A comparison of registered and unregistered female sex workers in Tijuana, Mexico

Substance use, economic vulnerability, and HIV/STI risk among female sex workers in Mexico

BACKGROUND

Economic hardship (e.g., difficulty to pay for basic needs) has been associated with increased HIV/STI risk among female sex workers (FSW), and may be exacerbated by high levels of substance use. Few studies have assessed the intersection of economic hardship, substance use, and HIV/STI risk among FSW.

METHODS

Quantitative data were collected via questionnaires among 469 FSW residing in Tijuana and Ciudad Juarez, Mexico. Using logistic regression, we assessed the role of economic hardship on the association between substance use (past 30-days alcohol use, drug use, or injection drugs use with clients, and past 6-months drug use) and testing positive for an STI (also an indicator of HIV risk).

RESULTS

Drug use in the preceding six months was significantly associated with testing positive for an STI (AOR = 1.8, CI: 1.1 = 2.9, p = .02); no difference in this association was found by whether women reported economic hardship. Past 30-day drug use with clients was associated with STI infection, but only among those who did not report economic hardship (AOR = 1.5, 95% CI: 1.1-1.9, p < .01).

CONCLUSIONS

Findings suggest that economic hardship influences the association between substance use and increased risk for HIV/STI among FSW; however, these associations may be more complex than previously hypothesized.

Molecular epidemiology of HIV-1 among adult female sex workers at the Guatemala-Mexico border

ABSTRACTSex workers have been demonstrated to have increased vulnerabilities to HIV and a high population prevalence of the disease. Despite their increased risk, sex workers have been underrepresented in molecular epidemiology studies assessing HIV in Mesoamerica. This study aims to describe the sociodemographic characteristics and phylogenetic profile of HIV-1 within a cohort of HIV-positive female sex workers (FSW) situated at the Guatemala-Mexico border. HIV viral sequences were collected from a cohort of FSW ≥18 years of age from San Marcos, Guatemala (n = 6) and compared to viral sequences collected as part of the Mesoamerican Drug Resistance Monitoring Programme to assess HIV viral diversity in Mexico and Guatemala (n = 3956). All of the FSW sampled were determined to have genetically unrelated HIV infections, suggesting multiple introductions of the virus and/or the potential existence of populations not captured by current surveillance efforts. Many reported numerous vulnerabilities that may have heightened their risk of acquiring and transmitting HIV through sex work activities. Our phylogenetic analysis indicated that national surveillance programmes may not fully capture the viral diversity among FSW and their clients within this region. Additional research is needed to fully capture HIV diversity and transmission in Mesoamerica, especially in the Guatemala-Mexico border region.

Typologies and Correlates of Police Violence Against Female Sex Workers Who Inject Drugs at the México-United States Border: Limits of De Jure Decriminalization in Advancing Health and Human Rights

Decriminalization of sex work is increasingly promoted as a structural measure to improve the health of vulnerable groups. In México, sex work is not illegal, but knowledge of policies' street-level impact is limited. This study describes typologies of police violence against female sex workers who inject drugs (FSWID), identifying risk and protective factors for violence exposure to inform policy responses. Survey data were collected during 2008-2010 among HIV-negative FSWID in a behavioral intervention in Tijuana and Ciudad Juarez (N = 584). Latent class analysis identified typologies of police violence in the past 6 months: asked for money, money taken, syringes taken, asked for sex, and sexually assaulted. Structural equation modeling (SEM) predicted latent class membership using sociodemographic, behavioral and risk environment factors, controlling for age, education, marital status, and city. Recent police violence was reported by 68% of FSWID, with three typologies emerging: Low (36.6%); Material (47.8%): having money/syringes taken or being asked for money; and Material/Sexual (15.7%): material violence and being asked for sex or sexually assaulted. In multivariable SEM, Material Violence was associated with: being jailed [adjusted Odds Ratio (aOR) = 4.34], HIV testing (aOR = 2.18), and trading sex indoors (aOR = 1.66). Factors associated with Material/Sexual Violence included: being jailed (aOR = 41.18), injecting with clients (aOR = 3.12), earning more money for sex without a condom (aOR = 2.88), being raped by a client (aOR = 2.13), drinking with clients (aOR = 2.03), receiving substance use treatment (aOR = 1.95), being <18 when first trading sex (aOR = .43), trading sex outdoors (aOR = .53), and poor working conditions (aOR = .56). Despite de jure decriminalization of sex work, police violence against FSWID at the México-United States border is pervasive with implications for sex- and drug-related harms. Closing gaps in policy implementation and mitigating material/sexual violence from police is imperative to decreasing economic vulnerability, risk of overdose and HIV, and improving engagement in HIV and harm reduction services.

Prevalence and correlates of SARS-CoV-2 seropositivity among people who inject drugs in the San Diego-Tijuana border region

BACKGROUND

People who inject drugs may be at elevated SARS-CoV-2 risk due to their living conditions and/or exposures when seeking or using drugs. No study to date has reported upon risk factors for SARS-CoV-2 infection among people who inject drugs.

METHODS AND FINDINGS

Between October, 2020 and June, 2021, participants aged ≥18 years from San Diego, California, USA and Tijuana, Baja California, Mexico who injected drugs within the last month underwent interviews and testing for SARS-CoV-2 RNA and antibodies. Binomial regressions identified correlates of SARS-CoV-2 seropositivity.

RESULTS

Of 386 participants, SARS-CoV-2 seroprevalence was 36.3% (95% CI: 31.5%-41.1%); 92.1% had detectable IgM antibodies. Only 37.5% had previously been tested. Seroprevalence did not differ by country of residence. None tested RNA-positive. Most (89.5%) reported engaging in ≥1 protective behavior [e.g., facemasks (73.5%), social distancing (46.5%), or increasing handwashing/sanitizers (22.8%)]. In a multivariate model controlling for sex, older age, and Hispanic/Latinx/Mexican ethnicity were independently associated with SARS-CoV-2 seropositivity, as was engaging in sex work (AdjRR: 1.63; 95% CI: 1.18-2.27) and having been incarcerated in the past six months (AdjRR: 1.49; 95% CI: 0.97-2.27). Comorbidities and substance using behaviors were not associated with SARS-CoV-2 seropositivity.

CONCLUSIONS

In this community-based study of people who inject drugs in the San Diego-Tijuana border region, over one third were SARS-CoV-2 seropositive, exceeding estimates from the general population in either city. We found no evidence that substance use behaviors were associated with an elevated risk of SARS-CoV-2 infection, but observed that circumstances in the risk environment, notably sex work and incarceration, were independently associated with higher SARS-CoV-2 seroprevalence. Our findings suggest that a binational policy response to COVID-19 mitigation is warranted beyond the closure of the U.S.-Mexico border. Furthermore, decriminalizing sex work and drug use could reduce the burden of COVID-19 among people who inject drugs.

Mujeres Unidas: Addressing Substance Use, Violence, and HIV Risk through Asset-Based Community Development for Women in the Sex Trade

This paper examines the prevalence of and potential for community mobilization (CM) and its association with HIV/STI risk, substance use, and violence victimization among women, particularly those using substances, in the sex trade in Tijuana, Mexico.

METHODS

195 women participated in Mujeres Unidas (K01DA036439 Urada) under a longitudinal survey study, "Proyecto Mapa de Salud" (R01DA028692, PI: Brouwer). Local health/social service providers (N = 16) were also interviewed.

