1. HIV status among discordant couples in sub-Saharan Africa: A meta-analysis involving more than 13,000 discordant couples Oghenowede Eyawo, 1 Damien de Walque, 2 Nathan Ford, 3 Gloria Gakii, 4 Richard Lester, 5 Edward Mills 6 1)Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada; 2) Development Research Group, The World Bank, Washington DC, USA; 3) Centre for Infectious Disease Epidemiology and Research, University of Cape Town, South Africa; 4)Pumwani Sex-worker Cohort, University of Nairobi, Nairobi, Kenya; 5)Department of Microbiology, Faculty of Medicine, University of Nairobi, Nairobi, Kenya; 6)Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada

2. Sero-discordancy and sub-Saharan Africa  The first Demographic and Health Survey (DHS) suggest: in at least two thirds of couples where at least one of the partners is HIV-positive, only one person is infected  Sero-discordant couples make up a significant number (2/3) of infected couples A substantial # of infections continue to occur within individuals living in a stable relationship  Persons in sero-discordant couple relationship are at particularly high risk of becoming infected

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5. Objectives  The relative HIV-burden within heterosexual discordant partnerships in sub-Saharan Africa is, in fact, poorly understood.  The objective of this study is to determine the gender balance of index case infections among sero-discordant couples in sub-Saharan Africa

6. Methods  We undertook a systematic review of sero- discordancy in stable relationships to determine the gender balance of index case infections in the region.  HIV-discordancy in a relationship: as one existing among married as well as unmarried couples that are in a stable habitual relationship.

7. Methods  Extensive search: we examine published and unpublished data  Secondary analysis: used supplemental data from DHS survey from 14 countries in sub- Saharan Africa

8. Methods  We conducted a random effects meta-analysis and meta-regression analysis to evaluate overall proportion of HIV-index cases  We examined gender gap score by country, urban vs. rural populations, HIV prevalence, mean age difference between men and women  We conducted a sensitivity analysis of pooled cohort proportion to ensure there was no duplication  Analysis: StatsDirect (version 2.7.6, Manchester) and STATA (version 10.0, College Station, TX)

9. Results  Primary data: 25 distinct cohorts in 7 countries + 3 multi-country cohorts, totaling 12,865 couples  Ave. follow-up: 27.3 months (range 9-84)  Secondary data: DHS data from 14 countries totaling 1,145 couples

10. Results  Pooled overall DerSimonian-Laird analysis (primary data): F+ M- couples in stable heterosexual sero-discordant relationships at 47% (95% CI: 43-52%) Demonstrates no significant difference in the # of female +ve couples compared to male +ve sero- discordant couples

11. Meta-analysis Results: primary data Forest plot showing results of the random effects meta-analysis (27 studies)

12. Meta-analysis Results: primary data Forest plot showing results of the random effects meta-analysis (27 studies)

13. Meta-analysis Results: secondary data Forest plot showing results of the random effects meta-analysis (14 studies)

14. Meta-analysis Results: secondary data Forest plot showing results of the random effects meta-analysis (14 studies)

15. Results  Large variability  Meta-regression primary analysis: association with effect size: Urban vs. rural residence Latitude Gender equity Older age  DHS data: meta-regression Gender equity Decreased HIV prevalence

16. Important Findings  A significant proportion of infected couples have women as the infected partner  On average, women are as likely to be the index partner as men in a sero-discordant couple

17. Discussion  These findings seem counter-intuitive to the large body of opinion demonstrating male sexual behaviours and risk taking  Reflects research bias in part  Relatively fewer studies examine women sexual risk taking in stable relationships

18. Necessary Emphasis It is important to emphasise that:  This study is not aimed at assigning blame to either gender  We hope this study will stimulate a more gender-balanced approach in the orientation of behavioural research and prevention interventions

19. Strength & Limitations  We searched extensively both published and unpublished data  We are aware that there are many more unpublished cohorts existing within routine programme, including cohorts in which discordant couples may not be aware of their status  We supplemented our searches with DHS data

20. Conclusions Implications for Prevention Strategies  This review provide a fresh basis for discussions and action points that can guide HIV/AIDS programming.  Sero-discordant couples, especially uninfected partners should be a priority prevention target group  In particular, programmes focusing on sero- discordant couples should be planned to equally target both men and women alike.