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1.  Amphetamine-type stimulants and HIV infection among men who have sex with men: implications on HIV research and prevention from a systematic review and meta-analysis 
HIV infections and the use of amphetamine-type stimulants (ATS) among men who have sex with men (MSM) have been increasing internationally, but the role of ATS use as a co-factor for HIV infection remains unclear. We aimed to summarize the association between ATS use and HIV infection among MSM.
We conducted a systematic search of MEDLINE, EMBASE, GLOBAL HEALTH and PsycINFO for relevant English, peer-reviewed articles of quantitative studies published between 1980 and 25 April 2013. Pooled estimates of the association – prevalence rate ratios (PRR, cross-sectional studies), odds ratio (OR, case-control studies) and hazard ratio (HR, longitudinal studies), with 95% Confidence Intervals (CI) – were calculated using random-effects models stratified by study design and ATS group (meth/amphetamines vs. ecstasy). We assessed the existence of publication bias in funnel plots and checked for sources of heterogeneity using meta-regression and subgroup analysis.
We identified 6710 article titles, screened 1716 abstracts and reviewed 267 full text articles. A total of 35 publications were eligible for data abstraction and meta-analysis, resulting in 56 records of ATS use. Most studies (31/35) were conducted in high-income countries. Published studies used different research designs, samples and measures of ATS use. The pooled association between meth/amphetamine use and HIV infection was statistically significant in all three designs (PRR=1.86; 95% CI: 1.57–2.17; OR=2.73; 95% CI: 2.16–3.46 and HR=3.43; 95% CI: 2.98–3.95, respectively, for cross-sectional, case-control and longitudinal studies). Ecstasy use was not associated with HIV infection in cross-sectional studies (PRR=1.15; 95% CI: 0.88–1.49; OR=3.04; 95% CI: 1.29–7.18 and HR=2.48; 95% CI: 1.42–4.35, respectively, for cross-sectional, case-control and longitudinal studies). Results in cross-sectional studies were highly heterogeneous due to issues with ATS measurement and different sampling frames.
While meth/amphetamine use was significantly associated with HIV infection among MSM in high-income countries in all study designs, evidence of the role of ecstasy in HIV infection was lacking in cross-sectional studies. Cross-sectional study design, measurement approaches and source populations may also be important modifiers of the strength and the direction of associations. Event-specific measure of individual drug is required to establish temporal relationship between ATS use and HIV infection. HIV prevention programmes targeting MSM should consider including interventions designed to address meth/amphetamine use.
PMCID: PMC4302169  PMID: 25609214
HIV; amphetamine-type stimulants; MSM; systematic review; meta-analysis; risk behaviour; meth/amphetamine; ecstasy
2.  The effects of female sex, viral genotype and IL28B genotype on spontaneous clearance of acute hepatitis C virus infection 
Hepatology (Baltimore, Md.)  2013;59(1):109-120.
Although 20–40% of persons with acute HCV infection demonstrate spontaneous clearance, the time-course and factors associated with clearance remain poorly understood. We investigated the time to spontaneous clearance and predictors among participants with acute HCV using Cox proportional hazards analyses. Data for this analysis were drawn from an international collaboration of nine prospective cohorts evaluating outcomes following acute HCV infection. Among 632 participants with acute HCV, 35% were female, 82% were Caucasian, 49% had IL28B CC genotype (rs12979860), 96% had injected drugs ever, 47% were infected with HCV genotype 1 and 5% had HIV co-infection. Twenty-eight percent were HCV antibody negative/RNA positive at the time of acute HCV detection (early acute HCV). During follow-up, spontaneous clearance occurred in 173 of 632 and at one year following infection, 25% (95%CI: 21%, 29%) had cleared virus. Among those with clearance, the median time to clearance was 16.5 weeks (IQR: 10.5, 33.4 weeks), with 34%, 67% and 83% demonstrating clearance at three, six and twelve months. Adjusting for age, factors independently associated with time to spontaneous clearance included female sex [adjusted hazards ratio (AHR) 2.16; 95%CI 1.48, 3.18], IL28B CC genotype (vs. CT/TT, AHR 2.26; 95%CI 1.52, 3.34), and HCV genotype 1 (vs. non-genotype 1, AHR 1.56; 95%CI 1.06, 2.30). The effect of IL28B genotype and HCV genotype on spontaneous clearance was greater among females compared to males.
Female sex, favorable IL28B genotype and HCV genotype 1 are independent predictors of spontaneous clearance. Further research is required to elucidate the observed sex-based differences in HCV control.
PMCID: PMC3972017  PMID: 23908124
injection drug use; hepatitis C virus; HIV; incident infection; longitudinal studies
3.  HIV treatment outcomes among people who inject drugs in Victoria, Australia 
BMC Infectious Diseases  2014;14(1):707.
People who inject drugs (PWID) are a key population affected by HIV. We assessed the effectiveness of HIV treatment among a clinical cohort of people living with HIV (PLHIV) diagnosed and referred for community-based antiretroviral therapy (ART) in Victoria, Australia.
HIV notification data from a central statewide registry were matched with HIV clinical data from two large HIV treatment centers in Melbourne. We used survival analysis and Cox proportional hazard models to estimate time to AIDS and death for PWID in HIV treatment, compared with non-injectors, in the period 1996 – 2008.
