TB Modeling and Translational Epi Group

Group Members


David Dowdy

Associate Professor

David Dowdy is an Associate Professor of Epidemiology, International Health, and General Internal Medicine at Johns Hopkins. His research interests include epidemiological study of TB and TB/HIV, mechanistic modeling of TB epidemics, economic evaluation of TB interventions (especially for diagnosis and case finding), and translation of TB data into appropriate frameworks for decision-making. He joined the faculty at Hopkins in 2011 and also practices general internal medicine in urban East Baltimore. He sits on the Steering Committee of the TB Modeling and Analysis Consortium, serves as Associate Editor of the International Journal of Tuberculosis and Lung Disease, and is the Principal Investigator of multiple research grants from the National Institutes of Health and other funding agencies to evaluate TB transmission and interventions in the United States, South Africa, Uganda, and Southeast Asia. When not at work, you can often find him baking cookies, playing tennis, or climbing with his teenage daughter.

Jonathan Golub


My research focuses on the epidemiology of tuberculosis in South Africa, Brazil, India and the US, with specific focus on the drivers of TB in these settings. I am currently leading a cluster randomized trial in South Africa observing diagnostic and treatment practices for latent TB infection among HIV-infected patients at 14 HIV clinics. Also, in South Africa, I lead a smoking cessation clinical trial among HIV-infected patients and projects investigating indoor air pollution, smoking, and potential mHealth solutions for many patient populations. I also lead a study investigating TB treatment outcomes among TB patients with diabetes in India, and other studies in India looking at impact of indoor air pollution and smoking on TB in this setting.

Emily Kendall

Assistant Professor

Emily Kendall, MD, is an Assistant Professor in the Division of Infectious Diseases in the JHU School of Medicine. As an infectious diseases clinician as well as a mathematical modeler, she seeks to improve the treatment of tuberculosis using computational frameworks combined with preclinical, clinical, and epidemiologic data. She is interested in individualizing therapy based on patient and TB strain characteristics, optimizing the use of novel drugs and regimens for TB treatment, preventing emergence of new drug resistance, and anticipating the impact of treatment guidelines and policies on TB epidemics.

Todd Fojo

Assistant Professor

I am an Assistant Professor in the Division of General Internal. In addition to my medical degree, I have a background in computer science and statistics. My research centers on improving the individual- and population-level health of persons with TB or HIV and mental health comorbidities using innovative statistical and machine learning algorithms. Specific projects include making personalized predictions about psychiatric disease and HIV control, as well as population-level models to forecast TB and HIV epidemics under a range of potential interventions.

Colleen Hanrahan

Assistant Scientist

Colleen Hanrahan is an Assistant Scientist in the Epidemiology Department at Johns Hopkins School of Public Health. Her primary interest area is the intersection of the global HIV and TB pandemics. Her current work focuses on operational research on the implementation and patient impact of new and existing TB diagnostics, isoniazid preventive therapy, and active case finding approaches for TB. She is also interested in evaluating approaches to initiate and retain HIV positive individuals in care. Colleen has spent 3 years living in South Africa, and brings a wealth of “on the ground” research experience as well as a deep love for the African continent.

Parastu Kasaie

Assistant Scientist

Parastu Kasaie (MS, PhD) is an Assistant Scientist in the department of Epidemiology at the Johns Hopkins Bloomberg School of Health. Her research interests lie at the intersection of Operations Research, Epidemiology and Data Sciences. Her methodological expertise is in development and analysis of computer simulation models, and in particular the class of agent-based simulations, for study of disease epidemics in human populations. She has applied these models to study of Tuberculosis (TB) and HIV/AIDS epidemics, focusing on derivers of transmissions, confection of multiple infectious diseases, and patterns of aging and comorbidities among others. Calibrated against epidemiological data, these simulation models provide a powerful tool to explain the current trends in data, predict future trends under various assumptions and compare the impact of alternative interventions for prevention and control of disease. Parastu is currently supported on a K01 career development grant from NIH focusing on studying the epidemic of HIV/AIDS and other Sexually Transmitted Infections (STIs) among Men who have Sex with Men (MSM) in Baltimore City. In collaborations with the PHOENIx multinational clinical trial, she's also leading a modeling study on assessing the impact of MDRTB latent preventive therapy among households of MDRTB cases in India.

