HIV incidence/prevalence

Published on March 17, 2015 by

Are HIV prevalence and incidence declines in sub-Saharan Africa driven by changes in sexual risk behaviour?

Individuals across Africa may have changed their sexual behaviour following the visibility of AIDS in the public sphere in the mid to late 1990s. Though each change in behaviour may have been small, the changes affected simultaneously different aspects of individual sexuality, and added up cumulatively into a moderate reduction in sexual behaviour at the individual level. In turn, this change in individual behaviour was translated into massive disruption of sexual networks at the population level. This made it difficult for HIV to propagate in the population leading to large declines in HIV incidence and prevalence.

Short item Published on September 16, 2014

Study of laboratory tests to discern ‘recently’ from ‘non-recently’ acquired HIV infection opens new possibilities for HIV surveillance and clinical management of HIV

Robust tests for recent HIV infection (as opposed to just HIV infection) would substantially reduce the enormous challenges of estimating HIV incidence (the rate of occurrence of new infections). This article of SACEMA and the related Policy Brief provides the results of the first independent evaluation of five incidence assays conducted by the Consortium for the Evaluation and Performance of HIV Incidence Assays.

Short item Published on June 17, 2014

The HIV Epidemic in Southern Africa – Is an AIDS-Free Generation Possible?

According to the President’s Emergency Plan for AIDS Relief (PEPFAR), an AIDS-free generation entails that first, no one will be born with the virus; second, that as people get older, they will be at a far lower risk of becoming infected than they are today; and third, that if they do acquire HIV, they will get treatment that keeps them healthy and prevents them from transmitting the virus to others. We argue that an AIDS-free generation is possible in Southern Africa, but not unless the high rates of incident infections in key populations are reduced.

Short item Published on March 13, 2014

Defining optimality of a test for recent infection for HIV incidence surveillance

SACEMA has been very active in refining the use of laboratory tests for identifying recent infection (in particular of HIV) for the purpose of estimating disease incidence. We have just published a conceptual analysis of the notion of ‘test optimisation’ in a surveillance context, which should help clarify some persistent confusion that has hindered discourse in this area for years.

Published on November 28, 2013 by

The HIV epidemic in eastern and southern Africa

Eastern and southern Africa remains the region most affected by the HIV epidemic in the world and accounts for more than 50% of the global burden of HIV. Significant progress has been made in recent years in the response to the epidemic in the region: new HIV infections and AIDS deaths have fallen while prevention and treatment services for HIV have increased substantially. While several challenges still remain, there is renewed optimism that the elimination of HIV and AIDS is not an impossible goal.

Published on June 12, 2013 by

20th Conference for Retroviruses and Opportunistic Infections: Highlights, and Developments in HIV Incidence Estimation

The headline-grabber at the 20th Conference for Retroviruses and Opportunistic Infections (CROI) was the ‘functional cure’ of an HIV-infected child. A key success of the ‘Mississippi miracle’ is that no latent reservoir of replication-competent HIV developed in the infant. The study of latent reservoirs, and prospects for eliminating these through treatment, in adults and infants, was the topic of many sessions. Apart from the laboratory science, a number of results from studies and modelling exercises were presented, assessing a number of risk factors and interventions for various conditions. Of particular relevance to the work of SACEMA is the topic of HIV incidence estimation. CEPHIA hosted a satellite session, focussed on the first independent assessments of incidence assays for HIV incidence estimation in cross-sectional studies.

Published on March 18, 2013 by

Oscillating Migration Driving HIV and TB in sub-Saharan Africa

The system of oscillating labour migration, especially to the gold mines in South Africa, has helped to spread TB throughout southern Africa and it now helps to spread HIV. This article illustrates this link by reporting on a study on the impact of migrant labour in the mines in South Africa on the burden of HIV and TB in Mozambique. Furthermore, modelling studies have shown that even if we maintain the same patterns of sexual behaviour the presence or absence of migration can lead to dramatically different outcomes. Unless a comprehensive and fully coordinated multi-country and multi-sectoral programme is implemented and followed through, we may find that the HIV and TB epidemics are far more resilient than consideration of the epidemics in each country suggests.

Published on March 18, 2013 by

Different ways to estimate the mean duration of “recent HIV infection” as measured by the BED assay

Robust affordable means for estimating HIV incidence at the population level continue to be elusive and much desired. As resources are invested in developing more appropriate tests for recent infection, the methods for evaluating and optimising the performance of candidate tests need to be further refined. We have recently explored a range of statistical methods for estimating the mean duration of recent infection (MDRI) by investigating a data set from Harare, Zimbabwe. We investigated whether there is an optimum way of estimating the mean recency duration for this dataset. We also ask how estimates of the mean recency duration and incidence are affected by our choice of cut-off and whether these effects differ with our choice of estimation method.

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