Of the 871 individuals, 93 (10.8%) had injecting as an exposure category and 671 (86%) had ever commenced ART. Adjusted analysis showed younger age, high initial CD4 cell count (>500 cells/mm3) or ever having a CD4 cell count >500/mm3, and more recent calendar year of ART commencement were all associated with reduced hazards for AIDS and death, while older age, low initial CD4 cell count (<200/mm3), ever having a CD4 count <200/mm3 (before or during treatment) and high initial viral load (>5 log10) were associated with increased risk of AIDS and death. PWID were no more likely to experience AIDS (HR 0.98[0.54 – 1.80]) or death (HR 0.78 [0.18 – 3.42]) than non-injectors.
Survival of HIV-infected PWID on HIV treatment was equivalent to non-injectors. CD4 cell count, initial viral load, calendar year of commencing ART and age are more important determinants of AIDS and mortality than injecting status for in-treatment PLHIV in Victoria, Australia.
PMCID: PMC4298908  PMID: 25523753
HIV; PWID; IDU; Mortality; Australia
4.  Cohort Profile: The International Collaboration of Incident HIV and Hepatitis C in Injecting Cohorts (InC3) Study 
The International Collaboration of Incident HIV and Hepatitis C in Injecting Cohorts (InC3) Study is an international multi-cohort project of pooled biological and behavioural data from nine prospective cohorts of people who inject drugs (PWID). InC3 brings together researchers from Australia, Canada, USA and the Netherlands with expertise in epidemiology, biostatistics, clinical and behavioural sciences, virology and immunology to investigate research questions relevant to hepatitis C virus (HCV) and HIV outcomes. InC3 was established to: (i) create a merged multi-cohort study of pooled data from well-characterized cohorts of PWID with prospective data on HIV and HCV infections, with a particular focus on HCV; (ii) facilitate new studies not possible within individual cohorts; and (iii) bring together researchers across disciplines to answer a broad range of research questions. Study cohorts identify acute HCV cases through follow-up of high-risk HCV antibody–negative PWID or through clinical referral networks. To date, data from 1986 to 2010 have been received from all contributing cohorts, with 821 HCV-infected and 1216 HCV-uninfected participants (overall, n = 2037). Data collected include demographics, host genetics, HCV ribonucleic acid testing, alanine aminotransferase testing, HIV/hepatitis B virus testing, HCV therapy, loss to follow-up and mortality. Potential collaborators should contact the InC3 PI Dr Kimberley Page ( for further information.
PMCID: PMC3887561  PMID: 23203695
5.  Injection drug users’ involvement in drug dealing in the downtown eastside of Vancouver: Social organization and systemic violence 
Illicit drug markets are a key component of the risk environment surrounding injection drug use. However, relatively few studies have explored how injection drug users’ (IDUs) involvement in drug dealing shapes their experiences of drug market-related harm. This exploratory qualitative study aims to understand IDUs’ dealing activities and roles, as well as the perceived benefits and risks related to participation in illicit drug markets, including experiences of drug market violence.
Ten IDUs with extensive involvement in drug dealing activities were recruited from the Vancouver Injection Drug User Study (VIDUS) and participated in semi-structured qualitative interviews, which elicited discussion of experiences dealing drugs, perceived benefits and hazards related to dealing, and understandings of drug market violence.
Participant's involvement in drug market activities included corporate sales, freelance or independent sales, and opportunistic sales termed “middling” as well as drug market-related hustles entailing selling bogus drugs and robbing dealers. Participants primarily dealt drugs to support their own illicit drug use, and we found that arrest and criminal justice involvement, hazards stemming from drug debts, and drug market-related violence were key risks related to dealing activities.
The challenges of managing personal consumption while selling drugs exacerbates the hazards associated with drug dealing. Efforts to address drug dealing among IDUs should consider both drug dependency and the material conditions that propel drug users towards dealing activities. Interventions should explore the potential of combining enhanced drug treatment programs with low threshold employment and alternative income generation opportunities.
PMCID: PMC3911907  PMID: 23664788
injection drug use; drug dealing; risk environment; violence
6.  Injection Drug Use and Hepatitis C Virus Infection in Young Adult Injectors: Using Evidence to Inform Comprehensive Prevention 
The hepatitis C virus (HCV) virus epidemic is ongoing in the United States and globally. Incidence rates remain high, especially in young adult injection drug users. New outbreaks of HCV in the United States among young adults, in predominantly suburban and rural areas, have emerged and may be fueling an increase in HCV. This paper discusses some key HCV prevention strategies that to date have not been widely researched or implemented, and wherein future HCV prevention efforts may be focused: (1) reducing sharing of drug preparation equipment; (2) HCV screening, and testing and counseling; (3) risk reduction within injecting relationships; (4) injection cessation and “breaks”; (5) scaled-up needle/syringe distribution, HCV treatment, and vaccines, according to suggestions from mathematical models; and (6) “combination prevention.” With ongoing and expanding transmission of HCV, there is little doubt that there is a need for implementing what is in the prevention “toolbox” as well as adding to it. Strong advocacy and resources are needed to overcome challenges to providing the multiple and comprehensive programs that could reduce HCV transmission and associated burden of disease worldwide in people who inject drugs.
