Prevalence and Correlates of Injecting with Visitors from the United States Among People Who Inject Drugs in Tijuana, Mexico

Cross-border infectious disease transmission is a concern related to drug tourism from the U.S. to Mexico. We assessed this risk among people who inject drugs (PWID) in Tijuana, Mexico. We measured the prevalence and identified correlates of injecting with PWID visiting from the U.S. among PWID in Tijuana using univariable and multivariable logistic regression. Of 727 participants, 18.5% injected during the past 6 months in Mexico with U.S. PWID described mostly as friends (63%) or acquaintances (26%). Injecting with U.S. PWID was independently associated with higher education [adjusted odds ratio (aOR) = 1.13/year], deportation from the U.S. (aOR = 1.70), younger age at first injection (aOR = 0.96/year), more lifetime overdoses (aOR = 1.08), and, in the past 6 months, backloading (aOR = 4.00), syringe confiscation by the police (aOR = 3.02) and paying for sex (aOR = 2.98; all p-values < 0.05). Nearly one-fifth of PWID in Tijuana recently injected with U.S. PWID, and their reported risk behaviors could facilitate cross-border disease transmission.

Oral and vaginal HIV pre-exposure prophylaxis product attribute preferences among female sex workers in the Mexico-US border region

To assess the potential uptake of HIV pre-exposure prophylaxis (PrEP) products among female sex workers (FSWs) vulnerable to HIV infection, we examined the influence of product attributes on willingness to use products among 271 HIV-negative FSWs in Tijuana and Ciudad Juarez, Mexico (2016-2017). Via five-point Likert scale ratings, participants indicated their willingness to use hypothetical products with six attributes: formulation (pill, gel, liquid, or ring), frequency of use (daily, on-demand, or monthly), cost per use (10 or 200 pesos), effectiveness (40% or 80%), side effects (none or mild), and access point (healthcare clinic or non-governmental organization). Conjoint analysis was used to determine the impact of attributes on product ratings and identify preferred product attributes. Multinomial logistic regression was used to identify factors associated with formulation preferences. In both cities, formulation and frequency of use had the greatest impact on ratings. Participants in Ciudad Juarez indicated a strong preference for oral pills, whereas participants in Tijuana indicated roughly equal preferences for oral pills and vaginal gels. Monthly product use was preferred in both cities. Compared to preferring oral pills (38%), preferring vaginal gels (28%) was associated with practicing vaginal lubrication (adjusted odds ratio = 2.08; 95% confidence interval: 1.07-4.04). Oral PrEP may be acceptable to many FSWs in Tijuana and Ciudad Juarez; however, continued development of behaviorally-congruent vaginal PrEP products may also facilitate uptake and ensure sufficient coverage.

Drug-related behaviors independently associated with syphilis infection among female sex workers in two Mexico-US border cities

AIMS

To identify correlates of active syphilis infection among female sex workers (FSWs) in Tijuana and Ciudad Juarez.

DESIGN

Cross-sectional analyses of baseline interview data. Correlates of active syphilis (antibody titers >1 : 8) were identified by logistic regression. Setting Tijuana and Ciudad Juarez, two Mexican cities on the US border that are situated on major drug trafficking routes and where prostitution is quasi-legal.

PARTICIPANTS

A total of 914 FSWs aged > or =18 years without known human immunodeficiency virus (HIV) infection who had had recent unprotected sex with clients.

MEASUREMENTS

Baseline interviews and testing for syphilis antibody using Treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR) tests.

FINDINGS

Median age and duration in sex work were 32 and 4 years, respectively. Overall, 18.0% had ever injected drugs, 14.2% often or always used illegal drugs before or during sex in the past month, 31.4% had clients in the last 6 months who injected drugs, and 68.6% reported having clients from the United States. Prevalence of HIV and active syphilis were 5.9% and 10.3%, respectively. Factors independently associated with active syphilis included injecting drugs (AOR: 2.39; 95% CI: 1.40, 4.08), using illegal drugs before or during sex (AOR: 2.06; 95% CI: 1.16, 3.65) and having any US clients (AOR: 2.85; 95% CI: 1.43, 5.70).

