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Background and Aims: Many previous studies have used cross-sectional approaches to measure associations between injecting drug users' (IDUs') characteristics and hepatitis C virus (HCV) status, and identified independent predictors of antibody to HCV (anti-HCV) positivity including duration of injecting, needle-sharing history and prior imprisonment. Although HCV transmission between IDUs occurs primarily through blood transfer during close physical interactions, the contribution of social network data to prediction of HCV status has not been previously assessed. Methods: 215 injecting drug users and their injecting network members were recruited in Melbourne, Australia between July 2005 and August 2006. Logistic regression was used to analyze behavioral and social network data for predictors of HCV exposure. Results: IDUs' HCV exposure status was independently associated with the age of first injection of their injecting network members (adjusted OR=2.82, P=0.019) and the HCV exposure status of those network members (adjusted OR = 6.17, P<0.001), in addition to several `traditional' behavioral and lifetime variables. Conclusions: Patterns of exposure to the hepatitis C virus are influenced by the characteristics of members of IDU5' social networks. HCV RNA and/or antibody testing are an important part of any HCV prevention strategy for IDU5; increased availability of testing and sharing HCV status information within social networkswould enable more IDUs to avoid infection. [ABSTRACT FROM AUTHOR]

The social networks of 49 ethnic Vietnamese injecting drug users (IDUs) and 150 IDUs of other ethnicities recruited in Melbourne, Australia, were examined for ethnic differences in distribution of hepatitis C virus infection risk using social network analysis and molecular epidemiology. Vietnamese IDUs were more highly connected than non-Vietnamese IDUs, and more likely to be members of dense injecting sub-networks. More related infections were detected in IDUs with discordant ethnicities than were captured in the social network data; nonetheless, most dyads and most IDU pairs with related infections had matching ethnicity, confirming that mixing was assortative on that criterion. Mixing was not obviously dissortative by risk; low-risk Vietnamese IDUs injected more frequently than did correspondingly low-risk non-Vietnamese IDUs, but results for other measures were reversed or equivocal. Network measurements suggest that ethnic Vietnamese IDUs are at elevated risk of blood-borne infection, a conclusion supported by their relatively high HIV prevalence. [ABSTRACT FROM AUTHOR]

BACKGROUND: Tattooing in prison represents a unique combination of risk factors for blood borne virus (BBV) transmission because it is illicitly performed by untrained operators with homemade, unsterile, and frequently-shared equipment. It occurs in a setting where a high proportion of people are already infected with hepatitis C virus (HCV) and other BBVs. OBJECTIVES: This study measured the frequency of tattoo acquisition by prisoners inside and outside prison, and the associations between tattooing, injecting drug use, and HCV infection risk. METHODS: A cross-sectional survey was conducted in correctional facilities in Victoria, Australia. Participants completed a questionnaire that asked about injecting drug use and tattooing and provided a finger-prick blood sample that was tested for HCV antibody. RESULTS: Six hundred and forty-two prisoners participated in the study; 449 had ever been tattooed, of whom 182 (41%) had been tattooed in adult or juvenile prison. Of the participants who were not tattooed professionally, 27% reported someone using the same needle, and 42% reported someone had used the ink before them. Prisoners with a history of drug injection were more likely to have a tattoo and to have acquired a tattoo in prison (OR 3.0; CI 1.7-5.4). The HCV antibody-positive prisoners were more likely to have acquired a tattoo in prison compared with HCV antibody-negative prisoners. CONCLUSIONS: Acquiring a tattoo in prison was common and the reports of sharing the tattooing needle and ink was high, placing prisoners at risk of acquiring HCV through tattooing in prison. Trials need to be undertaken that evaluate the risk and benefits of legal tattoos in prison. [ABSTRACT FROM AUTHOR]

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]

Coverage is an important dimension in measuring the effectiveness of needle and syringe programmes in providing sterile injecting equipment for people who inject drugs. The World Health Organization (WHO), the United Nations Office on Drugs and Crime (UNODC) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) currently recommend methods for measuring coverage at the population level, that is, across an estimated population of people who inject drugs within a given geographical area. However, population-level measures of coverage rely on highly uncertain population estimates and cannot capture the different levels of syringe acquisition and injecting episodes among individual users. Consequently, such measures only broadly evaluate the extent of programme service delivery, rather than describe how people who inject drugs as individuals and sub-groups interact with needle and syringe programmes. In response to these limitations, several researchers have proposed measuring coverage at the individual level, by the percentage of injecting episodes in relation to the number of sterile needles and syringes acquired. These measures evaluate coverage according to each individual's needs. Such measures provide enhanced information for planning and monitoring of harm reduction programmes and have now been used in multiple international research studies. We advise that WHO, UNODC and UNAIDS add individual-level coverage measurement methods to their international monitoring guidelines for harm reduction programmes. By doing this, more responsive and effective programmes can be created to better reduce injecting risk behaviours and blood-borne virus transmission among people who inject drugs.

