AIDS and Behavior

, Volume 16, Issue 7, pp 1746–1752 | Cite as

Is Concurrency Driving HIV Transmission in Sub-Saharan African Sexual Networks? The Significance of Sexual Partnership Typology



Recently, there has been debate about the role of concurrent partnerships in driving the transmission of HIV, particularly in Southern Africa, where HIV prevalence is up to 25 % in many heterosexual populations and where evidence from sexual behavior surveys also suggests high levels of male concurrency. While mathematical modeling studies have shown that concurrency has the potential to enhance the speed at which HIV spreads in a population, empirical studies up to now have failed to provide conclusive evidence supportive of these effects. Here we discuss some reasons for the apparent discrepancy between theoretical and empirical studies. We propose that studying the impact of concurrency on HIV transmission should be differentiated by taking more insight from social and behavioral studies on sexual partnerships into account. We also suggest that a more rigorous definition is needed for when a factor is considered a driving force for HIV epidemic spread. We illustrate this with a modeling example.


Concurrent partnerships HIV transmission Sub-Saharan Africa Sexual networks Mathematical models Basic reproduction number 


Reciéntemente se ha debatido el rol que las parejas concurrentes tienen en impulsar la transmisión de VIH, particularmente en Sudáfrica, donde la prevalencia en muchas poblaciones heterosexuales es de hasta 25 % y la evidencia de comportamiento sexual también sugiere altos niveles de concurrencia en hombres. Mientras que estudios con modelos matemáticos muestran que la concurrencia tiene el potencial de aumentar la velocidad de propagación de VIH en la población, hasta ahora estudios empíricos no han logrado mostrar evidencia concluyente sobre estos efectos. Aquí discutimos algunas razones de la aparente discrepancia entre los estudios teóricos y empíricos. Proponemos que estudios sobre el impacto de la concurrencia en la transmisión de VIH se deberían diferenciar considerando mayor entendimiento proveniente de estudios sociales y conductuales sobre parejas sexuales. También proponemos que se necesita una definición más rigurosa para cuando un factor se considera fuerza impulsora de propagación de una epidemia de VIH. Empleamos un modelo para ilustrar un ejemplo.


