Juliet Pulliam

Director, SACEMA and Associate Professor of Mathematics

Prof Juliet Pulliam took over as Director in July 2016. She came to SACEMA from the University of Florida, where she spent five years as a faculty member in the Department of Biology and the Emerging Pathogens Institute (EPI). Since 2012, she has served as Program Director for the International Clinics on Infectious Disease Dynamics and Data (ICI3D) Program, a collaboration between EPI and SACEMA.

Before moving to UF in 2011, Juliet spent three years as a Research and Policy for Infectious Disease Dynamics (RAPIDD) Program Fellow at the US National Institute of Health’s Fogarty International Center and a year as a postdoctoral fellow at the Center for Disease Ecology at Emory University. She received a PhD in Ecology and Evolutionary Biology from Princeton University in 2007. Her research integrates principles from epidemiology and ecology to address fundamental and applied research questions related to the impact and control of infectious diseases.

Wim Delva

Deputy Director: Research

A medical doctor and epidemiologist, Wim Delva has a joint research appointment at SACEMA and the International Centre for Reproductive Health at Ghent University in Belgium. He is interested in the application of the statistical, epidemiological and mathematical modelling techniques to describe and analyse the behavioural and biological processes underlying generalised HIV epidemics in sub-Saharan Africa.

His current research centres around the role of age disparate relationships, concurrency and oscillating migration in the spread of HIV in Southern Africa, and the potential impact of early HIV treatment and concurrency reduction on the prevalence and incidence of HIV.

Gavin Hitchcock

Assistant Director: Training

Gavin has been involved with SACEMA since 2009 as consultant on training and capacity building, and is currently Assistant Director: Training. He monitors the well-being and progress of SACEMA’s Masters and PhD students in Stellenbosch and elsewhere, and has responsibility for the design and implementation of SACEMA’s training programmes. He is a Zimbabwean, educated at the Universities of Oxford (Mathematics) and Keele (PhD in topology), and subsequently based in the Dept of Mathematics at the University of Zimbabwe.

He has taught many of the core university mathematics courses, specializing in the teaching of topology, mathematical analysis and history of mathematics, while working in topology and (more recently) history of mathematics. He is the recipient of a Distinguished Teacher Award from the University of Zimbabwe for university teaching and for contributions to mathematics enrichment, Olympiad training and talent search in schools in the Southern African region.

Lynnemore Scheepers

Research Manager

Lynnemore Scheepers is the Research Manager for SACEMA. Prior to joining SACEMA, she worked for several years in research management at UCT and CPUT.

Alex Welte

Research Professor

The biggest single issue that has Alex has been engaged with over the last few years is the challenge of defining, and then applying in the field, laboratory based characterizations of 'recent infection'. This idea, and the SACEMA group's work in this area, has attracted a lot of interest in recent years as it offers tremendous potential to improve epidemiological surveillance. Tools arising out of this work are available from the Comprehensive R Archive Network, as a package called inctools.

Alex was director of SACEMA from July 2010 to June 2016. Before that, Alex was in the School of Computational and Applied Mathematics at the University of the Witwatersrand, where he was involved with SACEMA projects since the beginning of the centre's existence. A physicist by training, he is interested in a diverse range of projects involving the mathematical modeling of biological, chemical and population-dynamic processes.

Roxanne Beauclair


Roxanne received her training in Anthropology (MA) and Epidemiology (MPH) from University of Cape Town. She is currently coordinating and analysing data from a survey that investigates the relationship between sexual relationship dynamics and HIV. She is also engaged in qualitative research that investigates reasons for age-disparate relationships and sexual concurrency.

Trust Chibawara


Eduard Grebe


John Hargrove

Senior Research Fellow

John was appointed as SACEMA director in early 2006 and remained director until June 2010, when he handed over stewardship of SACEMA to incoming director Alex Welte. John worked for more than 30 years in the field of tsetse fly biology and control, applying mathematical analytical and modelling techniques in the field of physiology, behaviour and population dynamics.

Maggie Moses

General Assistant

Martin Nieuwoudt

Senior Researcher

Prof. Martin Nieuwoudt completed a PhD in Bioengineering at the University of Pretoria in Gauteng South Africa. He has an extensive multi-disciplinary Biomedical research background. His interests are biosystems modelling and epidemiological statistics. He is currently appointed as a Researcher at SACEMA.

Amanda October

SACEMA Administrator

Jacky Snoep

Research Professor

Jacky holds the SACEMA-SARCHI research chair in: "Mechanistic modelling of health and epidemiology" and is interested in detailed mathematical modelling of disease states. Thus far he has focused mostly on metabolism, with the aim to gain a deep understanding in the biochemical principles that underlie the metabolic differences that are observed in healthy versus diseased persons. He focuses on diseases that are important in the South African context: HIV/Aids, TB, malaria and type II diabetes.

Jacky has a strong background in experimental biochemistry/microbiology and in mathematical modelling of biochemical pathways. He is a strong proponent of complete reproducibility in model construction and validation workflows. To enhance this he is active in data and model management (via his affiliation with the University of Manchester, collaborating with Carole Goble in the FAIRDOM team), and in the Silicon Cell initiative (via his affiliation with the Vrije Universiteit in Amsterdam, collaborating with Hans Westerhoff).

Glyn Vale

Visiting Research Fellow

Cari van Schalkwyk

Researcher in Statistics

Cari van Schalkwyk studied Mathematical Statistics at the University of Stellenbosch and started her relationship with SACEMA in 2007 through her Masters project on estimating mean duration of recent HIV infection for the ZVITAMBO data. She started working at SACEMA as a Statistician in November 2010 and has been involved in several projects in house, with the Desmond Tutu TB Centre and with the WHO.

Brian Williams

Visiting Senior Research Fellow

Dr Brian Williams, who helped to set up SACEMA with Prof Wayne Getz and Prof Ekkehard Kopp, is now retired having spent the last ten years of his working life in the World Health Organization. Since retiring he has continued to work closely with SACEMA and has been one of the main driving forces behind the use of anti-retroviral therapy to stop AIDS and prevent TB. He continues to be active in both teaching and research.