Objective: We sought to establish the extent of repeat participation in a large annual cross-sectional survey of people who inject drugs and assess its implications for analysis., Results: We used "porn star names" (the name of each participant's first pet followed by the name of the first street in which they lived) to identify repeat participation in three Australian Illicit Drug Reporting System surveys. Over 2013-2015, 2468 porn star names (96.2%) appeared only once, 88 (3.4%) twice, and nine (0.4%) in all 3 years. We measured design effects, based on the between-cluster variability for selected estimates, of 1.01-1.07 for seven key variables. These values indicate that the complex sample is (e.g.) 7% less efficient in estimating prevalence of heroin use (ever) than a simple random sample, and 1% less efficient in estimating number of heroin overdoses (ever). Porn star names are a useful means of tracking research participants longitudinally while maintaining their anonymity. Repeat participation in the Australian Illicit Drug Reporting System is low (less than 5% per annum), meaning point-prevalence and effect estimation without correction for the lack of independence in observations is unlikely to seriously affect population inference.

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.

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.)

Needle and syringe program (NSP) coverage is commonly used to assess NSP effectiveness. However, existing measures don't capture whether persons who inject drugs (PWIDs) stockpile syringes, an important and novel aspect of NSP coverage. In this study, we determine the extent of stockpiling in a sample of Australian PWIDs and assess whether including stockpiling enhances NSP coverage measures. As part of the Illicit Drug Reporting System study, PWIDs reported syringes procured and given away, total injections in the last month, and syringes currently stockpiled in 2014. We calculated NSP coverage with and without stockpiling to determine proportional change in adequate NSP coverage. We conducted receiver operating characteristic curve analysis to determine whether inclusion of stockpiled syringes in the measure improved sensitivity in discriminating cases and noncases of risky behaviors. Three-quarters of the sample reported syringe stockpiling, and stockpiling was positively associated with nonindigenous background, stable accommodation, no prison history, longer injecting careers, and more frequent injecting. Compared with previous measures, our measure was significantly better at discriminating cases of risky behaviors. Our results could inform NSP policy to loosen restricted-exchange practice, allowing PWIDs greater flexibility in syringe procurement practices, promoting greater NSP coverage, and reducing PWIDs' engagement in risky behaviors., (© The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Unlabelled: Hepatitis C virus reinfection and spontaneous clearance of reinfection were examined in a highly characterised cohort of 188 people who inject drugs over a five-year period. Nine confirmed reinfections and 17 possible reinfections were identified (confirmed reinfections were those genetically distinct from the previous infection and possible reinfections were used to define instances where genetic differences between infections could not be assessed due to lack of availability of hepatitis C virus sequence data). The incidence of confirmed reinfection was 28.8 per 100 person-years (PY), 95%CI: 15.0-55.4; the combined incidence of confirmed and possible reinfection was 24.6 per 100 PY (95%CI: 16.8-36.1). The hazard of hepatitis C reinfection was approximately double that of primary hepatitis C infection; it did not reach statistical significance in confirmed reinfections alone (hazard ratio [HR]: 2.45, 95%CI: 0.87-6.86, p=0.089), but did in confirmed and possible hepatitis C reinfections combined (HR: 1.93, 95%CI: 1.01-3.69, p=0.047) and after adjustment for the number of recent injecting partners and duration of injecting. In multivariable analysis, shorter duration of injection (HR: 0.91; 95%CI: 0.83-0.98; p=0.019) and multiple recent injecting partners (HR: 3.12; 95%CI: 1.08-9.00, p=0.035) were independent predictors of possible and confirmed reinfection. Time to spontaneous clearance was shorter in confirmed reinfection (HR: 5.34, 95%CI: 1.67-17.03, p=0.005) and confirmed and possible reinfection (HR: 3.10, 95%CI: 1.10-8.76, p-value=0.033) than primary infection. Nonetheless, 50% of confirmed reinfections and 41% of confirmed or possible reinfections did not spontaneously clear., Conclusions: Hepatitis C reinfection and spontaneous clearance of hepatitis C reinfection were observed at high rates, suggesting partial acquired natural immunity to hepatitis C virus. Public health campaigns about the risks of hepatitis C reinfection are required.

