Juliet Pulliam


Prof. Juliet Pulliam is Director of SACEMA and an Associate Professor of Mathematics at Stellenbosch University. Prior to moving to SACEMA in July 2016, she spent five years as a faculty member at the University of Florida, where she was also the inaugural director of the International Clinics on Infectious Disease Dynamics and Data (ICI3D) Program from 2012-2016. Juliet received a PhD in Ecology and Evolutionary Biology from Princeton University in 2007, after which she spent a year as a postdoctoral fellow at the Center for Disease Ecology at Emory University and 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. Her research focuses on quantitative approaches to infectious disease epidemiology, particularly zoonotic and vector-borne infections in resource-limited settings.

Wim Delva

Deputy Director: Research

A medical doctor and epidemiologist, Prof. 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

As Assistant Director for Training at SACEMA, Dr Gavin Hitchcock is responsible for all training workshops conducted by SACEMA and for the overall training and supervision of all SACEMA-funded students throughout South Africa. He is a topologist by training and also works in the fields of History of Mathematics and Mathematics Education. He has long experience in university teaching and academic program design and management in Southern Africa and received a Distinguished Teacher Award from the University of Zimbabwe in 2001.

Lynnemore Scheepers

Research Manager

Lynnemore Scheepers is the Research Manager for SACEMA. She has a background in research management and finance. Prior to joining SACEMA in 2008, 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.

Larrise Bolton

SACEMA Postdoctoral Fellow

Eduard Grebe


Eduard is a Researcher at SACEMA who works primarily on HIV incidence estimation. He was the principal analyst for the CEPHIA collaboration, an international consortium established to independently evaluate HIV incidence assays (i.e. laboratory tests for ‘recent’ HIV infection, used in cross-sectional incidence estimation) and serves on the World Health Organisation’s technical working group on HIV incidence assays. He is also the maintainer of the open source inctools package for the R statistical programming language, which provides implementations of standard methods for cross-sectional incidence estimation and for ‘calibrating’ tests for recent infection. He has a background in social science, having obtained his PhD in economics from the University of Cape Town for work on HIV/AIDS policy and civil society health activism in Sub-Saharan Africa.

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.

Marijn Hazelbag

SACEMA Postdoctoral Fellow

Perceval Maturure

Technical Officer

Perceval joined SACEMA as a Technical Officer in 2018. He comes from industry, where he has served several roles in his career, which include Systems Administrator, Tutor: Programming and Mathematics, IT Manager, SQL Database Administrator and Website Developer. He is passionate about the use of Software and Database Technologies for scientific research.

Maggie Moses

General Assistant

Zinhle Emily Mthombothi

Junior Researcher

Amanda October

SACEMA Administrator

Olugbenga Oluwagbemi

DST-NRF Innovation Postdoctoral Research Fellow

Masimba Paradza

Training Coordinator

Paradza joined SACEMA as Training Coordinator in 2018. He spent more than six years as a Lecturer and postgraduate programme coordinator at the University of the Western Cape since 2012. He holds a BSc Honours in Physics from the Midlands State University and a BSc Honours in Astrophysics and Space Science from the University of Cape Town. He was awarded an MSc in Physics by Rhodes University in 2009. His current PhD research focuses on the applications of non-extensive statistics to high energy physics. Masimba has also taught physics at MSU in Zimbabwe (2004-2006); and computational methods to honours students of the National Astrophysics and Space Science Programme at UCT (2009-2018). He also volunteered to write several text books in Mathematics and Physical Sciences under Siyavula, a Free High School Science Text Books project. These textbooks are currently being used by grades 10, 11, and 12 in South Africa.

Carl Pearson

Research Fellow

Joseph Sempa

SACEMA Postdoctoral Fellow

Jacky Snoep


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).

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

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.