Members

Katherine (Kate) Ellingson, PhD, CIC
Associate Professor of Epidemiology

Katherine (Kate) Ellingson, PhD, is a dedicated epidemiologist with a career rooted in public service and academic leadership. She began her postdoctoral career as an Epidemic Intelligence Service Officer and Health Scientist at the Centers for Disease Control and Prevention (CDC), where she focused on infection prevention, antibiotic resistance, healthcare-associated infections (HAIs), and outbreak response to global public health threats such as H1N1, Ebola, and Zika. She also led capacity-building initiatives to strengthen infection prevention practices in resource-limited settings and served as the agency’s subject matter expert on hand hygiene in healthcare.

Following her work at CDC, Kate joined the Oregon Health Authority as a Senior Epidemiologist. In this role, she directed the state’s mandatory HAI reporting program, led outbreak investigations, and developed programs to improve injection safety and mitigate infectious disease risks statewide.

In 2017, Kate joined the Department of Epidemiology and Biostatistics at the University of Arizona’s College of Public Health. Her research portfolio encompasses infection prevention and occupational health related works. She has contributed as Principal Investigator or co-investigator to more than 15 funded research projects, and her work has resulted in over 60 peer-reviewed publications addressing critical issues in public health. Kate’s research combines rigorous quantitative methods, multidisciplinary collaboration, and practical applications, with ongoing projects that focus on reducing antimicrobial resistance, improving healthcare worker safety, and understanding the transmission dynamics of infectious diseases. She continues to partner with the CDC and other leading organizations to advance infection prevention strategies and translational research that impacts global public health. Kate has guided postdoctoral fellows, graduate students, and undergraduates, fostering their growth as researchers and public health professionals.

kellingson@arizona.edu

Areas of Expertise:

• Infection prevention
• Antimicrobial resistance and stewardship
• One Health
• Occupational health
• Healthcare-associated infections
• Implementation science
• Border health
• Hand hygiene
• Transfusion safety
• Outbreak investigation
• Surveillance and capacity-building in resource-limited settings
• Injection safety
• Valley Fever
• COVID-19

Cedar Mitchell, PhD
EIS Officer, Pima County 

An Epidemic Intelligence Service Officer who served in Pima County Health Department (PCHD) from 2022 to 2024, Dr. Mitchell now works for the CDC as a Career Epidemiology Field Officer in Montana.

While serving as an EIS officer at PCHD, Cedar led investigations of a fatal botulism case in Tucson, an outbreak at Pima Animal Care Center, rattlesnake bite surveillance in Arizona, a case series on malaria among recent migrants crossing the Mexican border, and syphilis screening. She also supported a West Nile Virus study of long-term impact on Arizonans. Additionally, Cedar collaborated with partners across the county to the launch Tucson’s first Healthy Companions clinic to serve housing-unstable populations and their pets simultaneously through mobile health clinics. For this project, she mentored MPH interns and invited other graduate students from MEZCOPH to volunteer.

As her analytic project for EIS, Cedar worked with students from Dr. Ellingson’s lab to analyze blood levels of PFAS among Arizona frontline workers enrolled in the CDC-funded AZ-HEROES study led by MEZCOPH and UA Health Sciences faculty. Her diverse and extensive contributions during her two years with PCHD made a significant impact on public health in Southern Arizona and on MEZCOPH graduate students.

Cedar.Mitchell@pima.gov

James Romine, PhD
Post-Doctoral Research Associate 
(Lab alumni from PhD-Epi program)

James Romine is a post-doc in Epidemiology for the AZ-HEROES study, working to support both analytic and operational efforts of the project. James joins the AZ-HEROES team after involvement in numerous Public Health initiatives, such as the Pima County Health Department's response to COVID-19 in long-term care facilities, as well as the community-based development of vector-borne disease interventions in northern Mexico and Nicaragua. As a Peace Corps volunteer in Nicaragua from 2010-2013, James supported community efforts to control Chagas disease and other infectious diseases. James enjoys hiking and exploring the Sonoran Desert wilderness.

romine@arizona.edu

Samantha Ruth, MS 

(PhD Past Rotation: KAPs on antibiotic use and vaccination for respiratory viruses)

Graduate Research Assistant

sruth@arizona.edu

Cynthia Porter, MS
Data Scientist with AZ HEROS and Fire Fighter Cancer Cohort Study

