Drug Tourism to Mexico: Impact of Mexico’s New Drug Law on HIV/HCV/TB Infection in U.S. Injection Drug Users

Funded by: NIH/NIDA, grant 1R01-DA031074; PI: Richard S. Garfein

On August 20th, 2009, Mexico enacted legislation decriminalizing possession of small amounts of psychoactive drugs for personal use, including methamphetamine, cocaine, heroin, marijuana and LSD. However, possession of illicit substances remains illegal in the United States, eliciting concern that U.S. drug users will travel to Mexico to purchase and use illegal drugs. San Diego, which shares the busiest land border crossing in the world with Tijuana, B.C., Mexico, may be at an increased risk for such “drug tourism”, thereby facilitating interaction between injection drug users (IDUs) from both countries. Previous studies estimate that 21% of San Diego IDUs have ever injected drugs in Mexico. An estimated 95% of IDUs in Tijuana have been infected with hepatitis C virus (HCV), compared to 25% among IDUs in San Diego. Additionally, two-thirds of IDUs in Tijuana test positive for M. tuberculosis (Mtb) infection compared with 10%-20% of San Diegan IDUs. These findings suggest that increased mixing between IDUs from both countries could increase incident HCV and Mtb infection in San Diego IDUs. The goal of this study is to examine the change in knowledge, attitudes (risk perceptions) and practices over time among IDUs residing in San Diego and to assess IDUs’ behaviors and HCV, Mtb, and HIV infection status over time subsequent to the change in Mexico’s drug laws. This study will follow 600 San Diegan IDUs for 24 months, with qualitative and quantitative interviews, and HCV, HIV and TB testing at semi-annual study visits. The study aims are as follows:

  • Aim 1: To identify sociodemographic, behavioral, and serologic differences between IDUs in San Diego who do and do not inject in Mexico
  • Aim 2: To describe how changes in knowledge, attitudes and perceptions about injecting drugs in Mexico influence behaviors among San Diego IDUs over time since Mexico’s drug law changed.
  • Aim 3: To determine whether IDUs from San Diego who inject in Mexico are at increased risk for incident HCV and Mtb infection compared to IDUs who do not inject in Mexico.

Principal Investigator: Richard S. Garfein, PhD, MPH

Collaborators: Steffanie Strathdee, Karla Wagner, Victoria Ojeda, Jose Luis Burgos, Lin Liu, Avelardo Valdez, Sergio Aguilar-Gaxiola, Antonio Munoz, Alfredo Valsco

Project Coordinator: Jazmine Cuevas-Mota