RESULTS

39% of women who participated in community mobilization activities used substances. In adjusted analyses (n = 135), participation in CM activities (n = 26) was more likely among women who did not report substance use (AOR: 4.36, CI: 1.11-17.16), perceived a right to a life free from violence (AOR: 9.28, CI: 2.03-59.26), talked/worked with peers in the sex trade to change a situation (AOR: 7.87, CI: 2.03-30.57), witnessed violence where they worked (AOR: 4.45, CI: 1.24-15.96), and accessed free condoms (AOR: 1.54, CI: 1.01-2.35). Forty-five of the women using substances demonstrated their potential for engaging in asset-based community development (ABCD) with service providers in Mujeres Unidas meetings.

CONCLUSION

Women using substances, vs. those who did not, demonstrated their potential to engage in ABCD strategies. Women's empowerment, safety, and health could be enhanced by communities engaging in ABCD strategies that build and bridge social capital for marginalized women who otherwise have few exit and recovery options.

The influence of migration in substance use practices and HIV/STI-related risks of female sex workers at a dynamic border crossing

We explored the association of international migration with substance use and HIV/STI risk factors among female sex workers (FSW). Using modified time-location sampling, we recruited 266 FSW at the Mexico-Guatemala border. Crude and adjusted logistic regression models were used to evaluate the relationships. HIV risks, such as frequent hard drug use and drug use in another country, were greater for migrant compared to nonmigrant FSW. However, more migrant versus nonmigrant FSW reported consistent condom use with clients and having a health card. Our study highlights regional patterns of substance use among FSW and risk or protective behaviors related to migration status.

Women in Sex Work and the Risk Environment: Agency, Risk Perception, and Management in the Sex Work Environments of Two Mexico-U.S. Border Cities

Sex work around the world takes place under conditions of structural violence and vulnerability. The México-U.S. border region is characterized by the presence of factors that increase the risk for health harms among female sex workers (FSW); located in this context, the risk environments of Tijuana and Ciudad Juárez have similar yet distinct characteristics that influence how risk is produced and experienced among FSWs. Exploring the ways in which FSWs enact agency in risk environments can illustrate how environmental characteristics shape perceived risks and the strategies that FSWs develop to manage them. This approach also identifies the limits that are placed by environmental characteristics over the capacity for harm reduction and prevention practices among FSWs. We analyzed the role of agency in the work environments of female sex workers and its relationship with risk perception and management in the cities of Tijuana and Cd. Juárez.

Prevalence and correlates of cervical abnormalities among female sex workers in Tijuana, Mexico

Objectives:

In Tijuana, Mexico, sex work is regulated by the municipal health department and includes regular testing for HIV and other sexually transmitted infections (STIs) for registered female sex workers (FSWs). However, Pap testing is missing from current sexual health assessments. We aimed to answer the following research questions: 1.) What is the prevalence of cervical abnormalities among a sample of FSWs in Tijuana, Mexico? 2.) What are the correlates of cervical abnormalities among a sample of FSWs in Tijuana, Mexico?

Study design:

From 2013-2014, a cohort of 300 FSWs in Tijuana, Mexico were recruited using modified time-location sampling. Participants were given Pap, HIV, and STI tests.

Results:

The prevalence of an abnormal Pap was 11.7% (35/300). FSWs ever registered with municipal health services were less likely to have an abnormal Pap result (4.8% vs 14.4%, p=0.03), were more likely to report a previous Pap test (88.1% vs 70.4%, p=.001), and were more likely to report a sexual health checkup in the last year (60.7% vs 37.0%, p<0.001) than those who had never been registered.

Conclusions:

FSWs remain at risk for cervical abnormalities, including those registered with the municipality.

We conducted Pap testing for female sex workers in Tijuana, Mexico and found that over 11% had abnormal Pap test results.

The Role of Gender in the Health and Human Rights Practices of Police: The SHIELD Study in Tijuana, Mexico

Globally, punitive drug law enforcement drives human rights violations. Drug control tactics, such as syringe confiscation and drug-related arrests, also cascade into health harms among people who use drugs. The role of police officer characteristics in shaping such enforcement and measures to reform police practices remains underexamined. We evaluated gender differences in syringe confiscation and syringe-related arrest behaviors among municipal police officers in Tijuana, Mexico, where syringe possession is legal. In the context of the SHIELD Study focusing on aligning policing with harm reduction measures, our baseline sample covered municipal police officers who reported having occupational contact with syringes. We used multivariable logistic regression with robust variance estimation via a generalized estimating equation to identify correlates of syringe-related policing behaviors. Among respondent officers (n=1,555), 12% were female. After considering possible confounding variables, such as district of service and work experience, female officers were significantly less likely to report confiscating syringes or arresting individuals for syringe possession. Consideration of officer gender is important in the design of interventions to improve the health and human rights of people who inject drugs and other highly policed groups, as well as measures to safeguard officer occupational safety. The feminization of law enforcement deserves special consideration as an imperative in reducing the public health harms of policing.

Substance Use among Female Sex Workers in Two US-Mexico Border Cities: Associations with Age of Entry

BACKGROUND

Research has documented consistent associations between entry into sex work as a minor and sexual HIV risk. However, previous studies have not examined whether substance use and related HIV risk are elevated among those who enter sex work under age 18.

METHODS

Quantitative data were collected via time-location sampling of 603 female sex workers (FSWs) ages 18 years and older residing in two Mexico-US border cities. Age of entry into sex work (categorized as 15 years or younger, 16-17 years, or 18 years and older) was assessed as a predictor of substance use (forced and voluntary) within the first month post-entry and recent (past 30 days) substance use with clients.

RESULTS

Compared to those who entered as adults, participants who entered sex work at age 15 or younger were significantly more likely to report drug use (AOR = 5.2, CI = 2.9-8.9) and forced drug use within the first 30 days of entry (AOR= 6.0, CI = 1.9-18.9), as well as past month drug use with clients (AOR= 3.4, CI = 1.9-5.8). Similar results were found among participants who entered sex work at age 16-17.

CONCLUSIONS

Increased risk of recent substance use with clients indicates continuing elevated risk for those entering sex work at these early ages. Early and forced substance use at entry may underlie the elevated risk of HIV infection consistently observed among this population.

Associations between sex work laws and sex workers' health: A systematic review and meta-analysis of quantitative and qualitative studies

BACKGROUND

Sex workers are at disproportionate risk of violence and sexual and emotional ill health, harms that have been linked to the criminalisation of sex work. We synthesised evidence on the extent to which sex work laws and policing practices affect sex workers' safety, health, and access to services, and the pathways through which these effects occur.

METHODS AND FINDINGS

We searched bibliographic databases between 1 January 1990 and 9 May 2018 for qualitative and quantitative research involving sex workers of all genders and terms relating to legislation, police, and health. We operationalised categories of lawful and unlawful police repression of sex workers or their clients, including criminal and administrative penalties. We included quantitative studies that measured associations between policing and outcomes of violence, health, and access to services, and qualitative studies that explored related pathways. We conducted a meta-analysis to estimate the average effect of experiencing sexual/physical violence, HIV or sexually transmitted infections (STIs), and condomless sex, among individuals exposed to repressive policing compared to those unexposed. Qualitative studies were synthesised iteratively, inductively, and thematically. We reviewed 40 quantitative and 94 qualitative studies. Repressive policing of sex workers was associated with increased risk of sexual/physical violence from clients or other parties (odds ratio [OR] 2.99, 95% CI 1.96-4.57), HIV/STI (OR 1.87, 95% CI 1.60-2.19), and condomless sex (OR 1.42, 95% CI 1.03-1.94). The qualitative synthesis identified diverse forms of police violence and abuses of power, including arbitrary arrest, bribery and extortion, physical and sexual violence, failure to provide access to justice, and forced HIV testing. It showed that in contexts of criminalisation, the threat and enactment of police harassment and arrest of sex workers or their clients displaced sex workers into isolated work locations, disrupting peer support networks and service access, and limiting risk reduction opportunities. It discouraged sex workers from carrying condoms and exacerbated existing inequalities experienced by transgender, migrant, and drug-using sex workers. Evidence from decriminalised settings suggests that sex workers in these settings have greater negotiating power with clients and better access to justice. Quantitative findings were limited by high heterogeneity in the meta-analysis for some outcomes and insufficient data to conduct meta-analyses for others, as well as variable sample size and study quality. Few studies reported whether arrest was related to sex work or another offence, limiting our ability to assess the associations between sex work criminalisation and outcomes relative to other penalties or abuses of police power, and all studies were observational, prohibiting any causal inference. Few studies included trans- and cisgender male sex workers, and little evidence related to emotional health and access to healthcare beyond HIV/STI testing.

