COVID-19 vaccine uptake among people who inject drugs in Tijuana Mexico.

Background: SARS-CoV-2 prevalence is elevated among people who inject drugs (PWID). In Tijuana, Mexico, COVID-19 vaccines became available to the general population in June 2021, but uptake among PWID was <10%. We studied COVID-19 vaccine uptake among PWID in Tijuana following implementation of a pop-up vaccination clinic. Methods: Beginning in October, 2020, PWID in Tijuana aged ≥18 years were enrolled into a longitudinal cohort study. At baseline and semi-annually, participants underwent interviewer-administered interviews on health behaviors and COVID-19 exposures through April 5, 2022. From June 21-September 20, 2021, staff referred PWID to a temporary COVID-19 vaccine pop-up clinic that was coincidentally established near the study office. Participants attending the clinic completed a short interview on barriers to vaccination and were offered facilitated access to free Janssen® COVID-19 vaccine. All participants were reimbursed $5 for this interview, regardless of whether or not they chose to be vaccinated. Poisson regression was used to evaluate the effect of the pop-up clinic on COVID-19 vaccination uptake, controlling forpotential confounders. Results: Of 344 participants, 136 (39.5%) reported having received at least one COVID-19 vaccine dose during the 10 months follow-up period, of whom 113 (83.1%) received vaccine at the pop-up clinic and 23 (16.9%) elsewhere. One third of those receiving COVID-19 vaccine during the pop-up clinic were previously vaccine hesitant. Attending the pop-up clinic was independently associated with higher rates of COVID-19 vaccination Adjusted Rate Ratio (AdjRR: 9.15; 95% CI: 5.68-14.74). Conclusions: We observed a significant increase in COVID-19 vaccine uptake associated with attending a temporary pop-up vaccine clinic in Tijuana suggesting that efforts to improve vaccination in this vulnerable population should include convenient locations and staff who have experience working with substance using populations. Since COVID-19 vaccination rates remain sub-optimal, sustained interventions to increase uptake are needed.

Correlates of recent overdose among people who inject drugs in the San Diego/Tijuana border region.

BACKGROUND: Along the Mexico-US border, illicitly manufactured fentanyls (fentanyl) have been detected in other illicit drugs, including street opioid formulations known as 'china white.' We studied correlates of recent overdose among people who inject drugs (PWID), focusing on the risk of knowlingly or unknowingly using fentanyl in china white. METHODS: From October 2020 - September, 2021 we surveyed participants in San Diego, California and Tijuana, Mexico and employed Poisson regression to identify correlates of recent overdose. RESULTS: Of 612 PWID, most were male (74.0 %), Latinx (71.9 %), US residents (67.0 %). Mean age was 43 years. In the last six months, 15.8 % experienced overdose, 31.0 % knowingly used fentanyl and 11.1 % used china white, of whom 77.9 % did not think it contained fentanyl. After controlling for sex and race, factors independently associated with risk of overdose included knowingly using fentanyl, using china white and not believing it contained fentanyl, recent drug rehabilitation, being stopped/arrested by police, and homelessness. Further, PWID who believed china white contained fentanyl were less likely to use it. CONCLUSIONS: Both intentional fentanyl use and unintentional exposure to fentanyl via china white were associated with overdose risk; however, PWID who believed china white contained fentanyl were less likely to use it. These data suggest that advanced drug checking systems should be implemented to empower PWID to avoid dangerous street formulations or to plan their drug use knowing its contents. Other overdose risk factors such as decreased tolerance following drug treatment, police interactions, and homelessness also require urgent intervention.

'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.

Impacting Binational Health through Leadership Development: A Program Evaluation of the Leaders across Borders Program, 2010-2014.

BACKGROUND: Workforce and leadership development is imperative for the advancement of public health along the U.S./Mexico border. The Leaders across borders (LaB) program aims to train the public health and health-care workforce of the border region. The LaB is a 6-month intensive leadership development program, which offers training in various areas of public health. Program curriculum topics include: leadership, border health epidemiology, health diplomacy, border public policies, and conflict resolution. METHODS: This article describes the LaB program evaluation outcomes across four LaB cohort graduates between 2010 and 2014. LaB graduates received an invitation to participate via email in an online questionnaire. Eighty-five percent (n = 34) of evaluation participants indicated an improvement in the level of binationality since participating in the LaB program. Identified themes in the evaluation results included increased binational collaborations and partnerships across multidisciplinary organizations that work towards improving the health status of border communities. Approximately 93% (n = 37) of the LaB samples were interested in participating in future binational projects while 80% (n = 32) indicated interest in the proposal of other binational initiatives. Participants expressed feelings of gratitude from employers who supported their participation and successful completion of LaB. DISCUSSION: Programs such as LaB are important in providing professional development and education to a health-care workforce along the U.S./Mexico border that is dedicated to positively impacting the health outcomes of vulnerable populations residing in this region.

