Abstract

Another day, another dollar: diseconomies of risk among female sex workers who inject drugs in two Mexican border cities

J.L. Burgos¹, R. Lozada², H. Staines-Orozco³, T.L. Patterson^4,5, J.S. Graff-Zivin⁶, S.A. Strathdee<sup>1

1</sup>University of California San Diego, Division of Global Public Health, La Jolla, United States, ²Baja California State Public Health Service, HIV/AIDS Prevention Program, Tijuana, Mexico, ³Faculty of Medicine, Autonomous University of Ciudad Juarez, Chihuahua, Mexico, ⁴University of California San Diego, Department of Psychiatry, La Jolla, United States, ⁵Veterans Administration San Diego Medical Center, La Jolla, United States, ⁶University of California San Diego, International Relations/ Pacific Studies, La Jolla, United States

Background: In free market societies, sex work is a commodity driven by standard supply and demand theory. In economic terms, risks associated with unprotected sex (e.g., HIV/STIs) represent 'opportunity costs' expected to increase price and reduce demand for unprotected sex. We explored factors associated with receiving more pay for unprotected versus protected sexual transactions among female sex workers who inject drugs (FSW-IDU) in two Mexican border cities.
Methods: FSW-IDUs ≥18 years old who reported recently injecting drugs and having unprotected sex with clients participated in an ongoing behavioral intervention in Tijuana and Ciudad Juarez. At baseline, participants underwent surveys and biological testing for HIV and STIs. Multivariable logistic regression evaluated correlates of receiving more pay for unprotected sexual transactions.
Results: To date, of 532 FSW-IDUs (286 in Tijuana, 246 in Ciudad Juarez), 46% reported receiving more money for unprotected versus protected sex (median in USD: $20 [IQR: $15-30] vs. $12.50 [IQR: $10-20]]; 6.9% tested positive for HIV and 52% for any other STI (i.e., syphilis, gonorrhea, Chlamydia, and trichomonas). Factors independently associated with receiving more money for unprotected sex included: reporting regular condom use with clients [AdjOR: 2.5, p< 0.01], rarely injecting with used syringes (AdjOR: 1.7, p< 0.02), injecting drugs less than once per day (AdjOR: 3.5, p=0.01), being aged < 30 years (AdjOR: 2.0, AOR: < 0.01), having more clients during the previous month (AdjOR: 1.1 per 10 client increase, p=0.01) and living in Ciudad Juarez vs. Tijuana (AdjOR: 4.2, p< 0.001).
Conclusions: Our preliminary findings suggest that FSW-IDUs who receive more pay for unprotected sex may be less likely to engage in high risk behaviors that could promote HIV transmission. HIV prevention programs should consider economic factors that may drive risk behaviors among FSW populations. Further research is warranted to better understand the role of economic factors in evolving HIV epidemics.