2018 Postgraduate Research Symposium: Exploring opportunities Risk behaviour and reinfection: Longitudinal sexual and drug use behaviours among HIV/HCV co-infected population in Australia Samira Hosseini Hooshyar PhD Candidate | Viral Hepatitis Research Program, Kirby Institute Supervisors: A/Professor Gail Matthews, Professor Gregory Dore, Dr. Marianne Martinello and A/Professor Jason Grebely

BACKGROUND The Control and Elimination of HCV from HIV-infected individuals within Australia Objective: To evaluate the feasibility of rapid scale-up of DAA treatments and impact on the proportion with HCV viraemia within the HIV-HCV population of Australia. Design: Observational cohort study Eligibility: Adults (≥18 years) HIV infection past (HCV Ab +, RNA -) or current (HCV Ab +ve, RNA +ve) HCV infection Assessments: Enrolment: 1 July 2014 - 22 March 2017 Follow-up1: 26 May 2017- 31 May 2018

49 95% 80% 2% 13% 79% 72% 595 70% 93% 4% Baseline Characteristics Age (mean) 49 Male 95% GBM 80% ATSI ethnicity 2% Cirrhosis 13% IDU ever 79% HCV RNA positive 72% CD4 (median, 106/L) 595 HIV VL BLoD 70% cART 93% HBsAg 4%

Injecting Risk behaviours at enrolment and follow-up 1 36% 35% 33% 33% 25% 24% 23% 17% 13% 11% * among Recent IDU

Sexual Risk behaviours at enrolment and follow-up 1 69% 68% 63% 51% 53% 40% 34% 25% P =0.000 P =0.002 P =0.020

Conclusion and next aims No evidence of increasing HCV risk behaviors to date Injecting risk remaining stable Some reduction in sexual risk behaviour Next steps: To identify associations with risk behaviours at baseline To evaluate factors associated with change in risk behaviours between enrolment and follow up To estimate the incidence of HCV reinfection and identify predictors of reinfection among participants Methods Logistic regression, Generalized estimating equations (GEE) and person‐time of observation and Exact Poisson regression analysis using extended data set from baseline and longitudinal surveys