CONCLUSIONS

Together, the qualitative and quantitative evidence demonstrate the extensive harms associated with criminalisation of sex work, including laws and enforcement targeting the sale and purchase of sex, and activities relating to sex work organisation. There is an urgent need to reform sex-work-related laws and institutional practices so as to reduce harms and barriers to the realisation of health.

'He's not my pimp': toward an understanding of intimate male partner involvement in female sex work at the Mexico-US border

Female sex work is often perceived as women being controlled by men. We used surveys and qualitative interviews with female sex workers and their intimate partners in two Northern Mexico cities to examine couples' own perceptions of their relationships and male partners' involvement in sex work. Among 214 couples, the median age was 34 and relationship duration was approximately 3 years. Only 10 women in the survey reported having a pimp, and the majority reported sole control over sex work decisions. Qualitative analyses revealed that while most men avoided direct involvement in sex work, they offered advice that was largely driven by concern for their partner's well-being. Our discussion of these results considers the broader socio-political context surrounding these relationships and how changing gender roles, economic insecurity and stigma shape couples' everyday social interactions. Assumptions that all sex workers' relationships are coercive and commercial marginalises these couples while leaving their health concerns unaddressed.

Motherhood and Risk for Human Immunodeficiency Virus/Sexually Transmitted Infections Among Female Sex Workers in the Mexico-US Border Region

BACKGROUND

Globally, female sex workers (FSWs) have been identified as a high-risk group for human immunodeficiency virus (HIV) and sexually transmitted infections (STIs). However, as women of reproductive age, FSWs also have children. Few studies have investigated if financial responsibilities associated with motherhood increase women's vulnerability to HIV and STIs among FSWs.

METHODS

From March 2013 to March 2014, 603 FSWs aged ≥18 years were recruited from Tijuana and Ciudad Juarez (Mexico) to participate in a study assessing HIV/STI risk environments.

RESULTS

Findings from logistic regression models indicate that FSWs who reported motherhood were more likely to report (in the past 30 days): a higher client volume (>30 clients) (adjusted odds ratio [AOR], 1.91; 95% confidence interval [CI], 1.27-2.87) and always using alcohol right before or during sex with clients in the past 30 days (AOR, 1.77; 95% CI, 1.19-2.61). In contrast, they were more likely to report consistent condom use for vaginal or anal sex with clients (AOR, 1.68; 95% CI, 1.10-2.55), less likely to report using drugs right before or during sex with clients (AOR, 0.38; 95% CI, 0.26-0.56) and less likely to have tested positive for STIs at baseline (AOR, 0.63; 95% CI, 0.43-0.91).

CONCLUSIONS

These results provide a glimpse of the complex relationship between motherhood and women who are sex workers. Understanding the convergence of motherhood and sex work and how this can influence a woman's decision when engaging in sex work and affect her health is essential to designing effective programs addressing reduce risk for HIV and STIs among FSWs in this region and elsewhere.

Prevalence of Trichomonas vaginalis and Human papillomavirus in female sex workers in Central Veracruz, Mexico

Female sex workers (FSWs) have been considered a key population for sexually transmitted infections (STIs); therefore, they are periodically screened as a requirement to obtain a work card. However, there is insufficient epidemiological data on STIs among FSWs in Mexico. The detection of Trichomonas vaginalis is limited to microscopic studies and the molecular screening of Human papillomavirus (HPV) is only done to women 35 years of age and older. The objective of this study was to determine the prevalence of T. vaginalis and HPV infections in FSWs in the city of Orizaba, Veracruz, Mexico. Samples from 105 FSWs were obtained by cervical swab and analyzed. The identification of T. vaginalis and HPV was performed by molecular methods. HPV DNA was identified in 5.71% of the samples with the presence of HPV16, HPV18, and HPV58. A percentage of 25.7% samples were positive for T. vaginalis for optical microscopy and 23.8% for PCR. The results of the study indicate the need to incorporate more sensitive methods for the timely diagnosis of STIs as well as comprehensive health promotion programs directed to the most vulnerable groups among FSWs.

Exploring the Context and Implementation of Public Health Regulations Governing Sex Work: A Qualitative Study with Migrant Sex Workers in Guatemala

Public health regulations practices surrounding sex work and their enforcement can have unintended consequences for HIV and sexually transmitted infection (STI) prevention and care among sex workers. This analysis was based on qualitative in-depth (n = 33) and focus groups interviews (n = 20) conducted with migrant female sex workers in Tecún Umán and Quetzaltenango, Guatemala, and explored the implementation of sex work regulations and related consequences for HIV prevention and care among migrant sex workers. Sex work regulations were found to have health-related benefits (e.g., access to HIV/STI testing) as well as negative impacts, such as abuse by police and harassment, detention/deportation of migrant sex workers. Whereas public health regulations may improve access to HIV/STI testing, their implementation may inadvertently jeopardize sex workers' health through unintended negative consequences. Non-coercive, evidence-based public health and sex work policies and programs are needed to expand access to HIV/STI prevention and care among migrant sex workers, while protecting their dignity and human rights.

Behavioral and Psychosocial Correlates of HIV Testing Among Male Clients of Female Sex Workers in Tijuana, Mexico

We use data collected from a sample of 400 male clients of female sex workers (FSW) to examine their HIV testing behavior. We present frequencies of HIV testing and used bivariate and multivariable analyses to assess its socio-demographic, behavioral, and psychosocial correlates. We found that the majority (55 %) of male clients of FSW in Tijuana, Mexico had never had an HIV test and the prevalence of HIV testing within the past year was low (9 %). In multivariable analyses, significant correlates of having ever tested for HIV were higher age, higher HIV knowledge score, lower sexual compulsiveness score, lower misogynistic attitudes score, having a condom break during sex with a FSW, and higher frequency of sex with a FSW while she was high. Our findings represent an important starting point for developing effective interventions to address the need to promote HIV testing among this population.

Sex Work Regulation and Sexually Transmitted Infections in Tijuana, Mexico

While reducing the transmission of sexually transmitted infections is a common argument for regulating sex work, relatively little empirical evidence is available regarding the effectiveness of these policies. We investigate the effects of highly publicized sex work regulations introduced in 2005 in Tijuana, Mexico on the incidence of trichomoniasis. State-level, annual data for the 1995-2012 period are employed that include the incidence rates of trichomoniasis by age group and predictor variables. We find that the regulations led to a decrease in the incidence rate of trichomoniasis. Specifically, while our estimates are somewhat noisy, the all-ages incidence rate in the 2005-2012 period is roughly 37% lower than what is predicted by our synthetic control estimates and corresponds to approximately 800 fewer reported cases of trichomoniasis per year. We find that the decreases are especially pronounced for 15-24 and 25-44 age cohorts. Copyright © 2016 John Wiley & Sons, Ltd.

