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Multiple factors affect injecting drug-related mortality, many of which will vary over time and between jurisdictions. There are relatively few studies of mortality among injecting drug users (IDU) in Australia. We aimed to provide data comparable to those reported internationally on the rate of mortality among IDU in Australia. We retrospectively examined mortality among participants (N=220) from the first Australian cohort study of IDU by linking coded personal identifier records with a national death register. The overall mortality rate among those followed-up was 0.83 per 100 PY (95% CI, 0.56-1.21 per 100 PY). This rate is lower than those reported internationally but comparable to the limited Australian data from other cohorts of IDU. Mortality was higher among males, most common among those aged in their early thirties and drug-related mortality occurred typically after substantial injecting careers. Extensive experience of incarceration (>/=3 times) was associated with increased risk of mortality. These results suggest that rates of mortality among Australian IDU may be lower than those reported internationally, with low HIV prevalence and Australia's long-held harm reduction framework potentially contributing to this result. Further studies using defined cohorts followed over time are needed to examine long-term outcomes among IDU in Australia. [ABSTRACT FROM AUTHOR]

Abstract Background In recent years social networking sites (SNSs) have grown rapidly in popularity. The popularity of these sites, along with their interactive functions, offer a novel environment in which to deliver health promotion messages. The aim of this paper is to examine the extent to which SNSs are currently being used for sexual health promotion and describe the breadth of these activities. Methods We conducted a systematic search of published scientific literature, electronic sources (general and scientific search engines, blogs) and SNSs (Facebook, MySpace) to identify existing sexual health promotion activities using SNSs. Health promotion activities were eligible for inclusion if they related to sexual health or behaviour, utilised one or more SNSs, and involved some element of health promotion. Information regarding the source and type of health promotion activity, target population and site activity were extracted. Results 178 sexual health promotion activities met the inclusion criteria and were included in the review; only one activity was identified through a traditional systematic search of the published scientific literature. Activities most commonly used one SNS, were conducted by not-for-profit organisations, targeted young people and involved information delivery. Facebook was the most commonly used SNS (used by 71% of all health promotion activities identified), followed by MySpace and Twitter. Seventy nine percent of activities on MySpace were considered inactive as there had been no online posts within the past month, compared to 22% of activities using Facebook and 14% of activities using Twitter. The number of end-users and posts in the last seven days varied greatly between health promotion activities. Conclusions SNSs are being used for sexual health promotion, although the extent to which they are utilised varies greatly, and the vast majority of activities are unreported in the scientific literature. Future studies should examine the key factors for success among those activities attracting a large and active user base, and how success might be measured, in order to guide the development of future health promotion activities in this emerging setting.

Abstract Background The Australian Government launched a mass media campaign in 2009 to raise awareness of the harms and costs associated risky drinking among young Australians. The aim of this study was to assess if young people attending a music festival who report frequent risky single occasions of drinking (RSOD) recognise the key message of the campaign, "Binge drinking can lead to injuries and regrets", compared to young people who report less frequent RSOD. Methods A cross-sectional behavioural survey of young people (aged 16-29 years) attending a music festival in Melbourne, Australia, was conducted in January 2009. We collected basic demographics, information on alcohol and other drug use and sexual health and behaviour during the previous 12 months, and measured recognition of the Australian National Binge Drinking Campaign key message. We calculated the odds of recognition of the key slogan of the Australian National Binge Drinking Campaign among participants who reported frequent RSOD (defined as reported weekly or more frequent RSOD during the previous 12 months) compared to participants who reported less frequent RSOD. Results Overall, three-quarters (74.7%) of 1072 participants included in this analysis recognised the campaign message. In the adjusted analysis, those reporting frequent RSOD had significantly lower odds of recognising the campaign message compared to those not reporting frequent RSOD (OR 0.7, 95% CI 0.5-0.9), whilst females had significantly greater odds of recognising the campaign message compared to males (OR 1.8, 95% CI 1.4-2.1). Conclusions Whilst a high proportion of the target group recognised the campaign, our analysis suggests that participants that reported frequent RSOD - and thus the most important group to target - had statistically significantly lower odds of recognising the campaign message.

Abstract Background Stigma is a key barrier for the delivery of care to patients living with HIV/AIDS (PLWHA). In the Asia region, the HIV/AIDS epidemic has disproportionately affected socially marginalised groups, in particular, injecting drug users. The effect of the stigmatising attitudes towards injecting drug users on perceptions of PLWHA within the health care contexts has not been thoroughly explored, and typically neglected in terms of stigma intervention. Methods Semi-structured interviews were conducted with a group of twenty Thai trainee and qualified nurses. Drawing upon the idea of 'social reciprocity', this paper examines the constructions of injecting drug users and PLWHA by a group of Thai nurses. Narratives were explored with a focus on how participants' views concerning the high-risk behaviour of injecting drug use might influence their attitudes towards PLWHA. Results The analysis shows that active efforts were made by participants to separate their views of patients living with HIV/AIDS from injecting drug users. While the former were depicted as patients worthy of social support and inclusion, the latter were excluded on the basis that they were perceived as irresponsible 'social cheaters' who pose severe social and economic harm to the community. Absent in the narratives were references to wider socio-political and epidemiological factors related to drug use and needle sharing that expose injecting drug users to risk; these behaviours were constructed as individual choices, allowing HIV positive drug users to be blamed for their seropositive status. These attitudes could potentially have indirect negative implications on the nurses' opinions of patients living with HIV/AIDS more generally. Conclusion Decreasing the stigma associated with illicit drugs might play crucial role in improving attitudes towards patients living with HIV/AIDS. Providing health workers with a broader understanding of risk behaviours and redirecting government injecting drug policy to harm reduction are discussed as some of the ways for stigma intervention to move forward.

Abstract Background The hepatitis C virus (HCV) is a major cause of drug-related morbidity and mortality, with incidence data implicating a wide range of HCV transmission risk practices. The Blood-Borne Virus Transmission Risk Assessment Questionnaire (BBV-TRAQ) is a content valid instrument that comprehensively assesses HCV risk practices. This study examines the properties of a new weighted BBV-TRAQ designed to quantify HCV transmission risk among injecting drug users (IDU). Methods Analyses of cross-sectional surveys of Australian IDU (N = 450) were used to generate normative data and explore the properties of a weighted BBV-TRAQ. Items weights were assigned according to expert key informant ratings of HCV risk practices performed during the development stages of the BBV-TRAQ. A range of item weights was tested and psychometric properties explored. A weighting scheme was recommended based on the plausibility of normative subscale data in relation to research evidence and the ability of BBV-TRAQ scores to discriminate between HCV positive and negative participants. Results While retaining the psychometric properties of the unweighted scale and demonstrating good internal reliability. By taking into account the relative transmission risk of a broad range of putative HCV practices, the weighted BBV-TRAQ produced promising predictive validity results among IDU based on self-report HCV status, particularly among young and less experienced injectors. Conclusion Brief, easy to administer and score, and inexpensive to apply, the utility of the BBV-TRAQ for community based education and prevention is enhanced by the application of item weights, potentially offering a valid surrogate measure for HCV infection among IDU.

Abstract Hepatitis C is the most common blood borne virus in Australia affecting over 200 000 people. Effective treatment for hepatitis C has only become accessible in Australia since the late 1990's, although active injecting drug use (IDU) remained an exclusion criteria for government-funded treatment until 2001. Treatment uptake has been slow, particularly among injecting drug users, the largest affected group. We developed a peer-based integrated model of hepatitis C care at a community drug and alcohol clinic. Clients interested and eligible for hepatitis C treatment had their substance use, mental health and other psychosocial comorbidities co-managed onsite at the clinic prior to and during treatment. In a qualitative preliminary evaluation of the project, nine current patients of the clinic were interviewed, as was the clinic peer worker. A high level of patient acceptability of the peer-based model and an endorsement the integrated model of care was found. This paper describes the acceptability of a peer-based integrated model of hepatitis C care by the clients using the service.

