title: Modelling HIV incidence and survival from age-specific seroprevalence after antiretroviral treatment scale-up in rural South Africa.
abstract: OBJECTIVE
  Our study uses sex-specific and age-specific HIV prevalence data from an ongoing population-based demographic and HIV survey to infer HIV incidence and survival in rural KwaZulu-Natal between 2003 and 2011, a period when antiretroviral treatment (ART) was rolled out on a large scale.
  
  
  METHODS
  Catalytic mathematical model for estimating HIV incidence and differential survival in HIV-infected persons on multiple rounds of HIV seroprevalence.
  
  
  METHODS
  We evaluate trends of HIV incidence and survival by estimating parameters separately for women and men aged 15-49 years during three calendar periods (2003-2005, 2006-2008, 2009-2011) reflecting increasing ART coverage. We compare model-based estimates of HIV incidence with observed cohort-based estimates from the longitudinal HIV surveillance.
  
  
  RESULTS
  Median survival after HIV infection increased significantly between 2003-2005 and 2009-2011 from 10.0 [95% confidence interval (CI) 8.8-11.2] to 14.2 (95% CI 12.6-15.8) years in women (P < 0.001) and from 10.0 (95% CI 9.2-10.8) to 14.0 (95% CI 10.6-17.4) years in men (P = 0.02). Our model suggests no statistically significant reduction of HIV incidence in the age-group 15-49 years in 2009-2011 compared with 2003-2005. Age-specific and sex-specific model-based HIV incidence estimates were in good agreement with observed cohort-based estimates from the ongoing HIV surveillance.
  
  
  CONCLUSIONS
  Our catalytic modelling approach using cross-sectional age-specific HIV prevalence data could be useful to monitor trends of HIV incidence and survival in other African settings with a high ART coverage.
authors.affiliation: aAfrica Centre for Health and Population Studies, University of KwaZulu-Natal, Somkhele, KwaZulu-Natal, South Africa bDepartment of Global Health and Population, Harvard School of Public Health, Harvard University, Boston, Massachusetts, USA cFaculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Joël
authors.initials: J
authors.lastname: Mossong
authors.forename: Erofili
authors.initials: E
authors.lastname: Grapsa
authors.forename: Frank
authors.initials: F
authors.lastname: Tanser
authors.forename: Till
authors.initials: T
authors.lastname: Bärnighausen
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Newell
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D044966:Anti-Retroviral Agents / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000401:mortality; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D012423:Rural Health / Q000706:statistics & numerical data*; D017678:Sex Distribution; D013019:South Africa / Q000453:epidemiology; D015996:Survival Rate; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents