Controlling and eliminating is never going to be easy and this issue of the SACEMA Quarterly is devoted to some of the recent developments that have been made in our attempts to manage TB.
Models of HIV and TB are well established and it is tempting to model the combination of HIV and TB by repeating a suitable TB model a number of times corresponding to the various states of HIV. This can, however, lead to a very complex model with tens, if not hundreds of parameters, requiring considerable computing power to run. Fortunately, the time scales over which the two infections progress are very different, allowing us to greatly simplify the problem.
Abstract: Twenty years ago, in 1997, I wrote the following piece reflecting on the Mothusimpilo project, an early attempt to understand and help to manage the epidemic of HIV in South Africa. I thought it might be interesting for you to look back on where we have come from.
The history of sub-Saharan Africa has been defined and determined to a large extent by the struggle against tropical diseases, many of them vector borne, including malaria, leishmaniasis, trypanosomiasis and many others. To add to this burden our continent has now to deal with the ravages of HIV and the consequent rise in tuberculosis. In this issue of the SACEMA Quarterly we discuss some of the key problems and ways in which we might be able to address and mitigate some of the challenges that we face in this regard.
World-wide South Africa has the largest epidemic of HIV and the biggest anti-retroviral programme. But reaching the UNAIDS 90-90-90 target by 2020 and ending AIDS by 2030 will require an expansion of surveillance and strengthening patient monitoring. Both are needed to monitor progress, identify and correct problems and to demonstrate success. Here we outline the current state of the epidemic and discuss important issues that should inform the National Strategic Plan to be launched on World AIDS Day in December.
Botswana has made substantial progress towards meeting the UNAIDS 90-90-90 target by 2020 under which 90% of people living with HIV will know their status, 90% of these will be on anti-retroviral therapy (ART), and 90% of these will have viral loads below 400/µL. In this paper we use a previously published model for Botswana to assess the future impact of their HIV control programme on new HIV infections, AIDS related mortality and the costs of doing this. We show that while treatment will have a major impact on incidence and mortality and will lead to net cost savings, prevention will lead to further small reductions in incidence and mortality, but will entail significant cost increases.
While we all believe in ‘inter-disciplinary research’, the reality often falls short of the intention. How then can we begin to learn each others languages, hear what others are saying, use our joint knowledge and understanding to throw light on important problems, and hopefully make the world a slightly better place?
As the world embraces immediate treatment for HIV, the game is not over: stigma and discrimination persist; drug procurement, supply and delivery are failing in many countries; ways must be found to ensure adherence with treatment to keep people alive, minimize resistance and stop transmission; thirty million people will need treatment for the next half-century or until a cure is found. This is an auspicious time to review a few of the many studies that have accumulated over the last fifteen years in support of providing treatment for people infected with HIV as early and as soon as possible
The relationship between narrative and paradigmatic thinking in science, at least in the world of natural philosophy and natural history, is crucial and yet seldom explicitly stated and rarely understood. Creativity in science lies primarily in the narrative mode of thinking and it is here that new discoveries are made and new ideas are found. While we should find ways to develop narrative thinking when teaching science we must also ensure that our students develop the necessary skills to manipulate the paradigmatic formulations of their theories.
UNAIDS has reported that the prevalence of people infected with HIV but who are not on ART, the incidence of HIV, and AIDS related mortality are falling. The Health Metrics Institute recently made their own, semi-independent, assessment of the trends in each of these indicators and reached similar conclusions with small differences arising from the use of somewhat different assumptions. Both analyses suggest that the world is on track to end AIDS by 2030, but this will depend on continued expansion of treatment at about the present rate together with supportive prevention efforts in Sub-Saharan Africa. Unfortunately, the data on which these analyses are based is weak in almost all places and better data on patient monitoring, follow-up and support, including drug procurement, supply and delivery, and better routing surveillance are needed.