1. Incidence and predictors of HIV and sexually transmitted infections among high risk couples in Northern Mexico: a prospective, multilevel study Angela M Robertson, Gudelia Rangel, Gustavo Martinez, Monica D Ulibarri, Jennifer L Syvertsen, Samuel A Bazzi, Scott Roesch, Heather A Pines, and Steffanie A Strathdee IAS 2014, Melbourne, Australia Funding: National Institutes of Health (NIH) grants R01 DA027772, R36 DA032376, T32 AI007384, T32 DA023356, K01 DA026307, and P30 AI060354-10. Contact: sstrathdee@ucsd.edu

2. Setting: Mexico-U.S. border 2 Sex work is socially tolerated and quasi legal in many Mexican border cities; high HIV/STI risk among sex workers/clients

3. Cohort of Sex Workers & Intimate Partners Proyecto Parejas: prospective mixed methods study of HIV/STIs among 214 sex workers & their 214 intimate male partners (n=428) in Tijuana & Ciudad Juarez, Mexico – Most couples always had unprotected sex together; condoms used for sex work – Heavy current drug use (62% heroin, 54% stimulants, 62% injected any drugs) 3

4. Findings Highlight Social/Economic Contexts of Risk 4 Time-varying predictors of new STIs (w/o HIV): Recent stimulant use (meth, crack, cocaine) increases women’s risk (aOR: 2.13; CI: 1.07–4.28 ) Women having regular sex work clients decreased their male partners’ risk (aOR: 0.38; CI: 0.14–1.03 ) Female Sex Workers Intimate Male Partners Incidence of all STIs  among FSWs than their male partners Women who reported physically assaulting partners also had decreased risk (aOR: 0.44; CI: 0.22–0.86)

5. More research is needed to understand how conflict and sex work earnings impact couples’ risk Couple interventions to promote communication and reduce conflict are needed 5 CONCLUSIONS Interventions that increase empowerment of sex workers (i.e., choice of clients, ability to avoid violence) may reduce their own HIV/STI incidence and that of their intimate male partners.

6. THANK YOU! Acknowledgements: Proyecto Parejas study participants & staff; NIH grants R01DA027772, R36DA032376, T32AI007384, T32DA023356, K01 DA026307, and P30 AI060354-10 Contact: Steffanie A Strathdee, PhD: sstrathdee@ucsd.edu Photos: O Loza, A Robertson, J Syvertsen, C Bava