Background and Aim: Forty percent of new hepatitis B virus (HBV) infections in Australia occur in people who inject drugs (PWID); long-term infection carries the risk of serious liver disease. HBV incidence among Australian PWID has not been measured since the advent of targeted (2001) and adolescent school-based "catch-up" (1998) vaccination programs. We measured HBV incidence and prevalence in a cohort of PWID in Melbourne, Australia and examined demographic and behavioral correlates of exposure and vaccination., Methods: Community-recruited PWID were surveyed about blood-borne virus risk behaviors and their sera tested for HBV markers approximately three-monthly over three years. Incidence was assessed using prospectively collected data. A cross-sectional design was used to examine prevalence of HBV exposure and vaccination at baseline. Poisson regression was used to identify correlates of HBV exposure and vaccination., Results: At baseline, 33.1% of participants (114/344) had been vaccinated against HBV, 40.4% (139/344) had been exposed (previously or currently infected), and 26.5% (91/344) were susceptible. HBV incidence was 15.7 per 100 person-years. Independent associations with HBV exposure included female gender, South-East Asian ethnicity, drug treatment in the past three months, injecting in prison, and prior exposure to hepatitis C virus. Independent associations with vaccination included being ≤ 25 years old, reporting HBV vaccination, and never having been to prison., Conclusions: HBV infection continues at high incidence among Australian PWID despite the introduction of free vaccination programs. Innovative methods are needed to encourage PWID to complete HBV vaccination., (© 2012 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Introduction: Studies have explored whether spontaneous clearance of hepatitis C virus (HCV) infection decreases the likelihood of reinfection or increases the probability of clearance. This analysis investigates whether the conflicting findings from these studies could be due to differences in frequency of HCV RNA testing., Methods: A model simulated the dynamics of HCV reinfection and clearance among a cohort of injection drug users. For different reinfection incidence and clearance rates, the model evaluated the accuracy of epidemiological studies that used different HCV testing frequencies., Results: Experimental estimates for the reinfection incidence and clearance probability will be accurate (<20% error) if the testing interval is less than the reinfection clearance duration. Otherwise, experimental estimates can greatly underestimate the real values (≤66% error if reinfection duration is 1 month and the testing interval is 3 months). Uncertainty in experimental estimates also increases at lower reinfection incidences, whereas for lower clearance probabilities the uncertainty in the estimated clearance probability increases but estimated reinfection incidence decreases., Discussion: Differences in HCV testing interval could account for most between-study variability in the estimated probability of clearing reinfections and is likely to have biased reinfection incidence estimates. Our findings suggest that a high reinfection clearance probability (>75%) is consistent with data.

Objective: To carry out a randomised controlled trial on the effect of a new method of health promotion-email and mobile phone text messages (short messaging service (SMS))-on young people's sexual health., Methods: 994 people aged 16-29 were recruited at a music festival to a non-blinded randomised controlled trial. Participants were randomised to either receive sexual health promotion messages (n=507) or the control group (n=487). The 12-month intervention included SMS (catchy sexually transmissible infections prevention slogans) and emails. Participants completed questionnaires at the festival at baseline and online after 3, 6 and 12 months. Outcomes were differences between the control and intervention groups in health-seeking behaviour, condom use with risky partners (new or casual partners or two or more partners within 12 months) and STI knowledge., Results: 337 (34%) completed all three follow-up questionnaires and 387 (39%) completed the final questionnaire. At 12 months, STI knowledge was higher in the intervention group for both male (OR=3.19 95% CI 1.52 to 6.69) and female subjects (OR=2.36 95% CI 1.27 to 4.37). Women (but not men) in the intervention group were more likely to have had an STI test (OR=2.51, 95% CI 1.11 to 5.69), or discuss sexual health with a clinician (OR=2.92, 95% CI 1.66 to 5.15) than their control counterparts. There was no significant impact on condom use. Opinions of the messages were favourable., Conclusion: This simple intervention improved STI knowledge in both sexes and STI testing in women, but had no impact on condom use. SMS and email are low cost, popular and convenient, and have considerable potential for health promotion., Clinical Trial Registration Number: Australian Clinical Trials Registry - ACTRN12605000760673.

Mobile phone text messages (SMS) are a promising method of health promotion, but a simple and low cost way to obtain phone numbers is required to reach a wide population. We conducted a randomised controlled trial with simultaneous brief interventions to (i) evaluate effectiveness of messages related to safer sex and sun safety and (ii) pilot the use of mobile advertising for health promotion. Mobile advertising subscribers aged 16-29 years residing in Victoria, Australia (n = 7606) were randomised to the 'sex' or 'sun' group and received eight messages during the 2008-2009 summer period. Changes in sex- and sun-related knowledge and behaviour were measured by questionnaires completed on mobile phones. At follow-up, the sex group had significantly higher sexual health knowledge and fewer sexual partners than the sun group. The sun group had no change in hat-wearing frequency compared with a significant decline in hat-wearing frequency in the sex group. This is the first study of mobile advertising for health promotion, which can successfully reach most young people. Challenges experienced with project implementation and evaluation should be considered as new technological approaches to health promotion continue to be expanded.

Hepatitis C virus (HCV) infection causes significant morbidity and mortality worldwide. T cells play a central role in HCV clearance; however, there is currently little understanding of whether the disease outcome in HCV infection is influenced by the choice of TCR repertoire. TCR repertoires used against two immunodominant HCV determinants--the highly polymorphic, HLA-B*0801 restricted (1395)HSKKKCDEL(1403) (HSK) and the comparatively conserved, HLA-A*0101-restricted, (1435)ATDALMTGY(1443) (ATD)--were analyzed in clearly defined cohorts of HLA-matched, HCV-infected individuals with persistent infection and HCV clearance. In comparison with ATD, TCR repertoire selected against HSK was more narrowly focused, supporting reports of mutational escape in this epitope, in persistent HCV infection. Notwithstanding the Ag-driven divergence, T cell repertoire selection against either Ag was comparable in subjects with diverse disease outcomes. Biased T cell repertoires were observed early in infection and were evident not only in persistently infected individuals but also in subjects with HCV clearance, suggesting that these are not exclusively characteristic of viral persistence. Comprehensive clonal analysis of Ag-specific T cells revealed widespread use of public TCRs displaying a high degree of predictability in TRBV/TRBJ gene usage, CDR3 length, and amino acid composition. These public TCRs were observed against both ATD and HSK and were shared across diverse disease outcomes. Collectively, these observations indicate that repertoire diversity rather than particular Vβ segments are better associated with HCV persistence/clearance in humans. Notably, many of the anti-HCV TCRs switched TRBV and TRBJ genes around a conserved, N nucleotide-encoded CDR3 core, revealing TCR sequence mosaicism as a potential host mechanism to combat this highly variant virus.

Background: Diaries are used in sexual behaviour research to reduce recall bias. Diary collection via mobile phone text messaging (SMS) has not been trialled previously in sexual behaviour research. This randomised controlled trial compared SMS, paper and online diaries on response rate, timeliness, completeness of data and acceptability. The correlation between behaviour reported in all three types of diaries and data collected in a retrospective questionnaire was also determined., Methods: Participants were recruited by telephone and randomised into one of three groups. They completed weekly sexual behaviour diaries for 3 months by SMS, online or paper (by post). An online survey was conducted at the end of 3 months to compare retrospective reports to the diaries and assess opinions on the diary collection method., Results: 72 participants were enrolled in the study, 24 in each group. Online diaries were more likely to be submitted late than SMS diaries (p<0.001). 3.9% of SMS diaries, 3.1% of paper diaries and 0.5% of online diaries were incomplete (p=0.001). Online data collection was the preferred mode for 51%. 65 participants completed the end point retrospective questionnaire. The correlation between the diary and questionnaire on sexual risk classification was substantial (kappa=0.74) regardless of diary mode., Conclusions: SMS is a convenient and timely method of collecting brief behavioural data, but online data collection was preferable to most participants and more likely to be complete. Data collected in retrospective sexual behaviour questionnaires were found to agree substantially with data collected through weekly self-reported diaries.

Background: Chlamydia is most common among young people, but only a small proportion of Australian young people are tested annually. Home-based chlamydia testing has been piloted in several countries to increase testing rates, but uptake has been low. We aimed to identify predictors of uptake of home-based chlamydia testing to inform future testing programs., Methods: We offered home-based chlamydia testing kits to participants in a sexual behaviour cross-sectional survey conducted at a music festival in Melbourne, Australia. Those who consented received a testing kit and were asked to return their urine or vaginal swab sample via post., Results: Nine hundred and two sexually active music festival attendees aged 16-29 completed the survey; 313 (35%) opted to receive chlamydia testing kits, and 67 of 313 (21%) returned a specimen for testing. One participant was infected with chlamydia (1% prevalence). Independent predictors of consenting to receive a testing kit included older age, knowing that chlamydia can make women infertile, reporting more than three lifetime sexual partners and inconsistent condom use. Independent predictors of returning a sample to the laboratory included knowing that chlamydia can be asymptomatic, not having had an STI test in the past six months and not living with parents., Conclusions: A low proportion of participants returned their chlamydia test, suggesting that this model is not ideal for reaching young people. Home-based chlamydia testing is most attractive to those who report engaging in sexual risk behaviours and are aware of the often asymptomatic nature and potential sequelae of chlamydia infection.