Cynthia Porter is an MS Epidemiology student at the Mel and Enid Zuckerman College of Public Health. Cynthia currently works as a graduate research assistant for the AZ-HEROES study which is funded by the CDC to study immune markers of protection against COVID-19 in healthcare workers, first responders, and essential workers. Cynthia's current research for the Ellingson lab focuses on predictors of COVID-19 infection in healthcare workers. Her current research interests include occupational health, cancer prevention, infectious disease and clinical trials, with research experience focusing on clinical research and maternal health. In her free time, Cynthia enjoys eating good food and spending time with her girlfriend and two dogs. 

cynthiaporter@arizona.edu

Priscila Ruedas, MPH
Research Program Administrator, Farmworker Enumeration

priscilaruedas@arizona.edu

Sana Khan, MPH
Data Scientist

Sana Khan is a doctoral candidate in Epidemiology at the Mel and Enid Zuckerman College of Public Health. She has been involved in the University of Arizona's COVID-19 response as part of the SAFER and Contact Tracing team. She is currently working on the CoVHORT study as a research assistant and is particularly interested in the role of stress on developing long-COVID. Sana is also a Data Analyst and Liason with Arizona HEROES and the CDC. Sana is interested in infectious disease epidemiology, specifically focuses on multidrug-resistant infections and how prescribing patterns influence antimicrobial resistance. She is also committed to the study of women's health and access to quality healthcare. Her previous research and clinical experience ranged from projects in neurology to cancer survivorship. 

sanakhan@arizona.edu

Ferris Ramadan, MS
Research Specialist, Sr. 

Ferris Ramadan is a Senior Research Coordinator for the Ellingson lab. His work predominantly focuses on antimicrobial stewardship, working with the Valley Fever Center for Excellence on coccidioidomycosis research questions, and most recently supporting the Pima County Health Department's COVID-19 response in long-term care homes. Ferris' decision to work with Dr. Ellingson and build a career in public health was motivated by a passion to improve people’s lives: "The unique beauty of public health is that I regularly draw upon a variety of disciplines - including statistics, biology, and health policy - and pragmatically apply these fields to effect change and educate communities." In his spare time, Ferris enjoys bike rides and hikes, bingeing Parks and Rec, and travel. 

ferrisr@arizona.edu

Zoe Baccum, MPH
One Health Student

(Now PhD student at ASU)

Melanie Rubio, BS
Graduate Research Assistant

Melanie Rubio is an MPH student with a concentration in Epidemiology. She currently works on the Community Engagement Retention Research (CERR) core for PAN- Healthy Minds for Life, a multi-site national study to discover personalized solutions to improve brain health and optimize brain health throughout the lifespan. She is also conducting a project to improve the infection prevention workforce development in Southern Arizona. Melanie‚Äôs current research interests are infectious disease epidemiology, sexual health and infection prevention. In her free time, Melanie enjoys spending time with her dog, watching movies and traveling.

rubiom1@arizona.edu

Caitlyn McFadden, MPH 

(PhD Past Rotation: Infection Prevention in long-term care)

Graduate Research Assistant

cmcfadde@arizona.edu

Theresa LeGros, MA
Research Specialist, Sr.

Theresa is a career evaluator with a passion for learning and living. Her philosophical approach to science is rooted in some of the ideas percolating in physics: we can’t really define (or “know”) something without understanding how it interacts with all of the other somethings. Her most cherished academic experiences have been researching primate ecology and conservation in Madagascar as an undergraduate, the deep learning and discovery that came with earning an MA in Biological Anthropology, and today pursuing a PhD in Public Health with a dissertation centered around school district reopening plans in response to COVID-19. 

drejza@arizona.edu

Gemma Parra
Undergraduate Honors Student, MPH

(Now at Emory, now Health Scientist at CDC)

Dilsharan Kaur
Graduate Research Assistant

Dilsharan is a doctoral student in Clinical Translational Sciences. She received her BS in Human Biology from the University of California, Merced. She has an interest in infectious disease epidemiology and clinical research. Her previous research experience involved finding bacteriophages as a part of the SEA-PHAGES program at UC Merced.

dkaur9@arizona.edu

Neha Mishra
Undergraduate Honors Student

(Now a medical student)

Neha Mishra is a senior undergraduate student in Public Health with an emphasis in Quantitative Methods. She is currently completing her public health internship at the Ellingson lab where she is assisting with an enumeration study of migrant and seasonal farmworkers in Yuma County. Neha's current research interests include border health, infectious diseases, and women's health. In addition to working at the Ellingson lab, she works in an immunology lab studying regulatory/accessory proteins of HIV and volunteers at a free clinic serving the underserved population in Tucson. In her free time, Neha enjoys hiking and reading.

nmishra@arizona.edu