Risk behaviours for HIV infection among travelling Mexican migrants: The Mexico-US border as a contextual risk factor.

The Mexico-US border region is a transit point in the trajectory of Mexican migrants travelling to and from the USA and a final destination for domestic migrants from other regions in Mexico. This region also represents a high-risk environment that may increase risk for HIV among migrants and the communities they connect. We conducted a cross-sectional, population-based survey, in Tijuana, Mexico, and compared Mexican migrants with a recent stay on the Mexico-US border region (Border, n = 553) with migrants arriving at the border from Mexican sending communities (Northbound, n = 1077). After controlling for demographics and migration history, border migrants were more likely to perceive their risk for HIV infection as high in this region and regard this area as a liberal place for sexual behaviours compared to Northbound migrants reporting on their perceptions of the sending communities (p < .05). Male border migrants were more likely to engage in sex, and have unprotected sex, with female sex workers during their recent stay on the border compared to other contexts (rate ratio = 3.0 and 6.6, respectively, p < .05). Binational and intensified interventions targeting Mexican migrants should be deployed in the Mexican border region to address migration related HIV transmission in Mexico and the USA.

Understanding the Impact of Migration on HIV Risk: An Analysis of Mexican Migrants' Sexual Practices, Partners, and Contexts by Migration Phase.

HIV risk among Mexican migrants varies across migration phases (pre-departure, transit, destination, interception, and return), but there is limited knowledge about specific sexual behaviors, characteristics of sexual partners, and sexual contexts at different migration stages. To fill the gap, we used data from a cross-sectional population-based survey conducted in Tijuana, Mexico. Information on migration phase and last sexual encounter was collected from 1219 male migrants. Our findings suggest that compared to pre-departure migrants, repeat migrants returning from communities of origin were more likely to have sex with male partners, use substances before sex, and not use condoms; migrants in the transit phase in the Mexican border were more likely to have sex with casual partners and sex workers; and migrants in the interception phase were more likely to engage in anal sex and use substances before sex. Sexual behaviors, partners, and contexts vary significantly among migrants at different migration phases. Tailored HIV prevention programs targeting Mexican migrants need to be developed and implemented at all migration phases.

A police education programme to integrate occupational safety and HIV prevention: protocol for a modified stepped-wedge study design with parallel prospective cohorts to assess behavioural outcomes.

INTRODUCTION: Policing practices are key drivers of HIV among people who inject drugs (PWID). This paper describes the protocol for the first study to prospectively examine the impact of a police education programme (PEP) to align law enforcement and HIV prevention. PEPs incorporating HIV prevention (including harm reduction programmes like syringe exchange) have been successfully piloted in several countries but were limited to brief pre-post assessments; the impact of PEPs on policing behaviours and occupational safety is unknown. OBJECTIVES: Proyecto ESCUDO (SHIELD) aims to evaluate the efficacy of the PEP on uptake of occupational safety procedures, as assessed through the incidence of needle stick injuries (NSIs) (primary outcome) and changes in knowledge of transmission, prevention and treatment of HIV and viral hepatitis; attitudes towards PWID, adverse behaviours that interfere with HIV prevention and protective behaviours (secondary outcomes). METHODS/ANALYSIS: ESCUDO is a hybrid type I design that simultaneously tests an intervention and an implementation strategy. Using a modified stepped-wedge design involving all active duty street-level police officers in Tijuana (N = ∼ 1200), we will administer one 3 h PEP course to groups of 20-50 officers until the entire force is trained. NSI incidence and geocoded arrest data will be assessed from department-wide de-identified data. Of the consenting police officers, a subcohort (N=500) will be randomly sampled from each class to undergo pre-PEP and post-PEP surveys with a semiannual follow-up for 2 years to assess self-reported NSIs, attitudes and behaviour changes. The impact on PWIDs will be externally validated through a parallel cohort of Tijuana PWIDs. ETHICS/DISSEMINATION: Research ethics approval was obtained from the USA and Mexico. Findings will be disseminated through open access to protocol materials through the Law Enforcement and HIV Network. TRIAL REGISTRATION NUMBER: NCT02444403.

Identifying opportunities to increase HIV testing among mexican migrants: a call to step up efforts in health care and detention settings.

