than two years (ORM-H = 1.6; CI = 1.09 – 2.34); having receptive anal sex past 30 days (ORM-H = 1.95; CI = 1.35 – 2.83); having oral sex with more than four clients past 30 days (ORM-H = 1.63; CI = 1.12 – 2.39). Conclusion The unprecedented high prevalence of pharyngeal Gonorrhea and anal HPV among MSW is significant given the high HIV prevalence among a relatively young population. Appropriate STIs is important in addressing the twin epidemics among MSM in Vietnam.

BACKGROUND:Genital human papillomavirus (HPV) is one of the most commonly diagnosed sexually transmitted infection (STIs) in men and women. Knowledge about HPV infection among men is limited. This study aims to determine correlates of adequate knowledge of HPV infection among men who attend an STI clinic in Puerto Rico.METHODS:A cross-sectional study of 206 men was conducted at an STI clinic in San Juan, PR. Adequate knowledge was defined as a score of at least 70% of correct responses among those men who reported having ever heard of HPV. Variables that achieved statistical significance in the bivariate analysis (p<0.05) were included in the multivariate logistic regression model.RESULTS:Although 52.5% of men reported having heard of HPV infection before the survey, only 29.3% of this sub-group had an adequate knowledge of HPV. Most men did not know that HPV is a risk factor for anal (38.7%), penile (50.0%) and oral (72.6%) cancer. Factors associated with adequate knowledge of HPV in age-adjusted models were being men who have sex with men (MSM) (OR=2.6;95%CI=1.1-6.1), self-report of genital warts (OR=3.2;95%CI=1.3-7.9) and herpes (OR=7.4;95% CI=2.2-25.1). MSM was marginally associated with adequate knowledge (OR=2.3;95% CI=0.9-5.9) and self-report of herpes remained significantly associated (OR=5.0;95%CI=1.3-18.4) in multivariate logistic regression analysis.CONCLUSIONS:Awareness and knowledge of HPV was very low in this group of men. Interventions to increase knowledge and awareness in this group are necessary to promote preventive practices for HPV-related cancers in high-risk groups.

INTRODUCTION:Circumcision among adult men has been widely promoted as a strategy to reduce human immunodeficiency virus (HIV) transmission risk. However, much of the available data derive from studies conducted in Africa, and there is as yet little research in the Caribbean region where sexual transmission is also a primary contributor to rapidly escalating HIV incidence.AIM:In an effort to fill the void of data from the Caribbean, the objective of this article is to compare history of sexually transmitted infections (STI) and HIV diagnosis in relation to circumcision status in a clinic-based sample of men in Puerto Rico.METHODS:Data derive from an ongoing epidemiological study being conducted in a large STI/HIV prevention and treatment center in San Juan in which 660 men were randomly selected from the clinic's waiting room.MAIN OUTCOME MEASURES:We assessed the association between circumcision status and self-reported history of STI/HIV infection using logistic regressions to explore whether circumcision conferred protective benefit.RESULTS:Almost a third (32.4%) of the men were circumcised (CM). Compared with uncircumcised (UC) men, CM have accumulated larger numbers of STI in their lifetime (CM = 73.4% vs. UC = 65.7%; P = 0.048), have higher rates of previous diagnosis of warts (CM = 18.8% vs. UC = 12.2%; P = 0.024), and were more likely to have HIV infection (CM = 43.0% vs. UC = 33.9%; P = 0.023). Results indicate that being CM predicted the likelihood of HIV infection (P value = 0.027).CONCLUSIONS:These analyses represent the first assessment of the association between circumcision and STI/HIV among men in the Caribbean. While preliminary, the data indicate that in and of itself, circumcision did not confer significant protective benefit against STI/HIV infection. Findings suggest the need to apply caution in the use of circumcision as an HIV prevention strategy, particularly in settings where more effective combinations of interventions have yet to be fully implemented.

Objective: Puerto Rico has one of the fastest growing HIV epidemics in the United States and - consistent with patterns observed in the Caribbean region as a whole - data on new infections shows the increased influence of sexual transmission in the local epidemic. Historically, both epidemiology and prevention activities have focused primarily on the islands’ large heroin injector population. Although the available surveillance data indicate high rates of STIs and HIV among men who have sex with men (MSM), there has been little social and behavioral research among MSM and hence little empirical information to inform intervention development and planning. Methods: Given the absence of data on MSM and their importance in the emerging epidemic on the island, this paper describes a sample of MSM patients in an STI/HIV treatment center in the San Juan metropolitan area between October 2009 and June 2011 (n=120). Assessment of sexual risk includes measures of onset of oral, vaginal, and anal sex, as well as current sexual practices and partner characteristics. Self-reported history of STI diagnoses and current HIV status are described. Results: Overall, MSM evidenced relatively large numbers of multiple, concurrent sexual partners, substantial age-discordance among partners, and limited condom use. Relative to HIV-negative MSM, HIV-positive MSM have had more cumulative male sexual partners in anal intercourse (p=0.005). HIV-negative MSM were more likely to have had sex without a condom at last receptive anal intercourse (p=0.012) as well as at last insertive anal sex intercourse (p=0.001). Conclusion: Priorities for advancing HIV interventions for MSM are delineated, including the need for targeted sexual health interventions, mental health services, and improved strategies for engaging and retaining MSM in health services.

Puerto Rico has one of the highest incidence rates of HIV in the U.S. Concurrent with increases in sexually transmitted infections (STI), an increasing share of the new infections in PR are associated with sexual transmission. Much of the available research on sexual risk in PR derives from STI/HIV surveillance data. There is limited social and epidemiological research on sexual risk in PR, particularly in hidden and often hard-to-reach populations at high risk. Despite the absence of substantial resources that most epidemiological studies require, a research collaboration was initiated in 2007 between researchers in the School of Public Health at the University of Puerto Rico and the Centro Latinoamericano de Enfermedades de Transmisión Sexual (CLETS), one of the largest publicly funded centers for STI/HIV screening and treatment in the San Juan metropolitan area. Structured as a case study in the development of community-based research collaborations, this paper describes the early history and development of the project, including formative research, recruitment and training of students, and evolution in the study design that contributed to the current configuration of the ongoing "Core" study. Preliminary data are presented, highlighting data from a number of subpopulations that may contribute to our understanding of the role of behavioral risk in the STI/HIV epidemics in PR. More generally, the paper may guide the development of similar collaboration elsewhere in the Caribbean where HIV risk is increasing but where resources for research in high risk settings and groups are scarce.