PMCID: PMC3722077  PMID: 23884063
hepatitis C virus; prevention; injection drug users; syringe access; counseling and testing; harm reduction; HCV treatment; HCV vaccine; combination prevention
7.  Housing Instability among People Who Inject Drugs: Results from the Australian Needle and Syringe Program Survey 
High rates of substance dependence are consistently documented among homeless people, and are associated with a broad range of negative outcomes among this population. Investigations of homelessness among drug users are less readily available. This study examined the prevalence and correlates of housing instability among clients of needle syringe programs (NSPs) via the Australian NSP Survey, annual cross-sectional seroprevalence studies among NSP attendees. Following self-completion of a brief, anonymous survey and provision of a capillary blood sample by 2,396 NSP clients, multivariate logistic regressions identified the variables independently associated with housing instability. Nineteen percent of ANSPS participants reported current unstable housing, with primary (‘sleeping rough’; 5 %), secondary (staying with friends/relatives or in specialist homelessness services; 8 %), and tertiary (residential arrangements involving neither secure lease nor private facilities; 6 %) homelessness all evident. Extensive histories of housing instability were apparent among the sample: 66 % reported at least one period of sleeping rough, while 77 % had shifted between friends/relatives (73 %) and/or resided in crisis accommodation (52 %). Participants with a history of homelessness had cycled in and out of homelessness over an average of 10 years; and one third reported first being homeless before age 15. Compared to their stably housed counterparts, unstably housed participants were younger, more likely to be male, of Indigenous Australian descent, and to report previous incarceration; they also reported higher rates of key risk behaviors including public injecting and receptive sharing of injecting equipment. The high prevalence of both historical and current housing instability among this group, particularly when considered in the light of other research documenting the many adverse outcomes associated with this particular form of disadvantage, highlights the need for increased supply of secure, affordable public housing in locations removed from established drug markets and serviced by health, social, and welfare support agencies.
PMCID: PMC3732681  PMID: 22733170
Homeless persons; Intravenous substance abuse; Needle exchange programs; Sentinel surveillance; Behavioral risk factor surveillance system
8.  Increased hepatitis C virus vaccine clinical trial literacy following a brief intervention among people who inject drugs 
Drug and alcohol review  2012;32(4):419-425.
Background and Aims
While people who inject drugs are at high risk of hepatitis C virus (HCV) infection and will be the target population for future HCV vaccine trials, little is known about clinical trial literacy (CTL) in this group. We assessed the impact of a brief intervention (BI) designed to improve HCV vaccine CTL among people who inject drugs in Sydney, Australia.
Design and Methods
People who inject drugs enrolled in a community-based prospective observational study between November 2008 and September 2010 (n = 102) completed a CTL assessment followed immediately by the BI. Post-test assessment was conducted at 24 weeks.
The median age of the sample was 27 years, 73% were male and 60% had 10 or less years of schooling. The median time since first injection was five years and 20% reported daily or more frequent injecting. The mean number of correct responses increased from 5.3 to 6.3/10 (t = −.4.2; 101df, P < 0.001) 24 weeks post-intervention. Statistically significant differences were observed for three knowledge items with higher proportions of participants correctly answering questions related to randomisation (P = 0.002), blinding (P = 0.005) and vaccine-induced seropositivity (P = 0.003) post-intervention.
Discussion and Conclusions
A significant increase in HCV vaccine CTL was observed, suggesting that new and relatively novel concepts can be learned and recalled in this group. These findings support the feasibility of future trials among this population.
PMCID: PMC3567229  PMID: 23113829
hepatitis C virus; injecting drug use; clinical trial literacy; brief intervention; vaccine preparedness study
9.  ‘It’s more about the heroin’: Injection drug users’ response to an overdose warning campaign in a Canadian setting 
Addiction (Abingdon, England)  2013;108(7):1270-1276.
To assess heroin injectors’ perceptions of and responses to a warning issued by public health officials regarding high-potency heroin and increases in fatal overdoses.
Semi-structured qualitative interviews
Vancouver, Canada.
Eighteen active heroin injectors
Semi-structured interview guide focussing on heroin injectors’ perceptions of and responses to the overdose warning, including reasons for failing to adhere to risk reduction recommendations.
Although nearly all participants were aware of the warning, their recollections of the message and the timing of its release were obscured by on-going social interactions within the drug scene focussed on heroin quality. Many injection drug users reported seeking the high potency heroin and nearly all reported no change in overdose risk behaviours. Responses to the warning were shaped by various social, economic and structural forces that interacted with individual behaviour and undermined efforts to promote behavioural change, including sales tactics employed by dealers, poverty, the high cost and shifting quality of available heroin, and risks associated with income-generating activities. Individual-level factors, including emotional suffering, withdrawal, entrenched injecting routines, perceived invincibility and the desire for intense intoxication also undermined risk reduction messages.
Among heroin injectors in British Columbia, a 2011 overdose warning campaign appeared to be of limited effectiveness and also produced unintended negative consequences that exacerbated overdose risk.
PMCID: PMC3913056  PMID: 23551565
heroin; injection drug use; overdose; public health warning
10.  Point-of-Care Testing for Chlamydia and Gonorrhoea: Implications for Clinical Practice 
PLoS ONE  2014;9(6):e100518.