Objective: To explain rising rates of sexually transmitted infections it is necessary to monitor trends among high risk groups, such as youth. Surveillance of risk behaviours and testing among a variety of populations in different settings is required. We monitored self-reported sexual behaviour among music festival attendees., Methods: Cross-sectional studies of young people's behaviour were conducted annually at a music festival between 2005 and 2008 using self-administered questionnaires. Logistic regression, adjusted for age and gender, determined trends in risk behaviours., Results: More than 5,000 questionnaires were completed. The proportion reporting multiple sexual partners in the past year remained stable from 2005 to 2008 and condom use with these partners increased. Reporting a new sexual partner in the past three months decreased, while condom use with new partners increased. Reporting a casual sexual partner increased and condom use with casual partners remained stable. Reporting a recent STI test increased from 23% in 2006 to 32% in 2008., Conclusions and Implications: Despite increases in STI notifications, most risk behaviours are decreasing in this group, possibly as a function of increased STI testing. Music festivals are a useful setting for monitoring behaviour trends within a sub-population of young people at relatively high risk of STIs.

Objective: We estimated the cost to the public health system of treating Injecting-Related Injuries and Diseases (IRIDs) in the three most populous states in Australia in the 12 months over 2005/06., Methods: We conducted a cost of illness analysis from the perspective of the public health system. Costs of treating IRIDs in the community were estimated from health service utilisation surveys of injecting drug users and physicians (yielding data on Government subsidised physician visits, medicines prescribed and emergency department presentations). Data on admitted hospitalisations in public hospitals due to IRIDs were extracted from State Government databases. Appropriate costs were attached to all Government-borne services and prescriptions to estimate the total cost to the public health system of treating IRIDs in 2005/06 in Queensland, NSW and Victoria., Results: Our estimate of the cost to the public health system of treating IRIDs in Queensland, NSW and Victoria in 2005/06 was $20 million., Conclusion: IRIDs are an under-recognised harm resulting from injecting drug use, but the economic burden of IRIDs in Australia are non-negligible. Research is needed to identify cost effective programs to reduce the clinical and economic burden caused by IRIDs, particularly to reduce hospitalisations due to IRIDs., Implications: General practitioners, clinicians and other health workers need to be alert to IRIDs in their injecting drug user clients to prevent progression to more serious disease and consequent elevation of the associated economic costs.

To analyse the immune correlates in a setting of recurrent exposure to hepatitis C virus (HCV), we studied T(CD8) responses in injecting drug users (IDUs) with different disease outcomes. Ex vivo HCV-specific T(CD8) responses assessed by interferon-gamma (IFNgamma) enzyme-linked immunospot (ELISPOT) were comparable in human lymphocyte antigen (HLA)-matched IDUs with spontaneous HCV clearance or persistent infection. A detailed characterization of these T(CD8) cells in age and HLA-matched IDUs demonstrated that HCV clearance and protection from reinfection correlated with HCV-specific T(CD8) cells that could proliferate in vitro, possessed cytotoxic potential and produced IFNgamma and tumour-necrosis factor-alpha, rather than with the circulating frequency of responding T(CD8) cells determined ex vivo. While validating the importance of multifunctional T(CD8) in mediating protection in IDUs with recurrent exposure to HCV our findings highlight that the magnitude and/or breadth of HCV-specific T(CD8) determined in ex vivo ELISPOT may not be the sole determinant of protection especially in a setting of recurrent exposure.

Introduction: The aim of this study was to ascertain whether the health of past and current smokers of illicit tobacco (chop-chop) differs from that of smokers of licit tobacco., Methods: The design was a telephone survey, stratified by state, using computer aided telephone interviewing, with households selected by random digit dialing from the telephone white pages. Setting was all Australian states and territories, 1,621 regular tobacco smokers aged 18+ years. Measures were social and personal characteristics of tobacco smokers, smoking histories and patterns, and health status (SF-8 and disability weights). Binary logistic regression was used to identify variables associated with current and lifetime chop-chop use., Results: Compared with licit-only tobacco smokers, current users of chop-chop had significantly greater odds of beginning smoking aged <16 years (odds ratio [OR] 1.65, 95% CI = 1.09-2.50), of reporting below-average social functioning (OR 1.61, 95% CI = 1.06-2.44), and of a measurable disability (OR 1.95, 95% CI = 1.08-3.51). Lifetime chop-chop users were relatively likely to be less than 45 years of age (OR 1.82, 95% CI = 1.38-2.39), report below-average mental health (OR 1.61, 95% CI = 1.22-2.13) and above-average bodily pain (OR 1.40, 95% CI = 1.06-1.85), smoke more than 120 cigarettes/week (OR 1.39, 95% CI = 1.06-1.83), and to have begun smoking aged <16 years (OR 1.33, 95% CI = 1.01-1.75)., Discussion: Current and lifetime users of chop-chop report significantly worse health than smokers of licit tobacco. Investigation of how to communicate this finding to current and potential chop-chop smokers is warranted.

