Diseases – like the examples of trypanosomes and HIV/AIDS – are not only perceived as causing negative effects; they also create jobs for people. Hence some people get nervous about what they are going to do when these diseases are under control. And is the latter actually going to happen?
This article is based on the presentation given by John Hargrove at the NRF Science for Society Lecture entitled Ending HIV/AIDS in South Africa held on 1 December 2016 in Stellenbosch. He argues that the proactive use of ART (Treatment as Prevention or TasP) provides a powerful weapon for combatting the HIV epidemic, and that we also have the tools for monitoring and evaluating the progress of that programme. Mathematical modelling has played an important role, both in suggesting appropriate interventions, and in developing new monitoring methods, but we are still in for a long journey.
In the last week of June 2016, fifteen scientists converged on Stellenbosch for a week-long intensive workshop, hosted by SACEMA, aimed at sharing their knowledge of the problems and prospects associated with modelling the population dynamics of tsetse flies (Glossina spp) and the trypanosomes that they transmit in Africa to game animals, domestic livestock and humans.
We are changing the guard at SACEMA. Alex Welte, who has managed “the shop” so effectively for the last five years has decided to step down. His successor, Dr Juliet Pulliam of the University of Florida, is expected to succeed him in late June 2016. It is appropriate, then, to look back at Alex’s substantial contribution to our organisation.
Scientists offering papers for publication will be becoming increasingly aware of a significant change in the attitude of journals to the publication of the data used to reach conclusions drawn in their manuscript. New regulations are moving rapidly and uncompromisingly towards a policy where all of the data, and related metadata, required to replicate the reported findings must be made freely available to the world at large. There is much to be said in favour of this argument, but one wonders whether journals have thought through some of the ramifications of the new policy.
Over the past eight years SACEMA has collaborated with the African Institute for Mathematical Sciences (AIMS) and North American scientists in running workshops now held annually at AIMS in Muizenberg, and in the United States at the University of Florida. This editorial particularly celebrates the inputs of five North American scientists who have given freely of their time and efforts in making this valuable training effort possible.
All models are imperfect, but unless the model both accounts for the known biology of the disease and is challenged with data this might not be detected.
One of the articles in this edition concerns the modelling of the control of the tsetse-borne disease trypanosomiasis using trypanocides or insecticide-treated livestock. SACEMA has been short-listed for WHO/TDR funding of a project focussing on modelling the way in which various climate change scenarios might affect the population dynamics of tsetse flies and the trypanosomes that they transmit. For this study we have access to large, long-term, unique archives of data of the type required to address these questions. These data will be augmented during the study through field studies in Zimbabwe and Tanzania, aimed at understanding the spatiotemporal variability of disease threat and how this is likely to change at different locations and altitudes in the context of climate change. Field studies will address particularly the problem of the interface between humans and tsetse, and suggest optimal methods of disease control.
In order to assess the effects of Treatment as Prevention (TaP) on HIV incidence, results from HIV testing over time need to be available. This links to two aspects of information retention – data storage and data usage – which are discussed and illustrated by the case of HIV testing data in this editorial.
With effect from 1 July 2010 I have stepped down as Director of SACEMA. I shall continue to work as a Senior Research Fellow, focussing on my research in the area of tsetse and trypanosomiasis biology and control. The Director’s position has been filled by Dr Alex Welte, who has moved to Stellenbosch from the Computational and Applied Mathematics (CAM) at the University of the Witwatersrand. Alex is no stranger to SACEMA having been involved from the earliest days and he made a huge contribution to our early development in helping to secure major international funding. There is every reason to be extremely optimistic about an exciting future for SACEMA under Alex Welte’s leadership and I am sure you will all join me in wishing Alex well as the head of this organisation over the coming years.