  1. 1.
    Diez Roux AV. Integrating social and biologic factors in health research: a systems view. Ann Epidemiol. 2007;17:569–74.PubMedCrossRefGoogle Scholar
  2. 2.
    Morris M, Kretzschmar M. Concurrent partnerships and the spread of HIV. AIDS. 1997;11:641–8.PubMedCrossRefGoogle Scholar
  3. 3.
    Lurie M, Rosenthal S, Williams B. Concurrency driving the African HIV epidemics: where is the evidence? Lancet. 2009;374:1420; author reply 1420–1421.Google Scholar
  4. 4.
    Lurie MN, Rosenthal S. Concurrent partnerships as a driver of the HIV epidemic in sub-Saharan Africa? The evidence is limited. AIDS Behav. 2010;14:17–24; discussion 25–18.Google Scholar
  5. 5.
    Mah TL. Prevalence and correlates of concurrent sexual partnerships among young people in South Africa. Sex Transm Dis. 2010;37:105–8.PubMedCrossRefGoogle Scholar
  6. 6.
    Bove R, Valeggia C. Polygyny and women’s health in sub-Saharan Africa. Soc Sci Med. 2009;68:21–9.PubMedCrossRefGoogle Scholar
  7. 7.
    Glynn JR, Buve A, Carael M, Macauley IB, Kahindo M, Musonda RM, et al. Is long postpartum sexual abstinence a risk factor for HIV? AIDS. 2001;15:1059–61.PubMedCrossRefGoogle Scholar
  8. 8.
    Carael M. Sexual behavior. In: Cleland J, Ferry B, editors. Sexual behavior and AIDS in the developing world. Findings from a multisite study. London: Taylor and Francis; 1995. p. 75–123.Google Scholar
  9. 9.
    Kelly R, Gray RH, Valente TW, Sewankambo NK, Serwadda D, Wabwire-Mangen F, et al. Concurrent and non-concurrent sexual partnerships and risk of prevalent and incident HIV. In: International AIDS conference, Durban, South Africa; 2000.Google Scholar
  10. 10.
    Reniers G, Tfaily R. Polygyny and HIV in Malawi. Demogr Res. 2008;19:1811–30.PubMedCrossRefGoogle Scholar
  11. 11.
    Reniers G, Watkins S. Polygyny and the spread of HIV in sub-Saharan Africa: a case of benign concurrency. AIDS. 2010;24:299–307.PubMedCrossRefGoogle Scholar
  12. 12.
    Morris M, Kretzschmar M. Concurrent partnerships and transmission dynamics in networks. Soc Netw. 1995;17:299–318.CrossRefGoogle Scholar
  13. 13.
    Tanser F, Barnighausen T, Hund L, Garnett GP, McGrath N, Newell ML. Effect of concurrent sexual partnerships on rate of new HIV infections in a high-prevalence, rural South African population: a cohort study. Lancet. 2011;378:247–55.PubMedCrossRefGoogle Scholar
  14. 14.
    Morris M, Kretzschmar M. A microsimulation study of the effects of concurrent partnerships on the spread of HIV in Uganda. Math Pop Stud. 2000;8:109–33.CrossRefGoogle Scholar
  15. 15.
    Kretzschmar M, Morris M. Measures of concurrency in networks and the spread of infectious disease. Math Biosci. 1996;133:165–95.PubMedCrossRefGoogle Scholar
  16. 16.
    Kretzschmar M. Graphs and line graphs as a model for contact patterns. Zeitschrift fuer Angewandte Mathematik und Mechanik. 1996;76:433–6.CrossRefGoogle Scholar
  17. 17.
    UNAIDS Reference Group. Consultation on concurrent sexual partnerships: recommendations from a meeting of the UNAIDS reference group on estimates, modelling and projections held in Nairobi, Kenya, April 20–21, 2009; 2009.Google Scholar
  18. 18.
    Glynn JR, Dube A, Kayuni N, Floyd S, Molesworth A, Parrott F, et al. Measuring concurrency: an empirical study of different methods in a large population-based survey and evaluation of the UNAIDS guidelines. AIDS. 2012;26:977–85.PubMedCrossRefGoogle Scholar
  19. 19.
    Carael M, Kretzschmar M. Measuring concurrent partnerships: back on track. AIDS. 2012;26:1027–9.PubMedCrossRefGoogle Scholar
  20. 20.
    Kuate S, Mikolajczyk RT, Forgwei GW, Tih PM, Welty TK, Kretzschmar M. Time trends and regional differences in the prevalence of HIV infection among women attending antenatal clinics in 2 provinces in Cameroon. J Acquir Immune Defic Syndr. 2009;52:258–64.PubMedCrossRefGoogle Scholar
  21. 21.
    Green EC, Mah TL, Ruark A, Hearst N. A framework of sexual partnerships: risks and implications for HIV prevention in Africa. Stud Fam Plann. 2009;40:63–70.PubMedCrossRefGoogle Scholar
  22. 22.
    Leclerc-Madlala S. Age-disparate and intergenerational sex in southern Africa: the dynamics of hyper vulnerability. AIDS. 2008;22(Suppl 4):S17–25.PubMedCrossRefGoogle Scholar
  23. 23.
    Leclerc-Madlala S. Cultural scripts for multiple and concurrent partnerships in southern Africa: why HIV prevention needs anthropology. Sex Health. 2009;6:103–10.PubMedCrossRefGoogle Scholar
  24. 24.
    Nelson SJ, Hughes JP, Foxman B, Aral SO, Holmes KK, White PJ, et al. Age- and gender-specific estimates of partnership formation and dissolution rates in the Seattle sex survey. Ann Epidemiol. 2010;20:308–17.PubMedCrossRefGoogle Scholar
  25. 25.
