Only a fraction of new HIV infections occur within identifiable stable discordant couples in sub-Saharan Africa

Hiam Chemaitelly, James D. Shelton, Timothy B. Hallett, Laith J. Abu-Raddad

Research output: Contribution to journalArticle

29 Citations (Scopus)


OBJECTIVE: To estimate the contribution of HIV-1 sero-conversions among stable HIV sero-discordant couples (SDCs) to total HIV population-level incidence in sub-Saharan Africa. DESIGN AND METHODS: We constructed a mathematical model, grounded in nationally representative demographic and epidemiological data, that estimates the annual number of HIV-1 transmissions from the infected partners to the uninfected partners among established SDCs, and compares its value to an estimate for the overall HIV population-level incidence in 20 countries in sub-Saharan Africa. We defined identifiable HIV-1 transmissions among SDCs as those that a hypothetical screening and intervention program would have the potential to avert. Uncertainty and sensitivity analyses were incorporated to assess the robustness of the findings. RESULTS: Across the 20 countries, an average of 29% (range: 10-52%) of new HIV-1 infections occurred in which one partner in an identifiable SDC infected the other. The percentage of total HIV new infections in a country that occurred within such identifiable SDCs tended to be lower in countries with larger general population HIV epidemics. For most countries, HIV-1 incidence among SDCs is unlikely to exceed 50% of new HIV infections in the whole population. CONCLUSION: Only a fraction of HIV-1 heterosexual transmissions occur within identifiable SDCs. Prevention within SDCs at scale requires a series of potentially challenging programmatic requirements to be met. Despite the importance of prevention programs aiming at protecting the sero-negative partner in an SDC, a wider strategy utilizing the full range of prevention modalities, which would limit the original generation of SDCs, is also needed.

Original languageEnglish
Pages (from-to)251-260
Number of pages10
Issue number2
Publication statusPublished - 14 Jan 2013



  • HIV incidence
  • demographic and health surveys
  • mathematical model
  • sero-discordant couples
  • sub-Saharan Africa

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Infectious Diseases

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