The potential impact and cost of focusing HIV prevention on young women and men: A modeling analysis in western Kenya

Abstract

ObjectiveWe compared the impact and costs of HIV prevention strategies focusing on youth (15–24 year-old persons) versus on adults (15+ year-old persons), in a high-HIV burden context of a large generalized epidemic.DesignCompartmental age-structured mathematical model of HIV transmission in Nyanza, Kenya.InterventionsThe interventions focused on youth were high coverage HIV testing (80% of youth), treatment at diagnosis (TasP, i.e., immediate start of antiretroviral therapy [ART]) and 10% increased condom usage for HIV-positive diagnosed youth, male circumcision for HIV-negative young men, pre-exposure prophylaxis (PrEP) for high-risk HIV-negative females (ages 20–24 years), and cash transfer for in-school HIV-negative girls (ages 15–19 years). Permutations of these were compared to adult-focused HIV testing coverage with condoms and TasP.ResultsThe youth-focused strategy with ART treatment at diagnosis and condom use without adding interventions for HIV-negative youth performed better than the adult-focused strategy with adult testing reaching 50–60% coverage and TasP/condoms. Over the long term, the youth-focused strategy approached the performance of 70% adult testing and TasP/condoms. When high coverage male circumcision also is added to the youth-focused strategy, the combined intervention outperformed the adult-focused strategy with 70% testing, for at least 35 years by averting 94,000 more infections, averting 5.0 million more disability-adjusted life years (DALYs), and saving US$46.0 million over this period. The addition of prevention interventions beyond circumcision to the youth-focused strategy would be more beneficial if HIV care costs are high, or when program delivery costs are relatively high for programs encompassing HIV testing coverage exceeding 70%, TasP and condoms to HIV-infected adults compared to combination prevention programs among youth.ConclusionFor at least the next three decades, focusing in high burden settings on high coverage HIV testing, ART treatment upon diagnosis, condoms and male circumcision among youth may outperform adult-focused ART treatment upon diagnosis programs, unless the adult testing coverage in these programs reaches very high levels (>70% of all adults reached) at similar program costs. Our results indicate the potential importance of age-targeting for HIV prevention in the current era of ‘test and start, ending AIDS’ goals to ameliorate the HIV epidemic globally.

The impact, cost and cost‐effectiveness of oral pre‐exposure prophylaxis in sub‐Saharan Africa: a scoping review of modelling contributions and way forward

“…Alsallaq et al . find that in Nyanza, Kenya a youth‐focused strategy of combination prevention which includes PrEP for high‐risk adolescent girls and young women can be cost‐effective.…”

“…A greater impact was observed with combination prevention portfolios that include PrEP compared to those that did not . Modelling indicates that PrEP has an increasing role in optimal prevention portfolios at high budget availability , but other interventions, including enhanced testing and ART, male circumcision and condom promotion, may be more cost‐effective for prioritization , Table . A single analysis investigated resource optimization and the use of a specific incidence benchmark for PrEP eligibility.…”

“…These studies span from 2007 to 2017 with 42 studies modelling oral PrEP in sub‐Saharan Africa and two studies with non‐specific settings but of relevance for generalized HIV epidemics. Applications of country‐specific modelling of oral PrEP occurred predominantly for South Africa and Kenya , followed by Botswana , Zambia , and one application each for Zimbabwe , Mozambique , Nigeria , and Uganda . Select country‐specific results were additionally presented in two studies .…”

“… find that PrEP for the general population does not provide value for money in the context of ART scale‐up. The general consensus from optimization analyses is that it is better value to prioritize expanding ART access before adding PrEP , Table . When there is very high budget availability, PrEP can be a cost‐effective addition ; however, the likelihood of such high budgets is unknown.…”

The influence of mobility among high-risk populations on HIV transmission in Western Kenya

“…The 2012 AIDS Indicator Survey found that approximately 1 out 4 adults in Siaya and Homa Bay counties were living with HIV, as were 1 out of 5 adults in Kisumu and Migori counties (NASCOP, 2014a). Some studies attribute high HIV infection rates to high levels of risk in the general population (Blaizot et al., 2016, Wachira et al., 2012), especially youth (Alsallaq et al., 2017, Wachira et al., 2014) and those living in communities with historically low rates of male circumcision (Anderson et al., 2014), while others have reported that high-risk sub-populations such as female sex workers (FSW) contribute substantially to HIV transmission in this region (Gouws and Cuchi, 2012, Vandenhoudt et al., 2013).…”