title: Polydrug use among IDUs in Tijuana, Mexico: correlates of methamphetamine use and route of administration by gender.
abstract: Tijuana is situated on the Mexico-USA border adjacent to San Diego, CA, on a major drug trafficking route. Increased methamphetamine trafficking in recent years has created a local consumption market. We examined factors associated with methamphetamine use and routes of administration by gender among injection drug users (IDUs). From 2006-2007, IDUs > or =18 years old in Tijuana were recruited using respondent-driven sampling, interviewed, and tested for HIV, syphilis, and TB. Logistic regression was used to assess associations with methamphetamine use (past 6 months), stratified by gender. Among 1,056 participants, methamphetamine use was more commonly reported among females compared to males (80% vs. 68%, p < 0.01), particularly, methamphetamine smoking (57% vs. 34%; p < 0.01). Among females (N = 158), being aged >35 years (AOR, 0.2; 95% CI, 0.1-0.6) was associated with methamphetamine use. Among males (N = 898), being aged >35 years (AOR, 0.5; 95% CI, 0.3-0.6), homeless (AOR, 1.4 (0.9-2.2)), and ever reporting sex with another male (MSM; AOR, 1.9; 95% CI, 1.4-2.7) were associated with methamphetamine use. Among males, a history of MSM was associated with injection, while sex trade and >2 casual sex partners were associated with multiple routes of administration. HIV was higher among both males and females reporting injection as the only route of methamphetamine administration. Methamphetamine use is highly prevalent among IDUs in Tijuana, especially among females. Routes of administration differed by gender and subgroup which has important implications for tailoring harm reduction interventions and drug abuse treatment.
authors.affiliation: Division of Global Public Health, Department of Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0507, USA. mrusch@ucsd.edu
authors.forename: Melanie L
authors.initials: ML
authors.lastname: Rusch
authors.forename: Remedios
authors.initials: R
authors.lastname: Lozada
authors.forename: Robin A
authors.initials: RA
authors.lastname: Pollini
authors.forename: Alicia
authors.initials: A
authors.lastname: Vera
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Patterson
authors.forename: Patricia
authors.initials: P
authors.lastname: Case
authors.forename: Stefanie A
authors.initials: SA
authors.lastname: Strathdee
mesh_terms: D015492:AIDS Serodiagnosis; D000328:Adult; D000368:Aged; D019969:Amphetamine-Related Disorders / Q000453:epidemiology*; D015897:Comorbidity; D055030:Drug Users / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D012737:Sex Factors; D011477:Sex Work / Q000706:statistics & numerical data; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012749:Sexually Transmitted Diseases / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D013588:Syphilis Serodiagnosis; D055815:Young Adult