CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

cervicovaginal sE-cad levels and lower cervicovaginal MIP-3α levels, there was no evidence of an association after controlling for BV Nugent score. Conclusion: Subclinical epithelial barrier disruption is unlikely to be a major mechanism underpinning increased HIV acquisition among individuals with HSV-2 infection. No immune predictors of increased HSV-2 susceptibility were apparent, although the genital microbiome may play an important role. 1169 HIV and STIs in US Bisexual Men and Gay Men: Clinical Implications and Service Needs Thomas Carpino 1 , Kaitlyn Atkins 1 , Cristian S. Acero 2 , Iaah Lucas 2 , Hector Moran 1 , Sarah Murray 1 , Travis H. Sanchez 2 , Stefan Baral 1 1 The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, 2 Emory University, Atlanta, GA, USA Background: Bisexual individuals comprise over half of LGBTQ+ persons in the United States (US), yet remain understudied in HIV and STI research. Goals to end the US HIV epidemic require reaching bisexual cisgender men who have sex with men (MSM) who may have different sexual health behaviors and prevention/care needs than gay-identified MSM. Methods: We analyzed data from self-identified bisexual (n=778) and gay (n=3290) MSM who participated in the 2022-2023 American Men's Internet Survey (AMIS), a cross-sectional online study of MSM aged 15 and older in the US who have had same-sex anal sex within the past 12 months. We evaluated self-reported HIV and STI diagnosis (chlamydia, gonorrhea, syphilis, and mpox) within a past year, testing activities, sexual practices, PrEP use, experiences of outness, and healthcare-related stigma, and associations with sexual identity. Results: Lifetime HIV testing was 9.1% less prevalent in bisexual men compared to gay men (p=0.001), and 58.7% (n=451) of bisexual men received an HIV test in the prior year (Table). Lifetime PrEP use was 18.6% lower in bisexual compared to gay men (p=0.001). Among MSM who had initiated PrEP, 73.1% of bisexual men (n=182) reported PrEP use in the past 12 months, compared to 78.0% (n=1235) of gay men. Bisexual men reported lower rates of past-year STI testing (p=0.001) and diagnosis (chlamydia, mpox: p<0.01; syphilis: p=0.016). Compared to gay men, bisexual men were 32.5% less likely to be out to providers (p=0.001) and 12.5% less likely to discuss sex with providers (p=0.001). Among bisexual men, outness to healthcare providers was not associated with anticipated healthcare stigma, but among gay men, outness was associated with lower anticipated healthcare stigma (p=0.001). Conclusion: Despite lower HIV and STI prevalence among bisexual men in our study, we found disparities in uptake of PrEP, suggesting a need for research into barriers to PrEP and/or tailored messaging for this group. Greater anticipated healthcare stigma, lower outness, and less frequent conversations about sexual practices among bisexual men highlight a need to ensure healthcare providers adequately address the HIV and sexual health needs of this population. These findings provide a more comprehensive understanding of considerations to inform testing, prevention, and reducing anticipated healthcare stigma among bisexual men. The figure, table, or graphic for this abstract has been removed. 1170 Relevance of Asymptomatic STIs in a High-Risk Population of MSM Undergoing Periodic Screening Rosario Palacios, Cristinia Gómez-Ayerbe , María López-Jódar, Isabel A. Pérez Hernández, Isabel Viciana, Marina Villalobos, Victoria García, Jesús Santos Hospital Virgen de la Victoria, Málaga, Spain Background: One of the limitations in the control of STIs is that many of them are asymptomatic, making diagnosis, treatment, and contact tracing challenging. The objective of this study is to analyze the significance of asymptomatic STIs in a high-risk population (MSM) that undergoes regular screening for these infections Methods: This was a single-center study involving two populations: our cohort of MSM on PrEP (Pre-Exposure Prophylaxis) and People Living with HIV (PLHIV) followed up at our clinic, both at risk of STIs, who undergo STI screening every 3-6 months (including serological tests, cultures, and nucleic acid amplification tests in pharyngeal, rectal, and urethral/urine samples). The following STIs were analyzed: Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Lymphogranuloma venereum (LGV), and syphilis. Study period: November 1, 2022, to June 30, 2023. Proportions were compared using the chi-squared test or Fisher's exact test. Statistical analysis was performed using SPSS 24.0 software. Results: During this period, STI screening was conducted on 788 individuals on PrEP and 456 PLHIV, all MSM. A total of 560 STIs were diagnosed (359 in