"He invited me and didn't ask anything in return" Migration and Mobility as Vulnerabilities for Sexual Exploitation among Female Adolescents in Mexico

Although human trafficking is recognized as a major human rights violation, there is limited evidence regarding the vulnerabilities that contribute to female adolescents' risk of being forced or coerced into the sex trade. Vulnerabilities such as gender-based violence, economic and social inequalities have been shown to shape the risk of sexual exploitation among adolescents. In-depth interviews (n=18) with current sex workers who reported being deceived or forced into the sex trade as adolescents (<17 years old) were analysed to explore their experiences of migration and mobility in Mexico. Driven by socio-economic and vulnerabilities in home communities, adolescents often engaged in internal migration and mobility to other Mexican communities and states. Migration and mobility further predisposed them to social isolation, economic hardship and abuse, which were used as tools to trick them into the sex trade. Policies that support safer migration for adolescents in origin, transit, and destination communities are needed.

Can Policy Interventions Affect HIV-Related Behaviors? A Systematic Review of the Evidence from Low- and Middle-Income Countries

In their response to HIV, many countries have adopted and enacted policies to reduce transmission and increase HIV-related service use. Theoretically, policy-level interventions for HIV prevention have the potential to improve health behavior outcomes. These policy interventions vary in their scale, from relatively minor changes in clinical policy to major national legal initiatives. Assessing the effectiveness of HIV policy interventions is a challenging undertaking. While many policies exist and guide HIV programmes, relatively few have specifically been evaluated for their effects on reducing HIV risk taking or increasing HIV health-seeking behaviors. Thus, questions on the effectiveness of policy interventions to prevent HIV and change HIV-related risk behaviors remain largely unanswered. To address this current gap in the literature, we systematically reviewed the existing evidence on the effect of HIV policy interventions on changing HIV-related behaviors in low-and middle-income countries.

Changes in Condom Use Over Time Among Female Sex Workers and Their Male Noncommercial Partners and Clients

Female sex workers (FSWs) often report inconsistent condom use with clients and noncommercial male partners, yet changes in condom use with various partner types during participation in observation studies remains underexplored. This longitudinal study of 214 FSWs and their male, noncommercial partners in the Mexico-U.S. border region, where HIV prevalence among FSWs continues to be high, utilized negative binomial regressions to examine changes in condom use with intimate partners and clients (regular and nonregular) over 24 months. Condom use decreased over time among couples in Ciudad Juarez, but there was no change in condom use among couples in Tijuana. FSWs' condom use with regular and nonregular clients significantly increased over time, which is consistent with previous research finding behavioral changes when participating in observational studies. Findings suggest the need for continued efforts to promote condom use among FSWs and their noncommercial male partners in addition to clients.

Quantitative, Qualitative and Geospatial Methods to Characterize HIV Risk Environments

Increasingly, ‘place’, including physical and geographical characteristics as well as social meanings, is recognized as an important factor driving individual and community health risks. This is especially true among marginalized populations in low and middle income countries (LMIC), whose environments may also be more difficult to study using traditional methods. In the NIH-funded longitudinal study Mapa de Salud, we employed a novel approach to exploring the risk environment of female sex workers (FSWs) in two Mexico/U.S. border cities, Tijuana and Ciudad Juárez. In this paper we describe the development, implementation, and feasibility of a mix of quantitative and qualitative tools used to capture the HIV risk environments of FSWs in an LMIC setting. The methods were: 1) Participatory mapping; 2) Quantitative interviews; 3) Sex work venue field observation; 4) Time-location-activity diaries; 5) In-depth interviews about daily activity spaces. We found that the mixed-methodology outlined was both feasible to implement and acceptable to participants. These methods can generate geospatial data to assess the role of the environment on drug and sexual risk behaviors among high risk populations. Additionally, the adaptation of existing methods for marginalized populations in resource constrained contexts provides new opportunities for informing public health interventions.

Enhancing the Ethical Conduct of HIV Research with Migrant Sex Workers: Human Rights, Policy, and Social Contextual Influences

BACKGROUND

Migrant sex workers are often highly marginalized and disproportionately experience health and social inequities, including high prevalence of HIV, sexually transmitted infections, and human rights violations. In recent years, research involving migrant sex workers has increased, yet many knowledge gaps remain regarding how best to protect research participant rights and welfare. Our objective was to identify key challenges and opportunities related to the responsible conduct of HIV research with migrant sex workers.

METHODS

Focus groups and interviews conducted with 33 female sex workers ≥18 years old at the Guatemala-Mexico border from June 2013-February 2014 were analyzed. Participants were recruited through community outreach by a local HIV prevention organization to sex work establishments such as bars, hotels, street corners, and truck stops.

RESULTS

Key themes influencing research engagement for migrant sex workers included researcher mistrust and fear related to research participation, rooted in the social isolation frequently faced by recent migrants; intersecting concerns related to immigration status, fear of criminalization, and compliance with sex work regulations; and perceived benefits and risks of HIV/STI testing for migrants (e.g., immigration implications, stigma) represent potential barriers and opportunities for the responsible conduct of research involving migrant sex workers.

CONCLUSIONS

Results highlight the intersection between the human rights vulnerabilities of migrant sex workers and barriers to research participation, including social isolation of migrants and policy/legal barriers related to immigration and sex work. Findings illustrate the need for researchers to develop population-tailored procedures to address fears related to immigration and criminalization, and to reinforce positive and non-stigmatizing relationships with migrant sex workers. Community-led efforts to reduce stigma and foster community organization and supports for migrant sex workers are recommended, as are broader policy shifts that move away from punitive legal approaches towards approaches that safeguard and prioritize the human rights of migrant sex workers.

Reducing HIV Risks in the Places Where People Drink: Prevention Interventions in Alcohol Venues

Apart from individual alcohol drinking behavior, the context or places where people drink play a significant role in HIV transmission risk. In this paper, we review the research that has been conducted on alcohol venues to identify the social and structural factors (e.g., social norms, sexual behavior) that are associated with HIV risk in these places, to review HIV prevention interventions based in alcohol venues, and to discuss appropriate methodologies for alcohol venue research. Alcohol venues are defined here as places that sell or serve alcohol for onsite consumption, including bars, bottle stores, nightclubs, wine shops, and informal shebeens. Despite the many established HIV risk factors at play in alcohol venues, limited prevention strategies have been implemented in such places. A total of 11 HIV prevention interventions or programs were identified. HIV prevention interventions in alcohol venues may be conducted at the individual, social, or structural level. However, multilevel interventions that target more than one level appear to lead to the most sustainable behavior change. Strategies to incorporate alcohol venues in biomedical prevention strategies including antiretroviral therapy for alcohol users are also discussed.

HIV Transmission Networks in the San Diego-Tijuana Border Region

BACKGROUND

HIV sequence data can be used to reconstruct local transmission networks. Along international borders, like the San Diego-Tijuana region, understanding the dynamics of HIV transmission across reported risks, racial/ethnic groups, and geography can help direct effective prevention efforts on both sides of the border.

METHODS

We gathered sociodemographic, geographic, clinical, and viral sequence data from HIV infected individuals participating in ten studies in the San Diego-Tijuana border region. Phylogenetic and network analysis was performed to infer putative relationships between HIV sequences. Correlates of identified clusters were evaluated and spatiotemporal relationships were explored using Bayesian phylogeographic analysis.

FINDINGS

After quality filtering, 843 HIV sequences with associated demographic data and 263 background sequences from the region were analyzed, and 138 clusters were inferred (2-23 individuals). Overall, the rate of clustering did not differ by ethnicity, residence, or sex, but bisexuals were less likely to cluster than heterosexuals or men who have sex with men (p = 0.043), and individuals identifying as white (p ≤ 0.01) were more likely to cluster than other races. Clustering individuals were also 3.5 years younger than non-clustering individuals (p < 0.001). Although the sampled San Diego and Tijuana epidemics were phylogenetically compartmentalized, five clusters contained individuals residing on both sides of the border.

