Health, harm reduction, and social service providers' perspectives on the appropriateness and feasibility of peer distribution of HIV self-test kits among people who use drugs.

BACKGROUND: People who use drugs (PWUD) experience elevated HIV risk and numerous barriers to facility-based HIV testing. HIV self-testing (HIVST) could circumvent many of those barriers and is acceptable among PWUD, yet HIVST implementation for PWUD is limited. Service providers' perspectives on specific HIVST delivery strategies could help increase availability for PWUD. METHODS: From April-November 2021, we interviewed 16 health, harm reduction, and social service providers working with PWUD in San Diego, CA. Interviews and rapid thematic analysis explored perspectives on HIVST's utility and appropriateness, as well as the feasibility of and anticipated challenges with specific HIVST delivery strategies, including peer or secondary distribution. RESULTS: Participants viewed HIV as a significant threat to PWUD health and confirmed the presence of numerous barriers to local facility-based HIV testing. Participants viewed HIVST as a promising and potentially empowering solution. Based on community familiarity with secondary distribution of harm reduction supplies (i.e., naloxone) and information, participants viewed secondary distribution of HIVST kits as an appropriate and feasible strategy for increasing the reach of HIVST, but also described potential barriers (e.g., engaging socially disconnected individuals, ensuring linkages to services following HIVST) and provided suggestions for alternative HIVST kit delivery models (e.g., harm reduction vending machines). CONCLUSIONS: Service providers viewed secondary distribution of HIVST kits among PWUD as promising, appropriate, and feasible, yet specialized efforts may be needed to reach the most marginalized individuals and ensure consistent provision of educational information and referral supports that maximize the impact of this approach.

Hepatitis C antibody prevalence, correlates and barriers to care among people who inject drugs in Central California.

Hepatitis C (HCV) infection among people who inject drugs (PWID) is a major public health concern. We examined correlates of HCV antibody (anti-HCV) seropositivity and characteristics of prior HCV testing and treatment among PWID in Fresno, California, which has among the highest prevalence of injection drug use (IDU) in the United States. We surveyed 494 peer-recruited PWID (≥18 years of age) in 2016 about their experiences with HCV testing and treatment, and conducted HCV and HIV antibody testing for all participants. Bivariate analyses and multivariable logistic regressions were used to identify correlates of anti-HCV seropositivity. A majority (65%) tested positive for anti-HCV, with 32% of those being unaware of their HCV status. Anti-HCV seroprevalence was independently and positively associated with older age (AOR = 1.11 per year, 95% CI = 1.06, 1.17), years injecting (AOR = 1.08 per year, 95% CI = 1.03, 1.13), distributive syringe sharing (AOR = 2.76, 95% CI = 1.29, 5.94), having syringes confiscated by police (AOR = 2.65, 95% CI = 1.22, 5.74), ever trading sex (AOR = 3.51, 95% CI = 1.40, 8.81) and negatively associated with being Black/African American (non-Hispanic) (AOR = 0.06, 95% CI = 0.01, 0.47). Prior HCV testing was associated with older age, ever getting syringes from a syringe services program, and having interactions with police. For those aware of their anti-HCV seropositivity, only 11% had initiated treatment; reasons for not seeing a physician regarding diagnosis included not feeling sick (23%), currently using drugs/alcohol (19%) and not knowing where to go for HCV medical care (19%). Our findings highlight the importance of expanding community-based access to sterile syringes alongside HCV testing and treatment services, particularly at syringe service programs where PWID may be more comfortable seeking testing and treatment.

Mobile phone and internet use among people who inject drugs: Implications for mobile health interventions.

Background: Mobile health (mHealth) interventions have the potential to improve substance use treatment engagement and outcomes, and to reduce risk behaviors among people who inject drugs (PWID). However, there are few studies assessing mobile technology use among PWID and none have investigated continuity of mobile phone use. Methods: We surveyed 494 PWID. We used bivariate (independent-sample t- and chi-square tests) and multivariate (logistic regression) analyses to determine whether mobile phone and/or internet use differed as a function of participant- and/or injection-related characteristics. Results: Most participants (77%) had a mobile phone, with 67% having a phone that was free of charge. Participants with a phone were significantly less likely to be homeless (AOR = 0.28), to have shared syringes (AOR = 0.53), and to have reused syringes (AOR = 0.26) in the past 3 months. We observed high rates of phone and number turnover, with more than half reporting that they got a new phone (57%) and/or number (56%) at least once within the past 3 months. Most participants were familiar with using the internet (80% ever use), though participants who had ever used the internet were younger (AOR = 0.89), were less likely to be homeless (AOR = 0.38), were less likely to have shared syringes (AOR = 0.49), and were more likely to have injected methamphetamine by itself (AOR = 2.49) in the past 3 months. Conclusions: Overall, mobile technology and internet use was high among our sample of PWID. Several factors should be considered in recruiting diverse samples of PWID to minimize bias in mHealth study outcomes, including mobile phone access and protocol type (text- vs internet-based).