10.2% (90/881), with 19 (21.1%) new diagnoses. Prevalence of STIs was: CT 18.3% (161/881); NG 4.2% (37/881); TV 12.5% (110/881); syphilis 3.9% (34/881); and HBV 1.5% (13/881). 31.7% (279/881) had at least one non-HIV STI (CT, NG, TV, syphilis, or HBV). 879/881 (99.8%) of participants collected their results, with 98.9% (871/881) receiving same-day results. Of 272 (30.9%) participants with a curable STI (CT, NG, TV, or syphilis), 270 (99.3%) received same day treatment. Partner notification slips were provided to 260 participants with a curable STI, with 81 (31.2%) partners attending for treatment. 84.6% (11/13) of individuals diagnosed with hepatitis B were linked to secondary care. Conclusion: There is limited testing for CT, NG, TV, or HBV available across public sector health services, including ANC, in Southern Africa. There is urgent need to implement strategies for prevention, detection, and treatment for these highly prevalent STIs. The high uptake and provision of same-day results and treatment in this study demonstrate acceptability and feasibility. However, less than 10% of pregnant clients were approached, owing to limited testing capacity. Further implementation research is urgently needed to address scalability, in order to expand integrated STI testing at ANC clinics.

Poster Abstracts

1168 Genital Immune Correlates of Prevalent and Incident Herpes Simplex Virus 2 (HSV-2) Infection Suji Udayakumar 1 , James Pollock 1 , Sanja Huibner 1 , Mary Kung'u 2 , Rhoda Kabuti 2 , Erastus Irungu 2 , Pauline Ngurukiri 2 , Peter Muthoga 2 , Wendy Adhiambo 2 , Helen Weiss 3 , Janet Seeley 3 , Tara Beattie 3 , Joshua Kimani 2 , Rupert Kaul 1 , for the Maisha Fiti Study Champions 1 University of Toronto, Toronto, Canada, 2 Partners for Health and Development, Nairobi, Kenya, 3 London School of Hygiene & Tropical Medicine, London, United Kingdom Background: Most herpes simplex virus type 2 (HSV-2) infections are asymptomatic, but infection increases genital CD4+ T cell activation and risk of HIV acquisition. We examine associations of seroprevalent and seroincident HSV-2 infection with genital immune parameters, including soluble E-cadherin (sE-cad), a biomarker of epithelial barrier disruption. Methods: This longitudinal study was nested within the Maisha Fiti cohort of 1003 females who sell sex in Nairobi, Kenya. Among 731 HIV-negative participants, HSV-2 serostatus was assessed by Kalon HSV-2 IgG assay at baseline and follow up. Soluble genital immune factors were assayed in cervicovaginal secretions using a multiplex electro-chemiluminescent immunoassay (MSD), and socio-behavioural characteristics assessed by questionnaire. Socio-behavioural characteristics and immune parameters were compared between HSV-2 seropositive and seronegative participants using chi-square and Mann-Whitney U tests and examined using linear regression models controlling for potential confounders. Socio-behavioural characteristics and immune parameters reported to be predictive of HSV-2 acquisition were also similarly compared between participants with incident infection and those who were seronegative throughout the study period. Results: 414 (57%) participants were HSV-2 seropositive at baseline. Compared with women who were HSV-2 seronegative, women who were HSV-2 seropositive were older (p<0.01) and more likely to report intravaginal washing (p=0.02). Cervicovaginal sE-cad levels did not vary based on HSV-2 serostatus (median = 73590 vs 69934 pg/mL, p=0.21), and IL-6 levels were lower in seropositive participants (p<0.01). HSV-2 seroincidence was 10.7 per 100 person years among the 317 initially seronegative participants; incident infection was associated with increased age (p<0.01), a higher number of clients (p<0.01), and bacterial vaginosis (BV; present in 32% vs 15% of seroconverters, p<0.01). Although women who acquired HSV-2 infection had higher baseline

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