Dr. Ruiz's career has focused predominantly on research pertaining to HIV prevention. She has served as the sole behavioral scientist and the Acting Chief of the Prevention Sciences Branch, Division of AIDS, at the National Institutes of Allergy and Infectious Diseases. In this capacity, she worked primarily with the HIV Prevention Trials Network, a worldwide collaborative clinical trials network that develops and tests the safety and efficacy of primarily non-vaccine interventions designed to prevent HIV transmission. She has also worked in the public policy arena, both as a study director with the Institute of Medicine and as the Acting Director for Public Policy at amfAR, The Foundation for AIDS Research. Dr. Ruiz's current interests include addressing behavioral, social, and policy issues pertaining to the development and implementation of non-vaccine HIV prevention strategies and examining the social and structural factors that impede HIV prevention efforts in vulnerable and disenfranchised populations. Her current research focuses on examining the epidemic impact of that policy change on HIV infection and linkage to care outcomes in the District of Columbia (R01DA031649; PI: MS Ruiz). Dr. Ruiz is also interested in youth physical activity, particularly in the context of developing upstream interventions to build resilience among adolescents as a way of mitigating social and structural factors that may later increase risk for HIV/AIDS. She is currently collaborating with a community organization to evaluate the mental and physical health benefits of sports participation -- particularly resisting peer pressure for risky sex and drug use -- among low-income African American adolescents in Washington, DC. Dr. Ruiz currently teaches Masters-level courses and one undergraduate level course in the School of Public Health. She is an enthusiastic professor who is constantly striving to find innovative and exciting ways to engage her students in the course material. She is an active mentor of undergraduate, Masters- and doctoral-level students.