Background: Gay and bisexual men (GBM) remain overrepresented among syphilis diagnoses in Australia and globally. The extent to which changes in sexual networks associated with HIV pre-exposure prophylaxis (PrEP) and treatment as prevention (TasP) may have influenced syphilis transmission among GBM at the population-level is poorly understood. We describe trends in syphilis testing and incidence among GBM in Australia over eleven years spanning widespread uptake of HIV PrEP and TasP., Methods: We analysed linked clinical data from GBM aged 16 years or older across a sentinel surveillance network in Australia from January 1, 2012, to December 31, 2022. Individuals with at least two clinic visits and with at least two syphilis tests during the observations period were included in testing and incidence analyses, respectively. Annual rates of testing and infectious syphilis incidence from 2012 to 2022 were disaggregated by HIV status and PrEP use (record of PrEP prescription; retrospectively categorised as ever or never-PrEP user). Cox regression explored associations between demographics, PrEP use and history of bacterial sexually transmissible infections (STIs) and infectious syphilis diagnosis., Findings: Among 129,278 GBM (mean age, 34.6 years [SD, 12.2]) included in testing rate analyses, 7.4% were living with HIV at entry and 31.1% were prescribed PrEP at least once during the study period. Overall syphilis testing rate was 114.0/100 person-years (py) and highest among GBM with HIV (168.4/100 py). Syphilis testing increased from 72.8/100 py to 151.8/100 py; driven largely by increases among ever-PrEP users. Among 94,710 GBM included in incidence analyses, there were 14,710 syphilis infections diagnosed over 451,560 person-years (incidence rate = 3.3/100 py). Syphilis incidence was highest among GBM with HIV (6.5/100 py), followed by ever-PrEP users (3.5/100 py) and never-PrEP users (1.4/100 py). From 2012 to 2022, syphilis incidence increased among ever-PrEP users from 1.3/100 py to 5.1/100 py, and fluctuated between 5.4/100 py and 6.6/100 py among GBM with HIV. In multivariable Cox regression, previous syphilis diagnosis (adjusted hazard ratio [aHR] = 1.98, 95% CI = 1.83-2.14), living with HIV (aHR = 1.83, 95% CI = 1.12-1.25) and recent (past 12 m) prescription of PrEP (aHR = 1.78, 95% CI = 1.61-1.97) were associated with syphilis diagnosis., Interpretation: Syphilis trends between GBM with HIV and GBM with evidence of PrEP use have converged over the past decade in Australia. Our findings recommend targeting emergent syphilis control strategies (e.g. doxycycline post-exposure prophylaxis) to GBM with prior syphilis diagnoses, using HIV PrEP or who are living with HIV., Funding: Australian Department of Health and Aged Care, National Health and Medical Research Council., Competing Interests: M.W.T. reports speakers’ honoraria, consultancy fees and investigator-initiated research grants from Gilead Sciences. R.G. has received research support funding from Cepheid and SpeeDx. M.E.H. reports investigator-initiated research grants from Gilead Sciences and Abbvie outside of the submitted work. M.A.S. reports investigator-initiated research grants from Gilead Sciences and Abbvie and consulting fees from Gilead Sciences outside of the submitted work. M.B. reports medical advisory boards and speakers’ honoraria from Gilead Sciences and ViiV Healthcare, and funding to attend scientific meetings from Gilead Sciences, investigator-initiated research grants from ViiV Healthcare. EPFC is supported by an Australian National Health and Medical Research Council (NHMRC) Emerging Leadership Investigator Grant (GNT1172873), and has received speakers’ honoraria from Gilead Sciences, MSD and CSL Seqirus. CKF is supported by an Australian NHMRC Leadership Investigator Grant (GNT1172900). VC received payment from Gilead Science for participation on advisory board. DO is CEO of Health Equity Matters, Australia's peak community HIV organization, for part of the period during which the research was undertaken. All other authors declare no conflicts of interest., (© 2024 The Author(s).)

Introduction: Despite universal access to government-funded direct-acting antivirals (DAAs) in 2016, the rate of hepatitis C treatment uptake in Australia has declined substantially. Most hepatitis C is related to injecting drug use; reducing the hepatitis C burden among people who inject drugs (PWID) is, therefore, paramount to reach hepatitis C elimination targets. Increasing DAA uptake by PWID is important for interrupting transmission and reducing incidence, as well as reducing morbidity and mortality and improving quality of life of PWID and meeting Australia's hepatitis C elimination targets., Methods and Analysis: A cluster randomised cross-over trial will be conducted with three intervention arms and a control arm. Arm A will receive rapid hepatitis C virus (HCV) antibody testing; arm B will receive rapid HCV antibody and rapid RNA testing; arm C will receive rapid HCV antibody testing and same-day treatment initiation for HCV antibody-positive participants; the control arm will receive standard of care. The primary outcomes will be (a) the proportion of participants with HCV commencing treatment and (b) the proportion of participants with HCV achieving cure. Analyses will be conducted on an intention-to-treat basis with mixed-effects logistic regression models., Ethics and Dissemination: The study has been approved by the Alfred Ethics Committee (number HREC/64731/Alfred-2020-217547). Each participant will provide written informed consent. Reportable adverse events will be reported to the reviewing ethics committee. The findings will be presented at scientific conferences and published in peer-reviewed journals., Trial Registration Number: NCT05016609., Trial Progression: The study commenced recruitment on 9 March 2022 and is expected to complete recruitment in December 2024., Competing Interests: Competing interests: JSD, MH and AP report investigator-iniated funding to their institution from Gilead Sciences, AbbVie and Merck. JSD reports honoraria to his institution from Gilead Sciences and AbbVie., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Introduction: Longitudinal studies can provide timely and accurate information to evaluate and inform COVID-19 control and mitigation strategies and future pandemic preparedness. The Optimise Study is a multidisciplinary research platform established in the Australian state of Victoria in September 2020 to collect epidemiological, social, psychological and behavioural data from priority populations. It aims to understand changing public attitudes, behaviours and experiences of COVID-19 and inform epidemic modelling and support responsive government policy., Methods and Analysis: This protocol paper describes the data collection procedures for the Optimise Study, an ongoing longitudinal cohort of ~1000 Victorian adults and their social networks. Participants are recruited using snowball sampling with a set of seeds and two waves of snowball recruitment. Seeds are purposively selected from priority groups, including recent COVID-19 cases and close contacts and people at heightened risk of infection and/or adverse outcomes of COVID-19 infection and/or public health measures. Participants complete a schedule of monthly quantitative surveys and daily diaries for up to 24 months, plus additional surveys annually for up to 48 months. Cohort participants are recruited for qualitative interviews at key time points to enable in-depth exploration of people's lived experiences. Separately, community representatives are invited to participate in community engagement groups, which review and interpret research findings to inform policy and practice recommendations., Ethics and Dissemination: The Optimise longitudinal cohort and qualitative interviews are approved by the Alfred Hospital Human Research Ethics Committee (# 333/20). The Optimise Study CEG is approved by the La Trobe University Human Ethics Committee (# HEC20532). All participants provide informed verbal consent to enter the cohort, with additional consent provided prior to any of the sub studies. Study findings will be disseminated through public website (https://optimisecovid.com.au/study-findings/) and through peer-reviewed publications., Trial Registration Number: NCT05323799., Competing Interests: Competing interests: Burnet Institute has received investigator initiated clinical research funding form Gilead Sciences, AbbVie and Merck unrelated to this grant., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background & Aims: Detecting hepatitis C virus (HCV) reinfection among key populations helps prevent ongoing transmission. This systematic review aims to determine the association between different testing intervals during post-SVR follow-up on the detection of HCV reinfection among highest risk populations., Methods: We searched electronic databases between January 2014 and February 2023 for studies that tested individuals at risk for HCV reinfection at discrete testing intervals and reported HCV reinfection incidence among key populations. Pooled estimates of reinfection incidence were calculated by population and testing frequency using random-effects meta-analysis., Results: Forty-one single-armed observational studies (9453 individuals) were included. Thirty-eight studies (8931 individuals) reported HCV reinfection incidence rate and were included in meta-analyses. The overall pooled estimate of HCV reinfection incidence rate was 4.13 per 100 per person-years (py) (95% confidence interval [CI]: 3.45-4.81). The pooled incidence estimate among people who inject drugs (PWID) was 2.84 per 100 py (95% CI: 2.19-3.50), among men who have sex with men (MSM) 7.37 per 100 py (95% CI: 5.09-9.65) and among people in custodial settings 7.23 per 100 py (95% CI: 2.13-16.59). The pooled incidence estimate for studies reporting a testing interval of ≤6 months (4.26 per 100 py; 95% CI: 2.86-5.65) was higher than studies reporting testing intervals >6 months (5.19 per 100 py; 95% CI: 3.92-6.46)., Conclusions: HCV reinfection incidence was highest in studies of MSM and did not appear to change with retesting interval. Shorter testing intervals are likely to identify more reinfections, help prevent onward transmission where treatment is available and enable progress towards global HCV elimination, but additional comparative studies are required., (© 2023 The Authors. Liver International published by John Wiley & Sons Ltd.)

People who inject drugs are at risk of acute bacterial and fungal injecting-related infections. There is evidence that incidence of hospitalizations for injecting-related infections are increasing in several countries, but little is known at an individual level. We aimed to examine injecting-related infections in a linked longitudinal cohort of people who inject drugs in Melbourne, Australia. A retrospective descriptive analysis was conducted to estimate the prevalence and incidence of injecting-related infections using administrative emergency department and hospital separation datasets linked to the SuperMIX cohort, from 2008 to 2018. Over the study period, 33% (95%CI: 31-36%) of participants presented to emergency department with any injecting-related infections and 27% (95%CI: 25-30%) were admitted to hospital. Of 1,044 emergency department presentations and 740 hospital separations, skin and soft tissue infections were most common, 88% and 76%, respectively. From 2008 to 2018, there was a substantial increase in emergency department presentations and hospital separations with any injecting-related infections, 48 to 135 per 1,000 person-years, and 18 to 102 per 1,000 person-years, respectively. The results emphasize that injecting-related infections are increasing, and that new models of care are needed to help prevent and facilitate early detection of superficial infection to avoid potentially life-threatening severe infections.