Young people's sexual behaviour is influenced by their perceptions of peer norms. In this survey of 445 people aged 16 to 29 years, 69% of participants believed they had fewer lifetime sexual partners than average. The mean number of actual lifetime partners reported was 5.5 and the mean perceived 'average' partners for peers was 6.6 (P < 0.01). When broken down by age and sex, the discrepancy was only significant for females aged 16 to 19. Comparison to a national survey also showed that peers' average sexual experience was overestimated. Adolescents are highly susceptible to the influence of peer norms, hence it is concerning that their perceptions of these norms are so distorted.

Background and Aims: Current injecting drug users (IDU) in major street drug markets within greater Melbourne were recruited to a longitudinal study on blood borne viruses. Here we investigated risk factors for hepatitis C virus (HCV), hepatitis B virus (HBV) and HIV infection in these IDU at the time of their recruitment., Methods: Three hundred and eighty-two IDU completed detailed questionnaires on their drug use and risk behaviours, and provided blood samples for serology testing. These data were analysed using univariate and multivariate techniques., Results: The overall prevalence of exposure to HCV, HBV and HIV was estimated at 70%, 34% and <1%, respectively. Independent predictors of HCV exposure were history of imprisonment (RR 1.34, 95% CI 1.19-1.52), use of someone else's needle or syringe (RR 1.23, 95% CI 1.07-1.42), >7.6years length of time injecting (RR 1.21, 95% CI 1.07-1.37), and originating from Vietnam (RR 1.12, 95% CI 1.07-1.18). Independent predictors of HBV exposure were HCV exposure (RR 2.15, 95% CI 1.35-3.43), >7.6years length of time injecting (RR 1.57, 95% CI 1.17-2.13) and originating from outside Australia (RR 1.60, 95% CI 1.22-2.10). Neither prison- nor community-applied tattoos predicted HCV or HBV exposure. Up to 31% of IDU who injected for 1year or less were HCV antibody positive, as were 53% of those who injected for 2years or less., Conclusions: Ongoing engagement with young IDU, through the provision of harm reduction education and resources, is critical if we are to address blood borne viral infections and other health and social harms associated with injecting drug use.

Unlabelled: An estimated 170 million people worldwide carry the hepatitis C virus (HCV), and in more developed countries the prevalence and incidence of HCV is particularly high among injecting drug users (IDUs). Spontaneous clearance of HCV infection and reinfection is well recognized but the level of protection against further infection conferred by HCV infection and clearance remains uncertain. We conducted a prospective study of HCV infection in IDUs recruited in Melbourne, Australia, using a much shorter median testing interval than in previous studies. Incidences of naive infection and reinfection were calculated by the person-year method and Cox proportional hazards regression used to adjust for covariates. A significantly higher HCV incidence rate was measured in previously infected IDUs (46.8% per year) compared with HCV-naive IDUs (15.5% per year). The hazard ratio for previously infected IDUs compared to HCV-naive IDUs, after adjustment for time-dependent covariates, was 2.54 (95% confidence interval, 1.11-5.78, P > |z| < 0.05). Viral persistence after reinfection appeared similar to that following naive infection., Conclusion: Our data suggest that HCV infection in IDUs is more likely following prior infection and clearance than in HCV-naive individuals, implying no increased immunity against further infection. This result has important implications for the future development of an HCV vaccine.

Introduction and Aims: Drug use is becoming normalised among young Australian people involved in music sub-cultures. We aimed to determine prevalences of illicit drug use in this population and associations between preferences for different music genres and recent use of particular illicit drugs., Design and Methods: A cross-sectional questionnaire of young people (aged 16-29 years) attending a music festival., Results: Of 939 respondents, 46% had used illicit drugs (principally cannabis) in the past month, a significantly higher proportion than among respondents to the 2004 National Drug Strategy Household Survey (18%). Participants who favoured dance/house or rap music were more likely to have used illicit drugs recently than the remainder of the sample, while those who favoured pop or alternative music were less likely to have used drugs in the past month., Discussion and Conclusions: These data suggest that music festival attendees use illicit drugs more commonly than their age-matched cohort in the general community, and that music festivals venues (particularly those that cater for dance/house and rap) would be appropriate places for interventions to promote safer drug use.

Short messaging service (SMS) (a.k.a. text messaging) is a fast, low cost and popular mode of communication among young people, and these advantages can be used in a variety of ways in the field of sexual health. This paper reviews the current published and grey literature and discusses applications of SMS in sexual health and the evidence base for their effectiveness. Examples of uses of SMS in sexual health include: communication between sexual health clinics and patients, partner notification and contact tracing, contraception reminders and sexual health promotion and education. However, although SMS has been applied in many ways to improve sexual health and there is some evidence of its effectiveness, very few of the applications described in this article have been evaluated. As SMS is likely to become more and more commonly used for sexual health purposes, evaluation of its benefits and effectiveness is essential.