HIV testing and counseling is a critical component of HIV prevention efforts and core element of current "treatment as prevention" strategies. Mobility, low education and income, and limited access to health care put Latino migrants at higher risk for HIV and represent barriers for adequate levels of HIV testing in this population. We examined correlates of, and missed opportunities to increase, HIV testing for circular Mexican migrants in the U.S. We used data from a probability-based survey of returning Mexican migrants (N=1161) conducted in the border city of Tijuana, Mexico. We estimated last 12-months rates of HIV testing and the percentage of migrants who received other health care services or were detained in an immigration center, jail, or prison for 30 or more days in the U.S., but were not tested for HIV. Twenty-two percent of migrants received HIV testing in the last 12 months. In general, utilization of other health care services or detention for 30 or more days in the U.S. was a significant predictor of last 12-months HIV testing. Despite this association, we found evidence of missed opportunities to promote testing in healthcare and/or correctional or immigration detention centers. About 27.6% of migrants received other health care and/or were detained at least 30 days but not tested for HIV. Health care systems, jails and detention centers play an important role in increasing access to HIV testing among circular migrants, but there is room for improvement. Policies to offer opt-out, confidential HIV testing and counseling to Mexican migrants in these settings on a routine and ethical manner need to be designed and pilot tested. These policies could increase knowledge of HIV status, facilitate engagement in HIV treatment among a highly mobile population, and contribute to decrease incidence of HIV in the host and receiving communities.

Migrants in transit: the importance of monitoring HIV risk among migrant flows at the Mexico-US border.

We conducted a probability-based survey of migrant flows traveling across the Mexico-US border, and we estimated HIV infection rates, risk behaviors, and contextual factors for migrants representing 5 distinct migration phases. Our results suggest that the influence of migration is not uniform across genders or risk factors. By considering the predeparture, transit, and interception phases of the migration process, our findings complement previous studies on HIV among Mexican migrants conducted at the destination and return phases. Monitoring HIV risk among this vulnerable transnational population is critical for better understanding patterns of risk at different points of the migration process and for informing the development of protection policies and programs.

Substance Use Across Different Phases of the Migration Process: A Survey of Mexican Migrants Flows.

This study examined the levels of substance use and changes across different migration stages, including pre-departure, travel, destination, and return, among Mexican migrants converging on the US-Mexico border. A cross-sectional survey was conducted in Tijuana, Mexico, between 2009 and 2010 among Mexican migrants returning from the US and those travelling from other Mexican regions. The overall prevalence of last 12-month at-risk drinking, illicit drug use, and current smoking, was 42.3, 17.7 and 31.4%, respectively. Compared to pre-departure migrants, males were at increased risk for illicit drug use at the destination and return stages. In contrast, females' alcohol consumption at the destination stage was lower than at pre-departure (p < 0.05). The level of smoking was stable across all stages for both genders. In the destination stage, undocumented migrants were more likely to use illicit drugs relative to their documented peers (p < 0.05). Binational interventions promoting substance use reduction are needed among this mobile population.

Seasonal influenza vaccination among Mexican migrants traveling through the Mexico-US border region.

OBJECTIVE: Mobile populations are at high risk for communicable diseases and can serve as a bridge between sending and receiving communities. The objective of this study is to determine the rates of, and factors associated with, seasonal influenza vaccination among Mexican migrants traveling through the US-Mexico border. METHODS: We used a 2013 cross-sectional population-based survey of adult mobile Mexican migrants traveling through the Mexico-US border region (N=2313; weighted N=652,500). We performed a multivariable logistic regression analysis to model the odds of receiving an influenza vaccination in the past year by sociodemographics, migration history, health status, and access to health care. RESULTS: The seasonal influenza vaccination rate in this population was 18.6%. Gender, health status, and health insurance were associated with the likelihood to receive an influenza vaccination. CONCLUSION: Overall, the rates of seasonal influenza vaccination in circular Mexican migrants are low compared to adults in Mexico and the US Efforts are needed to increase influenza vaccination among this highly mobile population, particularly in adults with chronic conditions.

Reductions in HIV/STI incidence and sharing of injection equipment among female sex workers who inject drugs: results from a randomized controlled trial.

BACKGROUND: We evaluated brief combination interventions to simultaneously reduce sexual and injection risks among female sex workers who inject drugs (FSW-IDUs) in Tijuana and Ciudad Juarez, Mexico during 2008-2010, when harm reduction coverage was expanding rapidly in Tijuana, but less so in Juarez. METHODS: FSW-IDUs ≥18 years reporting sharing injection equipment and unprotected sex with clients within the last month participated in a randomized factorial trial comparing four brief, single-session conditions combining either an interactive or didactic version of a sexual risk intervention to promote safer sex in the context of drug use, and an injection risk intervention to reduce sharing of needles/injection paraphernalia. Women underwent quarterly interviews and testing for HIV, syphilis, gonorrhea, Chlamydia and Trichomonas, blinding interviewers and assessors to assignment. Poisson regression with robust variance estimation and repeated measures ordinal logistic regression examined effects on combined HIV/STI incidence and receptive needle sharing frequency. FINDINGS: Of 584 initially HIV-negative FSW-IDUs, retention was ≥90%. After 12 months, HIV/STI incidence decreased >50% in the interactive vs. didactic sex intervention (Tijuana:AdjRR:0.38,95% CI:0.16-0.89; Juarez: AdjRR:0.44,95% CI:0.19-0.99). In Juarez, women receiving interactive vs. didactic injection risk interventions decreased receptive needle-sharing by 85% vs. 71%, respectively (p = 0.04); in Tijuana, receptive needle sharing declined by 95%, but was similar in active versus didactic groups. Tijuana women reported significant increases in access to syringes and condoms, but Juarez women did not. INTERPRETATION: After 12 months in both cities, the interactive sexual risk intervention significantly reduced HIV/STI incidence. Expanding free access to sterile syringes coupled with brief, didactic education on safer injection was necessary and sufficient for achieving robust, sustained injection risk reductions in Tijuana. In the absence of expanding syringe access in Juarez, the injection risk intervention achieved significant, albeit more modest reductions, suggesting that community-level interventions incorporating harm reduction are more powerful than individual-level interventions. TRIAL REGISTRATION: clinicaltrials.gov NCT00840658.

