Dr. Onyebuchi Arah named interim chair of the UCLA Fielding School of Public Health’s Department of Epidemiology

Dr. Onyebuchi “Onyi” Arah, professor in the UCLA Fielding School of Public Health’s Department of Epidemiology for more than 15 years, will serve as interim chair of the department beginning July 1, 2026.

“I am certain that the Department of Epidemiology will continue to thrive with Dr. Arah at the helm,” said Dr. Ron Brookmeyer, dean and distinguished professor of biostatistics at UCLA Fielding. “Dr. Arah is a highly cited researcher and physician who has published exceptional work on a range of topics, including epidemiologic methodology, causal inference, and vaccine epidemiology.”

Arah, also a professor in UCLA’s Department of Statistics and Data Science and co-director of the university’s Practical Causal Inference Lab, will succeed Dr. Zuo-Feng Zhang, the current department chair, who will step down after five years of exemplary service and transition full time to his role as distinguished professor of epidemiology. 

"It has been a true privilege to serve as chair of the Department of Epidemiology; I have deeply valued the time spent working alongside our exceptional faculty, staff, and students - an experience that has been both professionally rewarding and personally meaningful,” Zhang said. "I am especially pleased that Dr. Arah will serve as interim chair - he is an outstanding leader and a highly respected epidemiologist, known not only for his scholarly excellence but also for his genuine care and commitment to faculty, staff, and students.”

Since joining UCLA in 2009, Arah has held various administrative and academic leadership positions, including serving as associate dean for global health at UCLA Fielding, as director of UCLA Fielding’s Center for Global and Immigrant Health, and as an associate dean in the Division of Graduate Education. Additionally, he is a former president of the Society for Epidemiologic Research (SER), which is the largest global organization for epidemiologists, representing over 3,500 institutions across more than 100 countries.

“This is a true honor, and I’m very moved to be recognized in this way,” Arah said. “Dr. Zhang is a gifted scholar and administrator, and I am inspired by his record and plan to build upon it, moving forward.”

A physician trained at the University College Hospital, Ibadan, and the University of Ibadan in Nigeria, Arah earned graduate degrees from Erasmus University Rotterdam, where he received his MSc, DSc, and MPH degrees, and at the Faculty of Medicine of the University of Amsterdam where he earned his PhD. from He also trained at the University of Cambridge, in the United Kingdom, and is currently an Honorary Skou Professor at Aarhus University, in Denmark.