THAC0204 - Oral Abstract Session
Treatment as prevention for HIV in South Africa: different models show consistency in occurrence, but difference in timing of elimination and the overall impact of the intervention
Presented by Jan A.C. Hontelez (Netherlands).
J.A.C. Hontelez1,2,3, M.N. Lurie4, T. Bärnighausen3,5, R. Bakker1, R. Baltussen2, F. Tanser3, T.B. Hallett6, M.-L. Newell3, S.J. de Vlas1
1Erasmus MC, University Medical Center Rotterdam, Public Health, Rotterdam, Netherlands, 2Radboud University Nijmegen Medical Center, Nijmegen International Center for Health Systems Research and Education (NICHE), Nijmegen, Netherlands, 3Africa Centre for Health and Population Studies, University of KwaZulu-Natal, Mtubatuba, South Africa, 4Brown University Warren Alpert School of Medicine, Providence, United States, 5Harvard School of Public Health, Department of Global Health and Population, Boston, United States, 6Imperial College London, London, United Kingdom
Background: Treating all HIV infected patients with antiretroviral therapy (ART) has been suggested to eliminate HIV in high-endemic countries. However, the predicted impact of this universal test and treat (UTT) intervention has not been confirmed using different models.
Methods: We developed 9 different models of the South African HIV epidemic in a stepwise approach of increasing complexity and realism (figure 1). The simplest model resembles the deterministic model by Granich et al, while the most detailed model is a stochastic microsimulation model (STDSIM) , which, among others, includes sexual networks and different HIV stages. Similar to Granich et al, we examined the impact and cost-effectiveness of a UTT intervention of annual screening and immediate ART for HIV infected adults (aged 15+) starting in 2012 and scaled-up to 90% coverage in 2019.
[Figure 1. Stepwise approach of model development]
Results: The predicted impact of UTT on the HIV prevalence in South Africa differs substantially between the simplest and most detailed model, yet both models predict elimination of HIV (figure 2). Surprisingly, the current ART roll-out of treatment at ≤350 cells/µL is already having such a substantial impact on incidence, that it will drive HIV into an elimination phase at around 2050, even without UTT. However, UTT is still cost-effective as many additional life-years will be saved (figure 3).
[Figure 2. epidemiological impact of UTT]
[Figure 3. Cost, impact, and cost-effectiveness]
Conclusions: Our results confirm previous conclusions that the HIV epidemic in South Africa can be eliminated through a strategy of universal testing and treatment at 90% coverage. However, models that capture more details underlying the HIV transmission dynamics show that elimination is more likely to occur at a later point in time. Also, UTT is a cost-effective intervention, but less efficient in reducing infection than previously predicted because the current ART treatment policy in South Africa alone will already drive HIV into elimination.
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