Consider the Source: Associations between Syringe Sources and Risky Injection Behaviors in California's Central Valley.

BACKGROUND: Sterile syringe access is critical to prevent serious viral and bacterial infections among people who inject drugs (PWID) but many areas across the United States lack sufficient access. Although California law allows nonprescription pharmacy syringe sales and syringe services programs (SSPs), access gaps remain in the largely rural Central Valley. OBJECTIVE: The purpose of this study was to examine syringe access and related injection behaviors among PWID in Fresno, California. METHODS: We used respondent driven sampling to recruit 494 individuals for a survey about syringe access and injection behaviors between April and September 2016. Participants were ≥18 years old and injected at least twice in the past 30 days. Descriptive statistics examined syringe access and logistic regression determined if discrete syringe source categories were significantly associated with syringe sharing and/or reuse. RESULTS: A majority (67%) obtained syringes from an authorized source; SSPs were most common (59%), while few reported pharmacy purchase (14%). Unauthorized sources were even more common (79%), primarily friends (64%) or someone on the street (37%). Compared to PWID who used only authorized sources, those using only unauthorized sources had a higher odds of syringe sharing (AOR = 3.40, 95% CI: 1.66, 6.95) and syringe reuse (AOR = 6.22; 95% CI: 2.24, 17.29), as did those who reported mixed sources (AOR = 3.78; 95% CI: 1.90, 7.54 and AOR = 4.64; 95% CI: 2.08, 10.35). CONCLUSIONS: Our findings demonstrate a need to expand syringe access in nonurban California to prevent the syringe sharing and reuse that contributes to serious viral and bacterial infections among PWID.

"Violence and love and drugs it all goes hand in hand": A mixed methods analysis of the substance abuse, violence, and HIV/AIDS syndemic among women who use methamphetamine.

Background: The synergistic epidemics of substance use, violence, and HIV/AIDS, also known as the SAVA syndemic, disproportionately affects vulnerable women in the United States. Methamphetamine use is closely linked with physical and sexual violence, including intimate partner violence (IPV), which heightens women's vulnerability to HIV. This mixed methods study examined the prevalence and correlates of violence among women who use methamphetamine, (n = 209) enrolled in an HIV intervention study in San Diego, California. Methods: At baseline, 209 women completed an interviewer-administered computer-assisted survey. A sub set of women who reported lifetime IPV (n = 18) also participated in qualitative interviews to contextualize our understanding of patterns of violence over time. Results: In the overall cohort, reports of lifetime (66.0%) and past 2-month (19.6%) IPV were prevalent. Moreover, women reported lifetime physical only (27.3%), sexual only (6.2%), or both forms of violence (50.7%) by multiple perpetrators. Factors independently associated with lifetime IPV were having unprotected sex with a steady partner (odds ratio [OR]: 2.50, 95% confidence interval [CI]: 1.04, 6.00) and being high on methamphetamine during unprotected sex with a steady partner (OR: 2.56, 95% CI: 1.30, 5.09) within the past 2 months. Our qualitative narratives illuminated how IPV in women's steady relationships often reflects a culmination of violent victimization throughout their lifetime which is further exacerbated by methamphetamine use and sexual risk through gendered power dynamics. Conclusions: HIV prevention interventions should address the SAVA syndemic in a holistic manner, including the role of methamphetamine use in the context of women's abusive steady relationships.

Sharing Research, Building Possibility: Reflecting on Research with Men Who Have Sex with Men in Kenya.

Sharing our research with participants and communities is a standard and critically important ethical practice in anthropology, but do we use such opportunities to their full potential? In this article, I reflect on the possibilities generated by a community dissemination event to share my research with men who have sex with men and engage in sex work in Kisumu, Kenya. Drawing on Arjun Apaddurai's concept of an "ethics of possibility" that pushes beyond ordinary ethical practice, I reflect upon engagement with participants in the research process and advocate for greater emphasis on research dissemination events as a strategy to make research more meaningful to communities. Although my project was initially framed around HIV, what emerged were men's desire for spirituality, belonging, and new possibilities of inclusive citizenship that better attend to men's health and well-being. Research dissemination creates a critical space to generate ethnographic insight and guide theoretically rich applied health research.

