CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

1273 Identification of Clinical Phenotypes in MSM With HIV From a Prospective Study on Acute HCV and STIs

Pablo Ryan 1 , Juan Berenguer 2 , Luis Ramos 3 , Leire Pérez-Latorre 2 , Ignacio de los Santos 4 , Laura Bermejo Plaza 5 , Santos del Campo Terrón 6 , Eva Orviz 7 , Pilar Ruiz-Seco 8 , Rafael Torres 8 , Juan C. López 2 , Beatriz Brazal 9 , José M. Bellón 2 , Luz Martín-Carbonero 3 , Juan González-García 3 1 Hospital Universitario Infanta Leonor, Madrid, Spain, 2 Hospital General Universitario Gregorio Marañón, Madrid, Spain, 3 Hospital Universitario La Paz, Madrid, Spain, 4 Hospital Universitario de La Princesa, Madrid, Spain, 5 Hospital Universitario 12 de Octubre, Madrid, Spain, 6 Hospital Universitario Ramon y Cajal, Madrid, Spain, 7 Hospital Universitario Clínico San Carlos, Madrid, Spain, 8 Servicio Madrileño de Salud, Madrid, Spain, 9 Fundación SEIMC-GeSIDA, Madrid, Spain Background: This study aimed to identify clinical phenotypes (CPs) among MSM with HIV enrolled in a prospective study on acute/recent HCV infections (ARHCV) and bacterial STIs and to assess their correlation with different risk profiles. Methods: Between 2021 and 2023, MSM with HIV were recruited from 12 centers across the Madrid region. Participants were assessed at baseline, 6 months, and 12 months. At each visit (or when indicated), screening for HCV and STIs was conducted alongside questionnaires on sexual behavior, substance use, and mental health (using HADS and adult ADHD scales). A total of 38 variables spanning four domains—sociodemographic/clinical, mental health, sexual behavior, and substance use—were analyzed. Principal component analysis (PCA) was used for dimensionality reduction, followed by participant clustering via Hierarchical Clustering (HC) as the primary method and K-means clustering (KMC) for sensitivity analysis. The adequacy of the PCA model was evaluated using the Kaiser-Meyer-Olkin (KMO) measure and Bartlett’s test. Statistical analyses were performed in R version 4.4.1 (packages: Tidyverse, Cluster, Factoextra, NbClust, tidyr). Results: 529 MSM were enrolled (median age 41 years, 88% Caucasian, 62% native Spaniards). During follow-up, 332 STIs (114 syphilis, 121 gonorrhea, 97 chlamydia) were diagnosed in 212 participants, and ARHCV was detected in 24 participants. PCA revealed 6 factors explaining 59% of the observed variability (KMO score: 0.794) and HC identified 3 optimal CPs (Figure): CP1: 328 participants (62.0%) with a lower frequency of high-risk sexual practice (receptive condomless anal sex) and minimal drug use. CP2: 133 participants (25.1%) engaging in frequent high-risk sexual practices and moderate drug use. CP3: 68 participants (12.9%) with a history of very high-risk sexual practices (e.g., fisting) and significant drug use, including injection and intrarectal administration. ARHCV was identified in 4 participants (1.2%) in CP1, 4 (3.0%) in CP2, and 16 (23.5%) in CP3 (P < 0.001). One or more STIs were diagnosed in 114 participants (34.8%) in CP1, 61 (45.9%) in CP2, and 37 (54.4%) in CP3 (P = 0.003). Sensitivity analysis using KMC confirmed these findings. Conclusions: MSM with HIV can be categorized into distinct CPs with varying risk levels for ARHCV and STIs. These findings can inform more targeted prevention, screening, and intervention strategies for HCV and STIs in this population.

