HIV incidence

Published on November 30, 2015 by

Lessons from the 2012 national HIV household survey to improve mathematical modelling for HIV policy

The most recent South African National HIV Prevalence, Incidence and Behaviour Survey conducted in 2012 incorporated new tools for generating greater information about the current state of the HIV epidemic from the national household survey. The results from the direct HIV incidence estimates from the multi-assay recent infection algorithm from the survey and estimates from more conventional modelling approaches to estimating incidence were found to generate fairly similar results. The 2012 household survey data also provided an opportunity to externally validate model projections over time.

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 June 13, 2012 by

What does it take to reduce the rate of new HIV infections by 50% in KwaZulu-Natal, South Africa?

Household surveys estimate the proportion of HIV infected persons in KwaZulu-Natal at a level of ~23% of the population. What is urgently needed is to seek ways to reduce HIV incidence while caring for existing infections in KZN. The emerging course of action against HIV spread is to use a combination of prevention interventions rather than relying on individual tools. This article discusses mathematical modelling conducted to forecast the impact of combined interventions at both the short- and long-term. The modelling shows the importance of repeated high coverage of testing, linkage to care, starting treatment on time (at CD4 count 350 or less), and high coverage of circumcision in order to reduce the rate of HIV infection in KZN.

Short item Published on March 15, 2012

Does doubling the per-sex-act risk of HIV infection increase incidence?

One question repeatedly arises at meetings in which HIV risk and prevention are discussed: should health authorities be concerned by factors that increase the per-sex-act risk of HIV infection by 2-3 fold? The rationale by some health practitioners is that the risk of acquiring HIV infection is low, in the region of 0.04% and 1.7% Read More

Published on June 21, 2010 by

Editorial: TB conference 2010

The central theme of this SACEMA Quarterly is the HIV/TB co-epidemic. From 1-4 June 2010 the 2nd TB conference was held in Durban, in which most of the presentations discussed TB in relation to HIV. A SACEMA affiliate presented a study concluding that intensified HIV testing and early initiation of antiretroviral therapy (ART) for women and men aged 25-40 would optimise the cost-effectiveness of applying the test-and-treat strategy in South Africa, as this would have the largest impact on TB as well. One of the main articles in this Quarterly discusses whether ART will help, and to what extend, in lowering TB incidence. Other articles focus on meaningful statistical modelling in public health, and the Zibambele programme (job creation and poverty alleviation) and it’s role in the battle against HIV/AIDS and TB. Finally, the new director of SACEMA is announced: Dr. Alex Welte.

Short item Published on March 22, 2010

Impact of early treatment on HIV incidence

In November 2009 the Flemish Research Fund and the Flemish Interuniversity Council approved two proposals concerning “Data-driven modelling of the impact of wide-scale, early HIV treatment on the incidence of HIV in South Africa”. Both projects will be launched in 2010 and involve research and capacity building components as well as efforts to intensify the Read More

Published on March 22, 2010 by

Editorial: Examining HIV incidence

The central theme of this first SACEMA Quarterly Epidemiological Update of 2010 is the rate of occurrence of new HIV infections – also known as HIV incidence. The issue is examined through three distinct perspectives: 1) Recent advances in measuring the HIV incidence in a population, and/or how it changes over time, 2) estimating the relative importance of various ‘modes of transmission’ in contributing to new cases of HIV infection, and 3) the use of antiretroviral treatment of infected individuals to curb their infectivity and hence reduce HIV incidence.

Published on March 22, 2010 by

HIV incidence using cross-sectional surveys: recent theoretical developments

Prevalence and incidence are the two most important indicators of the state of an epidemic. The most common way in which incidence is measured is by follow-up of an initially uninfected cohort. For infections with a relatively short duration, another method for estimating incidence is available using a cross-sectional survey. Unfortunately, HIV has a long asymptomatic phase before the onset of immune failure and AIDS. In this article a way to estimate HIV incidence using biomarkers in cross-sectional surveys is described and the challenges of this approach are discussed.

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