INTERPRETATION

This study sampled ~ 7% of HIV infected individuals in the border region, and although the sampled networks on each side of the border were largely separate, there was evidence of persistent bidirectional cross-border transmissions that linked risk groups, thus highlighting the importance of the border region as a "melting pot" of risk groups.

FUNDING

NIH, VA, and Pendleton Foundation.

Sex Work, Heroin Injection, and HIV Risk in Tijuana: A Love Story

The relationships between female sex workers and their non-commercial male partners are typically viewed as sites of HIV risk rather than meaningful unions. This ethnographic case study presents a nuanced portrayal of the relationship between Cindy and Beto, a female sex worker who injects drugs and her intimate, non-commercial partner who live in Tijuana, Mexico. Based on ethnographic research in Tijuana and our long term involvement in a public health study, we suggest that emotions play a central role in sex workers' relationships and contribute in complex ways to each partner's health. We conceptualize Cindy and Beto's relationship as a "dangerous safe haven" in which HIV risk behaviors such as unprotected sex and syringe sharing convey notions of love and trust and help sustain emotional unity amidst broader uncertainties, but nevertheless carry very real health risks. Further attention to how emotions shape vulnerable couples' health remains a task for anthropology.

Social Support and Sexual Risk Among Establishment-Based Female Sex Workers in Tijuana

Social support can affect health outcomes of female sex workers. In this inductive feminist grounded theory study based on 20 in-depth interviews, we explore how establishment-based female sex workers in Tijuana perceive the impact of the connections among women on their lives and health. Participants elected to discuss the importance of social support from mothers, sisters, friends, and co-workers, and the empowering and disempowering aspects of these relationships. In previous studies, scholars demonstrated the efficacy of formal organization of female sex workers in promoting the mitigation of sexual and HIV risk. We show the importance of informal ties with other women. Some participants mentioned competitive relationships, others talked about cooperation and the desire for a venue to learn from one another. Social interactions with other women are especially empowering when female sex workers can openly engage in "woman talk" that may contribute to the mitigation of sexual and HIV risk.

Incidence and Predictors of HIV and Sexually Transmitted Infections Among Female Sex Workers and Their Intimate Male Partners in Northern Mexico: A Longitudinal, Multilevel Study

Preventing human immunodeficiency virus (HIV) infection and other sexually transmitted infections (STIs) requires an understanding of sexual relationship factors beyond the individual level. We estimated HIV/STI incidence and identified time-varying predictors of STI acquisition in a prospective cohort study of female sex workers and their intimate (noncommercial) male partners in northern Mexico. From 2010 to 2013, couples underwent behavioral and biological assessments biannually for 24 months. Among 413 initially HIV-uninfected participants, 8 seroconverted during follow-up. Incidence of HIV (1.12 cases/100 person-years (PY)), chlamydia (9.47 cases/100 PY), active syphilis (4.01 cases/100 PY), and gonorrhea (1.78 cases/100 PY) was higher among women than among men (HIV: P = 0.069; all STIs combined: P < 0.001). In multivariable conditional logistic regression with individual fixed effects and correlated error terms within couples, risk of STI acquisition was significantly higher among women who had recently used cocaine, crack, or methamphetamine (adjusted odds ratio (OR) = 2.13, 95% confidence interval (CI): 1.07, 4.28). STI risk was lower among women who reported physically assaulting their male partners (adjusted OR = 0.44, 95% CI: 0.22, 0.86) and among men whose female partners had regular sex-work clients (adjusted OR = 0.38, 95% CI: 0.14, 1.03). Improving vulnerable couples' sexual health will require addressing the contexts in which drug use, interpersonal conflict, and economic vulnerability converge.

The changing face of HIV in Latin America and the Caribbean

Latin America and the Caribbean (LAC) is a region with similarities and important disparities. In recent years LAC has witnessed achievements, with HIV prevalence rates relatively stable for LA and decreasing for the Caribbean. However average values hide differences. General population HIV prevalence in LAC is 0.4 % on average. In the Caribbean there are fewer new HIV infections but HIV prevalence among adults exceeds 1 % in several countries. It is estimated that 31 % of adults living with HIV in LA and 52 % of adults in the Caribbean are women. Unprotected sex is the main route of HIV transmission in LAC. Men who have sex with men and transgender women are the populations with the highest prevalence (10.6 % and 17.7 % respectively); however other key populations such as female sex workers (4.9 %), drug users (range 1 %-49.7 % for intravenous drug users), prisoners and indigenous populations are also important. LAC has the highest anti-retroviral treatment coverage of any low- and middle-income region in the world, but women and children are less likely than men to receive treatment. There is an important pending agenda to address the gaps in information, prevention, and care for HIV in LAC.

Human rights violations against sex workers: burden and effect on HIV

We reviewed evidence from more than 800 studies and reports on the burden and HIV implications of human rights violations against sex workers. Published research documents widespread abuses of human rights perpetrated by both state and non-state actors. Such violations directly and indirectly increase HIV susceptibility, and undermine effective HIV-prevention and intervention efforts. Violations include homicide; physical and sexual violence, from law enforcement, clients, and intimate partners; unlawful arrest and detention; discrimination in accessing health services; and forced HIV testing. Abuses occur across all policy regimes, although most profoundly where sex work is criminalised through punitive law. Protection of sex workers is essential to respect, protect, and meet their human rights, and to improve their health and wellbeing. Research findings affirm the value of rights-based HIV responses for sex workers, and underscore the obligation of states to uphold the rights of this marginalised population.

Examining negative effects of early life experiences on reproductive and sexual health among female sex workers in Tijuana, Mexico

OBJECTIVE

To explore experiences during childhood and adolescence that influenced reproductive and sexual health among women who had entered the sex industry in adolescence.

METHODS

A qualitative study was conducted using information provided by 25 female sex workers (FSWs) from Tijuana, Mexico, who reported entering the sex industry when younger than 18 years. In-depth, semi-structured interviews were conducted with all participants between January 31, 2011, and July 8, 2011.

RESULTS

Four interrelated themes that shaped health experiences-early sexual abuse, early illicit drug use, ongoing violence, and limited access to reproductive and sexual health care-were identified. Participants reporting these experiences were at risk of unintended teenaged pregnancy, spontaneous abortion or stillbirth, and untreated sexually transmitted infections.

CONCLUSION

Programs and policies that address social, structural, and individual vulnerabilities during adolescence and adulthood are required to promote reproductive and sexual health among FSWs in Tijuana, Mexico.

Vulnerabilities faced by the children of sex workers in two Mexico-US border cities: a retrospective study on sexual violence, substance use and HIV risk

Most studies of female sex workers (FSWs) conducted in the Mexico-US border region have focused on individual HIV risk, centered on sexual behaviors and substance abuse patterns. Little attention has been drawn to the reality that sex workers are often parents whose children potentially face vulnerabilities unique to their family situation. The objective of the present study was to identify the vulnerabilities faced by the children of FSWs in two Mexican-US border cities. From 2008 to 2010, 628 FSW-injection drug users underwent interviewer-administered surveys and HIV/STI testing. Approximately one in five participants (20%) reported having a parent involved in sex work and majority referred it was their mother (88%). Close to one-third of participants (31%) reported first injecting drugs <18 years of age, and 33% reported they began working regularly as a prostitute <18 years of age. First drinking alcohol <18 years old (AOR = 1.87, 95%CI: 1.13-3.08), lifetime cocaine use (AOR = 1.76, 95%CI: 1.09-2.84), ever being forced or coerced into non-consensual sex as a minor (<18 years of age; AOR = 1.54, 95%CI: 1.01-2.35), and injecting drugs with used syringes in the prior month (AOR = 1.63, 95%CI: 1.07-2.49) were the factors associated with having had a parent involved in sex work. These findings begin to lay the groundwork for understanding the potential vulnerabilities faced by the children of sex workers. Understanding these potential needs is necessary for creating relevant, evidence-based interventions focused on supporting these women.

