Steffanie A. Strathdee is an infectious disease epidemiologist who focuses on HIV prevention in underserved, marginalized populations. She is leading studies of HIV risk behaviors among drug users and sex workers on the Mexico-US border, and has also led a cross-border HIV prevention training program. She has published over 300 peer-reviewed publications. Dr. Strathdee holds a Ph.D. from the University of Toronto, and is a professor in the University of California San Diego School of Medicine.