MOAC0101 - Oral Abstract
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. Sullivan1
1Emory 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
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]
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