Explaining racial disparities in HIV incidence in black and white men who have sex with men in Atlanta, GA: a prospective observational cohort study

Abstract

Purpose To describe factors associated with racial disparities in HIV incidence among men who have sex with men (MSM) in the United States. Methods In a longitudinal cohort of black and white HIV-negative MSM in Atlanta, HIV incidence rates were compared by race. Incidence hazard ratios (HR) between black and white MSM were estimated with an age-scaled Cox proportional hazards model. A change-in-estimate approach was used to understand mediating time-independent and -dependent factors that accounted for the elevated HR. Results Thirty-two incident HIV infections occurred among 260 black and 302 white MSM during 823 person-years (PY) of followup. HIV incidence was higher among black MSM (6.5/100PY; 95% CI: 4.2, 9.7) than white MSM (1.7/100PY; CI: 0.7, 3.3), and highest among young (18–24 years) black MSM (10.9/100PY; CI: 6.2, 17.6). The unadjusted hazard of HIV infection for black MSM was 2.9 (CI: 1.3–6.4) times that of white MSM; adjustment for health insurance status and partner race explained effectively all of the racial disparity. Conclusions Relative to white MSM in Atlanta, black MSM, particularly young black MSM, experienced higher HIV incidence that was not attributable to individual risk behaviors. In a setting where partner pool risk is a driver of disparities, it is also important to maximize care and treatment for HIV-positive MSM.

Impact of the Centers for Disease Control's HIV Preexposure Prophylaxis Guidelines for Men Who Have Sex With Men in the United States

“…This work builds on an earlier modeling project to investigate the causes and consequences of racial disparities in HIV incidence among MSM in the United States [15]. Parameters for sexual behavior were drawn from 2 empirical studies of MSM in Atlanta, Georgia [16].…”

“…Per-act factors influencing the transmission probability included viral load [21], condom use [22], receptive versus insertive sexual position [18], circumcision for an insertive negative partner [23], and the presence of the CCR5-Δ32 genetic allele [24,25]. After infection, persons were assigned into clinical care trajectories controlling rates of HIV diagnosis, ART initiation, and HIV viral suppression, to match empirical estimates of the prevalence of these states [15]. ART was associated with decreased viral load (and related transmission risk) [26] and extended life span [27].…”

Are Partner Race and Intimate Partner Violence Associated with Incident and Newly Diagnosed HIV Infection in African-American Men Who Have Sex with Men?

“…A study by Hernandez-Romieu et al found that HIV prevalence among Black MSM sexual networks was 36% compared to only 4% among White MSM sexual networks. 15 Previous studies have used these findings to propose that higher HIV incidence and prevalence among Black MSM may be explained by same race 1,3,[16][17][18][19] or older partners. 1,7,16,20,21 However, other analyses have contested the relationship between HIV incidence and partner race 22 or partner age.…”

Development of an Agent-Based Model to Investigate the Impact of HIV Self-Testing Programs on Men Who Have Sex With Men in Atlanta and Seattle (Preprint)

“…After infection, men were assigned into three clinical care trajectories: men who never initiate treatment, men who initiate treatment and become partially suppressed, and men who initiate treatment and become fully suppressed. The three trajectories had different rates of infectiousness, HIV diagnosis, ART initiation, HIV viral suppression, and progression to AIDS and death, in order to match empirical estimates of the prevalence of these states [25]. ART decreased viral load and its associated transmission risk [3] and extended the life span [26].…”