1272 Epidemiology of Bacterial STIs in MSM With or At Risk of HIV in the Region of Madrid (2021-2023) Luis Ramos 1 , Juan Berenguer 2 , Pablo Ryan 3 , Mar Vera 4 , Leire Pérez-Latorre 2 , Ignacio de los Santos 5 , María de Lagarde 6 , Santos del Campo Terrón 7 , Eva Orviz 8 , Beatriz Alvarez 9 , José Sanz 10 , Beatriz Brazal 11 , José M. Bellón 2 , Luz Martín Carbonero 1 , Juan González-García 1 1 Hospital Universitario La Paz, Madrid, Spain, 2 Hospital General Universitario Gregorio Marañón, Madrid, Spain, 3 Hospital Universitario Infanta Leonor, Madrid, Spain, 4 Centro Sanitario Sandoval, Madrid, Spain, 5 Hospital Universitario de La Princesa, Madrid, Spain, 6 Hospital Universitario 12 de Octubre, Madrid, Spain, 7 Hospital Universitario Ramon y Cajal, Madrid, Spain, 8 Hospital Universitario Clínico San Carlos, Madrid, Spain, 9 Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain, 10 Hospital Universitario Príncipe de Asturias, Madrid, Spain, 11 Fundación SEIMC GeSIDA, Madrid, Spain Background: We analyzed the epidemiology of bacterial STIs among MSM with HIV (MSM-WH) and those at risk of HIV (MSM-RH) in Madrid, evaluating associated risk factors. Methods: This prospective study (2021–2023) included MSM-WH from the Spanish Network of AIDS Research Cohort (CoRIS) and those treated for HCV with DAAs in the Madrid Coinfection Registry (Madrid-CoRE). MSM-RH were recruited from PrEP users at a public STI clinic. Participants were assessed at baseline and follow-up (6 and 12 months). Sexual and substance use behaviors were evaluated at baseline, with STI screening (PCR for gonorrhea and chlamydia in pharyngeal, urethral, and rectal swabs, and syphilis serology) at each visit or when indicated. Baseline prevalence and follow-up incidence were stratified by HIV status, excluding prevalent cases from incidence analysis. Poisson regression was used to identify associations between sociodemographic and behavioral factors and STI counts during the study period (baseline and follow up). Independent variables included age, country of origin, condomless anal sex (CLAX), chemsex, prior STI, and prior HCV, adjusted for cohort effects and observation time. Sensitivity analyses used logistic and Poisson regressions, separating prevalent and incident STIs. Results: A total of 1,372 MSM participated (733 MSM-WH, 639 MSM-RH). MSM-WH were older (41 vs. 37 years), and 60% were native Spaniards. In total, 725 STIs were detected in 535 participants. Baseline prevalence and incidence rates are provided in the table. The STI prevalence ratio for MSM-WH versus MSM-RH was 0.85 (95% CI: 0.68-1.07), and the STI incidence rate ratio (IRR) was 0.79 (95% CI: 0.66-0.95). Significant risk factors for STIs included chemsex (adjusted IRR [95% CI] 1.392 [1.174–1.651]), CLAX (aIRR 1.372 [1.047–1.796]), prior syphilis (aIRR 1.318 [1.062–1.636]), and prior chlamydia (aIRR 1.306 [1.076–1.586]). Older age (aIRR 0.988 [0.979–0.996]) and being a native Spaniard (aIRR 0.787 [0.678–0.913]) were associated with lower STI risk. Sensitivity analyses confirmed these associations. Conclusions: Both MSM-WH and MSM-RH exhibited high bacterial STI prevalence and incidence. Chemsex, CLAX, previous syphilis, and previous chlamydia infection were significant risk factors. STI screening and prevention strategies should prioritize these factors to reduce STI rates in MSM.

Poster Abstracts

1274 Prevalence and Incidence of HIV/STIs Among MSM and Men Who Have Sex With Women in the SAMURAI Study Thesla Palanee-Phillips 1 , Elizabeth (Liz) Montgomery 2 , Ellen Luecke 1 , Nkosiphile Ndlovu 1 , Sihle K. Zulu 1 , Krishnaveni Reddy 1 , Nompumelelo Sigcu 1 , Lindsay Kew 1 , Reolebogile Kgoa 2 , Chayla Hart 3 , Millicent Atujuna 3 , Katherine Gill 3 , Pippa Macdonald 2 , Alexandra Minnis 2 , for the SAMURAI Study Team 1 Wits Reproductive Health and HIV Institute, Johannesburg, South Africa, 2 RTI International, Berkeley, CA, USA, 3 Desmond Tutu HIV Foundation, Cape Town, South Africa Background: Syndromic management of STIs often limits their detection and targeted treatment. MSW typically display low health-seeking behavior and

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