Background: The hepatitis C virus (HCV) causes significant morbidity and mortality worldwide, and is highly prevalent among injecting drug users (IDUs). Whether initial HCV infection and clearance provides protection from reinfection has not been established, but is an important question for vaccine development., Objective: To elucidate an unusual history of HCV infection and clearance in an IDU., Study Design: The subject was interviewed and gave blood samples at approximately three-month intervals; all samples were tested for anti-HCV and HCV RNA, genotyped if RNA detected, and checked for mixed genotypes; phylogenetic analysis performed on the subject's and injecting partners' core HCV sequences., Results: We observed consecutive infections with HCV genotypes 3a, 1a and 6l, and intervening clearances, in a young IDU over 449 days. Genotypes 1a and 6l were probably acquired from the subject's injecting partners, who had genetically related infections., Conclusion: This case illustrates (1) the ease with which IDUs can acquire HCV, (2) that prior HCV infection does not protect against reinfection with heterologous strains, and (3) that IDUs can clear consecutive HCV infections. Our subject's history of HCV infection and clearance offers hope for vaccine development, yet demonstrates that HCV vaccines must have cross-genotypic effectiveness.

Background: Prevalences of sexually transmissible infections (STI), unsafe sex and abortions are increasing in Australia and people aged 16 to 29 are particularly at risk. We conducted a survey of behaviour, knowledge and perceptions of STI risk among young people attending a longstanding annual music festival called the Big Day Out., Methods: A structured questionnaire was administered to a cross-sectional sample of people aged 16 to 29 years attending a music festival (Big Day Out)., Results: Completed questionnaires were collected from 939 participants (507 females, 432 males) whose median age was 20 years. Of the participants, 751 (80%) had ever had vaginal or anal sex. In the previous year, 48% had multiple partners and in the past 3 months 66% had a new partner. Of these, 224 (39%; 30% of those who had ever had sex) did not use condoms all or most of the time and were classified as being at risk of STI; however, only 24% of those so classified perceived that they were at risk of an STI. In total, 43% of all sexually experienced participants had not used a condom because they reported being drunk or high at the time. STI knowledge was poor overall and male participants, those living in non-metropolitan regions, those under the age of 20 and those with less schooling scored relatively poorly., Conclusions: Our data suggest that young men and women who attend the Big Day Out are sexually active young adults with limited knowledge of STI and blood-borne viruses who regularly engage in behaviours that put them at risk of infection.

Objectives: To determine the overall rate of loss of workplace teaspoons and whether attrition and displacement are correlated with the relative value of the teaspoons or type of tearoom., Design: Longitudinal cohort study., Setting: Research institute employing about 140 people., Subjects: 70 discreetly numbered teaspoons placed in tearooms around the institute and observed weekly over five months., Main Outcome Measures: Incidence of teaspoon loss per 100 teaspoon years and teaspoon half life., Results: 56 (80%) of the 70 teaspoons disappeared during the study. The half life of the teaspoons was 81 days. The half life of teaspoons in communal tearooms (42 days) was significantly shorter than for those in rooms associated with particular research groups (77 days). The rate of loss was not influenced by the teaspoons' value. The incidence of teaspoon loss over the period of observation was 360.62 per 100 teaspoon years. At this rate, an estimated 250 teaspoons would need to be purchased annually to maintain a practical institute-wide population of 70 teaspoons., Conclusions: The loss of workplace teaspoons was rapid, showing that their availability, and hence office culture in general, is constantly threatened.

Multiple genotypes of the hepatitis C virus (HCV) were detected in five of 138 HCV RNA positive injecting drug users (IDUs) recruited in Melbourne, Australia. Two were detected by combined LiPA and core and NS5a region sequencing, and three more (selected for testing due to their high-risk behaviour) by heteroduplex mobility analysis. We conclude that the true prevalence of mixed infection in IDUs is undoubtedly higher than the 3.6% (five of 138) we observed, and is underestimated by LiPA, the most common method of genotyping. As responsiveness to HCV treatment varies significantly with genotype, a high prevalence of mixed HCV infections in IDUs must diminish overall treatment efficacy and lessen our ability to reduce the burden of HCV-related disease.