Sourya Shrestha

Research Associate

Sourya Shrestha is a Research Associate in the department of Epidemiology at the Johns Hopkins Bloomberg School of Health. He received his doctoral training in applied mathematics from the University of Michigan, and postdoctoral training in ecology and epidemiology of infectious diseases at Michigan and Hopkins, respectively. He is interested in developing mathematical and computational models of epidemiology of infectious diseases, and to ultimately use them to design and inform effective public health interventions. Although he maintains interest in the epidemiology of pneumococcus and dengue virus, tuberculosis (TB) is the primary focus of his current research. Some of his recent and ongoing work includes (i) understanding the heterogeneity of TB in the context of targeted interventions; (ii) modeling dynamics and control of domestic TB in the US (in collaboration with the CDC); and (iii) developing models to inform active case finding efforts in Pakistan and Bangladesh (in collaboration with IRD), and in Nepal (in collaboration with IMPACT TB team).

Hojoon Sohn

Assistant Scientist

Hojoon (BA, Bowdoin College; MPH, University of Michigan; PhD, McGill University), is an Assistant Scientist in the Department of Epidemiology (June 1st, 2019) at Johns Hopkins Bloomberg School of Public Health. My research focuses on an inter-disciplinary agenda that aims combine methodologies and topics across disease disciplines, including translational epidemiology, operations research, health economics, health systems and technology assessment. Through my research, I seeks to streamline health economic and epidemiology methods in both mode-based and field-based studies that can supplement evidence-based deisions in global and national-level policies and to innovate new data-gathering moethods/studies. I have more than 10 years of experience conducting tuberuclosis and HIV/AIDS studies in various low and middle-income countries (India, Lesotho, Malawi, Nepal, Peru, Philippines, South Africa, Thailand, Zambia, Uganda, Morocco, Timor Leste) as well as in high income countries (Canda, South Korea, United States). During my off-time, I enjoy spending my time with my son, Haewon, and playing the clarinet.

Post Docs

Youngji Jo

Post Doctoral Fellow

Youngji Jo is a post-doctoral fellow at the Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health (JHBSPH). She analyzes cost-effectiveness models of tuberculosis, and preventive therapy in the United States as well as costing and performance data for TB REACH program in Zambia. She earned her Ph.D. in Health Systems Program in the Department of International Health at JHBSPH. Her thesis research was about cost-effectiveness and scalability of an mHealth program, which uses mobile phones to improve pregnancy surveillance and care seeking of essential maternal and newborn health service in rural Bangladesh. She holds M.A. in International Relations/Economics at Johns Hopkins School of Advanced International Studies (SAIS) and a B.E. in Electrical Engineering at Seoul National University in South Korea.

Yeonsoo Baik

Post Doctoral Fellow

Yeonsoo Baik is a post-doctoral fellow in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health. Her research focuses on tuberculosis transmission and applying epidemiologic, geospatial, genotypic, and modeling analyses. She is further interested in implementing evidence-based and practical tuberculosis interventions based on her research findings.

Katherine Robsky

Post Doctoral Fellow

Katherine is a post-doctoral fellow in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health. Her dissertation research uses spatiotemporal patterns to identify populations at risk for TB that could be prioritized for preventive and case finding interventions in urban Kampala. She previously completed her MPH in Infectious Diseases at University of California, Berkeley and has worked in TB control and research in Thailand, California, and Namibia.


Melissa Schnure

PhD Candidate

Melissa is a PhD student in the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health. Her current work primarily focuses on modeling the integration of HIV and non-communicable diseases in the sub-Saharan African context. Melissa has previously worked on HIV prevention modeling, specifically for voluntary medical male circumcision (VMMC) and oral pre-exposure prophylaxis (PrEP). She holds a Master of Science in Infectious Disease Epidemiology from Johns Hopkins Bloomberg School of Public Health and a Bachelor of Arts in Ecology and Evolutionary Biology from Princeton University.