Perspectives on biomedical HIV prevention options among women who inject drugs in Kenya.

Due to heightened vulnerability to HIV from frequent engagement in sex work and overlapping drug-using and sexual networks, women who inject drugs should be a high priority population for pre-exposure prophylaxis (PrEP) and other biomedical HIV prevention tools. Kenya is one of the first African countries to approve oral PrEP for HIV prevention among "key populations," including people who inject drugs and sex workers. The objective of this study was to explore preferences and perceived challenges to PrEP adoption among women who inject drugs in Kisumu, Kenya. We conducted qualitative interviews with nine HIV-uninfected women who inject drugs to assess their perceptions of biomedical HIV interventions, including oral PrEP, microbicide gels, and intravaginal rings. Despite their high risk and multiple biomedical studies in the region, only two women had ever heard of any of these methods. All women were interested in trying at least one biomedical prevention method, primarily to protect themselves from partners who were believed to have multiple other sexual partners. Although women shared concerns about side effects and product efficacy, they did not perceive drug use as a significant deterrent to adopting or adhering to biomedical prevention methods. Beginning immediately and continuing throughout Kenya's planned PrEP rollout, efforts are urgently needed to include the perspectives of high risk women who use drugs in biomedical HIV prevention research and programing.

Negotiating sexual safety in the era of biomedical HIV prevention: relationship dynamics among male couples using pre-exposure prophylaxis.

Up to two-thirds of new cases of HIV transmission between gay, bisexual and other men who have sex with men in the USA are attributed to primary relationships. Understanding the relationship dynamics and sexual agreements of male-male couples can provide insight into HIV transmission patterns and prevention needs in this population. The daily use of antiretroviral pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV, but its negotiation and use within social and intimate relationship contexts remain understudied. We conducted semi-structured qualitative interviews with 20 male couples (n = 40 men) in which at least one partner was either using or in the process of initiating PrEP. Congruent with a theoretical focus on social theories of relationships and negotiated risk, couples were interviewed about relationship dynamics, trust, communication and sexual health practices, including their perception and use of PrEP. Overall, we found that couples showed heightened trust and communication when establishing open, sexual agreements and demonstrated high awareness of sexual risks and health practices in the context of PrEP use. This study demonstrates how understanding relationship dynamics can better inform HIV prevention and sexual health promotion efforts for male couples at risk of HIV.

'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.

Conceptualizing Neonatal Abstinence Syndrome as a Cascade of Care: A Qualitative Study With Healthcare Providers in Ohio.

BACKGROUND: The opioid epidemic remains a serious issue in the United States and presents additional challenges for women of childbearing age. An increasingly common complication of opioid use is neonatal abstinence syndrome (NAS), or infant withdrawal from in utero exposure to opioids. PURPOSE: The objective of our qualitative study was to identify service needs and barriers to care in the NAS epidemic in Ohio, which has among the highest rates of opioid use and NAS in the nation. METHODS: Drawing on interviews with 18 healthcare providers, we investigated the challenges, opportunities, and service gaps in treating NAS. Open-ended questions covered opioid misuse and drug treatment, provision of and barriers to healthcare, and suggestions to improve prevention and programming. Content analysis identified major themes. FINDINGS: Providers were primarily women (67%) and included individuals working in healthcare administrative positions, hospital settings, clinics, and social support positions for pregnant women or new mothers. Our results suggest that rather than an acute diagnosis, NAS is better conceptualized as a "cascade of care" including (1) prevention, (2) prenatal care, including drug treatment, (3) labor and delivery, and (4) aftercare. Providers identified challenges and opportunities at each stage of the cascade that could influence NAS outcomes. IMPLICATIONS FOR PRACTICE: Our results suggest that greater resources, coordination, and cross-disciplinary education are urgently needed across the cascade of care to effectively address NAS. IMPLICATIONS FOR RESEARCH: Framing NAS as a cascade of care allows researchers to identify points along a cascade where mothers and infants require enhanced care and access to social and health services.

Measuring Current Drug Use in Female Sex Workers and Their Noncommercial Male Partners in Mexico: Concordance Between Data Collected From Surveys Versus Semi-Structured Interviews.

