title: The potential impact and cost of focusing HIV prevention on young women and men: A modeling analysis in western Kenya.
abstract: OBJECTIVE
  We 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.
  
  
  METHODS
  Compartmental age-structured mathematical model of HIV transmission in Nyanza, Kenya.
  
  
  METHODS
  The 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.
  
  
  RESULTS
  The 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.
  
  
  CONCLUSIONS
  For 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.
authors.affiliation: New York University, New York, United States of America.
authors.forename: Ramzi A
authors.identifier: http://orcid.org/0000-0002-2496-9620
authors.initials: RA
authors.lastname: Alsallaq
authors.affiliation: New York University, New York, United States of America.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Buttolph
authors.affiliation: New York University, New York, United States of America.
authors.forename: Charles M
authors.initials: CM
authors.lastname: Cleland
authors.affiliation: Imperial College London, London, United Kingdom.
authors.forename: Timothy
authors.initials: T
authors.lastname: Hallett
authors.affiliation: University of Nairobi, Nairobi, Kenya.
authors.forename: Irene
authors.initials: I
authors.lastname: Inwani
authors.affiliation: Impact Research & Development Organization, Kisumu, Kenya.
authors.forename: Kawango
authors.initials: K
authors.lastname: Agot
authors.affiliation: New York University, New York, United States of America.
authors.forename: Ann E
authors.initials: AE
authors.lastname: Kurth
mesh_terms: D000293:Adolescent; D003362:Cost-Benefit Analysis; D019353:Endemic Diseases / Q000517:prevention & control*; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D006801:Humans; D015994:Incidence; D007630:Kenya / Q000453:epidemiology; D008297:Male; D015233:Models, Statistical; D012309:Risk-Taking; D021841:Safe Sex; D012680:Sensitivity and Specificity; D055815:Young Adult