CONCLUSIONS

Among female sex workers in Tijuana and Ciudad Juarez, drug-using behaviors were associated more closely with active syphilis than were sexual behaviors, suggesting the possibility of parenteral transmission of T. pallidum. Syphilis eradication programs should consider distributing sterile syringes to drug injectors and assisting FSWs with safer-sex negotiation in the context of drug use.

Deportation along the U.S.-Mexico border: its relation to drug use patterns and accessing care

Since migration has been linked to new drug trends and risky behaviors, and deported individuals face unique economic and social stressors, we investigated behaviors of injection drug users (IDUs) from Tijuana, Mexico in relation to deportation history. In 2005, IDUs > or =18 years old who injected within the prior month were recruited by respondent-driven sampling, administered a questionnaire, and underwent antibody testing for HIV, HCV, and syphilis. Logistic regression compared IDUs who reported coming to Tijuana due to deportation from the U.S. versus others in the study. Of 219 participants, 16% were deportees. Prevalence of HIV, HCV and syphilis was 3, 95 and 13%, respectively. Deportees had lived in Tijuana for a shorter time (median: 2 vs. 16 years), were more likely to inject multiple times/day (OR: 5.52; 95%CI: 1.62-18.8), but less likely to have smoked/inhaled methamphetamine (OR: 0.17; 95%CI: 0.17-0.86). Deportation history was inversely associated with receiving drug treatment (OR: 0.41; 95%CI: 0.19-0.89), recent medical care (OR: 0.37; 95%CI: 0.13-1.00), or HIV testing (OR: 0.44; 95%CI: 0.19-1.02). Deportees had different drug use patterns and less interaction with public health services than other study participants. Our study is an indication that migration history might relate to current risk behaviors and access to health care. More in-depth studies to determine factors driving such behaviors are needed.

[Experience in the management of the HIV patient among the physicians of the Secretaría de Salud]

OBJECTIVE

To determine the experience of the National Health Ministry physicians in the management of HIV-infected patients and in the use of antiretrovirals.

MATERIAL AND METHOD

A descriptive, observational and transversal study was performed, with support from the National AIDS Council from March to May 1998. Self-applicable questionnaires were filled by National Health Ministry physicians with experience in HIV patient clinical care, at the beginning of 5 different meetings on HIV/AIDS in several cities of the country. Statistical analysis included the chi-square test.

RESULTS

One hundred and eighty-one questionnaires were applied. The median of HIV patients attended by physicians was 4 (interval 1-97); 36.5% of the physicians had used antiretrovirals (35.4% prescribed nucleoside analogs and 9.9% protease inhibitors). The most frequently used drugs were AZT and/or ddl (40.3%); 17.7% had administered CD4+ lymphocyte count and 8.8% viral load.

CONCLUSIONS

The proportion of National Health Ministry physicians with experience in VIH patient care was low, as was the use of antiretrovirals. Efforts should be focus on improving care of HIV patients through physician training.

[Zidovudine plus didanosine in HIV infected asymptomatic patients previously treated with zidovudine]

OBJECTIVE

To evaluate if the combination of AZT/ddl offered any advantages in surrogate markers among HIV infected asymptomatic patients previously treated with AZT for at least six months.

METHODS

We used a prospective cohort of 269 asymptomatic HIV patients with CD4+ cell counts between 200 and 500 cells/microL. They were given didanosine (ddl 400 mg/d) in addition to AZT (500 mg/d) and had received AZT monotherapy for an average of 20 months. End points were progression to AIDS, death, or toxicity.

RESULTS

Median CD4+ cell count at the start of the combination therapy was 339 cells/microL which increased at three months to 451 and subsequently declined at 6, 12 and 18 months of followup (medians of 392, 360, 307 cells/microL respectively). Five patients progressed to AIDS, six developed toxicity (myelosuppression, hepatitis or pancreatitis) and 26 had minor side effects that required only dose reduction.

CONCLUSIONS

The addition of ddl to patients with prolonged ZDV monotherapy can be useful. CD4+ T cell counts showed a significant increase at 3 months with a gradual subsequent decline to below baseline at 18 months. Adverse effect of the drugs, although frequent, did not stop therapy in most patients.

