Low HIV incidence but high HCV incidence among people who inject drugs in Haiphong, Vietnam: Results of the ANRS 12299/NIDA P30DA011041 DRIVE-IN study M.K. Pham, J.P. Moles, H. Duong Thi, T. Nguyen Thi, G. Hoang Thi, T.T. Nham Thi, V. Vu Hai, H.O. Khuat Thi, R. Vallo, M. Peries, K. Arasteh, C. Quillet, J. Feelemyer, L. Michel, T. Hammett, N. Nagot, D. Des Jarlais, D. Laureillard, for DRIVE study group Thank you Mr Chairman, I am delighted to present, on behalf of the DRIVE study group, the results of the first phase of the DRIVE project. This project is a collaboration between teams from Vietnam including Community-based organisations, from New York, from Paris and from Montpellier (in the most beautiful region of France according to my colleagues).

“No Conflicts Of Interest To Declare” Conflict of Interest “No Conflicts Of Interest To Declare” The authors declare no conflict of interest for this communication.

Background In Vietnam, HIV control programs targeting persons who inject drugs (PWID), including harm reduction and scaled-up antiretroviral therapy (ART) have been implemented for about 10 years. National HIV prevalence declined from 30% in 2009 (66% in Hai Phong) to 10% in 2013 among PWID, with high geographical disparities. No information on current HIV incidence rate, nor on HCV incidence. In Vietnam, HIV control programs targeting persons who inject drugs (PWID), including harm reduction and scaled up ART have been implemented for about 10 years. Although HIV prevalence is declining in this group, the impact of this program on the rate of HIV new infections, but also on HCV transmission, remains unknown.

Objectives To estimate HIV and HCV prevalence and incidence among active PWID in Hai Phong, Vietnam To identify the determinants of HCV seroconversion among this group The objectives of this work were to estimate HIV and HCV prevalence and incidence among active PWID in Hai Phong, Vietnam, And to identify the determinants of HCV seroconversion among this same group.

Methods Community-based respondent driven sampling (RDS) survey among 'active PWID' in Haiphong, with HIV and HCV testing, implemented in October 2014 Active PWID = positive urine test for heroin + injection marks Longitudinal follow-up: HIV-negative participants and HCV-negative participants not on methadone maintenance therapy (MMT) were eligible for 1 year follow-up. HIV/HCV testing, behavioural questionnaire at 6 and 12 months Routine harm reduction activities and support to access MMT/HIV care by community-based organizations (CBO). Estimation of HIV and HCV incidence and identification of risk factors associated with HCV seroconversion. We carried out a community-based respondent driven sampling survey among 'active PWID' in Haiphong, including HIV and HCV testing. We meant by Active PWID drug users with positive urine test for heroin and presence of injection marks. Then, HIV-negative participants and HCV-negative participants who were not on methadone maintenance therapy (MMT) were eligible for 1 year follow-up. HIV/HCV serology was tested at 6 months and 1 year along with routine harm reduction activities from community-based organizations (CBO) who also supported to access MMT and HIV care. We estimated HIV and HCV incidence and risk factors associated with HCV seroconversion.

Results Among the 603 RDS participants, the HIV prevalence was 25% and HCV prevalence was 66%. 250 RDS participants were then included in the subsequent longitudinal study, of whom 204 RDS participants were enrolled in the cohort assessing HIV and HCV incidence, including 105 HIV-/HCV+ , 94 HIV-/HCV- and 5 HIV+/HCV-.

Baseline characteristics among PWID in Hai Phong HIV negative N=199 HCV negative N=99 Male sex 179 (89.9%) 89 (89.9%) Age (median [IQR]) 37 [30-45] 36 [30-43] Having ever been arrested 127 (63.8%) 63 (63.6%) Number of year of injection 6[2-12] 5[1-9] Number of injection in last month 90[60-90] 78[60-90] Meth use in last 3 m/urine detection 56 (28.1%) 27 (27.3%) Injection with used needle/syringe 7 (3.5%) 2 (2.0%) Number of sexual partner 1[1-4] No condom use with casual partner 4 (2.0%) 1 (1.0%) MSM (last 3 months) 19 (9.6%) 12 (12.1%) FSW (last 3 months) 17 (8.5%) 9 (9.1%) HIV-positive serology 5 (5.1%) HCV-positive serology 105 (52.8%) The characteristics of participants from the two cohorts (HIV and HCV) are presented in this table. Overall, participants presented very similar patterns with a median age of 36-37 years, and 5-6 years of injection history. They injected 2 to 3 times per day on average, and a quarter of them smoked methamphetamine over the previous 3 months. Participants reported few needles and syringes sharing practices, and few sexual risky behaviours.

