Abstract

MOAC0101 - Oral Abstract Session

Equal behaviors, unequal risks: the role of partner transmission potential in racial HIV disparities among men who have sex with men (MSM) in the US

Presented by Eli Rosenberg (United States).

E. Rosenberg¹, C. Kelley², B. O'Hara¹, P. Frew², J. Peterson³, T. Sanchez¹, C. del Rio⁴, P. Sullivan<sup>1

1</sup>Emory University Rollins School of Public Health, Epidemiology, Atlanta, United States, ²Emory University School of Medicine, Infectious Diseases, Atlanta, United States, ³Georgia State University, Psychology, Atlanta, United States, ⁴Emory University Rollins School of Public Health, Global Health, Atlanta, United States

Background: Differences in individual risk behavior do not explain the large disparities in HIV prevalence and incidence between black and white MSM in the US. Patterns of partner selection, virologic suppression in HIV-positive sex partners, and unprotected anal intercourse (UAI) may jointly contribute to these disparities, but are not well understood.
Methods: The InvolveMENt study is an ongoing cohort of black and white MSM in Atlanta designed to evaluate individual, dyadic, and community level factors that might explain HIV disparities. Participants are recruited from community-based venues, tested for HIV, and surveyed. We used Monte Carlo simulation with data about patterns of sexual partnering, UAI, and levels of virologic suppression among MSM in Atlanta to estimate how frequently black and white HIV-negative MSM would have UAI with a sex partner with transmission potential (viral load > 500 copies/ml).
Results: Among 556 MSM recruited to-date, the 12-month median number of UAI partners was 2 for both black and white men (p=0.19). Based upon HIV prevalence, viral-load estimates and reported partnership characteristics, the estimated average annual probabilities (95% CI) of having ≥ 1 UAI partner with transmission potential were 0.37 (0.32, 0.43) for black and 0.20 (0.15, 0.24) for white MSM (p < .0001). The estimated number of UAI partners to have a 50% chance of having a UAI partner with viral load > 500 copies/ml was 3 for black and 7 for white MSM.
Conclusions: HIV-negative black MSM have comparable risk behaviors, but have a substantially higher likelihood of encountering a UAI partner with viral load >500 copies/ml. Our results suggest a limited ability of behavioral interventions to eliminate racial disparities, and support the need to increase HIV testing with linkage to care and antiretroviral treatment of all HIV-positive MSM to reduce the risk of HIV transmission from sex partners.


[Figure: Simulation results]