Point-of-care (POC) testing for chlamydia (CT) and gonorrhoea (NG) offers a new approach to the diagnosis and management of these sexually transmitted infections (STIs) in remote Australian communities and other similar settings. Diagnosis of STIs in remote communities is typically symptom driven, and for those who are asymptomatic, treatment is generally delayed until specimens can be transported to the reference laboratory, results returned and the patient recalled. The objective of this study was to explore the clinical implications of using CT/NG POC tests in routine clinical care in remote settings.
In-depth qualitative interviews were conducted with a purposively selected group of 18 key informants with a range of sexual health and laboratory expertise.
Participants highlighted the potential impact POC testing would have on different stages of the current STI management pathway in remote Aboriginal communities and how the pathway would change. They identified implications for offering a POC test, specimen collection, conducting the POC test, syndromic management of STIs, pelvic inflammatory disease diagnosis and management, interpretation and delivery of POC results, provision of treatment, contact tracing, management of client flow and wait time, and re-testing at 3 months after infection.
The introduction of POC testing to improve STI service delivery requires careful consideration of both its advantages and limitations. The findings of this study will inform protocols for the implementation of CT/NG POC testing, and also STI testing and management guidelines.
PMCID: PMC4067364  PMID: 24956111
11.  Biomarker validation of recent unprotected sexual intercourse in a prospective study of young women engaged in sex work in Phnom Penh, Cambodia 
Sexually transmitted diseases  2013;40(6):462-468.
A study of female sex workers in Phnom Penh, Cambodia found self-reported condom use to be of questionable validity, particularly among amphetamine-type stimulant (ATS) users and those with multiple partners.
Accurate measurement of unprotected sex is essential in HIV prevention research. Since 2001, the 100% Condom Use Program targeting female sex workers (FSW) has been a central element of the Cambodian National HIV/AIDS Strategy. We sought to assess the validity of self-reported condom use using the rapid prostate-specific antigen (PSA) test among Cambodian FSW.
From 2009 to 2010 we enrolled 183 FSW in Phnom Penh in a prospective study of HIV risk behavior. PSA test results from the OneStep ABAcard® were compared to self-reported condom use in the past 48 hours at quarterly follow-up visits.
Among women positive for seminal fluid at the first follow-up visit, 42% reported only protected sex or no sex in the detection period. Discordant results were more likely among brothel and street-based FSW vs. entertainment (56% vs. 17%), recent (last 3 months) ATS users (53% vs. 20%), and those with >5 partners in the past month (58% vs. 13%). In multivariable regression models, positive PSA results were associated with recent ATS use (Adjusted Risk Ratio (ARR) = 1.5; 95% confidence interval (CI):1.1 – 2.2), having a non-paying last sex partner (ARR=1.7; CI:1.2 – 2.5), and sex work venue (ARR=3.0; CI:1.4 – 6.5). Correspondingly, women with a non-paying last sex partner were more likely to report unprotected sex (ARR=1.5; CI:1.1 – 2.2), but no associations were found with sex work venue or ATS use.
Results confirm the questionable validity of self-reported condom use among FSW. The PSA biomarker assay is an important monitoring tool in HIV/STI research including prevention trials.
PMCID: PMC3891890  PMID: 23680902
12.  Quilt Plots: A Simple Tool for the Visualisation of Large Epidemiological Data 
PLoS ONE  2014;9(1):e85047.
Graphical representation of data is one of the most easily comprehended forms of explanation. The current study describes a simple visualization tool which may allow greater understanding of medical and epidemiological data.
We propose a simple tool for visualization of data, known as a “quilt plot”, that provides an alternative to presenting large volumes of data as frequency tables. Data from the Australian Needle and Syringe Program survey are used to illustrate “quilt plots”.
Visualization of large volumes of data using “quilt plots” enhances interpretation of medical and epidemiological data. Such intuitive presentations are particularly useful for the rapid assessment of problems in the data which cannot be readily identified by manual review. We recommend that, where possible, “quilt plots” be used along with traditional quantitative assessments of the data as an explanatory data analysis tool.
PMCID: PMC3890282  PMID: 24454789
13.  Outreach for chlamydia and gonorrhoea screening: a systematic review of strategies and outcomes 
BMC Public Health  2013;13:1040.
High Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) prevalence have been reported in populations that do not regularly access health centres for sexually transmissible infections (STI) testing. We reviewed current outreach strategies used to increase access to STI testing and their outcomes.
We systematically reviewed the literature for English language studies published between 1 January 2005 and 28 January 2011 describing CT and/or NG screening programs in non-clinical outreach settings.
We identified 25 programs, with the majority occurring in either Australia (32%) or the United States (32%). The most common target groups were young people aged 15–29 years (52%), men who have sex with men (24%) and sex workers (8%). The median CT positivity was 7.7% (Inter Quartile Range [IQR]: 3.0%-11.1%, n=19 programs), and median NG positivity was 2.6% (IQR: 0.0%-8.0%, n=10). The median participation rate was 53% (IQR: 23.9%-81.3%), and a median of 79.6% (IQR: 55.1%-89.4%) of participants were tested, with a median of 100 tests conducted per program (IQR: 65–331, range: 11–1808). Across all settings the participation rate was highest among target groups gathering in community service venues (community centres, parenting centres, homeless shelters) (median=81.4%, n=4), and social venues (sporting venues or bars) (80.4%, n=1). Lower participation rates were found in street/public community areas (median=23.9%, n=3) and sex on premises venues (10.4% and 24.3%, n=2).
