CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

1.57-20.43, p=0.008), had group sex in the past 6 months (aOR 2.25; 95%CI 1.01- 5.05, p=0.049) and chlamydial coinfection (aOR 2.12; 95%CI 1.12-4, p=0.021). Conclusion: In this cohort, syphilis coinfection was 3 times higher among HIV-positive MSM than among TG despite TG reported riskier behaviors and higher vulnerability. This suggests that other factors such as sexual networks and biological factors of TG need to be explored to improve the targeting of HIV and STI prevention programs. 980 GAPS IN STI PREVENTION AMONG NIGERIAN MSM ADHERENT TO ART Rebecca G. Nowak 1 , Trevor Crowell 2 , Andrew Mitchell 1 , Teclaire Ndomb 3 , Babajide Keshinro Keshinro 4 , Sheila A. Peel 2 , Charlotte A. Gaydos 5 , Julie Ake 2 , William Blattner 1 , Stefan Baral 5 , Man Charurat 1 1 University of Maryland, Baltimore, MD, USA, 2 US Military HIV Research Program, Silver Spring, MD, USA, 3 Institute of Human Virology Nigeria, Abuja, Nigeria, 4 Walter Reed Program–Nigeria, Abuja, Nigeria, 5 The Johns Hopkins University, Baltimore, MD, USA Background: Once diagnosed with HIV, men who have sex with men (MSM) consistently show a decrease in the potential for onward HIV transmission through modifying sexual practices and engaging in antiretroviral therapy (ART). These health outcomes may also parallel a lower risk of developing bacterial sexually transmitted infections (STIs). Our objective was to evaluate whether engagement in care as quantified by the HIV cascade was associated with fewer incident rectal and urethral STIs among MSM of the TRUST/RV368 cohort study. Methods: FromMarch 2013-August 2017, all HIV-positive patients were offered ART at baseline and were tested every 3 months for Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG). Patients with a first negative STI result and a subsequent test result were included in the analysis (n=572) and further categorized by position in the cascade (47 ART-naïve; 365 ART initiated, 160 suppressed). Viral suppression was defined as more than 6 months below the limit of detection (<20copies/ml). STI incidence could occur repeatedly as long as a positive followed a negative diagnosis with incidence rates (IR) per 100-person years calculated using Poisson modelling. Cox proportional hazards modelling estimated hazard ratios (HR) after adjusting for baseline age, time-varying condomless sex, time-varying number of sexual partners, and wave of recruitment. Results: Median age was 25 years (interquartile range: 22-29). Mean (SD) months of follow-up varied by position in the cascade [ART-naïve: 7.4 (6.4), ART-initiated: 15.7 (9.1), suppressed: 19.9 (9.1)]. Crude incidence rates of rectal NG and CT per 100 person-years (PY) were 3-5 times higher than urethral NG and CT (Table 1). After adjusting for changes in sexual practices, there were no significant differences in the incidence rates of STIs by position in the HIV care cascade. The small amount of observed person-time for those not starting ART may have limited our ability to detect modest differences in the incidence rates between the suppressed and ART-naïve group. Conclusion: These data suggest that achieving viral suppression among MSM does not parallel a reduction in STI-related risk practices. Considering novel approaches such as increased condom choice, improved lubricants, and potentially presumptive treatment for those at higher risk of STIs may help curtail further transmission.

Poster Abstracts

981 HIGH HIV-1 INCIDENCE RATE AMONG ADULTS ATTENDING STI CLINICS IN SOUTHERN MALAWI Fatima G. Zulu 1 , Isaac Singini 2 , Dean Soko 3 , Treaser Thomas 4 , Johnstone Kumwenda 3 , Newton I. Kumwenda 5 1 CDC Malawi, Lilongwe, Malawi, 2 University of Cape Town, Cape Town, South Africa, 3 Malawi College of Medicine-Johns Hopkins University Research Project, Blantyre, Malawi, 4 University of Malawi, Blantyre, Malawi, 5 Johns Hopkins University, Baltimore, MD, USA Background: Knowing HIV incidence rate in a population is critical to the strategy of “’know your epidemic” for effective planning interventions against the epidemic. The objective of our study was to determine HIV incidence rate and risk factors among adults seeking STI care in three districts in Southern Malawi Methods: Between 2010 and 2013, HIV negative adults seeking STI care at clinics in Blantyre, Mulanje and Mwanza in Southern Malawi were enrolled in a prospective cohort study. At baseline, after HIV pre and posttest counseling, HIV negative individuals on rapid tests were consented to participate. Venous blood sample was tested for Acute HIV Infection (AHI) using RNA PCR. Data on demographics, sexual behavior, socioeconomic and health status were collected through direct interviews. At follow-up (FU) (every 3 months), venous blood was collected for HIV testing. Rapid test HIV positive results were confirmed using Western Blot (WB). Viral load (VL) was measured by RNA PCR among seroconverters. HIV Incidence rate was calculated by deviding number of HIV seroconversions observed by the follow–up duration in person-years (pys). After univariate analysis and adjustment with multivariate analysis, using the Cox Proportional Hazard model (HR), independent risk factors were identified. Chi- square or Fischer exact test for categorical and t-test for continuous variables were used to test differences among groups. Results: Preliminary results for Blantyre were previously reported at CROI in 2015. 1055 HIV negative adults were enrolled and followed up, 57%were females, mean age was 28.0 (range18 - 52). Overall, FU duration was 1813 pys and 76 seroconverted, the incidence rate was 4.2 [95%CI; 3.17-5.09] per 100 pys. In Mulanje district, 500 HIV negative adults were followed up for 835 pys and 21 seroconverted, the incidence rate was about 2.51 [95% CI, 1.48-4.38] per 100 pys. In Mwanza, 408 HIV negative adults were followed up for 600 pys, 12 seronconverted and the incidence rate was 1.9 per 100 pys. On multivariate analysis; having more than 2 sexual partners [HR=2.5: (95% CI; 1.3-4.8)], engaging in transactional sex [HR=2.1: 95% CI,1.4-3.2] and reporting ever using a male condom (HR=1.5: 95% CI, 0.9-2.4] were all independently associated

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