Concurrent sexual partnerships do not explain the HIV epidemics in Africa: a systematic review of the evidence

The notion that concurrent sexual partnerships are especially common in sub-Saharan Africa and explain the region's high HIV prevalence is accepted by many as conventional wisdom. In this paper, we evaluate the quantitative and qualitative evidence offered by the principal proponents of the concurrency hypothesis and analyze the mathematical model they use to establish the plausibility of the hypothesis

Treating cofactors can reverse the expansion of a primary disease epidemic

<p>Abstract</p> <p>Background</p> <p>Cofactors, "nuisance" conditions or pathogens that affect the spread of a primary disease, are likely to be the norm rather than the exception in disease dynamics. Here we present a "simplest possible" demographic model that incorporates two distinct effects of cofactors: that on the transmission of the primary disease from an infected host bearing the cofactor, and that on the acquisition of the primary disease by an individual that is not infected with the primary disease but carries the cofactor.</p> <p>Methods</p> <p>We constructed and analyzed a four-patch compartment model that accommodates a cofactor. We applied the model to HIV spread in the presence of the causal agent of genital schistosomiasis, <it>Schistosoma hematobium</it>, a pathogen commonly co-occurring with HIV in sub-Saharan Africa.</p> <p>Results</p> <p>We found that cofactors can have a range of effects on primary disease dynamics, including shifting the primary disease from non-endemic to endemic, increasing the prevalence of the primary disease, and reversing demographic growth when the host population bears only the primary disease to demographic decline. We show that under parameter values based on the biology of the HIV/<it>S. haematobium </it>system, reduction of the schistosome-bearing subpopulations (e.g. through periodic use of antihelminths) can slow and even reverse the spread of HIV through the host population.</p> <p>Conclusions</p> <p>Typical single-disease models provide estimates of future conditions and guidance for direct intervention efforts relating only to the modeled primary disease. Our results suggest that, in circumstances under which a cofactor affects the disease dynamics, the most effective intervention effort might not be one focused on direct treatment of the primary disease alone. The cofactor model presented here can be used to estimate the impact of the cofactor in a particular disease/cofactor system without requiring the development of a more complicated model which incorporates many other specific aspects of the chosen disease/cofactor pair. Simulation results for the HIV/<it>S. haematobium </it>system have profound implications for disease management in developing areas, in that they provide evidence that in some cases treating cofactors may be the most successful and cost-effective way to slow the spread of primary diseases.</p

Revisiting the economics of transactional sex: evidence from Tanzania

Transactional sex has been identified as one of the key structural drivers of the HIV epidemic. Mainstream economic analyses of this practice primarily conceptualise transactional sex in the language of rational choice, with the focus on behavioural decisions that women make over whether to engage in transactional interactions (or not). However, whilst providing some important insights in relation to the role of poverty and the importance of acknowledging that women are more than passive agents, these approaches fail to address the social and economic complexities of this practice that are reflected in the broader literature. Further, due to the technical framework used, there is a failure to deal with the broader socio-economic and historical underpinnings of this practice. Using evidence from fieldwork undertaken in Tanzania, we revisit the economics of transactional sex, and offer an alternative economic approach to understanding this practice. We explore the notion that transactional sex is an established local sexual norm, and how this norm is creatively applied and reapplied in a range of situations by different actors, including through participation in local value chains. Our analysis has a number of implications for future prevention efforts that differ from the current focus on microfinance as a means of empowering women

HIV/AIDS in Africa: Fertile Terrain

An interdisciplinary approach that incorporates biomedical data into an economic analysis provides the necessary foundation for HIV/AIDS policy in poor countries. This article examines the biomedical effects of economic conditions in Africa that contribute to high rates of HIV transmission. The results of statistical analysis show the correlation of economic and epidemiological variables (nutrition, distribution of income, and urbanisation) with rates of HIV. The economic/biomedical hypothesis implies a broad policy response for confronting HIV/AIDS in Africa and in Asia and Latin America.biomedical data, economic analysis, HIV/AIDS policy, Africa, HIV transmission,

Editorial: The political economy of HIV

Given all the positivity and self-congratulation over HIV in the international policy world, it might be hard to remember how many lives have been destroyed and continue to be devastated by this illness. Looking to UNAIDS headlines, we hear of plans for an ‘AIDS-free generation in Africa’, ‘ending the epidemic by 2030’ and ‘eliminating stigma and discrimination’. In this case, the boldness of the goals is partly driven by what Michel Sidibe´, Executive Director of UNAIDS, called ‘game-changers’ in his World AIDS Day message in 2011. Biomedical revolutions seem to have radically altered the environment for HIV transmission: antiretrovirals (ARVs) and drugs to reduce mother-to-child trans- mission promise to cut HIV transmission rates, as does male medical circumcision