[AIDS cases in the rural area in Mexico]

The objective of this paper is to describe the AIDS epidemic in rural areas of Mexico. Information from the National AIDS Registry and the 1990 XI National Census was used. Rural AIDS cases and urban cases were compared regarding notification time, sex, risk categories and migration information. Of the 19,090 AIDS cases reported to the first of July 1994, 699 (3.7%) were rural cases. The first five of these cases were reported in 1986, three years after the first cases had been reported in Mexico. The number of AIDS cases has been growing each year but in 1991. Cases have been reported by all Mexican states. The state with the highest prevalence was Nayarit with 102 cases per million inhabitants, followed by Morelos with 99, Jalisco with 90, and Colima and Tlaxcala with 84. A total of 25% of the rural cases are migrants who have been to the US, against 6.1% of cases from urban areas. The distribution by sex shows 21.3% of women affected against 14.4% of urban cases (p < 0.05). The rural female to male ratio is 1:4, while the urban ratio is 1:6. The prevalence rates are almost three times greater in men than in women. The rural AIDS pattern represents a problem not because of the number of people affected but because of the heterosexual way of transmission. We do not think that migration to the US is going to change. The rural AIDS epidemic is more recent and growing faster than that occurring in the urban setting.

[The epidemiology of AIDS/HIV in Mexico: from 1983 to March 1995]

The purpose of this study is to analyze the HIV/AIDS magnitude, distribution, frequency, patterns, trends, risk factors, risk groups, estimation and evaluation of interventions in Mexico during the last twelve years. Results of a summary of statistics and results from several sources are presented including the National Registry of AIDS cases, HIV sentinel surveillance in 18 cities of the country, analysis of death certificates, cross-sectional, longitudinal, observational, and intervention studies. As of March 1995, 34,230 AIDS cases, 120,000 HIV infections and 21,000 AIDS deaths are estimated. A damaged exponential growth with duplication of AIDS cases every 18 months can be seen. Epidemiological patterns of transmission are found primarily among men with homosexual and bisexual practices. The male:female ratio is 6 to 1. In 1992 AIDS was the 19th cause of death among the general population. At least two patterns of transmission have been identified: one is the western-urban pattern which contributes with more than 90% of cases and the other, more recent, has been described as Caribbean-rural. Blood transmission of AIDS shows a downward trend, and heterosexual and perinatal transmission is slightly increasing. Seroprevalence among adults is 0.06%: however, among groups with risk practices, rates up to 50% have been found. Risk factors are similar to those described in the literature in other countries, and have been used for designing interventions. Evaluation of interventions has been accomplished by demonstrating positive results in the prevention of blood transmission and sexual transmission among female commercial sex workers; prevention efforts directed to men with homosexual practices have not been successful. Between 77,000 and 88,000 cumulated AIDS cases are estimated in Mexico for the year 2000.

[The HIV/AIDS epidemic and women in Mexico]

This study presents an analysis of AIDS cases and seroprevalence of HIV infection among Mexican women, from the onset of the epidemic through June 1994, as well as the analysis of the social and cultural factors that put women in a powerless situation regarding the adoption of preventive measures. Since 1985, when the first AIDS cases among women were reported in Mexico and until June 1, 1994, a total of 2,767 cases have been reported, representing 14.8% of the total number of cases. The first cases of AIDS among women were associated to infected blood transfusions; however, in 1986, heterosexually transmitted cases began to appear. Currently, only 35% of newly reported AIDS cases are associated to blood transfusions while 64% of them are related to heterosexual transmission. In fact, two epidemics are evident: one transmitted through blood, showing a downward trend (duplication time 45 months), and a second one, heterosexually transmitted, increasing twice as fast (duplication time 27 months). The latter is expected to dominate AIDS epidemiology among women in the future. In general, women are more vulnerable to HIV/AIDS biologically, but also socially and culturally. Women's economic, social and cultural subordination to their sexual partners results in a situation that makes it difficult for them to assess their infection risk and even more, to negotiate taking preventive measures. This situation is even more disadvantageous to rural women and, together with the recent trend of the AIDS epidemic to ruralization and with internal and international migration (temporary work force migration to the USA), can result in deep demographic and social effects. We conclude that it is necessary to work on the design and assessment of preventive measures under women's control, that empower them to protect themselves even without their partner's awareness. Also, it is necessary to promote sexual education among young heterosexual couples on how to talk about sexual issues and negotiate the use of preventive measure according to their actual sexual practices.