The review indicated that although CT and NG outreach programs reached a relatively small number of people the yield of infections is high. Settings which appear to be more effective at encouraging participation appear to be those within an existing venue, rather than in public areas.
PMCID: PMC3819260  PMID: 24188541
Sexually transmissible infections; Outreach; Testing; Systematic review; Chlamydia
14.  Correlates of Susceptibility to Hepatitis B among People Who Inject Drugs in Sydney, Australia 
Despite a safe, effective vaccine, hepatitis B virus (HBV) vaccination coverage remains low among people who inject drugs (PWID). Characteristics of participants screened for a trial investigating the efficacy of financial incentives in increasing vaccination completion among PWID were examined to inform targeting of vaccination programs. Recruitment occurred at two health services in inner-city Sydney that target PWID. HBV status was confirmed via serological testing, and questionnaires elicited demographic, drug use, and HBV risk data. Multinomial logistic regression was utilized to determine variables independently associated with HBV status. Of 172 participants, 64% were susceptible, 17% exposed (HBV core antibody-positive), and 19% demonstrated evidence of prior vaccination (HBV surface antibody ≥ 10 mIU/ml). Compared with exposed participants, susceptible participants were significantly more likely to be aged less than 35 years and significantly less likely to be receiving current opioid substitution therapy (OST) and to test hepatitis C antibody-positive. In comparison to vaccinated participants, susceptible participants were significantly more likely to be male and significantly less likely to report daily or more frequent injecting, current OST, and prior awareness of HBV vaccine. HBV vaccination uptake could potentially be increased by targeting younger, less frequent injectors, particularly young men. In addition to expanding vaccination through OST, targeting “at risk” youth who are likely to have missed adolescent catch-up programs may be an important strategy to increase coverage. The lack of an association between incarceration and vaccination also suggests increasing vaccination uptake and completion in adult and juvenile correctional facilities may also be important.
PMCID: PMC3462823  PMID: 22684422
Hepatitis B virus; Substance abuse; Intravenous; Immunization; Public health
15.  Attitudes of men in an Australian male tolerance study towards microbicide use 
Sexual health  2008;5(3):273-278.
Vaginal microbicides are in development to provide new options for prevention of STIs. Although promoted as a female initiated product, men may influence the decision to use a microbicide and the way that it is used, so it is important to explore their views.
Men (n=36) enrolled in a 7-day, phase 1 clinical safety trial of SPL7013 Gel were interviewed pre and post-use of the gel. The trial did not include use of the gel during sex. Interviews were digitally-recorded and transcribed verbatim, and analysed using a framework approach.
The men (mean age 37 years) were interested in the idea of vaginal microbicides, had little knowledge about them, and varied beliefs about how they work. They tended to assess microbicide use in relation to condoms and lubricants. Many would want a microbicide to be as effective as condoms. Participants did not anticipate difficulties discussing use with their partners. Many thought that a microbicide would be less intrusive than condoms; some anticipated that the lubricating properties might enhance sexual pleasure. Some anticipated using a microbicide with a condom or with a lubricant, and a few raised questions about the timing of use and use during different types of sexual activity.
No major barriers to microbicide use were found in this sample of Australian men, who anticipated being willing to use them if they are shown to be safe and effective. Our findings should help to inform the design of further studies as well as future information materials and anticipatory guidance.
PMCID: PMC3777800  PMID: 18771643
microbicides; acceptability; sexuality; males
16.  STI in remote communities: improved and enhanced primary health care (STRIVE) study protocol: a cluster randomised controlled trial comparing ‘usual practice’ STI care to enhanced care in remote primary health care services in Australia 
BMC Infectious Diseases  2013;13:425.
Despite two decades of interventions, rates of sexually transmissible infections (STI) in remote Australian Aboriginal communities remain unacceptably high. Routine notifications data from 2011 indicate rates of chlamydia and gonorrhoea among Aboriginal people in remote settings were 8 and 61 times higher respectively than in the non-Indigenous population.
STRIVE is a stepped-wedge cluster randomised trial designed to compare a sexual health quality improvement program (SHQIP) to usual STI clinical care delivered in remote primary health care services. The SHQIP is a multifaceted intervention comprising annual assessments of sexual health service delivery, implementation of a sexual health action plan, six-monthly clinical service activity data reports, regular feedback meetings with a regional coordinator, training and financial incentive payments. The trial clusters comprise either a single community or several communities grouped together based on geographic proximity and cultural ties. The primary outcomes are: prevalence of chlamydia, gonorrhoea and trichomonas in Aboriginal residents aged 16–34 years, and performance in clinical management of STIs based on best practice indicators. STRIVE will be conducted over five years comprising one and a half years of trial initiation and community consultation, three years of trial conditions, and a half year of data analysis. The trial was initiated in 68 remote Aboriginal health services in the Northern Territory, Queensland and Western Australia.