BACKGROUND: Self-reports are commonly used to assess prevalence and frequency of drug use, but it is unclear whether qualitative methods like semi-structured interviews are as useful at obtaining such information as quantitative surveys. OBJECTIVES: This study compared drug use occurrence and frequency using data collected from quantitative surveys and qualitative interviews. We also examined whether combining data from both sources could result in significant increases in percentages of current users and whether the concordance between the two sets of data was associated with the type of drug use, age, gender and socioeconomic status. METHODS: Self- reports of recent marijuana, heroin, crack, cocaine, crystal/methamphetamine, inhalant, and tranquilizer use were collected using both methods from a cohort of Mexican female sex workers and their non-commercial male partners (n = 82). RESULTS: Participants were significantly less likely to report marijuana, cocaine and tranquilizer use and frequency of use during the qualitative interviews than during the quantitative surveys. Agreement on frequency of drug use was excellent for crystal/methamphetamine, heroin and inhalant use, and weak for cocaine, tranquilizers and marijuana use. Older participants exhibited significantly higher concordance than younger participants in reports of marijuana and methamphetamine use. Higher monthly income was significantly associated with higher concordance in crack use but lower concordance with marijuana use. CONCLUSIONS: Although use of such data can result in an underreporting of drug use, qualitative data can be quantified in certain circumstances to triangulate and confirm the results from quantitative analyses and provide a more comprehensive view of drug use.

A Qualitative Study of Substance use during Pregnancy: Implications for Reproductive Healthcare in Western Kenya.

Women who use alcohol and drugs are often in their childbearing years, creating a need for integrated substance abuse and reproductive health services. However, our understanding of the social context and drivers of substance use during pregnancy, particularly in developing countries, is limited and largely unaddressed in clinical care. Our qualitative research explored the reproductive health of women of childbearing age who inject drugs and its implications for healthcare in Kisumu, Kenya. We used in-depth, semi-structured qualitative interviews with 17 women who inject drugs to explore reproductive health topics including knowledge, practices, and clinical interactions related to substance use during pregnancy. All but one woman had a prior pregnancy and two were pregnant during our study. Alcohol and drug use was prevalent throughout pregnancy, often described as a coping mechanism for stress. Women received mixed advice from family and social contacts regarding alcohol use during pregnancy, leading to differing perceptions of its health effects. Healthcare providers infrequently screened women for alcohol or drug use. Our analysis highlights the need for culturally appropriate alcohol and drug screening and counseling to be included in integrated reproductive health services in western Kenya.

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.

STI/HIV test result disclosure between female sex workers and their primary, non-commercial male partners in two Mexico-US border cities: a prospective study.

OBJECTIVES: Disclosure of sexually transmitted infections (STI)/HIV diagnoses to sexual partners is not mandated by public health guidelines in Mexico. To assess the feasibility of couples-based STI/HIV testing with facilitated disclosure as a risk-reduction strategy within female sex workers' (FSW) primary partnerships, we examined STI/HIV test result disclosure patterns between FSWs and their primary, non-commercial male partners in two Mexico-US border cities. METHODS: From 2010 to 2013, 335 participants (181 FSWs and 154 primary male partners) were followed for 24 months. At semiannual visits, participants were tested for STIs/HIV and reported on their disclosure of test results from the previous visit. Multilevel logistic regression was used to identify individual-level and partnership-level predictors of cumulative (1) non-disclosure of ≥1 STI test result and (2) non-disclosure of ≥1 HIV test result within couples during follow-up. RESULTS: Eighty-seven percent of participants reported disclosing all STI/HIV test results to their primary partners. Non-disclosure of ≥1 STI test result was more common among participants who reported an STI diagnosis as part of the study (adjusted OR=3.05, 95% CI 1.13 to 8.25), while non-disclosure of ≥1 HIV test result was more common among participants in longer-duration partnerships (AOR=1.15 per year, 95% CI 1.03 to 1.28). Drug use before/during sex within partnerships was associated with non-disclosure of both STI (AOR=5.06, 95% CI 1.64 to 15.62) and HIV (AOR=4.51, 95% CI: 1.32 to 15.39) test results. CONCLUSIONS: STI/HIV test result disclosure was highly prevalent within FSWs' primary partnerships, suggesting couples-based STI/HIV testing with facilitated disclosure may be feasible for these and potentially other high-risk, socially marginalised couples.

Love, Trust, and HIV Risk Among Female Sex Workers and Their Intimate Male Partners.

