CROI 2024 Abstract eBook

Abstract eBook

Oral Abstracts

-8.4, -5.9]) and remained the same for males. Among male subpopulations, disparities increased among those with HIV attributable to male-to-male sexual contact (Absolute: EAPC = 1.2 [CI: 0.8, 1.5]; Relative: EAPC = 1.5 [CI: 1.0, 1.9]). Relative disparities increased among males aged 13 ─ 24 years (EAPC = 7.4 [CI: 7.0, 7.7] and males in the West (EAPC = 2.0% [CI: 1.1, 2.9]. Among female subpopulations, no increases in disparities were found. Conclusion: Overall, Black-White HIV diagnosis disparities mostly decreased in the United States, indicating progress toward eliminating disparities; however, increases or no changes were observed for some subpopulations, suggesting little to no progress in improvements for health equity. Efforts to address both absolute and relative disparities must be accelerated to eliminate Black-White disparities in HIV diagnosis. Estimating Lifetime Risk of a Diagnosis of HIV Infection Among MSM: United States, 2017-2021 Sonia Singh , Xiaohong Hu, Kristen L. Hess, Kashif Iqbal Centers for Disease Control and Prevention, Atlanta, GA, USA Background: Estimates of lifetime risk are used to compare the burden of disease across populations. This method may be a useful tool for clinicians, outreach workers and policy makers when describing the burden of HIV since it can be more easily understood by the general population. We estimated lifetime risk of a HIV diagnosis among MSM by race/ethnicity and age. Methods: HIV diagnosis, mortality and census population data were used to derive lifetime risk estimates and 95% confidence intervals of HIV diagnosis among MSM by race/ethnicity and age. HIV diagnoses data reported to the National HIV Surveillance System (NHSS) by December 2022 were used. The numbers of HIV diagnoses (NHSS) and non-HIV deaths (National Center for Health Statistics mortality data) during 2017−2021 were used to calculate probabilities of a HIV diagnosis at a given age, conditional on never having received a HIV diagnosis prior to that age using a competing risks method. The lifetime risk estimate is the cumulative probability of HIV diagnosis from birth. Comparisons were made to findings from a 2010−2014 analysis. The analysis was conducted in DevCan 6.7.3. Results: During 2017−2021, the lifetime risk of a HIV diagnosis among MSM was 1 in 7 overall. Lifetime risk among MSM was 1 in 3 for Black/African American persons, 1 in 5 for Hispanic/Latino persons, 1 in 7 for Native Hawaiian/ other Pacific Islander persons, 1 in 11 for American Indian/Alaska Native persons and 1 in 15 for Asian persons and White persons. Lifetime risk improved for all races/ethnicities except for American Indian/Alaska Native, Hispanic/Latino and Native Hawaiian/other Pacific Islander MSM which stayed the same, compared to 2010−2014 (Table). For 10-year age-conditional risk of a HIV diagnosis, the highest 10-year risk experienced overall and for all races/ethnicities was at age 20, with risk decreasing with age. Compared to 2010−2014, improvements occurred for some but not all race/ethnicities. Estimating missed diagnoses in 2020 due to COVID-19, the unadjusted lifetime risk (14.60%) was 2.6% lower than the adjusted risk (14.98%) among MSM. Conclusion: Overall, lifetime risk of HIV diagnosis improved among MSM, but this decrease was not seen across all races/ethnicities. The Ending the HIV Epidemic in the U.S. initiative is designed to scale up key HIV prevention and treatment strategies and is also working to address disparities. There is need for continued progress in HIV prevention and treatment since disparities persist by race/ethnicity among MSM.

1 University of Washington, Seattle, WA, USA, 2 Lund University, Lund, Sweden, 3 Kenyatta National Hospital, Nairobi, Kenya, 4 Bill and Melinda Gates Foundation, Seattle, WA, USA Background: Although recent modeling suggests needle-syringe programs have reduced parenteral HIV transmission among people who inject drugs (PWID) in Kenya, the prevalence in this population remains high (~14-20%, compared to ~4% in the larger population). Reducing transmission or acquisition requires understanding historic and modern transmission trends, but the relationship between the PWID HIV sub- epidemic and the general epidemic in Kenya is not well understood. Incorporating 6-times more HIV sequences from PWID in Kenya than in prior studies, we quantified rates and direction of HIV-1 transmission involving PWID and other populations from the coast and Nairobi regions. Methods: We aligned 303 new (2018-2021) HIV-1 pol sequences from PWID and their sexual and injecting partners with 2,666 previously published Kenyan sequences. We used genetic similarity cluster analysis (thresholds: patristic distance <0.045, aLRT >0.90) and maximum likelihood ancestral state reconstruction to estimate transmission histories at the population (female sex workers, men who have sex with men, PWID, or not key population) and regional (coast or Nairobi) levels. Transition counts estimate how often an ancestor sequence gave rise to a descendant sequence from a different population and/or region. Results: In this cohort, 1,081 participants lived with HIV, of whom 274 (25%) were not virally suppressed and 303 (28%) had sequences available. Of new PWID sequences, 55% were in phylogenetic clusters, and the vast majority were interspersed with sequences from other key populations and from those not in key populations. Only 22% of clusters containing PWID sequences included a second PWID sequence. Ancestral state reconstruction (Figure 1) identified substantial transmission between the coast and Nairobi regions and more not-PWID to PWID transmission than PWID to PWID transmission. Conclusion: Despite recruiting PWID from local injecting networks, we found minimal linked transmission in this population. This suggests low rates of recent parenteral transmission and supports interventions to reduce sexual transmission while maintaining needle-syringe programs. Because the epidemic among PWID and other populations are inter-related, interventions within the larger population, where we also observed the most transmission between regions, may have carry-over benefits for reducing HIV prevalence in PWID and vice versa. However, greater understanding of how PWID and non-PWID populations interact is needed.

Oral Abstracts

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Quantifying HIV-1 Transmission Between People Who Inject Drugs and Other Populations in Kenya Hanley Kingston1, Bhavna Chohan1, George Nduva2, Loice Mbogo3, Aliza Monroe-Wise1, Betsy Sambai1, Brandon Guthrie1, Sarah Masyuko1, David Bukusi3, John Scott1, Carey Farquhar1, Josh Herbeck4

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CROI 2024