Background: Gay and bisexual men using HIV pre-exposure prophylaxis (PrEP) are at increased risk for sexually transmissible infections. Hepatitis C virus (HCV) risk among PrEP users is less clear. We explored HCV prevalence and incidence among cohorts of gay and bisexual men using PrEP and sources of heterogeneity across studies., Methods: This was a systematic review and meta-analysis of open-label PrEP studies to April 2022 reporting HCV prevalence at baseline or incidence during follow-up among gay and bisexual men using PrEP. Pooled prevalence and incidence estimates were calculated using random-effects meta-analysis, and subgroup analyses were performed by study- and country-level characteristics, including availability of HCV direct-acting antiviral (DAA) therapy at time of study., Results: Twenty-four studies from 9 countries were included, with a total sample of 24 733 gay and bisexual men. Pooled HCV antibody baseline prevalence was 0.97% (95% CI, 0.63%-1.31%), and pooled HCV RNA baseline prevalence was 0.38% (95% CI, 0.19%-0.56%). Among 19 studies reporting HCV incidence, incidence ranged from 0.0 to 2.93/100 person-years (py); the pooled estimate was 0.83/100py (95% CI, 0.55-1.11). HCV incidence was higher in 12 studies that began follow-up before broad DAA availability (1.27/100py) than in 8 studies that began follow-up after broad DAA availability (0.34/100py) and higher in studies in Europe compared with North America and Australia., Conclusions: Early reports of high HCV incidence among PrEP-using cohorts likely reflect enrollment of individuals based on specific risk-based eligibility criteria for smaller studies and enrollment before DAA scale-up. In contexts where both DAAs and PrEP have been implemented at scale, studies report lower HCV incidence. PrEP-specific HCV testing guidelines should be guided by local epidemiology., Competing Interests: Potential conflicts of interest. M.W.T. has received speaker's honoraria, consultancy fees, and researcher-initiated funding from Gilead Sciences unrelated to this work. E.J.W.'s institution received funding from Gilead Sciences for E.J.W.'s work on an Advisory Board and for delivering educational content. V.J.C., D.M., and E.J.W. have received research funding from ViiV health care, not related to this work. J.S.D., M.E.H., and M.A.S.'s institution has received funding for research and speaking from Gilead Sciences and AbbVie. M.A.S. has received researcher-initiated research funding from Gilead Sciences and AbbVie and consultant fees from Gilead Sciences for activities unrelated to this work. All other authors report no potential conflicts., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Objectives: Direct-acting antivirals provide an opportunity to eliminate hepatitis C virus (HCV) as a public health threat in Australia, yet barriers to care remain. In this study, we use baseline data from a longitudinal cohort of people who inject drugs to understand differences in participant characteristics and explore experiences of stigma, health service utilisation and health literacy between three care cascade groups., Design: Cross-sectional., Setting: Community and private primary healthcare services in Melbourne, Australia., Participants: Participants completed baseline surveys between 19 September 2018 and 15 December 2020. We recruited 288 participants; the median age was 42 years (IQR: 37-49 years) and 198 (69%) were male. At baseline, 103 (36%) self-reported being 'not engaged in testing', 127 (44%) had HCV RNA positivity but were 'not engaged in treatment' and 58 (20%) were 'engaged in HCV treatment'., Outcome Measures: Descriptive statistics were used to present the baseline demographics, health service utilisation and experiences of stigma data. We explored differences in these scales between participant demographics using χ 2 test or fisher's exact tests, and differences between health literacy scores using one-way analysis of variance tests., Results: A majority were in regular contact with multiple health services, and most had previously been identified as at-risk of HCV. In the 12 months preceding baseline, 70% reported any experiences of stigma related to injecting drug use. Assessment of health literacy data identified gaps for those 'not engaged in testing' and 'not engaged in treatment' across two relevant domains: 'ability to appraise health information' and 'ability to actively engage with healthcare providers'., Conclusion: In eliminate hepatitis C experience, lower HCV testing and treatment may be explained by experiences of stigmatisation or gaps in health literacy. Enhanced interventions targeting people who inject drugs to promote HCV care are needed., Competing Interests: Competing interests: JD, MH, MAS and AP receive investigator-initiated research funding support from Gilead Sciences, Abbvie and Bristol-Myers Squibb and Merck. JD and his institution have received consultancies from Gilead, AbbVie and Merck. AP and their institution have received consultancies from Gilead. PH receives investigator-initiated research funding support from Gilead Sciences and Abbvie. PD has received an investigator-driven grant from Gilead Sciences for unrelated work on hepatitis C and an untied educational grant from Reckitt Benckiser for unrelated work on the introduction of buprenorphine-naloxone into Australia. He has served as an unpaid member on an Advisory Board for an intranasal naloxone product., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

This study aims to understand the time-to-treatment initiation pre and post DAA access to inform strategies to improve HCV care. The data for our study were derived from the SuperMIX cohort study of people who inject drugs in Melbourne, Australia. Time-to-event analysis using Weibull accelerated failure time was performed for data collected between 2009 and 2021, among a cohort of HCV-positive participants. Among 223 participants who tested positive for active hepatitis C infection, 102 people (45.7%) reported treatment initiation, with a median time-to-treatment of 7 years. However, the median time-to-treatment reduced to 2.3 years for those tested positive after 2016. The study found that treatment with Opioid Agonist Therapy (TR 0.7, 95% CI 0.6-0.9), engagement with health or social services (TR 0.7, 95% CI 0.6-0.9), and having a first positive HCV RNA test after March 2016 (TR 0.3, 95% CI 0.2-0.3) were associated with a reduced time-to-treatment initiation. The study highlights the need for strategies to improve engagement with health services, including drug treatment services into routine HCV care to achieve timely treatment.

Introduction: Despite the availability of effective, subsidised hepatitis B treatment, linkage to care and treatment rates remain very low globally. In Australia, specially trained primary care physicians (general practitioner, GPs) can prescribe hepatitis B treatment, however, most hepatitis B care occurs in specialist clinics. Increasing hepatitis B management by GPs in primary care clinics is essential to achieve national hepatitis B linkage to care and treatment targets by 2030.This pilot study determines the feasibility, acceptability and effectiveness of Simply B, a novel GP hepatitis B e-support package designed to increase hepatitis B management by GPs in primary care clinics., Methods and Analysis: This study will be conducted in three parts:Part A: A prospective open-label pilot intervention study, comparing the proportion of people with hepatitis B who are managed by their GP in primary care clinics before, 12 months and 24 months after implementation of the Simply B electronic hepatitis B support package.Part B: A nested qualitative health services feasibility study using semistructured interviews and thematic analysisPart C: Cost-effectiveness analysis., Ethics and Dissemination: This study has received ethics approval by St Vincent's Hospital. Data management and analysis will be centralised through the Department of Gastroenterology, St Vincent's Hospital., Trial Registration Number: NCT05614466., Competing Interests: Competing interests: JH has received investigator-initiated research funding (Gilead Australia Fellowship 2017, 2019) and speaker fees (2017) from Gilead Sciences, and speaker fees and investigator-initiated research funding from Eisai (2020, 2021)., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Broad direct-acting antiviral (DAA) access may reduce hepatitis C virus (HCV) incidence through a "treatment as prevention" (TasP) effect. We assessed changes in primary HCV incidence following DAA access among people living with HIV (PLHIV)., Methods: We used pooled individual-level data from six cohorts from the International Collaboration on Hepatitis C Elimination in HIV Cohorts (InCHEHC). Follow-up started from the first recorded negative HCV antibody test date and ended at last negative antibody test or estimated infection date. Follow-up was restricted to 2010-2019. We used segmented Poisson regression to model trends across pre-, limited- (i.e., restrictions on access) and broad-DAA access periods., Findings: Overall, 45,942 participants had at least one HCV antibody negative result and follow-up between 2010 and 2019. We observed 2042 incident HCV infections over 248,189 person-years (PY). Pooled incidence decreased from 0.91 per 100 PY in 2015 to 0.41 per 100 PY in 2019. Compared to the average pre-DAA period incidence (0.90 per 100 PY), average incidence was similar during the limited-DAA access period (Incidence rate ratio [IRR] = 0.98; 95%CI = 0.87, 1.11), and 52% lower during the broad-DAA access period (IRR = 0.48; 95%CI = 0.42, 0.52). The average annual decline in HCV incidence was 2% in the pre-DAA period; an additional 9% annual decline in incidence was observed during the limited-DAA access period (IRR = 0.91; 95%CI = 0.82, 1.00) and a further 20% decline in the broad-DAA access period (IRR = 0.80, 95%CI = 0.73, 0.89)., Interpretation: Our findings suggest that broad DAA access has a TasP effect on primary HCV incidence among PLHIV. Based on the initial years of DAA availability, the countries in the InCHEHC collaboration are on track to meet the World Health Organization's 80% HCV incidence reduction target for PLHIV by 2030., Funding: This study was funded by the Australian Government National Health and Medical Research Council (Grant number GNT1132902)., Competing Interests: Juan Berenguer reports honoraria for advice or public speaking from 10.13039/100006483AbbVie, 10.13039/100005564Gilead, 10.13039/100012781MSD, JANSSEN, and 10.13039/100010877ViiV Healthcare; and grants from 10.13039/100006483AbbVie, 10.13039/100005564Gilead, 10.13039/100012781MSD, and 10.13039/100010877ViiV Healthcare. Dominique L Braun reports honoraria for advice or public speaking from, 10.13039/100005564Gilead, 10.13039/100012781MSD and 10.13039/100010877ViiV Healthcare. Marina Klein reports grants for investigator-initiated studies from 10.13039/100010877ViiV Healthcare, 10.13039/100006483AbbVie, 10.13039/100004334Merck, and 10.13039/100005564Gilead, and consulting fees from 10.13039/100010877ViiV Healthcare, 10.13039/100006483AbbVie, and 10.13039/100005564Gilead, all outside the submitted work. Marina Klein is supported by a Tier I Canada Research Chair. Jeffrey V Lazarus acknowledges grants and speaker fees from 10.13039/100006483AbbVie, 10.13039/100005564Gilead Sciences and 10.13039/100012781MSD and speaker fees from Genfit, Intercept, Janssen, 10.13039/100015758Novo Nordisk and 10.13039/100010877ViiV, outside of the submitted work. Andri Rauch reports support to his institution for advisory boards and/or travel grants from 10.13039/100006483Abbvie, 10.13039/100012781MSD, 10.13039/100005564Gilead Sciences, and 10.13039/100004319Pfizer, and an investigator initiated trial (IIT) grant from 10.13039/100005564Gilead Sciences. All remuneration to Andri Rauch went to his home institution and not to Andri Rauch personally, and all remuneration was provided outside the submitted work. Karine Lacombe reports honoraria for advice or public speaking from 10.13039/100006483Abbvie, 10.13039/100005564Gilead, 10.13039/100012781MSD, Janssen and 10.13039/100010877ViiV Healthcare. Fabrice Bonnet reports grants from 10.13039/100005564Gilead and honoraria from 10.13039/100005564Gilead, 10.13039/100005564ViiV healthcare and 10.13039/100012781MSD. Maria Prins reports unrestricted research grants and speaker/advisor fees from 10.13039/100005564Gilead Sciences and 10.13039/100012781MSD; all of which were paid to her institution and unrelated to the current work. Marc van der Valk reports unrestricted research grants from 10.13039/100005564Gilead and 10.13039/100012781MSD and fees for participation in advisory boards from 10.13039/100005564Gilead, 10.13039/100012781MSD and 10.13039/100010877ViiV (all paid to his institution). Joseph S Doyle reports funding to his institution for investigator-initiated research from 10.13039/100005564Gilead Sciences and 10.13039/100006483AbbVIe, and honoraria to his institution for educational events from 10.13039/100006483AbbVie. Linda Wittkop reports grants/financial support for the work under consideration from the French Agency 10.13039/501100003323ANRS Emerging Infectious Diseases (10.13039/501100003323ANRS—MIE) paid to her institution. Gail Matthews reports grants from 10.13039/100005564Gilead, 10.13039/100006483AbbVie and 10.13039/100010877ViiV, all paid to her institution and financial support for participating in advisory board from 10.13039/100005564Gilead and 10.13039/100010877ViiV. The CEASE study is supported by 10.13039/100005567Gilead. Inma Jarrin reports grants from 10.13039/100012781MSD and 10.13039/100010877ViiV healthcare, all paid to her institution, honoraria for lectures/presentations from 10.13039/100005564Gilead and 10.13039/100010877ViiV healthcare, support from 10.13039/100005564Gilead for attending meetings/travel, and support from 10.13039/100005564Gilead to participate in an advisory board. Margaret Hellard reports investigator-initiated research grants from 10.13039/100005564Gilead and 10.13039/100006483Abbvie. Dominique Salmon reports support for attending meetings/travel from 10.13039/100005564Gilead and 10.13039/100006483AbbVie. Mark Stoové reports funding from 10.13039/100005564Gilead and 10.13039/100006483AbbVie for investigator-initiated research unrelated to this work and consultant fees from 10.13039/100005564Gilead Sciences for activities unrelated to this work., (© 2022 The Authors.)

