Chairs
![profile picture of Ashani Weeraratna](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2023-08/weeraratna-ashani-a.jpg?h=6294dc66&itok=AIzV06Qk)
Ashani T. Weeraratna, PhD
Ashani Weeraratna studies the molecular mechanisms involved in melanoma metastasis with particular emphasis on the Wnt signaling pathway. She is also interested in examining the changes in the tumor microenvironment and how they affect melanoma progression and therapy resistance. Weeraratna joined The Wistar Institute in 2011 as an assistant professor. In 2018, she was promoted to professor, and serves as the co-program leader of the Immunology, Microenvironment & Metastasis (IMM) Program.
![Elizabeth Stuart Elizabeth Stuart](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2023-06/elizabeth-stuart2.jpg?h=f7026c63&itok=noCY7d67)
Elizabeth Stuart, PhD
Elizabeth Stuart is the Frank Hurley and Catharine Dorrier Professor and Chair of the Department of Biostatistics. She also has joint appointments in Mental Health and Health Policy and Management. Stuart uses statistical methods to help learn about the effects of public health programs and policies, often with a focus on mental health and substance use. She previously served as the School’s executive vice dean for Academic Affairs.
![Marsha Wills-Karp Marsha Wills-Karp](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2021-04/marsha-wills-karp-2017.jpg?h=52605a11&itok=H3PFc0pL)
Marsha Wills-Karp, PhD, MS
Marsha Wills-Karp, a leader in the study of the molecular mechanisms of asthma, joined the Department of Environmental Health and Engineering as its chair in early 2012. She is also the founding director of the Division of Immunobiology in the Department of Pediatrics at Cincinnati Children’s Hospital Medical Center.
![Head shot of Shruti Mehta](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2024-05/shruti-mehta600x600.jpg?h=04d92ac6&itok=gZNQERSy)
Shruti Mehta, PhD, MPH
Shruti Mehta is the Dr. Charles Armstrong Professor and Chair as well as the Bloomberg Centennial Professor in the Department of Epidemiology. She is an accomplished infectious disease epidemiologist who focuses much of her own work on ensuring equitable access to prevention and treatment services for vulnerable and disenfranchised populations, including people who inject drugs and are at risk for or living with HIV or hepatitis C. Mehta is co-director of the Johns Hopkins Center for AIDS Research, and serves in advisory roles to the NIH Office of AIDS Research Advisory Council and has in the past served on the CDC/HRSA Advisory Committee on HIV, Viral Hepatitis, and STD Prevention and Treatment.
![Profile picture of Joanna Cohen](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2023-12/joannacohen600x600_0.jpg?h=04d92ac6&itok=YDOniObL)
Joanna Cohen, PhD, MHSc
Joanna Cohen is the Bloomberg Professor of Disease Prevention and the Director of the Institute for Global Tobacco Control at the Bloomberg School. She has been involved in tobacco policy research for 30 years. Cohen conducts research and capacity building to inform and advance interventions to reduce tobacco-caused death and disease. Trained in epidemiology and health policy, her research interests focus on the factors that affect the adoption and implementation of public health policies and on evaluating the beneficial effects and the unintended consequences of such policies.
![Keshia Pollack Porter Keshia Pollack Porter](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2021-04/associate-deans-keshia-pollack-porter.jpg?h=a1413d21&itok=52m_ScxE)
Keshia M. Pollack Porter, PhD, MPH
Keshia M. Pollack Porter is chair of the Department of Health Policy and Management and a Bloomberg Centennial Professor in the Department. Pollack Porter is an expert in advancing health equity and policy change that promotes safe and healthy environments.
![Profile picture of Judd Walson, MD, MPH](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2023-11/juddwalson_0.jpg?h=04d92ac6&itok=TYAXzsH9)
Judd Walson, MD, MPH
Judd Walson’s research spans public health programing, policy development, and clinical practice. His work focuses on identifying populations most vulnerable to preventable deaths and intervening to improve child survival, growth, and development. As chair, Walson continues to address major factors that underpin poverty and disease and lead to inequity and injustice across the world.
![Pamela Collins photo](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2023-06/pamelacollinsmentalhealth1800x1000.jpg?h=6e972868&itok=iap1CcVc)
Pamela Collins, MD, MPH
Pamela Collins is Professor and Chair of the Department of Mental Health. Her research and practice activities center on the intersections of mental health and HIV and the mental health of urban adolescents. She was recently the Principal Investigator of the HRSA-funded project, Capacity Building for Sustainable HIV Services, which engages five countries in the Caribbean, Eastern Europe, Africa, and Asia in capacity-strengthening in HIV, mental health, and related areas for improved HIV outcomes.
![Cynthia S. Minkovitz Cynthia S. Minkovitz](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2021-04/minkovitz-cynthia.jpg?h=a1413d21&itok=QdU92G2X)
Cynthia S. Minkovitz, MD, MPP
Cynthia Minkovitz is the William H. Gates, Sr. Professor and Chair in the Department of Population, Family and Reproductive Health. Her research focuses on enhancing the quality of preventive services for children and understanding the impact of systems reforms on the health and well-being of children and families. She holds a joint appointment in the School of Medicine’s Department of Pediatrics.
![Arturo Casadevall](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2022-05/chair-arturo-casadevall.jpg?h=52605a11&itok=rP6wa3XI)
Arturo Casadevall, MD, PhD
Arturo Casadevall is the Alfred and Jill Sommer Professor and Chair of the W. Harry Feinstone Department of Molecular Microbiology and Immunology. He is a globally known expert in humoral immunity, molecular biology, virulence and cryptococcosis.
![Mark Bittle](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2023-09/markbittle.jpg?h=04d92ac6&itok=s57OAfJl)
Mark J. Bittle, DrPH, MBA
Mark J. Bittle is a Bloomberg Centennial Teaching Professor and Chair of the schoolwide Doctor of Public Health (DrPH) program and faculty in the Department of Health Policy and Management. He also serves as director for the School's Master of Health Administration and the Master of Applied Science in Population Health Management. His work focuses on the organizational and management factors that influence physician alignment and managing change in complex organizations.
![Marie Diener-West Marie Diener-West](/https/publichealth.jhu.edu/sites/default/files/styles/profile_square/public/2021-04/marie-diener-west-2017.jpg?h=52605a11&itok=rKMiKlyL)
Marie Diener-West, PhD
Marie Diener-West is the Chair of the schoolwide Master of Public Health Program and the Helen Abbey and Margaret Merrell Professor of Biostatistics Education. Her research has focused on the design, conduct and analysis of multicenter clinical trials in ophthalmology and oncology, as well as statistical education.