Background: We aimed to measure the overlap between the social networks of injection drug users (IDUs) and the patterns of related hepatitis C virus (HCV) infections among IDUs., Methods: A cohort of 199 IDUs (138 of whom were HCV RNA positive) was recruited from a local drug scene in Melbourne, Australia, and was studied using social network analysis and molecular phylogenetic analysis of 2 regions of the HCV genome., Results: Eighteen clusters of related infections involving 51 IDUs (37.0% of HCV RNA-positive IDUs) were detected; these clusters could be separated into 66 discrete pairs. Twelve (18.2%) of the 66 IDU pairs with related infections reported having previously injected drugs together; conversely, only 12 (3.8%) of the 313 pairs of HCV RNA-positive IDUs who were injection partners had strong molecular evidence of related infections. The social and genetic distances that separated IDUs with identical genotypes were weakly associated. Significant clusters of phylogenetically related sequences identified from core region analysis persisted in the analysis of the nonstructural 5a protein region. Genotyping and sequence analysis revealed 2 mixed-genotype infections., Conclusions: Static social network methods are likely to gather information about a minority of patterns of HCV transmission, because of the difficulty of determining historical infection pathways in an established social network of IDUs. Nevertheless, molecular epidemiological methods identified clusters of IDUs with related viruses and provided information about mixed-genotype infection status.

Hepatitis C affects many millions of people worldwide and is at very high prevalence among people who inject drugs. In our study of hepatitis C virus (HCV) in the social networks of injecting drug users (IDUs), five IDUs with injecting careers of 9 years or more were HCV antibody and RNA negative. All injected frequently with HCV RNA-positive IDUs, and two had recently injected with the syringe of an RNA-positive IDU. Our data suggest the existence of immune protection from HCV infection.

Prisons are recognised worldwide as important sites for transmission of blood-borne viruses (BBVs). There are two reasons why transmission risks in prison are higher than in the community. First, in most western countries, many prison entrants have histories of injecting drug use, and thus already have high prevalences of BBVs. Second, the lack or under-supply of preventive measures (such as clean needle and syringes or condoms) in most prisons, combined with extreme social conditions, creates extra opportunities for BBV transmission. HIV prevalence in prisoners in more developed countries ranges from 0.2% in Australia to over 10% in some European nations. There are case reports of HIV being transmitted by sharing injecting equipment and sexual activity. Tattooing has been reported as a risk factor for the transmission of BBVs in prison. Access to condoms and needle and syringe programmes in prisons is extremely limited, despite success when they have been introduced. The vast majority of prison inmates are incarcerated for only a few months before returning to the community--thus they are, over the long term, more appropriately regarded as 'citizens' than 'prisoners'. Public health policy must involve all sections of the community, including prison inmates, if we are to reduce transmission of HIV and other BBVs.

We hypothesized that providing injecting drug users (IDUs) with free hepatitis C testing and counselling at a needle and syringe programme (NSP) would be an effective model. Between August 1999 and January 2000, our peer outreach worker offered these services from a busy NSP in western Melbourne. Over 300 counselling episodes were provided, and 47 IDUs who were not tested in the previous 12 months were given tests and full pre- and post-test counselling, and were interviewed about reasons for not being tested, their knowledge of hepatitis C, and their risk behaviour. Twenty-eight IDUs (59.6%) tested antibody-positive, demonstrating the need to improve testing coverage and compliance with counselling requirements. Most were not tested because they did not think they were at risk, but their reported behaviour and antibody test results showed otherwise. Twenty people returned for a second interview, and improvements in their risk behaviour and knowledge of hepatitis C were detected. Our experience suggests that demand exists for hepatitis C testing and counselling of IDUs in Melbourne's western suburbs, that testing and counselling improve IDUs' ability to avoid harm, and that delivery of these services by a trained and experienced peer located at an NSP is an appropriate and effective model.

Objective: To assess changes in risk behaviours for transmission of bloodborne viruses and incidences and prevalences of these viruses in a field-recruited cohort of injecting drug users., Design: Prospective longitudinal cohort study., Setting: Metropolitan and rural Victoria, June 1990 to December 1995., Subjects: 626 current injecting drug users (i.e., who had injected drugs within the previous 12 months)., Main Outcome Measures: Seroconversion to HIV and hepatitis B and C viruses (HBV and HCV), risk behaviours for infection., Results: HIV incidence was very low (0.2 per 100 person-years). HCV incidence was high (10.7 per 100 person-years), but fell throughout the study, although the downward trend did not reach statistical significance. HBV incidence was moderate (1.8 per 100 person-years) and did not fall. Prevalence of risk behaviours, notably sharing needles and syringes, decreased significantly., Conclusions: Significant change has occurred in the risk behaviours of the cohort, confirming results of cross-sectional studies of injecting drug use. This change may be responsible for the apparent decline in HIV and HCV incidence. Further studies are needed to monitor the incidence of bloodborne viruses in injecting drug users. Efforts to decrease risk of transmission should continue.