Introduction: Prevalence of lifetime-induced abortion in female sex workers (FSWs) in Kenya was previously estimated between 43% and 86%. Our analysis aimed at assessing lifetime prevalence and correlates, and incidence and predictors of induced abortions among FSWs in Kenya., Methods: This is a secondary prospective cohort analysis using data collected as part of the WHISPER or SHOUT cluster-randomised trial in Mombasa, assessing effectiveness of an SMS-intervention to reduce incidence of unintended pregnancy. Eligible participants were current FSWs, 16-34 years and not pregnant or planning pregnancy. Baseline data on self-reported lifetime abortion, correlates and predictors were collected between September 2016 and May 2017. Abortion incidence was measured at 6-month and 12-month follow-up. A multivariable logistic regression model was used to assess correlates of lifetime abortion and discrete-time survival analysis was used to assess predictors of abortions during follow-up., Results: Among 866 eligible participants, lifetime abortion prevalence was 11.9%, while lifetime unintended pregnancy prevalence was 51.2%. Correlates of lifetime abortions were currently not using a highly effective contraceptive (adjusted OR (AOR)=1.76 (95% CI=1.11 to 2.79), p=0.017) and having ever-experienced intimate partner violence (IPV) (AOR=2.61 (95% CI=1.35 to 5.06), p=0.005). Incidence of unintended pregnancy and induced abortion were 15.5 and 3.9 per 100 women-years, respectively. No statistically significant associations were found between hazard of abortion and age, sex work duration, partner status, contraceptive use and IPV experience., Conclusion: Although experience of unintended pregnancy remains high, lifetime prevalence of abortion may have decreased among FSW in Kenya. Addressing IPV could further decrease induced abortions in this population., Trial Registration Number: ACTRN12616000852459., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)

In 2020, the Australian state of Victoria experienced the longest COVID-19 lockdowns of any jurisdiction, with two lockdowns starting in March and July, respectively. Lockdowns may impact progress towards eliminating hepatitis C through reductions in hepatitis C testing. To examine the impact of lockdowns on hepatitis C testing in Victoria, de-identified data were extracted from a network of 11 services that specialize in the care of people who inject drugs (PWID). Interrupted time-series analyses estimated weekly changes in hepatitis C antibody and RNA testing from 1 January 2019 to 14 May 2021 and described temporal changes in testing associated with lockdowns. Interruptions were defined at the weeks corresponding to the start of the first lockdown (week 14) and the start (week 80) and end (week 95) of the second lockdown. Pre-COVID, an average of 80.6 antibody and 25.7 RNA tests were performed each week. Following the first lockdown in Victoria, there was an immediate drop of 23.2 antibody tests and 8.6 RNA tests per week (equivalent to a 31% and 46% drop, respectively). Following the second lockdown, there was an immediate drop of 17.2 antibody tests and 4.6 RNA tests per week (equivalent to a 26% and 33% drop, respectively). With testing and case finding identified as a key challenge to Australia achieving hepatitis C elimination targets, the cumulative number of testing opportunities missed during lockdowns may prolong efforts to find, diagnose and engage or reengage in care of the remaining population of PWID living with hepatitis C., (© 2022 The Authors. Journal of Viral Hepatitis published by John Wiley & Sons Ltd.)

Background: Although data from large implementation trials suggest that sexually transmissible infection (STI) risk increases among gay and bisexual men who initiate HIV pre-exposure prophylaxis (PrEP), there are few data on the trends in population-level STI incidence in the years following widespread PrEP implementation. We aimed to describe trends in bacterial STI incidence among gay and bisexual men using PrEP across Australia in the context of broad PrEP availability through Australia's subsidised medicines scheme., Methods: We analysed linked clinical data from HIV-negative gay and bisexual men aged 16 years or older who had been prescribed PrEP across a sentinel surveillance clinical network, including 37 clinics in Australia, between Jan 1, 2016, and Dec 31, 2019. Patients were included if they had STI testing at least twice during the observation period. Repeat testing methods were used to calculate chlamydia, gonorrhoea, syphilis, and any STI incidence rates during individuals' periods of PrEP use. Incidence rate ratios (IRRs) for estimated change in incidence per half calendar year (6-month) period were calculated using negative binomial regression. Secondary analyses compared STI incidence rates across individuals initiating PrEP in each year from 2016 to 2019, as well as by length of time using PrEP (per each additional 6 months of PrEP use)., Findings: 22 730 men were included in the analyses. During the observation period, 11 351 chlamydia infections were diagnosed in 6630 (30·1%) of 22 034 men over 25 991·2 person-years of PrEP use (incidence rate 43·7 cases [95% CI 42·9-44·5] per 100 person-years). Chlamydia incidence decreased from 48·7 cases per 100 person-years in July-December, 2016, to 42·0 cases per 100 person-years in July-December, 2019 (IRR for estimated change per 6-month period 0·98 [95% CI 0·97-0·99]; p=0·0031). 9391 gonorrhoea infections were diagnosed in 5885 (26·9%) of 21 845 men over 24 858·7 person-years of PrEP use (incidence rate 37·8 cases [95% CI 37·0-38·5] per 100 person-years). Gonorrhoea incidence decreased from 45·5 cases per 100 person-years in July-December, 2016, to 37·2 cases per 100 person-years in July-December, 2019 (IRR 0·97 [95% CI 0·96-0·98]; p<0·0001). Declines in chlamydia and gonorrhoea incidence were most prominent in the first 18 months of observation and incidence was stable thereafter. 2062 syphilis infections were diagnosed in 1488 (7·7%) of 19 262 men over 21 978·9 person-years of PrEP use (incidence rate 9·4 cases [95% CI 9·0-9·8] per 100 person-years). Syphilis incidence increased from 6·2 cases per 100 person-years in July-December, 2016, to 9·8 cases per 100 person-years in July-December, 2019 (IRR 1·08 [95% CI 1·05-1·10]; p<0·0001)., Interpretation: Chlamydia and gonorrhoea incidence among gay and bisexual men using PrEP were highest in the early months of PrEP implementation in Australia and stabilised at slightly lower rates thereafter following wider PrEP uptake. Lower prospective STI risk among people initiating PrEP in later years contributed to the observed trends in STI incidence. Widespread PrEP implementation can contribute to increased STI screening and detection., Funding: Australian Department of Health, National Health and Medical Research Council., Competing Interests: Declaration of interests MWT reports speakers' honoraria and investigator-initiated research grants from Gilead Sciences. RG reports research support funding from Gilead Sciences. CB reports honoraria from Gilead Sciences. EJW is the chair of the COVID-19 Taskforce of the Australasian Society of HIV, Viral Hepatitis, and Sexual Health Medicine, and reports investigator-initiated research funding from ViiV Healthcare, and consulting and travel fees from Gilead Sciences. AG reports research grants from Sequris and ViiV Healthcare, receipt of study drug from GlaxoSmithKline, and personal fees from Merck Sharp and Dohme. MEH reports investigator-initiated research grants from Gilead Sciences and Abbvie. MAS reports investigator-initiated research grants from Gilead Sciences and Abbvie and consulting fees from Gilead Sciences. All other authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Gay and bisexual men (GBM) who use pre-exposure prophylaxis (PrEP) are at increased risk of sexually transmitted infections (STIs) compared to those who don't use PrEP. Since the implementation of PrEP in Australia, it is possible that attitudes towards STIs have shifted in line with changes in risk and transmission dynamics in the context of increased screening. As the extent to which GBM utilise STI prevention strategies likely depends on their attitudes towards STIs and STI prevention, the aims of this study were to use latent class analysis (LCA) to classify GBM using PrEP on the basis of their attitudes towards STIs and reported risk behaviours, and examine how these categorisations relate to risk of STI acquisition. 1225 GBM who were previously enrolled in a PrEP implementation study (The PrEPX Study) completed a survey focused on sexual behaviours and attitudes towards STIs 1 year post-study follow-up. Data on chlamydia, gonorrhoea and syphilis testing and positivity were available through a sentinel network of participating study clinics. Using LCA, participants were allocated into four classes; Class 1, "Some concern and lowest risk"; Class 2, "Low concern and lower risk"; Class 3, " High concern and higher risk"; and Class 4, "Low concern and highest risk". The majority (78%) of participants were classified into Class 3 or Class 4, two groups which were distinguished by highly disparate attitudes towards STIs but with a similar proportion of participants diagnosed with a bacterial STI in the last 12 months (48% and 57%, respectively). Findings suggest that attitudes towards STIs among GBM using PrEP in Australia vary considerably, and this will likely influence their receptivity to different STI prevention strategies., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: By subsidising access to direct acting antivirals (DAAs) for all people living with hepatitis C (HCV) in 2016, Australia is positioned to eliminate HCV as a public health threat. However, uptake of DAAs has declined over recent years and new initiatives are needed to engage people living with HCV in care. Active follow-up of HCV notifications by the health department to the notifying general practitioner (GP) may increase treatment uptake. In this study, we explore the impact of using hepatitis C notifications systems to engage diagnosing GPs and improve patient access to treatment., Methods and Analysis: This study is a randomised controlled trial comparing enhanced case management of HCV notifications with standard of care. The intervention includes phone calls from a department of health (DoH) specialist HCV nurse to notifying GPs and offering HCV management support. The level of support requested by the GP was graded in complexity: level 1: HCV information only; level 2: follow-up testing advice; level 3: prescription support including linkage to specialist clinicians and level 4: direct patient contact. The study population includes all GPs in Tasmania who notified HCV diagnosis to the DoH between September 2020 and December 2021. The primary outcome is proportion of HCV cases who initiate DAAs after 12 weeks of HCV notification to the health department. Secondary outcomes are proportion of HCV notifications that complete HCV RNA testing, treatment workup and treatment completion. Multiple logistic regression modelling will explore factors associated with the primary and secondary outcomes. The sample size required to detect a significant difference for the primary outcome is 85 GPs in each arm with a two-sided alpha of 0.05% and 80% power., Ethics and Dissemination: The study was approved by University of Tasmania's Human Research Ethics Committee (Protocol ID: 18418) on 17 December 2019. Results of the project will be presented in scientific meetings and published in peer-reviewed journals., Trial Registration Number: NCT04510246., Trial Progression: The study commenced recruitment in September 2020 and end of study expected December 2021., Competing Interests: Competing interests: JD, MAS and MH report investigator-initiated research funding to their institution from Gilead Science, AbbVie and Merck. JD reports honoraria for speaking to his institution from Gilead Sciences and AbbVie and MAS reports consultant fees from Gilead Sciences. AEP has received investigator-initiated grant funding from Gilead Sciences, MSD and Abbvie and speaker fees from Gilead Sciences for unrelated work., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: The advent of direct acting antiviral therapy for hepatitis C virus (HCV) means the elimination of HCV is possible but requires sustained effort to achieve. Between 2016 and 2019, 44% of those living with HCV were treated in Australia. However, treatment uptake has declined significantly. In Australia, people who inject drugs (PWID) are the population most at risk of HCV acquisition. Eliminating HCV in Australia will require nuanced understanding of the barriers to HCV treatment experienced by PWID and tailored interventions to address these barriers. The EC-Experience Cohort study aims to explore the barriers and enablers reported by PWID to engagement in HCV care., Methods and Analysis: The EC-Experience Cohort study is a prospective cohort of PWID, established in Melbourne, Australia in 2018. Participants are assigned into three study groups: (1) those not currently engaged in HCV testing; (2) those diagnosed with HCV but not currently engaged in treatment and (3) those completed treatment. Participants complete a total of four interviews every 6 months across an 18-month study period. Predictors of experience of key outcome events along the HCV care cascade will be explored over time., Ethics and Dissemination: Ethical approval for the EC-Experience Cohort study was obtained by the Alfred Hospital Ethics Committee in Melbourne, Australia (Project Number: HREC/16/Alfred/164). All eligible participants are assessed for capacity to consent and partake in a thorough informed consent process. Results from the EC-Experience Cohort study will be disseminated via national and international scientific and public health conferences and peer-reviewed journal publications. Data from the EC-Experience Cohort study will improve the current understanding of the barriers to HCV care for PWID and guide the tailoring of service provision for specific subgroups. Understanding the barriers and how to increase engagement in care of PWID is critical to achieve HCV elimination goals., Competing Interests: Competing interests: JD, MH, MAS and AEP receive investigator-initiated research funding support from Gilead Sciences, Abbvie and Bristol-Myers Squibb and Merck. JD and his institution have received consultancies from Gilead, AbbVie and Merck. AEP and their institution have received consultancies from Gilead. PH receives investigator-initiated research funding support from Gilead Sciences and Abbvie. PD has received an investigator-driven grant from Gilead Sciences for unrelated work on hepatitis C and an untied educational grant from Reckitt Benckiser for unrelated work on the introduction of buprenorphine-naloxone into Australia. He has served as an unpaid member on an Advisory Board for an intranasal naloxone product., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Gay and bisexual men (GBM) are a key population affected by human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection. We aimed to measure HCV treatment effectiveness and to determine the population impact of treatment scale-up on HCV prevalence and incidence longitudinally among GBM., Methods: The co-EC Study (Enhancing Care and Treatment Among HCV/HIV Coinfected Individuals to Eliminate Hepatitis C Transmission) was an implementation trial providing HCV direct-acting antiviral treatment in Melbourne, Australia, during 2016-2018. Individuals with HCV/HIV coinfection were prospectively enrolled from primary and tertiary care services. HCV viremic prevalence and HCV antibody/viremic incidence were measured using a statewide, linked, surveillance system., Results: Among 200 participants recruited, 186 initiated treatment during the study period. Sustained virological response in primary care (98% [95% confidence interval {CI}, 93%-100%]) was not different to tertiary care (98% [95% CI, 86%-100%]). From 2012 to 2019, between 2434 and 3476 GBM with HIV infection attended our primary care sites annually, providing 13 801 person-years of follow-up; 50%-60% received an HCV test annually, and 10%-14% were anti-HCV positive. Among those anti-HCV positive, viremic prevalence declined 83% during the study (54% in 2016 to 9% in 2019). HCV incidence decreased 25% annually from 1.7/100 person-years in 2012 to 0.5/100 person-years in 2019 (incidence rate ratio, 0.75 [95% CI, .68-.83]; P < .001)., Conclusions: High treatment effectiveness by nonspecialists demonstrates the feasibility of treatment scale-up in this population. Substantial declines in HCV incidence and prevalence among GBM provides proof-of-concept for HCV microelimination., Clinical Trials Registration: NCT02786758., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Introduction: In 2018, the first Medically Supervised Injecting Room in Melbourne, Australia was officially opened. This study assessed whether this facility attracted people who inject drugs, who were socially vulnerable, and who engaged in drug-related behaviors associated with increased morbidity and mortality risk., Methods: This was a cross-sectional analysis of the frequency of Medically Supervised Injecting Room use during the first 18 months after opening (July 2018-December 2019) among 658 people who inject drugs participating in the Melbourne Injecting Drug User Cohort Study (SuperMIX). To examine the differences between no Medically Supervised Injecting Room use, infrequent use (<50% injections within the facility), and frequent use (≥50% of injections within the facility), RRRs were estimated using bivariate multinomial logistic regression analyses and postestimation Wald tests. Analyses were conducted in 2020., Results: A total of 451 participants (68%) reported no Medically Supervised Injecting Room use, 142 (22%) reported infrequent use, and 65 (10%) reported frequent use. Participants who reported either infrequent or frequent use of the facility were more socially vulnerable (e.g., more often homeless) and more likely to report risky drug-related behaviors and poor health outcomes than those who reported no use. Participants who reported frequent use of the facility were also more likely to live close to the facility than those reporting infrequent use., Conclusions: The Melbourne Medically Supervised Injecting Room attracted socially marginalized people who inject drugs who are most at risk of harms related to injecting drug use and therefore who are most in need of the service. To determine the long-term impact use of this facility on key health outcomes such as overdose, future studies should consider the differences in vulnerability and risk behavior of people who inject drugs who use the Medically Supervised Injecting Room when examining the outcomes associated with the use of the facility., (Copyright © 2021 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

We aimed to estimate how often urethral gonorrhoea is symptomatic among men in the Pre-Exposure Prophylaxis Expanded Victoria study. Eighty-seven percent of 213 cases of urethral gonorrhoea were symptomatic. Ensuring men with urethral gonorrhoea both recognize and present early for treatment is critical to reduce transmission., (© The Author(s) 2021. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: Gay and bisexual men with undiagnosed HIV contribute disproportionately to HIV transmission in Australia., Methods: In 2014 and 2018, we recruited men at gay venues and events in Sydney. Participants self-completed surveys and provided oral fluid samples for HIV testing. We calculated the prevalence of HIV and undiagnosed infection, and assessed changes in behavior, HIV testing, and the use of pre-exposure prophylaxis. We weighted the samples to adjust for differences in where participants were recruited between rounds. Two-sample tests of proportion were used to compare prevalence estimates and χ tests to assess differences between the samples., Results: In 2014, 944 men were recruited, and 890 men were recruited in 2018. In 2014, the weighted estimate of HIV prevalence was 6.1% [95% confidence intervals (CI): 4.6 to 7.6], of which 13.8% (95% CI: 5.0 to 22.7) was undiagnosed. In 2018, weighted HIV prevalence was 6.4% (95% CI: 4.8 to 8.0), of which 5.3% (95% CI: 0.5 to 11.1) was undiagnosed. Between 2014 and 2018 among all participants, men reporting at least 10 recent casual partners increased from 22.3% to 27.7% (P = 0.008), condomless anal intercourse with casual partners in the previous 6 months increased from 23.9% to 37.3% (P < 0.001), and sexually transmitted infection diagnoses in the previous year increased from 14.4% to 27.5% (P < 0.001). HIV testing and the use of pre-exposure prophylaxis in the previous 6 months increased from 49.6% to 56.3% (P = 0.004) and 2.0%-21.0% (P < 0.001), respectively., Conclusions: Repeated, bio-behavioral surveillance suggests the prevalence of undiagnosed HIV remains low in Sydney, despite gay and bisexual men reporting more casual sex partners, condomless sex, and sexually transmitted infections.

Background: Increases in sexually transmitted infections among gay and bisexual men (GBM) over the past decade have coincided with declines in condom use and rapid uptake of HIV preexposure prophylaxis (PrEP). We explored the impact of an antimicrobial gel-based point-of-sex intervention (gel-PSI) with a lower efficacy for reducing gonorrhea transmission risk than condoms on population-level gonorrhea incidence among GBM in Victoria, Australia., Methods: A deterministic compartmental model of HIV and gonorrhea transmission was used to project annual gonorrhea incidence from 2020 to 2025. Individuals were classified as HIV-negative (PrEP or non-PrEP users) or HIV-positive, and further stratified by gonorrhoea risk (high/low). All possible scenarios where between 0% and 100% of GBM using condoms transitioned to gel-PSI (considered a downgrade in protection) and 0% and 100% of GBM not using condoms transitioned to gel-PSI (considered an upgrade in protection), with gel-PSI efficacy ranging from 20% to 50%, were run., Results: The baseline scenario of no gel-PSI uptake (status quo) projected 94,367 gonorrhea infections between 2020 and 2025, with an exponentially increasing trend in annual infections. For a gel-PSI efficacy of 30%, a net reduction in cumulative gonorrhea incidence was projected, relative to the status quo, for any ratio of proportion of condom users "downgrading" to proportion of noncondom users "upgrading" to gel-PSI use of less than 2.6. Under the supposition of equal proportions of condom users and noncondom users switching to gel-PSI, a relative reduction was projected for any gel-PSI efficacy greater than 16%., Conclusions: Our model suggests that the introduction of a gel-PSI could have benefits for controlling gonorrhea transmission among GBM, even in scenarios where the gel-PSI is considerably less efficacious than condoms and when gel-PSI uptake leads to consequent reductions in consistent condom use.

Background: Hepatitis C elimination will require widespread access to treatment and responses at the health-service level to increase testing among populations at risk. We explored changes in hepatitis C testing and the cascade of care before and after the introduction of direct-acting antiviral treatments in Victoria, Australia., Methods: De-identified clinical data were retrospectively extracted from eighteen primary care clinics providing services targeted towards people who inject drugs. We explored hepatitis C testing within three-year periods immediately prior to (pre-DAA period) and following (post-DAA period) universal access to DAA treatments on 1st March 2016. Among ever RNA-positive individuals, we constructed two care cascades at the end of the pre-DAA and post-DAA periods., Results: The number of individuals HCV-tested was 13,784 (12.2% of those with a consultation) in the pre-DAA period and 14,507 (10.4% of those with a consultation) in the post-DAA period. The pre-DAA care cascade included 2,515 RNA-positive individuals; 1,977 (78.6%) were HCV viral load/genotype tested; 19 (0.8%) were prescribed treatment; and 12 had evidence of cure (0.5% of those RNA-positive and 63.6% of those eligible for cure). The post-DAA care cascade included 3,713 RNA-positive individuals; 3,276 (88.2%) were HCV viral load/genotype tested; 1,674 (45.1%) were prescribed treatment; and 863 had evidence of cure (23.2% of those RNA-positive and 94.9% of those eligible for cure)., Conclusion: Marked improvements in the cascade of hepatitis C care among patients attending primary care clinics were observed following the universal access of DAA treatments in Australia, although improvements in testing were less pronounced., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: JSD, DVS, MS, MH: Burnet Institute receives unrelated investigator-initiated research grants from Gilead Sciences, AbbVie, Merck/MSD, and Bristol Myers Squibb. MWT has received honoraria for speaking from Gilead Science. JSD: Honoraria for speaking from Gilead Sciences, Merck/MSD, and Abbvie; All other authors declare no conflicts of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Introduction: Female sex workers (FSWs) experience overlapping burdens of HIV, sexually transmitted infections and unintended pregnancy. Pre-exposure prophylaxis (PrEP) is highly efficacious for HIV prevention. It represents a promising strategy to reduce HIV acquisition risks among FSWs specifically given complex social and structural factors that challenge consistent condom use. However, the potential impact on unintended pregnancy has garnered little attention. We discuss the potential concerns and opportunities for PrEP to positively or negatively impact the sexual and reproductive health and rights (SRHR) of FSWs., Discussion: FSWs have high unmet need for effective contraception and unintended pregnancy is common in low- and middle-income countries. Unintended pregnancy can have enduring health and social effects for FSWs, including consequences of unsafe abortion and financial impacts affecting subsequent risk-taking. It is possible that PrEP could negatively impact condom and other contraceptive use among FSWs due to condom substitution, normalization, external pressures or PrEP provision by single-focus services. There are limited empirical data available to assess the impact of PrEP on pregnancy rates in real-life settings. However, pregnancy rates are relatively high in PrEP trials and modelling suggests a potential two-fold increase in condomless sex among FSWs on PrEP, which, given low use of non-barrier contraceptive methods, would increase rates of unintended pregnancy. Opportunities for integrating family planning with PrEP and HIV services may circumvent these concerns and support improved SRHR. Synergies between PrEP and family planning could promote uptake and maintenance for both interventions. Integrating family planning into FSW-focused community-based HIV services is likely to be the most effective model for improving access to non-barrier contraception among FSWs. However, barriers to integration, such as provider skills and training and funding mechanisms, need to be addressed., Conclusions: As PrEP is scaled up among FSWs, there is growing impetus to consider integrating family planning services with PrEP delivery in order to better meet the diverse SRHR needs of FSWs and to prevent unintended consequences. Programme monitoring combined with research can close data gaps and mobilize adequate resources to deliver comprehensive SRHR services respectful of all women's rights., (© 2020 The Authors. Journal of the International AIDS Society published by John Wiley & Sons Ltd on behalf of the International AIDS Society.)