Factors associated with pathways toward concurrent sex work and injection drug use among female sex workers who inject drugs in northern Mexico.

AIMS: To identify factors associated with time to initiation of (i) sex work prior to injecting drugs initiation; (ii) injection drug use prior to sex work initiation; and (iii) concurrent sex work and injection drug use (i.e. initiated at the same age) among female sex workers who currently inject drugs (FSW-IDU). DESIGN: Parametric survival analysis of baseline data for time to initiation event. SETTING: Tijuana and Ciudad Juarez situated on the Mexico-US border. PARTICIPANTS: A total of 557 FSW-IDUs aged ≥18 years. MEASUREMENTS: Interview-administered surveys assessing context of sex work and injection drug use initiation. FINDINGS: Nearly half (n = 258) initiated sex work prior to beginning to inject, a third (n = 163) initiated injection first and a quarter (n = 136) initiated both sex work and injection drug use concurrently. Low education and living in Ciudad Juarez accelerated time to sex work initiation. Being from a southern Mexican state and initiating drug use with inhalants delayed the time to first injection drug use. Having an intimate partner encourage entry into sex work and first injecting drugs to deal with depression accelerated time to initiating sex work and injection concurrently. Early physical abuse accelerated time to initiating sex work and injection, and substantially accelerated time to initiation of both behaviors concurrently. CONCLUSIONS: Among female sex workers who currently inject drugs in two Mexican-US border cities, nearly half appear to initiate sex work prior to beginning to inject, nearly one-third initiate injection drug use before beginning sex work and one-quarter initiate both behaviors concurrently. Predictors of these three trajectories differ, and this provides possible modifiable targets for prevention.

Correlates of STI symptoms among female sex workers with truck driver clients in two Mexican border towns.

BACKGROUND: Female sex workers (FSW) are at increased risk for HIV and other STI due to occupation-related risks and exposures. Long-distance truck drivers have been implicated in the spread of HIV, but less is known about HIV/STI risks of FSW servicing truck drivers, especially in North America. As part of an international collaborative pilot study, we interviewed FSWs servicing truck driver clients along two major transportation corridors to explore factors associated with recent STI symptoms. METHODS: A cross-sectional study of 200 FSW was conducted in Mexico: 100 from Nuevo Laredo (U.S. border); 100 from Ciudad Hidalgo (Guatemalan border). Eligibility criteria included age ≥18 years, speaking English or Spanish, and having ≥1 truck driver client in the past month. The main outcome was reporting any recent STI symptoms, defined as experiencing genital/anal warts, genital ulcers/sores, genital itching, or abnormal vaginal discharge in the past 6 months. Logistic regression was used to identify correlates of recent STI symptoms. RESULTS: Median age of FSW was 29 years, 74% were single, 87% had <9th grade education, and median income was 4000 pesos/month ($300 USD). Sex work occurred at a bar/cantina for 70%. One-quarter had never been tested for HIV, 53% reported lifetime drug use, 22% reported drinking alcohol before/during transactional sex and 17% reported recent STI symptoms. After controlling for age and study site, factors associated with STI symptoms were lifetime drug use (AOR 2.9, 95% CI 1.2-6.9), drug use before/during sex (AOR 2.8, 95% CI 1.1-7.1), alcohol use before/during sex (AOR 5.2, 95% CI 2.2, 12.6), forced sex ever (AOR 2.6, 95% CI 1.1-6.1), lifetime history of arrest (AOR 2.3, 95% CI 1.0-5.0), and being surveyed in Nuevo Laredo rather than Ciudad Hidalgo (AOR 4.8, 95% CI 2.0-10.0). CONCLUSIONS: The associations we observed between recent STI symptoms and drug and alcohol use suggest that interventions are needed that promote consistent and effective safer sex practices, especially while under the influence of alcohol or other substances.