STRIVE is the first cluster randomised trial in STI care in remote Aboriginal health services. The trial will provide evidence to inform future culturally appropriate STI clinical care and control strategies in communities with high STI rates.
Trial registration
Australian and New Zealand Clinical Trials Registry ACTRN12610000358044
PMCID: PMC3847940  PMID: 24016143
Aboriginal; Indigenous; Sexually transmitted infections; Chlamydia; Gonorrhoea; Trichomonas; Continuous quality improvement; Protocol; Prevalence; Remote
17.  Sex work and HIV in Cambodia: trajectories of risk and disease in two cohorts of high-risk young women in Phnom Penh, Cambodia 
BMJ Open  2013;3(9):e003095.
HIV prevalence among Cambodian female sex workers (FSW) is among the highest in Southeast Asia. We describe HIV prevalence and associated risk exposures in FSW sampled serially in Phnom Penh, Cambodia (Young Women's Health Study (YWHS)), before and after the implementation of a new law designed to combat human trafficking and sexual exploitation.
Cross-sectional analysis of baseline data from two prospective cohorts.
Community-based study in Phnom Penh, Cambodia.
Women aged 15–29 years, reporting ≥2 sexual partners in the last month and/or engaged in transactional sex in the last 3 months, were enrolled in the studies in 2007 (N=161; YWHS-1), and 2009 (N=220; YWHS-2) following information sessions where 285 and 345 women attended.
Primary outcomes
HIV prevalence, sexual risk behaviour, amphetamine-type stimulant (ATS) and alcohol use, and work-related factors were compared in the two groups, enrolled before and after implementation of the new law.
Participants in the two cohorts were similar in age (median 25 years), but YWHS-2 women reported fewer sex partners, more alcohol use and less ATS use. A higher proportion of YWHS-2 compared with YWHS-1 women worked in entertainment-based venues (68% vs 31%, respectively). HIV prevalence was significantly lower in the more recently sampled women: 9.2% (95% CI 4.5% to 13.8%) vs 23% (95% CI 16.5% to 29.7%).
Sex work context and risk have shifted among young FSW in Phnom Penh, following implementation of anti-prostitution and anti-trafficking laws. While both cohorts were recruited using the same eligibility criteria, more recently sampled women had lower prevalence of sexual risk and HIV infection. Women engaging more directly in transactional sex have become harder to sample and access. Future prevention research and programmes need to consider how new policies and demographic changes in FSW impact HIV transmission.
PMCID: PMC3773643  PMID: 24022389
18.  Candidate hepatitis C vaccine trials and people who inject drugs: Challenges and opportunities 
Vaccine  2010;28(45):7273-7278.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
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People who inject drugs (PWID) are at high risk of HCV. Limited evidence of the effectiveness of prevention interventions and low uptake of treatment in this group highlight the need for increased investment in biomedical interventions, notably safe and efficacious vaccines. While several candidates are currently in development, field trials in PWID present challenges, including ethical issues associated with trial literacy, informed consent and standards of care. Significant biological and social factors and differences between HIV and HCV suggest that HCV warrants targeted vaccine preparedness research to lay the groundwork for successful implementation of future trials.
PMCID: PMC3729933  PMID: 20831914
Hepatitis C virus; Vaccine; People who inject drugs
19.  Young Women Engaged in Sex Work in Phnom Penh, Cambodia, Have High Incidence of HIV and Sexually Transmitted Infections, and Amphetamine-Type Stimulant Use: New Challenges to HIV Prevention and Risk 
Sexually transmitted diseases  2011;38(1):33-39.
To estimate prevalence and incidence of HIV and sexually transmitted infections (STI) and associated risk factors among young women working as sex workers (SWs) in Phnom Penh, Cambodia.
A prospective study of young (<29 years) women working as SWs in brothels, entertainment establishments, and freelance. Sociodemographics, sexual risk, and use of amphetamine-type stimulants (ATS) (“yama” and “crystal”) were assessed by self-report. HIV and STI (Chlamydia trachomatis and Neisseria gonorrhoeae) testing were conducted on blood and urine specimens, respectively.
Baseline prevalences of HIV, C. trachomatis, and N. gonorrhoeae were 23%, 11.5%, and 7.8%, respectively. HIV incidence was 3.6 per 100 person-years (95% confidence interval [CI], 1.2%– 11.1%); STI incidence was 21.2 per 100 person-years (95% CI, 12.6%– 35.8%). At baseline, 26.5% reported recent ATS use. HIV infection was associated with freelance SW (adjusted odds ratio, 5.85; 95% CI, 1.59–21.58) and younger age of first sex (≤15 years; adjusted odds ratio, 3.06; 95% CI, 1.01–8.46). Incident STI was associated with duration (per year) of SW (adjusted hazard ratio, 1.1; 95% CI, 1.1–1.2) and recent yama use (adjusted hazard ratio, 3.9; 95% CI, 1.5–10.3).
HIV and STI infection rates were high among SWs working in various settings; freelancers had highest risk. ATS use was associated with incident STI. Venue of sex work and drug prevention should be considered in prevention programs.
PMCID: PMC3729941  PMID: 21085056
20.  Condom negotiation across different relationship types by young women engaged in sex work in Phnom Penh, Cambodia 
Global public health  2013;8(3):270-283.
