title: Attaining realistic and substantial reductions in HIV incidence: model projections of combining microbicide and male circumcision interventions in rural Uganda.
abstract: OBJECTIVE
  This study simulates the potential impact of male circumcision and female microbicide interventions, singularly and in combination, in rural Uganda.
  
  
  METHODS
  A dynamic model was parameterised and fitted to setting-specific data, and used to estimate the impact on HIV transmission of a microbicide and/or male circumcision intervention over 15 years. The proportion of circumcised men or women using microbicides was assumed to increase linearly from 0.18 (male circumcision) or 0.00 (microbicide use) to the final proportion 10 years later, then remain constant for 5 years. Women using microbicides were assumed to use the product in 80% of penile-vaginal sex acts. Male circumcision or microbicide use was assumed to reduce the per-act probability of HIV acquisition in men or women, respectively, by 60%.
  
  
  RESULTS
  Independently, to obtain a 30% relative reduction in HIV incidence at 15 years, the model suggests that the final proportion of women using microbicides would need to be 0.91 (95% CI 0.75 to 1.00) or the proportion of circumcised men would need to be 0.96 (0.83 to impact not possible). The same impact could be achieved by combining the interventions, eg, if the proportion of women using microbicides was 0.49 (0.39 to 0.56) and the proportion of circumcised men was 0.67 (0.57 to 0.74).
  
  
  CONCLUSIONS
  Under these assumptions, as separate interventions it is unlikely that increases in either the proportion of men circumcised or of women using microbicides could reduce HIV incidence by 30% or more at 15 years. A combination-prevention strategy using complementary interventions may be a more feasible approach to achieve substantial reductions in incidence.
authors.affiliation: Social and Mathematical Epidemiology Group, Centre for Mathematical Modelling of Infectious Disease, London School of Hygiene and Tropical Medicine, London, UK. andrew.cox@lshtm.ac.uk
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Cox
authors.forename: Anna M
authors.initials: AM
authors.lastname: Foss
authors.forename: Leigh Anne
authors.initials: LA
authors.lastname: Shafer
authors.forename: Rebecca N
authors.initials: RN
authors.lastname: Nsubuga
authors.forename: Peter
authors.initials: P
authors.lastname: Vickerman
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Hayes
authors.forename: Charlotte
authors.initials: C
authors.lastname: Watts
authors.forename: Richard G
authors.initials: RG
authors.lastname: White
mesh_terms: D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage*; D002944:Circumcision, Male / Q000706:statistics & numerical data*; D003140:Communicable Disease Control / Q000379:methods*; D003198:Computer Simulation; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control* / Q000635:transmission; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D012424:Rural Population; D014454:Uganda / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents