Manuel Gallardo

Correlates of HIV, sexually transmitted infections, and associated high-risk behaviors among male clients of female sex workers in Tijuana, Mexico.

Objectives:To determine sociodemographic and behavioral correlates of HIV infection among male clients of female sex workers (FSWs) in Tijuana. Methods:Four hundred men aged 18 years or older who had paid or traded for sex with a FSW in Tijuana during the past 4 months were recruited in Tijuanas ‘zone of tolerance,’ where prostitution is practiced openly under a municipal permit system. Efforts were made to balance the sample between residents of the United States (San Diego County) and of Mexico (Tijuana). Participants underwent interviews and testing for HIV, syphilis, gonorrhea, and Chlamydia. Logistic regression identified correlates of HIV infection. Results:Mean age was 36.6 years. One-quarter had injected drugs within the previous 4 months. Lifetime use of heroin, cocaine, and methamphetamine was 36, 50, and 64%, respectively. Men had frequented FSWs for an average of 11 years, visiting FSWs an average of 26 times last year. In the past 4 months, one-half reported having unprotected sex with a FSW; 46% reported being high fairly or very often when having sex with a FSW. Prevalence of HIV, syphilis, gonorrhea, and Chlamydia was 4, 2, 2.5, and 7.5%; 14.2% were positive for at least one infection. Factors independently associated with HIV infection were living in Mexico, ever using methamphetamine, living alone, and testing positive for syphilis. Conclusion:Male clients of FSWs in Tijuana had a high sex and drug risk profile. Although sexually transmitted infection prevalence was lower than among FSWs, HIV prevalence was comparable suggesting the need for interventions among clients to prevent spread of HIV and sexually transmitted infections.

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

Objective. Sex work is regulated in Tijuana, Mexico, but only half of the citys female sex workers (FSWs) are registered with the municipal health department, which requires regular screening for sexually transmitted infections (STIs) and human immunodeficiency virus (HIV). We examined correlates of registration to determine if it confers measurable health benefits. Methods. From 2004 to 2006, we interviewed FSWs in Tijuana ≥18 years of age who reported recent unprotected sex with at least one client and were not knowingly HIV-positive, and tested them for HIV, syphilis, gonorrhea, and chlamydia. Logistic regression identified factors associated with registration. Results. Of 410 FSWs, 44% were registered, 69% had been tested for HIV, 6% were HIV-positive, and 44% tested positive for any STI. Compared with unregistered FSWs, registered FSWs were more likely to have had HIV testing (86% vs. 56%, p<0.001) and less likely to test positive for any STI (33% vs. 53%, p<0.001) or HIV (3% vs. 8%, p=0.039). Factors independently associated with registration included ever having an HIV test (adjusted odds ratio [AOR] 5 4.19) and earning >

The harm inside: Injection during incarceration among male injection drug users in Tijuana, Mexico

30 per transaction without a condom (AOR52.41), whereas working on the street (AOR50.34), injecting cocaine (AOR50.06), snorting or smoking methamphetamine (AOR50.27), and being born in the Mexican state of Baja California (AOR50.35) were inversely associated with registration. Conclusion. Registered FSWs were more likely than unregistered FSWs to have had HIV testing and to engage in less drug use, but did not have significantly lower HIV or STI prevalence after adjusting for confounders. Current regulation of FSWs in Tijuana should be further examined to enhance the potential public health benefits of registration.

High prevalence of abscesses and self-treatment among injection drug users in Tijuana, Mexico.

Limited access to sterile syringes and condoms in correctional facilities make these settings high risk environments for HIV transmission. Although incarceration among injection drug users (IDUs) is common, there is limited information regarding specific IDU risk behaviors inside. We examined correlates of incarceration, injection inside and syringe sharing inside among male IDUs recruited in Tijuana, Mexico, using respondent driven sampling (RDS) (n=898). An interviewer administered survey collected data on sociodemographic, behavioral and contextual characteristics. Associations with (a) history of incarceration, (b) injection inside, and (c) syringe sharing inside were identified using univariate and multiple logistic regression models with RDS adjustment. Seventy-six percent of IDUs had been incarcerated, of whom 61% injected inside. Three quarters (75%) of those who injected shared syringes. U.S. deportation [adjusted odds ratio (AOR)=1.61; 95% confidence interval (CI): 1.07, 2.43] and migration (AOR=1.81; 95% CI: 1.12, 2.95) were independently associated with incarceration. Injection inside was independently associated with recent receptive syringe sharing (AOR=2.46; 95% CI: 1.75, 3.45) and having sex with a man while incarcerated (AOR=3.59; 95% CI: 1.65, 7.83). Sharing syringes inside was independently associated with having sex with a man while incarcerated (AOR=6.18; 95% CI: 1.78, 21.49). A majority of incarcerated IDUs reported injecting and syringe sharing during incarceration, and these IDUs were more likely to engage in sex with other men. Corrections-based interventions to reduce injection and syringe sharing are urgently needed, as are risk reduction interventions for male IDUs who have sex with men while incarcerated.

