Lab Members

(Post-Doctoral Researcher)

James Hollister is a Biostatistician at the Mel and Enid Zuckerman College of Public Health. He graduated with his PhD in Biostatistics from the University of Arizona in 2026. His dissertation was focused on applying a causal inference framework in epidemiological settings, particularly prospective cohort studies. He currently works for the Fire Fighter Cancer Cohort Study (FFCCS), a longitudinal study focused on the health and wellness of fire fighters across the United States. He previously worked with Dr. Ellingson as a graduate research assistant for the AZ-HEROES study, a CDC-funded project focused on COVID-19-related outcomes among frontline workers.

jameshollister@arizona.edu

(PhD Epidemiology Candidate)

Paulina Colombo is a PhD candidate in Epidemiology at the Mel and Enid Zuckerman College of Public Health, with a focus on healthcare epidemiology and antimicrobial stewardship. She is currently a pre-doctoral fellow supporting the epidemiology team at BeiGene, an oncology biotechnology company, and serves as a research assistant on a pilot project exploring antimicrobial stewardship and prescribing practices in animal shelters. Paulina has also earned a graduate certificate in healthcare informatics. Her proposed dissertation research investigates the role of interfacility transfers in the proliferation of multidrug-resistant organisms, a topic for which she was recently honored as a finalist in the 2024 SHEA Epi Competition.

paulinacolombo@arizona.edu

(PhD Epidemiology Student)

José Luis Camarena is a PhD student in Epidemiology with a minor in Biostatistics. His research interests include infectious disease epidemiology, vaccination, health disparities, and the social and structural factors that influence health. His dissertation focuses on HPV vaccination among youth, particularly in rural Arizona–Mexico border communities. His broader research and public health experience includes HIV prevention and care, healthcare-associated infections in Latin America, antimicrobial use, COVID-19, and infectious disease investigation and surveillance. José is passionate about using epidemiologic research to improve health and reduce disparities in underserved communities. Outside of work/school, he enjoys traveling, practicing yoga, and hiking around Tucson.

camarena@arizona.edu

(PhD Epidemiology Student)

Brooke Hawkes is a PhD student in Epidemiology at the Mel and Enid Zuckerman College of Public Health. She is currently a data analyst for the Asthma and Airway Disease Research Center, where she studies risk factors of respiratory diseases, such as asthma and COPD. With a minor in Computer Science, she has a strong interest in applying computational methods to disease prediction, prognosis, and omics analysis. Her previous research has covered a variety of topics, including immune response to COVID-19, antibiotic use in the US-Mexico border region, and occupational exposures and associated disease risk in firefighters.

brookehawkes@arizona.edu

(PhD Epidemiology Student)

Alexis Ortega is a fourth-year PhD student in Epidemiology with a minor in Biostatistics at the Mel and Enid Zuckerman College of Public Health. She is a National Institute of Health (NIH) Initiative for Maximizing Student Development (IMSD) fellow. Currently, she is a teaching assistant (TA) for introductory epidemiology courses and has been a TA for the UA Center for Rural Health’s Border Health Service Learning course. Her research interests are rural health, border health, health disparities, and infectious disease prevention.

alexisortega@arizona.edu

(PhD Epidemiology Student)

Azmat Sidhu, a PhD student in Epidemiology, conducted research at the American University in Cairo (AUC), studying cognitive health and aging through the AL-SEHA project. This longitudinal study explores healthy cognitive aging patterns in Egyptian populations and provides a comparative perspective on global aging research.

azmats@arizona.edu

(PhD Epidemiology Candidate)

Cynthia is a PhD candidate in epidemiology at the Mel and Enid Zuckerman College of Public Health. Cynthia currently works as a project coordinator as part of the Fire Fighter Cancer Cohort Study (FFCCS), working with firefighters to understand occupational exposures that drive cancer development. Her research interests include community engaged research, cancer biology, working with high dimensional datasets, epigenetics, occupational health, and statistical methods. When not in the lab or the field, Cynthia enjoys cooking, traveling, weightlifting, spending time with her dog, being outdoors, drinking good coffee, painting, and karaoke with her friends. 

cynthiaporter@arizona.edu

(DrPH Public Health Policy & Management Candidate)

Rachel is the Evaluation Manager where she works with all Campus Health departments to execute their data-related needs. She works closely with Campus Health leadership to help tell the story of the numbers. Rachel is also a proud graduate of the University of Arizona where she received her MPH in Health Policy and Management and is passionate about using health data to aid organizational goals. She currently serves on the CHS Quality Improvement team and uses her free time to earn her DrPH in Health Policy and Management.

(BS Pharmaceutical Student)

Garrett is an undergraduate student at the University of Arizona W.A. Franke Honors College pursuing a B.S. in Pharmaceutical Sciences with minors in Public Health and Medicinal Pharmacology and Toxicology. He joined Dr. Ellingson’s Lab as an NIH National Library of Medicine Undergraduate Scholar through the PHIRE Program. His research examines antibiotic use along the U.S.-Mexico border, including prescription and non-prescription use and antimicrobial resistance. He is currently analyzing Medicare Part D data to investigate geographic patterns in antibiotic prescribing along the U.S.-Mexico border; this ongoing project will serve as his Honors Thesis. His research interests include infectious disease, antimicrobial resistance, epidemiology, immunology, and pharmacology.

garrettkuch@arizona.edu

(BS Public Health Student)

bhavyamakkar@arizona.edu

(BS Epidemiology Student)

Anthony Padilla is a senior in Veterinary Science within the W.A. Franke Honors College at the University of Arizona. His undergraduate research focuses on evaluating antimicrobial use surveillance systems and disease monitoring frameworks across companion animal and livestock populations. Passionate about veterinary epidemiology. Anthony plans to pursue a Doctor of Veterinary Medicine degree following graduation to advance both animal and public health.

apadilla4@arizona.edu