OBJECTIVES: We examined correlates of love and trust among female sex workers and their noncommercial male partners along the Mexico-US border. METHODS: From 2011 to 2012, 322 partners in Tijuana and Ciudad Juárez, Mexico, completed assessments of love and trust. Cross-sectional dyadic regression analyses identified associations of relationship characteristics and HIV risk behaviors with love and trust. RESULTS: Within 161 couples, love and trust scores were moderately high (median 70/95 and 29/40 points, respectively) and correlated with relationship satisfaction. In regression analyses of HIV risk factors, men and women who used methamphetamine reported lower love scores, whereas women who used heroin reported slightly higher love. In an alternate model, men with concurrent sexual partners had lower love scores. For both partners, relationship conflict was associated with lower trust. CONCLUSIONS: Love and trust are associated with relationship quality, sexual risk, and drug use patterns that shape intimate partners' HIV risk. HIV interventions should consider the emotional quality of sex workers' intimate relationships.

Client perspectives on design and implementation of a couples-based intervention to reduce sexual and drug risk behaviors among female sex workers and their noncommercial partners in Tijuana and Ciudad Juárez, México.

This mixed-methods study examined the acceptability of a hypothetical couples-based HIV prevention program for female sex workers and their intimate (non-commercial) male partners in Mexico. Among 320 participants, 67 % preferred couples-based over individual programs, particularly among men. Reasons cited for preferring couples-based programs included convenience and health benefits for both partners. Participants reported that they would benefit from general health information and services, HIV counseling and testing, job training (particularly for men) and other services. However, qualitative interviews revealed that barriers relating to the environment (i.e., poor access to services), providers (i.e., lack of a therapeutic alliance), and intimate relationships (i.e., mistrust or instability) would need to be addressed before such a program could be successfully implemented. Despite women's concerns about privacy and men's preferences for gender-specific services, couples-based HIV prevention programs were largely acceptable to female sex workers and their intimate male partners.

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.

The promise and peril of pre-exposure prophylaxis (PrEP): using social science to inform prep interventions among female sex workers.

Advances in biomedical interventions to prevent HIV offer great promise in reducing the number of new infections across sub- Saharan Africa, particularly among vulnerable populations such as female sex workers. Several recent trials testing pre-exposure prophylaxis (PrEP) have demonstrated efficacy, although others have been stopped early for futility. Given the importance and complexities of social and behavioural factors that influence biomedical approaches to prevention, we discuss several key areas of consideration moving forward, including trial participation, adherence strategies, social relationships, and the structural factors that shape PrEP interest, use, and potential effectiveness among female sex workers in sub-Saharan Africa. Our review highlights the importance of involving social scientists in clinical and community-based research on PrEP. We advocate for a shift away from a singular "re-medicalization" of the HIV epidemic to that of a "reintegration" of interdisciplinary approaches to prevention that could benefit female sex workers and other key populations at risk of acquiring HIV.

Concurrent sexual partnerships among female sex workers and their non-commercial male partners in Tijuana and Ciudad Juarez, Mexico.

OBJECTIVES: To investigate the prevalence and correlates of concurrent (overlapping) sexual partnerships among female sex workers (FSWs) and their non-commercial male partners in two Mexico-US border cities. METHODS: A cross-sectional survey of FSWs and their non-commercial male partners was conducted in Tijuana and Ciudad Juárez, Mexico (2010-2011). Eligible FSWs and verified non-commercial partners were aged ≥18 years; FSWs had ever used hard drugs (lifetime) and recently exchanged sex for money, drugs or other goods (past month). Participants underwent baseline questionnaires obtaining dates of sex and condom use with ≤5 other recurring partners, including FSWs' regular clients. These dates were compared with dates of sex with enrolled study partners to determine overlap (ie, 'recurring' concurrency). Bivariate probit regression identified recurring concurrency correlates. RESULTS: Among 428 individuals (214 couples), past-year recurring concurrency prevalence was 16% and was higher among women than their non-commercial male partners (26% vs 6%). In 10 couples (5%), both partners reported recurring concurrency. The majority of couples (64%) always had unprotected sex, and most of the individuals (70%) with recurring concurrency 'sometimes' or 'never' used condoms with their concurrent partners. Recurring concurrency was positively associated with FSWs' income, men's caballerismo (a form of traditional masculinity) and men's belief that their FSW partners had sexually transmitted infections (STIs). CONCLUSIONS: Recurring concurrency, representing sustained periods of overlapping partnerships in which unprotected sex was common, should be addressed by couple-based STI prevention interventions.

Sex workers' noncommercial male partners who inject drugs report higher-risk sexual behaviors.

Female sex workers are less likely to use condoms with noncommercial male partners than clients. We compare noncommercial male partners who do and do not inject drugs in Tijuana and Ciudad Juárez, Mexico. Sexual risk behaviors were more prevalent among injectors, who could promote HIV/sexually transmitted infection transmission in this region.