Prevalence and correlates of HIV and sexually transmitted infections among female sex workers and their non-commercial male partners in two Mexico-USA border cities

Female sex workers (FSWs) acquire HIV and other sexually transmitted infections (STIs) through unprotected sex with commercial and non-commercial (intimate) male partners. Little research has focused on FSWs' intimate relationships, within which condom use is rare. We sought to determine the prevalence and correlates of HIV/STIs within FSWs' intimate relationships in Northern Mexico. From 2010 to 2011, we conducted a cross-sectional survey of FSWs and their non-commercial male partners in Tijuana and Ciudad Juárez, Mexico. Eligible FSWs and their verified male partners were aged ≥18 years; FSWs reported lifetime use of heroin, cocaine, crack, or methamphetamine and recently exchanged sex (past month). Participants completed baseline questionnaires and testing for HIV, chlamydia, gonorrhea, and syphilis. We determined the prevalence and correlates of individuals' HIV/STI positivity using bivariate probit regression. Among 212 couples (n = 424), prevalence of HIV was 2.6 % (n = 11). Forty-two (9.9 %) tested positive for any HIV/STIs, which was more prevalent among women than men (12.7 % vs. 7.1 %, p < 0.05). FSWs with regular sex work clients were less likely to test positive for HIV/STIs than those without regular clients. Similarly, male partners of FSWs who had regular clients were 9 % less likely to have HIV/STIs. Higher sexual decision-making power was protective against HIV/STIs for women. Men who recently used methamphetamine or reported perpetrating any conflict within steady relationships were more likely to test positive for HIV/STIs. Within FSWs' intimate relationships in two Mexican-US border cities, nearly one in ten partners tested positive for HIV/STIs. Couple-based prevention interventions should recognize how intimate relationship factors and social contexts influence HIV/STI vulnerability.

Hazardous drinking and HIV-risk-related behavior among male clients of female sex workers in Tijuana, Mexico

BACKGROUND AND OBJECTIVES

Male clients of female sex workers (FSWs) are at high risk for HIV. Whereas the HIV risks of alcohol use are well understood, less is known about hazardous alcohol use among male clients of FSWs, particularly in Mexico. We sought to identify risk factors for hazardous alcohol use and test associations between hazardous alcohol use and HIV risk behavior among male clients in Tijuana.

METHOD

Male clients of FSWs in Tijuana (n = 400) completed a quantitative interview in 2008. The AUDIT was used to characterize hazardous alcohol use. Multivariate logistic regression was used to determine independent associations of demographic and HIV risk variables with hazardous alcohol use (vs. non-hazardous).

RESULTS

Forty percent of our sample met criteria for hazardous alcohol use. Variables independently associated with hazardous drinking were reporting any sexually transmitted infection (STI), having sex with a FSW while under the influence of alcohol, being younger than 36 years of age, living in Tijuana, and ever having been jailed. Hazardous drinkers were less likely ever to have been deported or to have shared injection drugs.

DISCUSSION AND CONCLUSIONS

Hazardous alcohol use is associated with HIV risk, including engaging in sex with FSWs while intoxicated and having an STI among male clients of FSWs in Tijuana.

SCIENTIFIC SIGNIFICANCE

We systematically described patterns and correlates of hazardous alcohol use among male clients of FSWs in Tijuana, Mexico. The results suggest that HIV/STI risk reduction interventions must target hazardous alcohol users, and be tailored to address alcohol use.

Correlates of injecting in an HIV incidence hotspot among substance users in Tijuana, Mexico

BACKGROUND

Substance use and HIV are growing problems in the Mexico-U.S. border city of Tijuana, a sex tourism destination situated on a northbound drug trafficking route. In a previous longitudinal study of injection drug users (IDUs), we found that >90% of incident HIV cases occurred within an 'HIV incidence hotspot,' consisting of 2.5-blocks. This study examines behavioral, social, and environmental correlates associated with injecting in this HIV hotspot.

METHODS

From 4/06 to 6/07, IDUs aged ≥18 years were recruited using respondent-driven sampling. Participants underwent antibody testing for HIV and syphilis and interviewer-administered surveys eliciting information on demographics, drug use, sexual behaviors, and socio-environmental influences. Participants were defined as injecting in the hotspot if they most frequently injected within a 3 standard deviational ellipse of the cohort's incident HIV cases. Logistic regression was used to identify individual and structural factors associated with the HIV 'hotspot'.

RESULTS

Of 1031 IDUs, the median age was 36 years; 85% were male; HIV prevalence was 4%. As bivariate analysis indicated different correlates for males and females, models were stratified by sex. Factors independently associated with injecting in the HIV hotspot for male IDUs included homelessness (AOR 1.72; 95%CI 1.14-2.6), greater intra-urban mobility (AOR 3.26; 95%CI 1.67-6.38), deportation (AOR 1.58; 95%CI 1.18-2.12), active syphilis (AOR 3.03; 95%CI 1.63-5.62), needle sharing (AOR 0.57; 95%CI 0.42-0.78), various police interactions, perceived HIV infection risk (AOR 1.52; 95%CI 1.13-2.03), and health insurance status (AOR 0.53; 95%CI 0.33-0.87). For female IDUs, significant factors included sex work (AOR 8.2; 95%CI 2.2-30.59), lifetime syphilis exposure (AOR 2.73; 95%CI 1.08-6.93), injecting inside (AOR 5.26; 95%CI 1.54-17.92), arrests for sterile syringe possession (AOR 4.87; 95%I 1.56-15.15), prior HIV testing (AOR 2.45; 95%CI 1.04-5.81), and health insurance status (AOR 0.12; 95%CI 0.03-0.59).

CONCLUSION

While drug and sex risks were common among IDUs overall, policing practices, STIs, mobility, and lack of healthcare access were correlated with injecting in this HIV transmission hotspot. Although participants in the hotspot were more aware of HIV risks and less likely to report needle sharing, interventions addressing STIs and structural vulnerabilities may be needed to effectively address HIV risk.

The longitudinal association of venue stability with consistent condom use among female sex workers in two Mexico-USA border cities

We examined the relationship between venue stability and consistent condom use (CCU) among female sex workers who inject drugs (FSW-IDUs; n = 584) and were enrolled in a behavioural intervention in two Mexico-USA border cities. Using a generalized estimating equation approach stratified by client type and city, we found venue stability affected CCU. In Tijuana, operating primarily indoors was significantly associated with a four-fold increase in the odds of CCU among regular clients (odds ratio [OR]: 3.77, 95% confidence interval [CI]: 1.44, 9.89), and a seven-fold increase among casual clients (OR: 7.18, 95% CI: 2.32, 22.21), relative to FSW-IDUs spending equal time between indoor and outdoor sex work venues. In Ciudad Juarez, the trajectory of CCU increased over time and was highest among those operating primarily indoors. Results from this analysis highlight the importance of considering local mobility, including venue type and venue stability, as these characteristics jointly influence HIV risk behaviours.

