title: Treating curable sexually transmitted infections to prevent HIV in Africa: still an effective control strategy?
abstract: BACKGROUND
  Evidence regarding the effectiveness of sexually transmitted infection (STI) treatment for HIV prevention in Africa is equivocal, leading some policy makers to question whether it should continue to be promoted for HIV control. We explore whether treating curable STIs remains a cost-effective HIV control strategy in Africa.
  
  
  METHODS
  The model STDSIM was fitted to the characteristics of 4 populations in East and West Africa. Over the simulated HIV epidemics, the population-attributable fractions (PAFs) of incident HIV attributable to STIs, the impact of syndromic STI management on HIV incidence, and the cost per HIV infection averted were evaluated and compared with an estimate of lifetime HIV treatment costs (US $3500).
  
  
  RESULTS
  Throughout the HIV epidemics in all cities, the total PAF for. all STIs remained high, with > or = 50% of HIV transmission attributed to STIs. The PAF for herpes simplex virus type 2 increased during the epidemics, whereas the PAF for curable STIs and the relative impact of syndromic management decreased. The models showed that the absolute impact of syndromic management remains high in generalized epidemics, and it remained cost-saving in 3 of the 4 populations in which the cost per HIV infection averted ranged between US $321 and $1665.
  
  
  CONCLUSIONS
  Curable STI interventions may remain cost-saving in populations with generalized HIV epidemics, particularly in populations with high-risk behaviors or low male circumcision rates.
authors.affiliation: Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom. richard.white@lshtm.ac.uk
authors.forename: Richard G
authors.initials: RG
authors.lastname: White
authors.forename: Kate K
authors.initials: KK
authors.lastname: Orroth
authors.forename: Judith R
authors.initials: JR
authors.lastname: Glynn
authors.forename: Esther E
authors.initials: EE
authors.lastname: Freeman
authors.forename: Roel
authors.initials: R
authors.lastname: Bakker
authors.forename: J Dik F
authors.initials: JD
authors.lastname: Habbema
authors.forename: Fern
authors.initials: F
authors.lastname: Terris-Prestholt
authors.forename: Lilani
authors.initials: L
authors.lastname: Kumaranayake
authors.forename: Anne
authors.initials: A
authors.lastname: Buvé
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hayes
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000453:epidemiology; D000465:Algorithms; D003362:Cost-Benefit Analysis; D004196:Disease Outbreaks / Q000191:economics / Q000517:prevention & control*; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D015995:Prevalence; D012749:Sexually Transmitted Diseases / Q000453:epidemiology / Q000517:prevention & control*; D013269:Stochastic Processes