Results 45/204 (22%) participants did not reach 12 months f-up: 3 withdrew, 4 died, 22 were arrested and 16 moved out No HIV seroconversion during the 206 pers-yrs of follow-up (HIV incidence 95%CI: 0-1.8/100 pers-yrs). 18 participants seroconverted for HCV  HCV incidence of 19.4/100 pers-yrs [95%CI; 11.5-30.7]. 13/18 HCV seroconversion happened during the first 8 months HCV incidence of : 26.7/100 pers-yrs (14.2-45.6) w0 - w32 13.2/100 pers-yrs (4.3; 30.8) w32 - w64 159/204 participants remained after the follow-up period. The follow-up rate was 78%. No participant seroconverted for HIV during the 206 person-years of follow-up, giving an estimated HIV incidence ranging between 0 and 1.8/100PY (2.5% unilateral). However, 18 participants were detected HCV seroconverted during the follow-up giving an estimated HCV incidence of 19.4/100 person-years [95%CI; 11.5-30.7]. Especially 13/18 HCV seroconversion happened during the first eight months, so the HCV incidence was of 26.7/100 PY (95%CI: 14.2-45.6) until week 32 and of 13.2/100 PY (95%CI: 4.3; 30.8) between week 32 and week 64.

Factors associated with HCV seroconversion Crude OR (95%CI) Adjusted OR (95%CI) Sex* (female vs male/transgender) 1.9 (0.3-9.6) Age* (>27years) 0.4 (0.1-2.2) Time of injection (< 2 years) 1.8 (0.6-5.1) >73 injections per month 11.4 (3.6-36.9) 13.7 (3.3-71.6) Use of methamphetamine§ 0.5 (0.2-1.3) 0.3 (0.1-1.4) Accepted used syringe* 4.2 (0.1-341.5) Having shared syringe* 0.6 (0.1-3.4) Having one new sexual partner every 3 months* 0.3 (0.1-1.2) 0.3 (0.1-1.6) Having a primary sexual partner injecting drugs* 3.5 (0.3-34.0) Have been arrested during the at-risk period* 4.6 (6.0-38.0) 6.4 (0.5-87.4) Being under methadone during the at-risk period* 2.9 (0.2-27.7) In univariable analysis, the factors associated with HCV seroconversion were the number of injections per month, and having been arrested at least once during the course of the follow-up In multivariable analyses, only injecting more than 73 times per month was significantly associated with HCV seroconversion, with a high OR of 13.7. Interestingly, having been arrested was also positively associated with HCV seroconversion, but did not remain significant in the multivariable analysis. Of note, some injection practices such as sharing water were not recorded in the questionnaire. § normal model; * exact model

Conclusions Low HIV incidence among active PWID in Haiphong Larger data are required to confirm HIV is close to elimination among active PWID In contrast, the HCV incidence is unacceptably high. More investigations is required to understand the routes of HCV transmission. However, as in other settings, it is unlikely that harm reduction activities alone, even if adapted to HCV infection, will be able to control HCV in this group. Therefore, large access to HCV treatment is now a priority given the efficacy and safety of the DAA Further implementation studies are required to define an appropriate model of HCV testing and cure among PWID in Vietnam. Although our findings should be confirmed with more data, the HIV incidence among active PWID in Haiphong is remarkably low. This low HIV incidence likely results from the high coverage of harm reduction activities including MMT and ART. In contrast, HCV incidence is still unacceptably high, and more investigation must be done to understand why. However, as in other settings, it is unlikely that harm reduction activities alone, even if adapted to HCV infection, will be able to control HCV in this group. Therefore, large access to HCV treatment is now a priority given the efficacy and safety of the DAA. Further implementation studies are required to define an appropriate model of HCV testing and cure among PWID in Vietnam.

Acknowledgments Funding agencies: Agence Nationale de Recherches sur le SIDA et les hépatites virales (ANRS) and the US National Institute of Drug Abuse (NIDA) Haiphong Provincial Health authorities, Viet Tiep Hospital, Haiphong Dr. Vu Van Cong, Pr. Truong Thi Xuan Lien, Pr. F. Barré-Sinoussi The DRIVE scientific advisory board, and particularly Laurence Weiss and Jean-Pierre Daulouède All the participants enrolled in the study Finally, I would like to thank the ANRS, the NIDA and the Global Fund who contributed to fund this study, the ……