Cambodia's 100% Condom Use Programme is credited with an increase in consistent condom use in commercial sexual interactions and a decrease in HIV prevalence among female sex workers (FSWs). There has been little improvement in condom use between FSWs and non-commercial partners, prompting calls for more innovative approaches to increasing condom use in these relationships. To understand why condoms are used or not used in sexual interactions involving FSWs, we examined condom negotiation across different types of relationships. We conducted 33 in-depth interviews with young (15 to 29 years) women engaged in sex work in Phnom Penh. There was an important interplay between the meanings of condom use and the meanings of women's relationships. Commercial relationships were characterised as inherently risky and necessitated condom use. Despite a similar lack of sexual fidelity, sweetheart relationships were rarely construed as risky and typically did not involve condom use. Husbands and wives constructed their sexual interactions with each other differently, making agreement on condom use difficult. The lack of improvement in condom use in FSWs' non-commercial sexual relationships needs to be understood in relation to both sex work and the broader Cambodian sexual culture within which these relationships are embedded.
PMCID: PMC3729959  PMID: 23432108
female sex workers; condoms; sexually transmitted infections; HIV; Cambodia
21.  Correlates of amphetamine-type stimulants use and associations with HIV-related risks among young women engaged in sex work in Phnom Penh, Cambodia 
Drug and alcohol dependence  2011;120(1-3):119-126.
Amphetamine-type stimulant (ATS) use has increased in Cambodia and emerged as a significant problem among female sex workers (FSWs), potentially contributing to increased risk of HIV. We examined the prevalence of ATS use and its effect on sexual risk behaviors, and sexually transmitted infections (STI) among FSWs in Phnom Penh, Cambodia.
A one-year prospective study among young women engaged in sex work in brothels, entertainment establishments and on a freelance basis. Socio-demographics, sexual risks, and recent ATS use were assessed by self-report. Blood and urine samples were collected to detect HIV, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC). Bivariate and multivariate longitudinal analyses were conducted to assess the effects of ATS use on number of sex partners, inconsistent condom use with paying partners and incident STI.
ATS use was higher among women working freelance (35.6%) and in brothels (34.8%) compared to women working in entertainment establishments (17.7%) or in multiple venues (14.8%). ATS users reported more sex partners and days drunk in the previous month. In multivariate longitudinal analysis, ATS use was associated with having a higher number of sex partners (Adjusted Risk Ratio 1.49; 95% CI: 1.00–2.21) and incident STI (Adjusted Odds Ratio 5.41; 95% CI: 1.15–25.48), but not inconsistent condom use with paying partner.
ATS users had more sex partners, high level of alcohol use, and were at increased risk of STI. Our findings underscore ATS use as an important emerging risk exposure that should be integrated into HIV prevention interventions targeting this population.
PMCID: PMC3226861  PMID: 21820251
mphetamine-type stimulant; HIV/STI; Female sex workers; Cambodia; Risk behaviors
22.  Cervical human papillomavirus infection among young women engaged in sex work in Phnom Penh, Cambodia: prevalence, genotypes, risk factors and association with HIV infection 
BMC Infectious Diseases  2012;12:166.
Although cervical cancer is the leading cancer in Cambodia, most women receive no routine screening for cervical cancer and few treatment options exist. Moreover, nothing is known regarding the prevalence of cervical HPV or the genotypes present among women in the country. Young sexually active women, especially those with multiple sex partners are at highest risk of HPV infection. We examine the prevalence and genotypes of cervical HPV, as well as the associated risk factors among young women engaged in sex work in Phnom Penh, Cambodia.
We conducted a cross-sectional study among 220 young women (15–29 years) engaged in sex work in different venues including brothels or entertainment establishments, and on a freelance basis in streets, parks and private apartments. Cervical specimens were collected using standard cytobrush technique. HPV DNA was tested for by polymerase chain reaction (PCR) and genotyping using type-specific probes for 29 individual HPV types, as well as for a mixture of 10 less common HPV types. All participants were also screened for HIV status using blood samples. Multivariate logistic regression analyses were conducted to assess risk factors for any or multiple HPV infection.
The prevalence of cervical HPV 41.1%. HPV 51 and 70 were the most common (5.0%), followed by 16 (4.6%), 71 (4.1%) and 81 (3.7%). Thirty-six women (16.4%) were infected with multiple genotypes and 23.3% were infected with at least one oncogenic HPV type. In multivariate analyses, having HIV infection and a higher number of sexual partners were associated with cervical HPV infection. Risk factors for infection with multiple genotypes included working as freelance female sex workers (FSW) or in brothels, recent binge use of drugs, high number of sexual partners, and HIV infection.
This is the first Cambodian study on cervical HPV prevalence and genotypes. We found that HPV infection was common among young FSW, especially among women infected with HIV. These results underscore the urgent need for accessible cervical cancer screening and treatment, as well as for a prophylactic vaccine that covers the HPV subtypes present in Cambodia.
PMCID: PMC3436768  PMID: 22839728
23.  Twenty Thousand-Year-Old Huts at a Hunter-Gatherer Settlement in Eastern Jordan 
PLoS ONE  2012;7(2):e31447.