Identifying the HIV transmission bridge: which men are having unsafe sex with female sex workers and with their own wives or steady partners?

BACKGROUND Soft tissue infections are common among injection drug users (IDUs), but information on correlates and treatment in this highly marginalized population is lacking. METHODS Six hundred twenty-three community-recruited IDUs in Tijuana, Mexico, completed a detailed interview on abscess history and treatment. Univariate and multiple logistic regressions were used to identify factors independently associated with having an abscess in the prior 6 months. RESULTS Overall, 46% had ever had an abscess and 20% had had an abscess in the past 6 months. Only 12% had sought medical care for their most recent abscess; 60% treated the abscess themselves. The most common self-treatment method was to apply heated (24%) or unheated (23%) Aloe vera leaf. Other methods included draining the wound with a syringe (19%) or knife (11%). Factors independently associated with recent abscess were having income from sex work (adjusted odds ratio (aOR) 4.56, 95% confidence interval (CI) 2.08-10.00), smoking methamphetamine (aOR 1.65, 95% CI 1.05-2.62), seeking someone to help with injection (aOR 2.06, 95% CI 1.18-3.61), and reporting that police affected where they used drugs (aOR 2.14, 95% CI 1.15-3.96). CONCLUSIONS Abscesses are common among IDUs in this setting, but appropriate treatment is rare. Interventions to reduce barriers to medical care in this population are needed. Research on the effectiveness of Aloe vera application in this setting is also needed, as are interventions to provide IDU sex workers, methamphetamine smokers, and those who assist with injection with the information and equipment necessary to reduce abscess risk.

Correlates of seeking injection assistance among injection drug users in Tijuana, Mexico.

Objective: To gain insights into bridging behaviors and their correlates among male clients of female sex workers (FSWs). Methods: Men aged ≥18 years who recently paid or traded for sex with FSWs were recruited in Tijuana in 2008–2009. Participants underwent interviews and testing for HIV, chlamydia, syphilis, and gonorrhea. Logistic regression compared “bridgers” (clients who had unprotected sex with FSWs and with a wife or steady partner) with men who did not. Results: Of 383 men, 134 (35%) had a steady partner. Half (n = 70) of those had unprotected sex with both FSWs and the steady partner. Prevalence of any sexually transmitted infection or HIV was 16.5% among bridgers and 2.3% among nonbridgers. Compared with other clients, bridgers were more likely to use drugs during sex with FSWs (81.4% versus 46.9%, P < 0.0001), had higher sensation-seeking (P < 0.0001) and misogyny scores (P = 0.05) and were more likely to offer FSWs extra money for unprotected sex (34.4% versus 1.6%, P < 0.0001). Factors independently associated with bridging were as follows: using drugs during sex with FSWs [adjusted odds ratio (AOR): 3.4, P = 0.007], sensation seeking (AOR: 4.3 per unit increase, P = 0.05), and offering FSWs more money for unprotected sex (AOR: 24.5, P = 0.003). Conclusion: Sensation-seeking clients who use drugs during sex and coerce FSWs into unprotected sex may be less responsive to standard risk reduction interventions. Interventions are needed that target clients rather than rely on FSWs to change behaviors that may not be under their control.