Importance: Emerging evidence suggests that risk of bacterial sexually transmitted infections (STIs) increases among gay and bisexual men following initiation of HIV preexposure prophylaxis (PrEP)., Objective: To describe STI incidence and behavioral risk factors among a cohort of predominantly gay and bisexual men who use PrEP, and to explore changes in STI incidence following PrEP commencement., Design, Setting, and Participants: The Pre-exposure Prophylaxis Expanded (PrEPX) Study, a multisite, open-label intervention study, was nested within the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance (ACCESS) clinic network. A total of 4275 participants were enrolled (July 26, 2016-April 1, 2018) in Victoria, Australia. Of these, 2981 enrolled at 5 ACCESS clinics (3 primary care, 1 sexual health, and 1 community-based HIV rapid testing service), had at least 1 follow-up visit, and were monitored until April 30, 2018., Exposures: Upon enrollment, participants received daily oral tenofovir disoproxil fumurate and emtricitabine for HIV PrEP, quarterly HIV and STI testing, and clinical monitoring., Main Outcomes and Measures: The primary outcome was incidence of chlamydia, gonorrhea, or syphilis. Incidence rates and hazard ratios describing behavioral risk factors of STI diagnosis were calculated. Incidence rate ratios (IRRs), adjusted for change in testing frequency, described changes in STI incidence from 1-year preenrollment to study follow-up among participants with preenrollment testing data (n = 1378)., Results: Among the 2981 individuals (median age, 34 years [interquartile range, 28-42]), 98.5% identified as gay or bisexual males, 29% used PrEP prior to enrollment, 89 (3%) withdrew and were censored at date of withdrawal, leaving 2892 (97.0%) enrolled at final follow-up. During a mean follow-up of 1.1 years (3185.0 person-years), 2928 STIs were diagnosed among 1427 (48%) participants (1434 chlamydia, 1242 gonorrhea, 252 syphilis). STI incidence was 91.9 per 100 person-years, with 736 participants (25%) accounting for 2237 (76%) of all STIs. Among 2058 participants with complete data for multivariable analysis, younger age, greater partner number, and group sex were associated with greater STI risk, but condom use was not. Among 1378 participants with preenrollment testing data, STI incidence increased from 69.5 per 100 person-years prior to enrollment to 98.4 per 100 person-years during follow-up (IRR, 1.41 [95% CI, 1.29-1.56]). After adjusting for testing frequency, the increase in incidence from 1 year preenrollment to follow-up was significant for any STI (adjusted IRR, 1.12 [95% CI, 1.02-1.23]) and for chlamydia (adjusted IRR, 1.17 [95% CI, 1.04-1.33])., Conclusions and Relevance: Among gay and bisexual men using PrEP, STIs were highly concentrated among a subset, and receipt of PrEP after study enrollment was associated with an increased incidence of STIs compared with preenrollment. These findings highlight the importance of frequent STI testing among gay and bisexual men using PrEP.

Background: Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) is effective in reducing HIV risk in men who have sex with men (MSM). However, concerns remain that risk compensation in PrEP users may lead to decreased condom use and increased incidence of sexually transmitted infections (STIs). We assessed the impact of PrEP on sexual risk outcomes in MSM., Methods: We conducted a systematic review of open-label studies published to August 2017 that reported sexual risk outcomes in the context of daily oral PrEP use in HIV-negative MSM and transgender women. Pooled effect estimates were calculated using random-effects meta-analysis, and a qualitative review and risk of bias assessment were performed., Results: Sixteen observational studies and 1 open-label trial met selection criteria. Eight studies with a total of 4388 participants reported STI prevalence, and 13 studies with a total of 5008 participants reported change in condom use. Pre-exposure prophylaxis use was associated with a significant increase in rectal chlamydia (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.19-2.13) and an increase in any STI diagnosis (OR, 1.24; 95% CI, .99-1.54). The association of PrEP use with STI diagnoses was stronger in later studies. Most studies showed evidence of an increase in condomless sex among PrEP users., Conclusion: Findings highlight the importance of efforts to minimize STIs among PrEP users and their sexual partners. Monitoring of risk compensation among MSM in the context of PrEP scale-up is needed to assess the impact of PrEP on the sexual health of MSM and to inform preventive strategies.

Aims: To determine whether the self-reported personal wellbeing of a cohort of people who inject drugs (PWID) changes over time, and to identify longitudinal correlates of change., Methods: We used Personal Wellbeing Index (PWI) scores reported between April 2008 and February 2015 by 757 PWID (66% male) enrolled in the Melbourne Injecting Drug Use Cohort Study (2,862 interviews; up to seven follow-up waves). A mixed-effects model was used to identify correlations between changes in temporal variables and changes in individual PWI scores while controlling for demographic variables., Results: The cohort's mean PWI score did not significantly differ over time (between 54.4/100 and 56.7/100 across the first four interview waves), and was 25-28% lower than general Australian population scores (76.0/100). However, there were large variations in individuals' PWI scores between interviews. Increased psychological distress, moving into unstable accommodation, reporting intentional overdose in the past 12 months and being the victim of assault in the past six months were associated with declines in PWI scores., Conclusions: Participants experienced substantially lower levels of personal wellbeing than the general Australian population, influenced by experiences of psychological distress, assault, overdose and harms related to low socioeconomic status. The results of this study suggest a need to ensure referral to appropriate housing and health support services for PWID.

Background International non-occupational post-exposure prophylaxis (NPEP) guidelines recommend routine use of three drug NPEP regimens, despite absence of evidence for greater prevention efficacy compared with two drug regimens. This study examines the potential for excess HIV seroconversions among high-risk men who have sex with men (MSM) reporting receptive anal intercourse with a source of unknown HIV serostatus (RAIU) following a two-drug versus a three-drug NPEP regimen., Methods: Data for MSM in the Victorian NPEP service database between 10 August 2005 and 31 December 2012 were linked with all Victorian HIV notifications up to 31 December 2013. The primary outcome was NPEP failure following NPEP presentation among MSM reporting RAIU, stratified by the number of drugs prescribed., Results: Among 1482 MSM reporting 2002 episodes of RAIU and prescribed two- or three-drug NPEP, 70 seroconverted to HIV, but only 19 were considered possible NPEP failures. HIV diagnosis incidence among men reporting RAIU was 1.2/100 person years (PY) (95%CI=1.0-1.6); 1.1/100 PY (95%CI=0.8-1.4) among MSM prescribed two drugs and 2.2/100 PY (95%CI=1.4-3.7) among MSM prescribed three drugs (P<0.01). Of the 19 possible NPEP failures, 13 (0.7%) were prescribed two drugs and six (2.7%) three drugs (P<0.001)., Conclusions: This study suggests that two-drug NPEP regimens do not result in excess seroconversions compared with three-drug regimens when used following RAIU. Clinical services should carefully consider their use of three drug NPEP and whether resources might be better invested in other prevention strategies, particularly pre-exposure prophylaxis (PrEP).

Although high hepatitis C virus (HCV) prevalence has been observed in people who inject drugs (PWID) for decades, research suggests incidence is falling. We examined whether PWIDs' use of opioid substitution therapy (OST) and their needle-and-syringe sharing behaviour explained HCV incidence. We assessed HCV incidence in 235 PWID in Melbourne, Australia, and performed discrete-time survival with needle-sharing and OST status as independent variables. HCV infection, reinfection and combined infection/reinfection incidences were 7·6 [95% confidence interval (CI) 4·8-11·9], 12·4 (95% CI 9·1-17·0) and 9·7 (95% CI 7·4-12·6) per 100 person-years, respectively. Needle-sharing was significantly associated with higher incidence of naive HCV infection [hazard ratio (HR) 4·9, 95% CI 1·3-17·7] but not reinfection (HR 1·85, 95% CI 0·79-4·32); however, a cross-model test suggested this difference was sample specific. Past month use of OST had non-significant protective effects against naive HCV infection and reinfection. Our data confirm previous evidence of greatly reduced HCV incidence in PWID, but not the significant protective effect of OST on HCV incidence detected in recent studies. Our findings reinforce the need for greater access to HCV testing and prevention services to accelerate the decline in incidence, and HCV treatment, management and support to limit reinfection.