Ten thousand years before Neolithic farmers settled in permanent villages, hunter-gatherer groups of the Epipalaeolithic period (c. 22–11,600 cal BP) inhabited much of southwest Asia. The latest Epipalaeolithic phase (Natufian) is well-known for the appearance of stone-built houses, complex site organization, a sedentary lifestyle and social complexity—precursors for a Neolithic way of life. In contrast, pre-Natufian sites are much less well known and generally considered as campsites for small groups of seasonally-mobile hunter-gatherers. Work at the Early and Middle Epipalaeolithic aggregation site of Kharaneh IV in eastern Jordan highlights that some of these earlier sites were large aggregation base camps not unlike those of the Natufian and contributes to ongoing debates on their duration of occupation. Here we discuss the excavation of two 20,000-year-old hut structures at Kharaneh IV that pre-date the renowned stone houses of the Natufian. Exceptionally dense and extensive occupational deposits exhibit repeated habitation over prolonged periods, and contain structural remains associated with exotic and potentially symbolic caches of objects (shell, red ochre, and burnt horn cores) that indicate substantial settlement of the site pre-dating the Natufian and outside of the Natufian homeland as currently understood.
PMCID: PMC3280235  PMID: 22355366
24.  Developing and validating a scoring tool for identifying people who inject drugs at increased risk of hepatitis C virus infection 
BMJ Open  2012;2(1):e000387.
To develop and validate a scoring tool based on demographic and injecting risk behaviours to identify those who require additional, non-routine serological screening for hepatitis C virus (HCV) by assessing their personal risk.
Cross-sectional and prospective cohorts.
People who inject drugs (PWID) and attended Needle and Syringe Programs (NSP) in Australia during the period from 1998 to 2008.
Cross-sectional data included 16 127 PWID who attended NSP in Australia. Prospective data included 215 HCV-negative PWID who were recruited through street-based outreach, methadone clinics in Australia.
Primary and secondary outcome measures
HCV seroprevalence in the cross-sectional and HCV seroconversions in the prospective data sets.
Current study included 16 127 PWID who attended NSP in Australia. Type of drug last injected, frequency and duration of injecting, sharing needles and syringes or other injecting equipment and imprisonment history were associated with HCV infection in all age groups. Strong relationships between an individual's ‘HCV score’ and their risk of testing HCV antibody positive were observed. An estimated 78% (95% CI 75% to 81%), 82% (95% CI 80% to 84%), 80% (95% CI 78% to 82%) and 80% (95% CI 77% to 82%) of HCV infections across the age groups (<25, 25–29, 30–39 and ≥40 years) would be avoided if participants in the upper four quintiles of HCV scores fell instead into the lowest quintile.
Knowledge of HCV status has important implications for public health and care and treatment. Risk assessment strategies may assist in alerting PWID who are at increased risk of HCV infection to present for testing.
Article summary
Article focus
Although the risk factors for incident infection are well established, the literature suggests that a number of barriers may prevent PWID presenting for screening.
Study developed a scoring tool based on demographic and injecting risk behaviours to identify those who require additional, non-routine serological screening for HCV by assessing their personal risk.
Key messages
Current clinical practice guidelines recommend HCV screening of individuals with a history of injecting drugs.
However, this recommendation focuses on a single risk factor (ie, injecting drug use), whereas considering the cumulative effect of multiple risk factors among PWID can more precisely identify people in need of additional non-routine screening.
Strengths and limitations of this study
Our prediction equation is based on 11 years of data and >16 000 participants. Ideal risk assessment methods or prediction models should be derived from large representative samples.
The study population is limited to those who participated in the Australian Needle and Syringe Program Survey, which may result in selection bias.
We were not able to differentiate between acute, recent and chronic infections.
PMCID: PMC3253425  PMID: 22218720
25.  Testing for amphetamine-type stimulant (ATS) use to ascertain validity of self-reported ATS use among young female sex workers in Cambodia 
To assess concordance between self-reported amphetamine-type stimulant (ATS) use and toxicology results among young female sex workers (FSW) in Phnom Penh, Cambodia.
Cross-sectional data from the Young Women’s Health Study-2 (YWHS-2), a prospective study of HIV and ATS use among young (15 to 29 years) FSW in Phnom Penh, Cambodia, was analyzed. The YWHS-2 assessed sociodemographic characteristics, HIV serology, HIV risk, and ATS use by self-report and urine toxicology testing at each quarterly visit, the second of which provided data for this assessment. Outcomes include sensitivity, specificity, positive- and negative predictive values (overall and stratified by age), sex-work setting, and HIV status.
Among 200 women, prevalence of positive toxicology screening for ATS use was 14% (95% confidence interval [CI], 9.2, 18.9%) and concurrent prevalence of self-reported ATS was 15.5% (95% CI, 10.4, 20.6%). The sensitivity and specificity of self-reported ATS use compared to positive toxicology test results was 89.3% (25/28), and 96.5% (166/172), respectively. The positive predictive value of self-reported ATS use was 80.6% (25/31); the negative predictive value was 98.2% (166/169). Some differences in concordance between self-report and urine toxicology results were noted in analyses stratified by age group and sex-work setting but not by HIV status.
Results indicate a high prevalence of ATS use among FSW in Phnom Penh, Cambodia, and high concordance between self-reported and toxicology-test confirmed ATS use.
PMCID: PMC3507647  PMID: 23186171

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