HIV prevalence and sexual risk behaviour among non-injection drug users in Tijuana, Mexico

Assisted injection among injection drug users (IDUs) remains understudied. We recruited 1,056 IDUs using respondent-driven sampling in Tijuana, Mexico. Participants underwent HIV and syphilis testing and structured interviews. One-quarter (25%) sought injection assistance in the past 6 months. Seeking injection assistance was independently associated with being female (adjusted odds ratio [AOR]= 2.59; 95% confidence interval [CI]= 1.73-3.90), being born outside Baja California (AOR = 1.75; CI = 1.26-2.42), having recent abscesses (AOR = 2.59; CI = 1.93-3.47), using syringes previously used by others in the past 6 months (AOR = 1.99; CI = 1.45-2.71), and ever being arrested for carrying sterile syringes (AOR = 1.55; CI = 1.15-2.09).

Over-the-Counter But Out of Reach: A Pharmacy-Based Survey of OTC Syringe Sales in Tijuana, Mexico

Abstract Prior studies estimate HIV prevalence of 4% among injection drug users (IDUs), compared with 0.8% in the general population of Tijuana, Mexico. However, data on HIV prevalence and correlates among non-injecting drug users (NIDUs) are sparse. Individuals were recruited through street outreach for HIV testing and behavioural risk assessment interviews to estimate HIV prevalence and identify associated sexual risk behaviours among NIDUs in Tijuana. Descriptive statistics were used to characterise ‘low-risk’ NIDUs (drug users who were not commercial sex workers or men who have sex with men). Results showed that HIV prevalence was 3.7% among low-risk NIDUs. During the prior six months, 52% of NIDUs reported having >1 casual partner; 35% reported always using condoms with a casual partner; and 13% and 15%, respectively, reported giving or receiving something in exchange for sex. Women were significantly more likely than men to have unprotected sex with an IDU (p<0.01). Conclusions: The finding that HIV prevalence among NIDUs was similar to that of IDUs suggests that HIV transmission has occurred outside of traditional core groups in Tijuana. Broad interventions including HIV testing, condom promotion and sexual risk reduction should be offered to all drug users in Tijuana.

Cigarette-Smoking Intensity and Interferon-Gamma Release Assay Conversion among Persons Who Inject Drugs: A Cohort Study

Sterile syringe access is critical to HIV prevention efforts targeting injection drug users (IDUs) but some pharmacies do not sell syringes over-the-counter (OTC) even where such sales are legal. We conducted a pharmacy survey in Tijuana, Mexico (where OTC sales are legal) to characterize attitudes toward syringe sales and to explore support for expanding pharmacy-based HIV prevention efforts. Of 203 respondents, 28% supported OTC syringe sales to IDUs and 74% said their pharmacy required a prescription for at least some syringe sales. Support for OTC syringe sales was independently associated with selling OTC syringes, understanding the role of sterile syringes in HIV prevention, and recognizing pharmacies as an important health resource for IDUs. Most respondents supported an expanded role for pharmacies in HIV prevention, exclusive of OTC syringe sales. Our study provides information for developing interventions to promote OTC syringe sales and expanding pharmacy-based distribution of HIV-related information and resources.

Over here, it's just drugs, women and all the madness: The HIV risk environment of clients of female sex workers in Tijuana, Mexico

We analyzed data from a longitudinal cohort study of persons who inject drugs (PWID) in Tijuana, Mexico, to explore whether cigarette smoking increases the risk of interferon gamma release assay (IGRA) conversion. PWID were recruited using respondent driven sampling (RDS). QuantiFERON-TB Gold In-Tube (QFT) assay conversion was defined as interferon-gamma concentrations <0.35 IU/mL at baseline and ≥0.7 IU/mL at 18 months. We used multivariable Poisson regression adjusted for RDS weights to estimate risk ratios (RRs). Of 129 eligible participants, 125 (96.9%) smoked at least one cigarette during followup with a median of 11 cigarettes smoked daily, and 52 (40.3%) had QFT conversion. In bivariate analysis, QFT conversion was not associated with the number of cigarettes smoked daily (P = 0.716). Controlling for age, gender, education, and alcohol use, the RRs of QFT conversion for smoking 6–10, 11–15, and ≥16 cigarettes daily compared to smoking 0–5 cigarettes daily were 0.9 (95% confidence interval (CI), 0.5–1.6), 0.5 (95% CI, 0.3–1.2), and 0.7 (95% CI, 0.3–1.6), respectively. Although this study did not find an association between self-reported smoking intensity and QFT conversion, it was not powered sufficiently to negate such an association. Larger longitudinal studies are needed to fully explore this relationship.