P36.04
Background: Age-disparate relationships where the male partner is older than the female partner have been associated with increased HIV acquisition risk in women. A recent analysis of data from South Africa failed to observe an association between age-disparate partnerships and HIV acquisition. We assessed the association between partner age and HIV acquisition among South African women in VOICE.
Methods: VOICE was a randomized, double-blinded, placebo-controlled trial conducted at 11 sites in South Africa that assessed the safety and effectiveness of daily oral and vaginal chemoprophylaxis for HIV prevention in women. Cox proportional hazards models stratified by site were used to assess participant-reported male partner age at enrollment and HIV acquisition risk in the first year of follow-up.
Results: Among 4077 South African women enrolled, 3789 had complete data for this analysis. Of these, 26% and 5% reported having a male partner>5 and>10 years older at enrollment, respectively. There were 230 HIV infections within 1 year of follow-up (3181 person-years). Reporting a male partner>5 years older was not associated with HIV acquisition (HR 1.00; 95% CI 0.74, 1.35). Findings were similar for reporting a male partner>10 years older (HR 0.92; 95% CI 0.49, 1.74). Results for both male partner age categories were similar among younger and older women (women<25 years: male>5 years, HR 1.01 [95% CI 0.71, 1.44]; male>10 years, HR 1.24; [95% CI 0.58, 2.66] versus women≥25 years: male>5 years, HR 0.95 [95% CI 0.55, 1.65]; male>10 years, HR 0.68 [95% CI 0.21, 2.17]). Results were consistent after adjusting for known baseline risk factors for HIV acquisition in VOICE.
Conclusions: These data corroborate recent reports and may suggest a shift in local epidemiology of heterosexual HIV transmission. Given the limitations of these analyses (use of enrollment data and inclusion of only one partner in analysis), regular assessment of characteristics to identify women at greatest risk of HIV acquisition is needed.