Background: Previous research into psychological distress among people who inject drugs (PWID) is predominantly cross-sectional; we determined longitudinal predictors of change in psychological distress among a cohort of PWID., Method: We examined Kessler Psychological Distress Scale (K10) scores from 564 PWID (66% male) enrolled in the Melbourne Injecting Drug User Cohort Study. Gender-stratified linear models with fixed effects for each participant were used to examine correlates of change in individual K10 scores. Further linear regressions of adjusted K10 scores were used to measure correlations between demographic variables., Results: Participants reported higher K10 scores (higher psychological distress) than the general Australian population (mean K10 scores 23.4 (95%CI 22.6-24.2) and 14.5 (95%CI 14.3-14.7) respectively). The cohort's mean K10 score did not significantly differ over time, but individual variations were common. Women reported higher K10 scores than men (mean baseline K10 scores 25.2 (95%CI 23.9-26.6) and 22.4 (95%CI 21.5-23.3) respectively), however no significant differences remained after controlling for temporal factors. Key predictors of increases in K10 scores were being the victim of an assault in the past six months (P<0.001 for women and men) and intentionally overdosing in the past 12 months (P=.010 for women and P<0.001 for men)., Conclusions: PWID experience higher levels of psychological distress than the general population. Temporal rather than individual factors may account for the higher levels of psychological distress reported among women. Interventions to reduce rates of assault and/or intentional overdose should be explored to reduce high levels of psychological distress among PWID., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Online social networking platforms such as Facebook and Twitter have grown rapidly in popularity, with opportunities for interaction enhancing their health promotion potential. Such platforms are being used for sexual health promotion but with varying success in reaching and engaging users. We aimed to identify Facebook and Twitter profiles that were able to engage large numbers of users, and to identify strategies used to successfully attract and engage users in sexual health promotion on these platforms., Methods: We identified active Facebook (n = 60) and Twitter (n = 40) profiles undertaking sexual health promotion through a previous systematic review, and assessed profile activity over a one-month period. Quantitative measures of numbers of friends and followers (reach) and social media interactions were assessed, and composite scores used to give profiles an 'engagement success' ranking. Associations between host activity, reach and interaction metrics were explored. Content of the top ten ranked Facebook and Twitter profiles was analysed using a thematic framework and compared with five poorly performing profiles to identify strategies for successful user engagement., Results: Profiles that were able to successfully engage large numbers of users were more active and had higher levels of interaction per user than lower-ranked profiles. Strategies used by the top ten ranked profiles included: making regular posts/tweets (median 46 posts or 124 tweets/month for top-ranked profiles versus six posts or six tweets for poorly-performing profiles); individualised interaction with users (85% of top-ranked profiles versus 0% for poorly-performing profiles); and encouraging interaction and conversation by posing questions (100% versus 40%). Uploading multimedia material (80% versus 30%) and highlighting celebrity involvement (70% versus 10%) were also key strategies., Conclusion: Successful online engagement on social networking platforms can be measured through quantitative (user numbers and interactions) and basic qualitative content analysis. We identified the amount and type of host activity as key strategies for success, and in particular, regular individualised interaction with users, encouraging conversation, uploading multimedia and relevant links, and highlighting celebrity involvement. These findings provide valuable insight for achieving a high level of online engagement through social networking platforms to support successful health promotion initiatives.

Background: Increased global access and use of antiretroviral therapy (ART) for human immunodeficiency virus (HIV) has been postulated to undermine HIV prevention efforts by changing individual risk-taking behavior. This review aims to determine whether ART use is associated with changes in sexual or injecting risk-taking behavior or diagnosis of sexually transmitted infections (STIs)., Methods: A systematic review and meta-analysis was conducted of HIV-seropositive participants receiving ART compared with no ART use in experimental or observational studies. Primary outcomes included (1) any unprotected sexual intercourse, (2) STI diagnoses, and (3) any unsafe injecting behavior., Results: Fifty-eight studies met the selection criteria. Fifty-six studies containing 32 857 participants reported unprotected sex; 11 studies containing 16 138 participants reported STI diagnoses; and 4 studies containing 1600 participants reported unsafe injecting behavior. All included studies were observational. Unprotected sex was lower in participants receiving ART than in those not receiving ART (odds ratio [OR], 0.73; 95% confidence interval [CI], .64-.83; P < .001; heterogeneity I(2) = 79%) in both high-income (n = 38) and low-/middle-income country (n = 18) settings, without any evidence of publication bias. STI diagnoses were also lower among individuals on ART (OR, 0.58; 95% CI, .33-1.01; P = .053; I(2) = 92%); however, there was no difference in injecting risk-taking behavior with antiretroviral use (OR, 0.90; 95% CI, .60-1.35; P = .6; I(2) = 0%)., Conclusions: Despite concerns that use of ART might increase sexual or injecting risk-taking, available research suggests that unprotected sex is reduced among HIV-infected individuals on treatment. The reasons for this are not yet clear, although self-selection and mutually reinforcing effects of HIV treatment and prevention messages among people on ART are likely., (© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

This paper outlines a commentary response to an article published by Young and colleagues in Preventive Medicine that evaluated the feasibility of using Twitter as a surveillance and monitoring took for HIV. We draw upon the broader literature on disease surveillance and public health prevention using social media and broader considerations of epidemiological and surveillance methods to provide readers with necessary considerations for using social media in epidemiology and surveillance., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objectives: To develop a mathematical model to project the potential impact of hepatitis C virus (HCV) treatment on HCV infection prevalence among people who inject drugs (PWID)., Design and Setting: An existing model of HCV transmission among PWID was parameterised using data from Victoria, Australia, including specific parameter estimates of the number of people who are currently active injecting drug users, average duration of injecting, chronic HCV infection prevalence among PWID, annual mortality, and annual HCV treatment rate. We also explored the impact of prevalence uncertainty, program scale-up, and new treatments., Main Outcome Measure: Prevalence of chronic HCV infection among people who are currently active injecting drug users., Results: With annual treatment rates of 13, 17, or 25 per 1000 PWID, the model predicts relative prevalence reductions of 20%, 30%, and 50%, respectively, within 30 years. If new treatments giving higher sustained viral response rates are available in 5 years, estimated impact is increased by 21%–23% at 15 years, and 17%–38% at 30 years, depending on treatment rates., Conclusions: This model suggests that modest rates of current HCV treatment among PWID in Victoria, Australia could halve HCV infection prevalence among PWID in 30 years. This finding suggests that interventions aimed at increasing access to HCV treatment in community clinics will benefit individual PWID and reduce HCV infection prevalence.

Background: Despite widespread prescription of non-occupational post-exposure prophylaxis (NPEP) in Victoria, little is known about subsequent HIV acquisition among NPEP users. We linked the Victorian NPEP Service (VNPEPS) database and the Victorian HIV Surveillance Registry to determine the number, incidence rate and predictive factors of HIV seroconversions among users of the VNPEPS., Methods: Records from male patients that received NPEP in the VNPEPS database (n = 1420) between January 2001 and February 2008 were linked with all entries in the Victorian HIV Surveillance Registry up to May 2008., Results: Sixty-one men who presented to the VNPEPS were identified as HIV seropositive; 16 of these were diagnosed at initial presentation for NPEP. The incidence of HIV seroconversion in males who were HIV seronegative at first presentation for NPEP was 1.27 (95% confidence interval 0.95-1.70) per 100 person-years. There was no association between HIV seroconversion and number of NPEP presentations or age. The median age of seroconversion was 34.6 years., Conclusion: The incidence of HIV infection among men presenting to the VNPEPS is slightly lower than the HIV incidence in NPEP users in a recent Australian cohort study of men who have sex with men, but higher than HIV incidence in general gay male populations. Frequency of NPEP use was not associated with risk of HIV seroconversion. Examination of risk behaviour before and after NPEP use in this population is required to further assess the impact of NPEP availability and use on HIV incidence rates and risk behaviour in Australia.

Stigma within health care settings poses a considerable barrier to the provision of treatment and care for patients with HIV/AIDS (PLWHA). Southern China is located in a region with one of the world's fastest growing HIV/AIDS epidemics. Attitudes towards PLWHA amongst health workers are currently under-researched in this region. This paper examines the inter-relationships between prejudicial attitudes among Chinese medical students towards HIV/AIDS and attitudes towards three risk behaviors: injecting drug use (IDU), commercial sex (CS) and commercial blood donation (CBD). Medical students (N = 352) in Guangzhou were presented with two random vignettes; each describing a hypothetical male that was identical, except for the disease diagnosis (AIDS/leukemia) and the co-characteristic (IDU/CS/CBD/blood transfusion/no co-characteristic). After reading each vignette, participants completed a standard prejudicial scale. Univariate and multivariable analyses revealed significant levels of prejudice associated with AIDS, IDU and CS. Regardless of the disease, patients with IDU or CS were judged significantly worse than patients who had received a blood transfusion. No significant interactions were found between AIDS and the stigmatized co-characteristics. The findings suggest that prejudice towards PLWHA needs to be understood within the larger context of the stigma towards risk behaviors. Although non-significant interactions were found between AIDS and the stigmatized risk behaviors, the overlap between the local HIV/AIDS, IDU and CS populations suggests that addressing risk behavior-related prejudices could be critical for improving care and treatment for PLWHA.

Introduction and Aims: Experiencing previous non-fatal overdoses have been identified as a predictor of subsequent non-fatal overdoses; however, few studies have investigated the association between previous non-fatal overdose experiences and overdose mortality. We examined overdose mortality among injecting drug users who had previously been attended by an ambulance for a non-fatal heroin overdose., Design and Methods: Using a retrospective cohort design, we linked data on non-fatal heroin overdose cases obtained from ambulance attendance records in Melbourne, Australia over a 5-year period (2000-2005) with a national death register., Results: 4884 people who were attended by ambulance for a non-fatal heroin overdose were identified. One hundred and sixty-four overdose deaths occurred among this cohort, with an average overdose mortality rate of 1.20 per 100 person-years (95% CI, 1.03-1.40). Mortality rate decreased 10-fold after 2000 coinciding with widely reported declines in heroin availability. Being male, of older age (>35 years) and having been attended multiple times for previous non-fatal overdoses were associated with increased mortality risk., Discussion and Conclusions: As the first to show a direct association between non-fatal overdose and subsequent overdose mortality, this study has important implications for the prevention of overdose mortality. This study also shows the profound effect of macro-level heroin market dynamics on overdose mortality.