    Gorbach PM, Stoner BP, Aral SO, Whittington WL, Holmes KK. “It takes a village”: understanding concurrent sexual partnerships in Seattle, Washington. Sex Transm Dis. 2002;29:453–62.PubMedCrossRefGoogle Scholar
  26. 26.
    Wa Karanja W. Outside wives and inside wives in Nigeria: a study of changing perceptions in marriage. In: Parkin D, Nyamwaya D, editors. Transformation of African marriage. Manchester: Manchester University Press; 1987.Google Scholar
  27. 27.
    Shelton JD. Why multiple sexual partners? Lancet. 2009;374:367–9.PubMedCrossRefGoogle Scholar
  28. 28.
    Helleringer S, Kohler HP. Sexual network structure and the spread of HIV in Africa: evidence from Likoma Island, Malawi. AIDS. 2007;21:2323–32.PubMedCrossRefGoogle Scholar
  29. 29.
    Potterat JJ, Rothenberg RB, Muth SQ. Network structural dynamics and infectious disease propagation. Int J STD AIDS. 1999;10:182–5.PubMedCrossRefGoogle Scholar
  30. 30.
    Rocha LE, Liljeros F, Holme P. Simulated epidemics in an empirical spatiotemporal network of 50,185 sexual contacts. PLoS Comput Biol. 2011;7:e1001109.PubMedCrossRefGoogle Scholar
  31. 31.
    Diekmann O, Heesterbeek JAP. Mathematical epidemiology of infectious diseases: model building, analysis, and interpretation. Chichester: Wiley; 2000.Google Scholar
  32. 32.
    Pilcher CD, Tien HC, Eron JJ Jr, Vernazza PL, Leu SY, Stewart PW, et al. Brief but efficient: acute HIV infection and the sexual transmission of HIV. J Infect Dis. 2004;189:1785–92.PubMedCrossRefGoogle Scholar
  33. 33.
    Wawer MJ, Gray RH, Sewankambo NK, Serwadda D, Li X, Laeyendecker O, et al. Rates of HIV-1 transmission per coital act, by stage of HIV-1 infection, in Rakai, Uganda. J Infect Dis. 2005;191:1403–9.PubMedCrossRefGoogle Scholar
  34. 34.
    Koopman JS, Jacquez JA, Welch GW, Simon CP, Foxman B, Pollock SM, et al. The role of early HIV infection in the spread of HIV through populations. J Acquir Immune Defic Syndr Hum Retrovirol. 1997;14:249–58.PubMedCrossRefGoogle Scholar
  35. 35.
    Brenner BG, Roger M, Routy JP, Moisi D, Ntemgwa M, Matte C, et al. High rates of forward transmission events after acute/early HIV-1 infection. J Infect Dis. 2007;195:951–9.PubMedCrossRefGoogle Scholar
  36. 36.
    Lewis F, Hughes GJ, Rambaut A, Pozniak A, Leigh Brown AJ. Episodic sexual transmission of HIV revealed by molecular phylodynamics. PLoS Med. 2008;5:e50.PubMedCrossRefGoogle Scholar
  37. 37.
    Abu-Raddad LJ, Longini IM Jr. No HIV stage is dominant in driving the HIV epidemic in sub-Saharan Africa. AIDS. 2008;22:1055–61.PubMedCrossRefGoogle Scholar
  38. 38.
    Powers KA, Ghani AC, Miller WC, Hoffman IF, Pettifor AE, Kamanga G, et al. The role of acute and early HIV infection in the spread of HIV and implications for transmission prevention strategies in Lilongwe, Malawi: a modelling study. Lancet. 2011;378:256–68.PubMedCrossRefGoogle Scholar
  39. 39.
    Eaton JW, Hallett TB, Garnett GP. Concurrent sexual partnerships and primary HIV infection: a critical interaction. AIDS Behav. 2011;15:687–92.PubMedCrossRefGoogle Scholar
  40. 40.
    Chen MI, Ghani AC, Edmunds J. Mind the gap: the role of time between sex with two consecutive partners on the transmission dynamics of gonorrhea. Sex Transm Dis. 2008;35:435–44.PubMedCrossRefGoogle Scholar
  41. 41.
    Xiridou M, Geskus R, De Wit J, Coutinho R, Kretzschmar M. The contribution of steady and casual partnerships to the incidence of HIV infection among homosexual men in Amsterdam. AIDS. 2003;17:1029–38.PubMedCrossRefGoogle Scholar
  42. 42.
    Xiridou M, Geskus R, de Wit J, Coutinho R, Kretzschmar M. Primary HIV infection as source of HIV transmission within steady and casual partnerships among homosexual men. AIDS. 2004;18:1311–20.PubMedCrossRefGoogle Scholar
  43. 43.
    Leung KY. Transmission of infection along a dynamic sexual network with star-shaped components. MSc thesis. Utrecht: Utrecht University; 2011.Google Scholar
  44. 44.
    Leung KY, Kretzschmar M, Diekmann O. Dynamic concurrent partnership networks incorporating demography. 2012 (submitted).Google Scholar
  45. 45.
    Boily MC, Alary M, Baggaley RF. Neglected issues and hypotheses regarding the impact of sexual concurrency on HIV and sexually transmitted infections. AIDS Behav. 2012;16(2):304–11.Google Scholar
  46. 46.
    Padian NS, Manian S. The concurrency debate: time to put it to rest. Lancet. 2011;378:203–4.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  1. 1.Julius Centre for Health Sciences and Primary CareUniversity Medical Centre UtrechtUtrechtThe Netherlands
  2. 2.Centre for Infectious Disease ControlRIVMBilthovenThe Netherlands
  3. 3.Department of Social SciencesFree University of BrusselsBrusselsBelgium

Personalised recommendations