Chaoran Dong

Master's Student

Chaoran is a master student in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health. Her research interests primarily focus on economic evaluation in serving vulnerable populations, particularly with respect to priority setting and resource allocation in the healthcare system. She is also interested in health financing and innovative payment reform. With 4+ years of research experience in health economics, Chaoran’s work involves diverse topics such as TB, cancer screening, and long-term care. She previously earned a BA in Health Service Administration at Fudan University in China.

Chen Liu

Master's Student

Chen is a current master student at Johns Hopkins School of Public Health, studying Global Health Economics. She has professional and academic backgrounds in Health Economics, International Development, and Global and Public Health, with strong research and analytical skills developed during her three years of research and through professional work experience in the US and abroad. Chen is passionate about creating sustainable social impact and strengthening health systems through the cross-section of international development and public health. She previously earned a Bachelor of Science in Global and Public Health at Cornell University in 2018.


Nicholas Albaugh

Senior Research Program Coordinator

Nick Albaugh is a Senior Research Program Coordinator in the Department of Epidemiology at Johns Hopkins Bloomberg School of Public Health. His current research primarily focuses on contact tracing strategies for detecting TB in mobile rural and urban South African populations. His research interests include infectious disease transmission dynamics, spatial-temporal mapping, and international epidemic surveillance. He previously earned a Bachelor of Science in Community Health at the University of Maryland – College Park in 2017 and a Master of Science of Public Health in Global Disease Epidemiology and Control at Johns Hopkins Bloomberg School of Public Health in 2019.

Olivia Ferguson

Research Assistant

Olivia is a research assistant in the Department of Epidemiology. Her work primarily involves cost data collection and performing economic evaluation and cost effectiveness research on TB & HIV interventions. She received an Master of Science in Public Health, Health Economics, from The London School of Hygiene and Tropical Medicine in 2018, and has a BA in Economics & History from Villanova University. Her previous work looked at the cost effectiveness of the use of microloan programs to reduce intimate partner violence in Tanzania.

Joe Flack

Programmer Analyst

Joe is a programmer analyst specializing in data engineering, analysis, and web applications. He is a love of languages, both programming languages and spoken languages, including Python, R, C++, Java, JavaScript, Korean, and Japanese. He holds a BA in Philosophy from the University of Florida.

Isabella Gomes

Research Assistant

Isabella Gomes is a graduate student at Johns Hopkins Bloomberg School of Public Health. She is currently pursuing a Master in Public Health degree in Epidemiology and Biostatistics and is interested in the modeling and analysis of infectious disease dynamics and the epidemiology of tuberculosis in Bangladesh and South Africa. She previously earned a Bachelor of Arts in Ecology and Evolutionary Biology at Princeton University in 2016 and a Master of Arts in Investigative Journalism at Columbia University in 2017.

Jeff Pennington

Programmer Analyst

Jeff began programming at an early age and has used his skills as a problem solving tool for more than 20 years. After joining the Johns Hopkins TB Modeling team in 2014, he began to explore the disease modeling space through different projects on tuberculosis and HIV and discovered a new set of problems to which he can apply his programming knowledge. His main areas of interest include systems and parallel programming, novel user Interfaces and program optimization.

Austin Tucker

Senior Research Program Coordinator

Austin Tucker is a Senior Research Program Coordinator in the Department of Epidemiology at Johns Hopkins School of Public Health. His research primarily focuses on costing and economic evaluation methods for HIV and TB program interventions in resource-limited settings. Austin has experience organizing and developing tools for primary data collection efforts for costs as well as producing cost-effectiveness and econometric models to understand the value of health system interventions. His interests include international economic development, the effects health system constraints have on scale-up and cost-effectiveness, and the role of health economics in international policy agenda setting. In his free time Austin enjoy cycling, rock climbing with his girlfriend and playing basketball.