Modeling Combination Interventions to Prevent Human Immunodeficiency Virus in Adolescent Girls and Young Women in South Africa (HIV Prevention Trials Network 068)

Evaluation of the HIV-1 Polymerase Gene Sequence Diversity for Prediction of Recent HIV-1 Infections Using Shannon Entropy Analysis

HIV-1 incidence is an important parameter for assessing the impact of HIV-1 interventions. The aim of this study was to evaluate HIV-1 polymerase (pol) gene sequence diversity for the prediction of recent HIV-1 infections. Complete pol Sanger sequences obtained from 45 participants confirmed to have recent or chronic HIV-1 infection were used. Shannon entropy was calculated for amino acid (aa) sequences for the entire pol and for sliding windows consisting of 50 aa each. Entropy scores for the complete HIV-1 pol were significantly higher in chronic compared to recent HIV-1 infections (p < 0.0001) and the same pattern was observed for some sliding windows (p-values ranging from 0.011 to <0.001), leading to the identification of some aa mutations that could discriminate between recent and chronic infection. Different aa mutation groups were assessed for predicting recent infection and their performance ranged from 64.3% to 100% but had a high false recency rate (FRR), which was decreased to 19.4% when another amino acid mutation (M456) was included in the analysis. The pol-based molecular method identified in this study would not be ideal for use on its own due to high FRR; however, this method could be considered for complementing existing serological assays to further reduce FRR.

Modeling Cash Plus Other Psychosocial and Structural Interventions to Prevent HIV Among Adolescent Girls and Young Women in South Africa (HPTN 068)

Poverty alleviation programs can reduce HIV incidence but may have greater impacts when combined with other psychosocial interventions. We modeled the change in HIV incidence among South African adolescent girls and young women (AGYW) associated with combining a cash transfer (the South African Child Support Grant (CSG)) with other structural and behavioral interventions. We modeled observational data from the HPTN 068 study where 2328 HIV negative AGYW (13–20 years) were followed for 4 years. In a Monte Carlo simulation based on this cohort (N = 10,000), CSG receipt was not independently associated with HIV incidence. Providing the CSG combined with increasing caregiver care and reducing adolescent depression had the largest reduction in HIV incidence with the fewest number of combined interventions (RD − 3.0%; (95% CI − 5.1%, − 0.9%). Combining a monthly grant with interventions to increase caregiver care and reduce adolescent depression could substantially reduce HIV incidence above the provision of cash alone.