Modelling HIV incidence and survival from age-specific seroprevalence after antiretroviral treatment scale-up in rural South Africa

AIDS. 2013 Sep 24;27(15):2471-9. doi: 10.1097/01.aids.0000432475.14992.da.


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.

Design: 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.

Conclusion: 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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Anti-Retroviral Agents / therapeutic use
  • Cross-Sectional Studies
  • Female
  • HIV Infections / drug therapy
  • HIV Infections / epidemiology*
  • HIV Infections / mortality
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Models, Theoretical*
  • Rural Health / statistics & numerical data*
  • Sex Distribution
  • South Africa / epidemiology
  • Survival Rate
  • Young Adult


  • Anti-Retroviral Agents