Sexual risk behaviours and barriers to HIV testing among clients of female sex workers in Guatemala: a qualitative study

Few interventions have targeted clients of female sex workers in Central America, despite their potential role in HIV/STI prevention. Semi-structured interviews were conducted with 30 clients of female sex workers on attitudes towards prevention of HIV/STIs, barriers to condom use and behaviour towards HIV/STI testing and treatment in Escuintla, Guatemala. Despite high knowledge of condoms as an HIV/STI preventive measure, the decision to use them was often based on the client's social judgment of the woman's sexual conduct. Regular clients reported lower condom use. Clients' risk perception diminished with the awareness of the public HIV/STI clinic addressed to female sex workers. Most preferred private clinics to increase confidentiality and were reluctant to take the HIV test for fear of a positive result. Outreach programmes offering HIV/STI counselling and testing to clients of female sex workers could increase their test uptake and health-seeking behaviour and reduce potential transmission to the general population.

Venue-level correlates of female sex worker registration status: a multilevel analysis of bars in Tijuana, Mexico

In Tijuana, Mexico, sex work is regulated by the municipal government, through registration cards issued to female sex workers (FSWs) for an annual fee. Registration has been associated with decreased drug use and increase condom use and HIV testing. Previously, it was demonstrated that FSWs operating in bars were more likely than street-based FSWs to be registered. This implies that certain venues may be more accessible to local authorities for the enforcement of this type of programme. Taking a novel multilevel approach, we examined whether venue characteristics of bars reflecting greater organised management and visibility affect registration status of FSWs. In an analysis of venue-level characteristics, predictors of being registered were availability of free condoms at work and distance to the main sex strip; however, these were not independently associated after inclusion of FSWs' income, illicit drug use and history of HIV testing. Our findings suggest that sex work regulations may inadvertently exclude venues in which the more vulnerable and less visible FSWs, such as injection drug users and those with limited financial resources, are situated. Efforts to revise or reconsider sex work regulations to ensure that they best promote FSWs' health, human and labour rights are recommended.

Social support and recovery among Mexican female sex workers who inject drugs

This qualitative study describes social support that female sex workers who inject drugs (FSW-IDUs) receive and recovery efforts in the context of relationships with family and intimate partners. We conducted thematic analysis of in-depth interviews with 47 FSW-IDUs enrolled in an intervention study to reduce injection/sexual risk behaviors in Tijuana, Mexico. FSW-IDUs received instrumental and emotional social support, which positively and negatively influenced recovery efforts. Participants reported how some intimate partners provided conflicting positive and negative support during recovery attempts. Problematic support (i.e., well-intended support with unintended consequences) occurred in strained family relationships, limiting the positive effects of support. Mexican drug treatment programs should consider addressing social support in recovery curricula through evidence-based interventions that engage intimate partners, children and family to better reflect socio-cultural and contextual determinants of substance abuse.

HIV risk behaviors differ by workplace stability among Mexican female sex workers with truck driver clientele

Background

In a study of female sex workers (FSWs) servicing truck driver clients in Mexican border cities, we evaluated differences in HIV/STI risk behaviours determined by workplace.

Design and Methods

Our study was cross-sectional and its population comprised 100 FSWs from Nuevo Laredo (US border) and 100 FSWs from Ciudad Hidalgo (Guatemalan border). The main outcome was primary place of sex work defined as unstable (street, vehicle, gas station, etc.) vs stable (bar, brothel, and hotel). Logistic regression was used to identify correlates associated with trading sex at unstable workplaces in the last month.

Results

Of the FSWs surveyed, 18% reported an unstable workplace. The majority of FSWs surveyed were young (<30 years), single, had <9^th grade education, and had worked in the sex trade for a median of 4.9 years. After controlling for study site, FSWs with unstable vs stable workplaces were more likely to have a majority/all truck driver clientele, but were less likely to have visited a gynaecologist in the last year (OR 0.1, 95% CI 0.03-0.4) or ever had an HIV test (OR 0.1, 95% CI 0.06-0.3), and there was a trend towards lower condom use self-efficacy scores (OR 0.8 per unit increase, 95% CI 0.7-1.0). On multivariate regression, unstable workplace was associated with having majority/all truck driver clientele, being surveyed in Nuevo Laredo, and decreased odds of ever having an HIV test.

Conclusions

Among Mexican FSWs with truck driver clients, providing safe indoor spaces for sex work may help facilitate public health interventions that improve HIV/STI prevention and reproductive health outcomes.

Prevalence of HIV and other sexually transmitted infections and factors associated with syphilis among female sex workers in Panama

Objectives

Biological and behavioural surveillance of HIV and sexually transmitted infections (STIs) among populations at highest risk have been used to monitor trends in prevalence and in risk behaviours. Sex work in Panama is regulated through registration with the Social Hygiene Programme, Ministry of Health. We estimated prevalence of HIV and STIs, and factors associated with active syphilis among female sex workers (FSWs).

Methods

A cross-sectional study using venue-based, time-space sampling was conducted among FSWs in Panama from 2009 to 2010. FSWs were interviewed about sociodemographic characteristics, sexual risk behaviour, health history and drug use using an anonymous structured questionnaire. Blood was collected for serological testing of HIV and other STIs. Factors associated with active syphilis were studied using logistic regression analysis.

Results

The overall HIV-1 prevalence of 0.7% varied by FSW category; 1.6% in 379 unregistered, and 0.2% in 620 registered FSWs. Overall prevalence (and 95% CI) of STIs were: syphilis antibody, 3.8% (2.7% to 5.2%); herpes simplex virus type 2 antibody (anti-HSV-2), 74.2% (71.4% to 76.9%); hepatitis B surface antigen, 0.6% (0.2% to 1.3%); hepatitis B core antibody, 8.7% (7.0% to 10.6%); and hepatitis C antibody, 0.2% (0.0% to 0.7%). In multivariate analysis, registration (adjusted OR (AOR)=0.35; 95% CI 0.16 to 0.74), having a history of STI (AOR=2.37; 95% CI 1.01 to 5.58), forced sex (AOR=2.47; 95% CI 1.11 to 5.48), and anti-HSV-2 (AOR=10.05; 95% CI 1.36 to 74.38) were associated with active syphilis.

Conclusions

Although HIV prevalence is low among FSWs in Panama, unregistered FSWs bear a higher burden of HIV and STIs than registered FSWs. Programmes aimed at overcoming obstacles to registration, and HIV, STI and harm reduction among unregistered FSWs is warranted to prevent HIV transmission, and to improve their sexual and reproductive health.

Situating HIV risk in the lives of formerly trafficked female sex workers on the Mexico-US border

Due to stigma and the psychosocial repercussions of past trauma and abuse, survivors of sex trafficking may experience increased susceptibility to violence, revictimization, and various harmful health outcomes, including HIV infection. Given the paucity of research characterizing the experiences of formerly trafficked female sex workers (FSWs), we set out to describe and contextualize perceptions of HIV risk among women who have experienced past episodes of sex trafficking and who are currently engaged in sex work in Tijuana, Mexico. Based on semi-structured interviews and ethnographic fieldwork, we describe the following interrelated themes as influencing formerly trafficked FSWs' perceptions and experiences of HIV risk: economic vulnerability; susceptibility to violence; and psychological trauma. Our findings highlight the need for HIV prevention efforts to incorporate broader structural and social interventions aimed at reducing vulnerability to violence and human rights abuses among this population and improving their general economic, psychological, and social well-being.

The emerging HIV epidemic on the Mexico-U.S. border: an international case study characterizing the role of epidemiology in surveillance and response

PURPOSE

Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome surveillance data are critical for monitoring epidemic trends, but they can mask dynamic subepidemics, especially in vulnerable populations that underuse HIV testing. In this case study, we describe community-based epidemiologic data among injection drug users (IDUs) and female sex workers (FSWs) in two northern Mexico-U.S. border states that identified an emerging HIV epidemic and generated a policy response.

METHODS

We draw from quantitative and qualitative cross-sectional and prospective epidemiologic studies and behavioral intervention studies among IDUs and FSWs in Tijuana, Baja California, and Ciudad Juarez, Chihuahua.

