November 2012

Published on November 30, 2012 by

Editorial: Climate change and tsetse flies

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.

Published on November 30, 2012 by

Modelling the control of Trypanosomiasis using trypanocides or insecticide-treated livestock

Across sub-Saharan Africa, several species of trypanosome, transmitted by tsetse flies (Glossina spp), cause human and animal trypanosomiasis. While interventions can be directed against either the vector or the parasite, emphasis has usually been on the use of drugs to treat the disease both in humans and in livestock. Several advances in our understanding of tsetse biology and ecology and improvements in the cost-effectiveness of tsetse control have revived interest in the vector control approach to disease management. This article discusses and compares two different approaches to the control of trypanosomiasis in cattle: either we can control the disease by treating cattle with insecticides that kill the tsetse vectors without having any direct effect on the trypanosomes. Or we can inject the cattle with trypanocides that kill the parasites but leave the tsetse flies unharmed.

Published on November 30, 2012 by

Projecting the impacts of Xpert MTB/RIF using virtual Implementation

The introduction and scale-up of new tools for the diagnosis of tuberculosis (TB) has the potential to make a huge difference to the lives of millions of people. To realise these benefits and make the best decisions, policy makers need answers to many difficult questions about which new tools to implement and where in the diagnostic algorithm to apply them cost effectively. Here we explore virtual implementation as a tool to predict the health system, patient, and community impacts of alternative diagnostics and diagnostic algorithms for TB, in order to facilitate context specific decisions on scale-up. Virtual implementation is an approach that can model the impacts of implementation of a new diagnostics by taking data from the context being considered alongside data from contexts where the new technology has been implemented (probably as a trial).

Published on November 30, 2012 by

Challenges with using estimates when calculating ART need among adults in South Africa

Annually, the Foundation for Professional Development (FPD) collects information on HIV/AIDS service provision in the City of Tshwane and estimates service needs. In order to estimate need for ART among adults, data on the number on ART are used from the Department of Health, and data on the number in need from the Statistics South Africa mid-year population estimates report (based on Spectrum Software estimates). When comparing the 2010 and 2011 Statistics South Africa reports the number in need of ART dramatically decreased, and became even lower than the number receiving ART. Although the difference is most likely due to changes in the calculation done by Statistics South Africa, no detailed and confirmed explanation can be offered at the moment. This article intends to provide a constructive contribution to the discussion about the use of model-derived estimates of the need for ART.

Short item Published on November 30, 2012

Update on HIV incidence estimation from prevalence data

Accurate HIV incidence estimates are essential for monitoring the HIV epidemic, determining public health priorities and assessing the impact of interventions.  There are many approaches to estimating incidence. The “gold standard” approach is through observational studies, in which subjects are periodically monitored for HIV infection. However, such studies are time consuming, expensive and may provide Read More

Short item Published on November 30, 2012

Interesting article: Potential interaction between injectable hormonal contraception and HIV risk

At the end of September 2012 an article was published in AIDS with the title Modelling the global competing risks of a potential interaction between injectable hormonal contraception and HIV risk. As some, but not all, observational studies have suggested an increase in risk of HIV acquisition for women using injectable hormonal contraception (IHC), this Read More

Short item Published on November 30, 2012

Brown International Advanced Research Institutes

Brown International Advanced Research Institutes (BIARI) represents a unique professional development initiative to provide a platform for outstanding young faculty and practitioners from the global south and emerging economies to engage in a sustained, high-level intellectual and policy dialogue with leading scholars in their fields. The institutes will be held June 8-22, 2013. To learn Read More

Short item Published on November 30, 2012

Human resources for universal access to ART

In the SACEMA Quarterly we regularly report on issues (effects, costs) related to universal access to antiretroviral treatment (ART) or treatment as prevention (TaP). A recently published article focuses on the human resources needed for this approach. This because availability of human resources may now be the most important barrier to achieving universal access to Read More