CROI 2020 Abstract eBook

Abstract eBook

Poster Abstracts

(py) of follow-up. Incidence of first HCV infection decreased significantly (p- trend=0.04) over time during the study period: 0.98/100py (2014), 0.82/100py (2015), 0.67/100py (2016) and 0.45/100py (2017). The stronger decrease occurred in 2017 (33% reduction from 2016 to 2017). In sensitivity analyses, similar trends were observed when the date of first positive HCV was used as a proxy for the time of infection, or when follow-up was ceased at the date of last clinical visit or 12 months after for patients lost to follow-up. Conclusion: The observed decrease in primary HCV infections among HIV- infected MSMmay be related to a concomitant and continuous scaling-up in DAA use, which was especially marked in HIV-HCV coinfected individuals. The declining trend may also be considered in parallel with the rising incidence of HCV infection recently reported among HIV-negative MSM receiving preexposure prophylaxis (PrEP), suggesting a transfer of the epidemic from the former to the latter.

598 LARGE HEPATITIS C TRANSMISSION CLUSTER IDENTIFIED AMONG HIV- POSITIVE MSM IN BANGKOK Win Min Han 1 , Donn J. Colby 1 , Apichaya Khlaiphuengsin 2 , Tanakorn Apornpong 1 , Stephen J. Kerr 1 , Sasiwimol Ubolyam 1 , Eugène Kroon 1 , Nittaya Phanuphak 1 , Anchalee Avihingsanon 1 , Kiat Ruxrungtham 1 , Praphan Phanuphak 1 , Pisit Tangkijvanich 2 1 Thai Red Cross AIDS Research Center, Bangkok, Thailand, 2 Chulalongkorn University, Bangkok, Thailand Background: A rapidly emerging HCV outbreak has recently been observed among HIV-positive men who have sex with men (MSM) living in Bangkok, Thailand. Little is known regarding the transmission networks among this population. Methods: MSM with both acute (Feibig stages 1 to 5) and chronic HIV infection and with incident HCV infections were identified in research cohorts at the Thai Red Cross AIDS Research Centre. Incident HCV infections were defined as seroconversion from anti-HCV antibody negative to positive after initiating ART. NS5B regions of the HCV genome (404 and 471 bps) were amplified using nested-PCR and sequenced. Phylogenetic inference was constructed by Maximum Likelihood methods in MEGA X.0.5 software with 1000 bootstrap samplings. Clusters were identified using ClusterPicker with support and genetic distance thresholds of 85% and of 4.5%, respectively. Results: A total of 48 (25 acute HIV and 23 chronic HIV) MSM with incident HCV infection and amplifiable NS5B sequences were included in the analysis. Median (interquartile range, IQR) HCV RNA was 6.3 (5.3-6.9) IU/mL. HCV genotype (GT) was 85% GT 1a and 15% GT 3a or 3b. Median age at HCV diagnosis was 34 (IQR, 28-41) years. 83.3% (40/48) had history of syphilis infection and 36% (16/44) reported crystal methamphetamine use. Only 2 (4%) reported ever injecting drugs, both crystal methamphetamine. Six (12.5%) were HBV co-infected, all of whom had chronic HIV. In the phylogenetic clustering analysis, 83% belonged to one of two clusters: one large (n=36, 75%) and one small (n=4, 8%) cluster (Figure). All clusters were GT 1a. Overall mean genetic distance was 0.10 (SE=0.02). Participants with acute HIV infection were more likely to be in a cluster (92%) than those with chronic infection (74%). Conclusion: Phylogenetic analysis showing a high degree of clustering confirms that the HCV epidemic in the HIV-infected MSM community in Bangkok is recent and rapidly expanding. This epidemic is independent of past HCV transmission among people who inject drugs in Thailand, which was largely GT 3. Crytal methamphetamine use is high in participants with HCV infection, and previous reports have identified chemsex and group sex parties as factors associated with HCV transmission. HCV antibody testing should be regularly performed for MSM on ART in Bangkok, and direct-acting antivirals being offerred to all MSM with HCV infection might contain this HCV epidemic from spreading further.

Poster Abstracts

599 ORAL PRESCRIPTION OPIOID USE AS A HIGH-RISK INDICATOR FOR HCV INFECTION Benjamin A. Hack 1 , Utsav Timalsina 2 , Emily Paku 2 , Brittany Wilkerson 2 , Eshetu Tefera 2 , Stephen Fernandez 2 , Dawn Fishbein 2 1 Georgetown University, Washington, DC, USA, 2 MedStar Health Research Institute, Hyattsville, MD, USA Background: The opioid epidemic across the U.S. poses an array of public health concerns, especially HCV transmission. HCV is now widely-curable, yet incident rates are increasing due to the opioid epidemic. Despite the established trajectory from oral prescription opioids (OPOs) to opioid use disorder (OUD), OUD to injection drug use (IDU), and IDU to HCV, we have found no studies or guidelines establishing OPOs as a defined risk factor (RF) for HCV infection. In this study we observed HCV testing and antibody reactivity (HCVAb+) in patients receiving OPOs, hypothesizing that they should be considered an HCV RF, critical in the global effort toward HCV elimination. Methods: The study was conducted on all patients with any OPO reported in the EHR at a large regional US healthcare system between January 2017 and December 2018. Chi-square and Student t-tests were used for univariate comparisons; multivariate logistic regression was used for independent variable associations. Statistical significance was defined as p<0.05; Epi Info and SAS v 9.4 were used for statistical analyses; IRB approval was received. Results: 115,415 persons received any OPO (Table 1); 8.6% (932) were HCVAb+ when tested and not previously diagnosed (10,900); 3.4% (3,893) had an OUD diagnosis, 20.6% (803) of whomwere HCV tested. Of those HCVAb+ (1,421), 25.4% (361) had an OUD diagnosis. In the Birth Cohort born between 1945-65 (BC), black race (ORadj 2.22, CI95 1.90-2.59), male (2.45, 2.12-2.82) and OUD (6.97, 5.60-8.67) were independent predictors of HCVAb+; white race (1.68, 1.32-2.13) and OUD (9.65, 7.46-12.48) in the non-BC. Conclusion: These results offer three applicable conclusions: 1) in a large population prescribed oral opioids, HCVAb+ was 8.6%, higher than our previously published data (2.5%) and US rate (1.7%); thus, OPOs should be incorporated as a defined RF for HCV counseling and retesting; 2) although OUD may lead to known HCV RFs, only 20% of patients diagnosed with OUD were tested; thus, efforts should be increased to improve HCV RF awareness; and, 3) although the trajectory from OPOs to OUD to IDU to HCV would predict that a majority of HCVAb+ patients have OUD, only 25% of those HCVAb+ were

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