RESULTS

The recognition that the HIV epidemic on Mexico's northern border was already well established in subgroups in whom it had been presumed to be insignificant was met with calls for action and enhanced prevention efforts from researchers, nongovernmental organizations, and policy makers.

CONCLUSIONS

Successful policies and program outcomes included expansion of needle-exchange programs, a nationwide mobile HIV prevention program targeting marginalized populations, a successful funding bid from the Global Fund for HIV, TB, and Malaria to scale up targeted HIV-prevention programs, and the establishment of bi-national training programs on prevention of HIV and substance use. We discuss how epidemiologic data informed HIV prevention policies and suggest how other countries may learn from Mexico's experience.

Mobility and HIV in Central America and Mexico: a critical review

Mobility is a key determinant of HIV/sexually transmitted infection (STI) transmission dynamics in Asia and Africa. Scant data exist regarding its dynamic impacts on HIV/STI risk in Central America and Mexico. Our objective was to critically review the epidemiology and social and structural context of HIV/STI risk among mobile populations in Central America and Mexico. Eligible articles were published in English or Spanish between January 1, 2000 and August 31, 2010; conducted in Central America or Mexico; specified the mobile population included; and described primary research. 2045 records were screened, 275 articles reviewed, and 22 studies included. Mobility is associated with increased HIV risk behaviors, though it also may increase preventive behaviors. Among mobile groups in Central America and Mexico, social isolation, the socio-economic impacts of displacement, gender inequalities, and stigma/discrimination shape HIV risk. Epidemiologic research and multi-level interventions that target and engage vulnerable groups in transit stations are recommended.

Burden of HIV among female sex workers in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Female sex workers are a population who are at heightened risk of HIV infection secondary to biological, behavioural, and structural risk factors. However, three decades into the HIV pandemic, understanding of the burden of HIV among these women remains limited. We aimed to assess the burden of HIV in this population compared with that of other women of reproductive age.

METHODS

We searched PubMed, Embase, Global Health, SCOPUS, PsycINFO, Sociological Abstracts, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Web of Science, and POPLine for studies of female sex workers in low-income and middle-income countries published between Jan 1, 2007, and June 25, 2011. Studies of any design that measured the prevalence or incidence of HIV among female sex workers, even if sex workers were not the main focus of the study, were included. Meta-analyses were done with the Mantel-Haenszel method with a random-effects model characterising an odds ratio for the prevalence of HIV among female sex workers compared with that for all women of reproductive age.

FINDINGS

Of 434 selected articles and surveillance reports, 102 were included in the analyses, representing 99,878 female sex workers in 50 countries. The overall HIV prevalence was 11·8% (95% CI 11·6-12·0) with a pooled odds ratio for HIV infection of 13·5 (95% CI 10·0-18·1) with wide intraregional ranges in the pooled HIV prevalence and odds ratios for HIV infection. In 26 countries with medium and high background HIV prevalence, 30·7% (95% CI 30·2-31·3; 8627 of 28,075) of sex workers were HIV-positive and the odds ratio for infection was 11·6 (95% CI 9·1-14·8).

INTERPRETATION

Although data characterising HIV risk among female sex workers is scarce, the burden of disease is disproportionately high. These data suggest an urgent need to scale up access to quality HIV prevention programmes. Considerations of the legal and policy environments in which sex workers operate and actions to address the important role of stigma, discrimination, and violence targeting female sex workers is needed.

FUNDING

The World Bank, UN Population Fund.

Study protocol for the recruitment of female sex workers and their non-commercial partners into couple-based HIV research

Background

Researchers are increasingly recognizing the importance of addressing sexual and drug-related HIV risk within the context of intimate relationships rather than solely focusing on individual behaviors. Practical and effective methods are needed to recruit, screen, and enroll the high risk and hard-to-reach couples who would most benefit from HIV interventions, such as drug-using female sex workers (FSWs) and their intimate, non-commercial partners. This paper outlines a bi-national, multidisciplinary effort to develop and implement a study protocol for research on the social context and epidemiology of HIV, sexually transmitted infections (STI), and high risk behaviors among FSWs and their non-commercial male partners in Tijuana and Ciudad Juarez, Mexico. We provide an overview of our study and specifically focus on the sampling, recruitment, screening, and successful enrollment of high risk couples into a public health study in this context.

Methods/Design

We used targeted and snowball sampling to recruit couples through the female partner first and administered a primary screener to check her initial eligibility. Willing and eligible females then invited their primary male partners for couple-based screening using a couple verification screening (CVS) instrument adapted from previous studies. The CVS rechecked eligibility and separately asked each partner the same questions about their relationship to "test" if the couple was legitimate. We adapted the original protocol to consider issues of gender and power within the local cultural and socioeconomic context and expanded the question pool to create multiple versions of the CVS that were randomly administered to potential couples to determine eligibility and facilitate study enrollment.

Discussion

The protocol successfully enrolled 214 high risk couples into a multi-site public health study. This work suggests the importance of collaborating to construct a study protocol, understanding the local population and context, and drawing on multiple sources of input to determine eligibility and verify the legitimacy of relationships. We provide a practical set of tools that other researchers should find helpful in the study of high risk couples in international settings, with particular relevance to studies of FSWs and their intimate partners.

How important are venue-based HIV risks among male clients of female sex workers? A mixed methods analysis of the risk environment in nightlife venues in Tijuana, Mexico

In 2008, 400 males ≥18 years old who paid or traded for sex with a female sex worker (FSW) in Tijuana, Mexico, in the past 4 months completed surveys and HIV/STI testing; 30 also completed qualitative interviews. To analyze environmental sources of HIV vulnerability among male clients of FSWs in Tijuana, we used mixed methods to investigate correlates of clients who met FSWs in nightlife venues and clients' perspectives on venue-based HIV risk. Logistic regression identified micro-level correlates of meeting FSWs in nightlife venues, which were triangulated with clients' narratives regarding macro-level influences. In a multivariate model, offering increased pay for unprotected sex and binge drinking were micro-level factors that were independently associated with meeting FSWs in nightlife venues versus other places. In qualitative interviews, clients characterized nightlife venues as high risk due to the following macro-level features: social norms dictating heavy alcohol consumption; economic exploitation by establishment owners; and poor enforcement of sex work regulations in nightlife venues. Structural interventions in nightlife venues are needed to address venue-based risks.

Effects of government registration on unprotected sex amongst female sex workers in Tijuana; Mexico

BACKGROUND

Sex work is partially regulated in Tijuana, but little is known of its health effects. A recent behavioural intervention amongst female sex workers (FSWs) decreased incidence of HIV/STIs by 40%. We evaluated effects of sex worker regulation on condom use amongst FSWs randomized to this intervention.

METHODS

FSWs aged ≥18 years who reported unprotected sex with ≥1 client in the last 2 months and whether they were registered with Tijuana's Municipal Health Department underwent a brief, theory-based behavioural intervention to increase condom use. At baseline and 6 months, women underwent interviews and testing for HIV, syphilis, Chlamydia trachomatis and Neisseria gonorrhoeae. Negative binomial regression was used to determine the effect of registration on numbers of unprotected sex acts and cumulative HIV/STI incidence.

RESULTS

Of 187 women, 83 (44%) were registered. Lack of registration was associated with higher rates of unprotected sex (rate ratio: 1.7, 95% CI: 1.2-2.3), compared to FSWs who were registered, after controlling for potential confounders.

CONCLUSIONS

Registration predicted increased condom use amongst FSWs enrolled in a behavioural intervention. Public health programmes designed to improve condom use amongst FSWs may benefit from understanding the impact of existing regulation systems on HIV risk behaviours.