Farnesoid X receptor agonist for the treatment of chronic hepatitis B: A safety study

The nuclear farnesoid X receptor (FXR) regulates bile acid homeostasis and is a drug target for metabolic liver diseases. FXR also plays an important role in hepatitis B virus (HBV) DNA transcription. In vitro and in mice, FXR agonist treatment leads to inhibition of viral replication and a decline in viral proteins, pregenomic RNA (pgRNA) and HBV DNA levels. We aimed to translate this to a clinical use by primarily evaluating the safety and secondary the anti-viral effect of Vonafexor, a FXR agonist, in chronic hepatitis B (CHB) patients. In total, 73 CHB patients were enrolled in a two-part Phase Ib double-blind, placebo-controlled trial. Patients were randomized to receive oral Vonafexor (100, 200 and 400 mg once daily, or 200 mg twice daily), placebo, or entecavir (Part A, n = 48) or to receive Vonafexor (300 mg once daily or 150 mg twice daily), or placebo, combined with pegylated-interferon-α2a (Part B, n = 25) for 29 days. Patients were followed up for 35 days. Enrolled CHB patients were mostly HBeAg-negative. Vonafexor was overall well tolerated and safe. The most frequent adverse events were moderate gastrointestinal events. Pruritus was more frequent with twice-daily compared with once-daily regimens (56%-67% vs. 16%, respectively, p < 0.05). Vonafexor monotherapy of 400 mg once daily decreased HBsAg concentrations (-0.1 log₁₀  IU/mL, p < 0.05), and Vonafexor/pegylated-IFN-α2a combination therapy decreased HBcrAg and pgRNA. In conclusion, Vonafexor was safe with a decline in HBV markers observed in CHB patients suggesting a potential anti-viral effect the therapeutic potential of which has to be evaluated in larger trials.

Simple actions to support breastfeeding can avoid unwanted weaning in infants younger than 6 months hospitalized for bronchiolitis: A before/after study (Bronchilact II)

BACKGROUND

Admission to hospital with bronchiolitis may adversely affect breastfeeding. Correct advice and support have been pointed out as a determining factor.

OBJECTIVES

We conducted a telephone survey to evaluate a set of actions to promote breastfeeding during hospitalization for acute bronchiolitis.

METHODS

Population: All patients 6 months of age or younger hospitalized with acute bronchiolitis and receiving at least partial breastfeeding were eligible for the study. Patients discharged home whose parents accepted to be contacted by phone were also included.

INTERVENTION

We established a set of actions to promote breastfeeding (posters, flyers, staff training, and equipment) in all pediatric wards attending to these patients.

COMPARISON

This was a cross-sectional study conducted during two epidemic seasons of bronchiolitis in a tertiary care hospital. Data on continued breastfeeding at 3 months (0.5-6; median, range) postdischarge were collected by telephone and compared with the same set of data collected from patients with bronchiolitis in the same setting the year before the intervention.

OUTCOME

We conducted a telephone survey to evaluate whether some actions regarding breastfeeding might diminish the risk of unwanted weaning during hospitalization for bronchiolitis. The primary outcome was the proportion of stopped or reduced breastfeeding at discharge. Secondary objectives were to evaluate whether there were factors associated with breastfeeding modification.

RESULTS

The results of the evaluation before intervention (phase 1) are published by Heilbronner et al. In Phase 1 of our study, 84 patients were included and 43 mothers (51%) reported that breastfeeding was modified by hospitalization of their child: 20.4% stopped, 14% switched to partial breastfeeding, and 16.6% reduced breastfeeding. These mothers stated that causes of breastfeeding disturbances were lack of support and advice (63%), followed by severity of the child's respiratory disease (32%), logistical hospital difficulties (30%), and personal organizational issues (9.3%). The intervention took place in September. After the intervention, 50 patients could be included in the study between October 1and December 31, 2016. Among them, 40 (80%) mothers kept breastfeeding as before, four (8%) stopped, four (8%) switched to partial breastfeeding, and two (4%) reduced breastfeeding without stopping. Bronchiolitis was more severe among patients with altered breastfeeding in terms of ventilatory support.

CONCLUSION

Bronchiolitis is a high-risk event for breastfeeding disruption but interventions to promote breastfeeding might help to prevent the risk of unwanted weaning. More severe bronchiolitis probably poses the highest risk of weaning and the need for supplementary nutrition.

Implementation research to evaluate an educational intervention for people who inject drugs

Objective

In the context of disseminating harm reduction (HR) programmes in Europe, the Eurosider project aims to study the transferability of an effective educational intervention for people who inject drugs (PWID) to four European countries (Bulgaria, Greece, Portugal and Romania). This intervention, entitled Individually-Tailored Support and Education for Safer Injection (ITSESI), has been shown to reduce HIV-Hepatitis C Virus (HCV) risk practices by offering educational supervision during all phases of the injection sequence, from pre- to post-injection.

Methods

The project employs mixed methods and implementation science. The exploratory first step used qualitative interviews and other available data in each country. The second step consists in implementing and evaluating the intervention using a 6-month study conducted among 300 PWID enrolled in the 4 countries. They are interviewed at baseline and at 6 months. The third step will consist in designing, promoting and disseminating all the tools necessary to transfer ITSESI at the European level.

Results

Results from the exploratory phase highlighted two main determining factors for the feasibility of implementing ITSESI: funding and a repressive legal context. Preliminary results from a quantitative analysis of data from the second step will provide a baseline description of the 300 PWID.

Discussion

Findings to date indicate that an exploratory phase is crucial to adapt and transfer the intervention to local contexts and to evaluate it. More globally, the Eurosider project will 1) help understand each local context to adapt the intervention accordingly; 2) assess the feasibility and effectiveness of ITSESI in different contexts; 3) promote and disseminate tools and training to implement the intervention at the European level.

Key messages

People who inject drugs in European countries report HIV-HCV risk practices and adequate prevention should be provided. The implementation of an innovative educational intervention for people who inject drugs may be one response but requires to take into account contextual factors: funding and repressive drug policy.

Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity.

FINDINGS

We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40-2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28-2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94-1·65) and a 21% increase in HCV (1·21, 1·02-1·43) acquisition risk.

INTERPRETATION

Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID.

FUNDING

Engineering and Physical Sciences Research Council, National Institute for Health Research, National Institutes of Health.

High-fidelity simulation in training dental students for medical life-threatening emergency

INTRODUCTION

Any dental surgeon may be faced with a critical life-threatening emergency situation. In our university, all students in dentistry receive a standard course on emergency first aid. The aim of this prospective, comparative, single-centre study was to determine whether additional training on a high-fidelity patient simulator would improve student performance.

METHODS

After approval by an Ethical Committee and written informed consent, the students of the Simulation group (n=42) had full-scale high-fidelity training on a patient simulator SimMan 3G^™ (3 hours by six students). They participated in pairs in two scenarios (airway obstruction, seizures, allergies, vasovagal syncope, asthma, chest pain). The first scenario was simple, and the second was a progression to cardiac arrest. Three months later, the Simulation group and the Control group (n=42) participated in a test session with two scenarios. The primary end point was the score at the test session (with a standardised scoring grill, direct observation and audio-video recording). Data were median and 25%-75% percentiles.

RESULTS

High-fidelity training strongly improved the score on the test obtained by the students of the Simulation group (146 [134-154]) which was much higher (P<.0001) than in the Control group (77 [67-85]). Technical as well as non-technical skills components of the scores were improved. In addition, performances of the Simulation group were increased between the training and the test. Simulation session was very positively assessed by the students.

CONCLUSIONS

The results support the systematic introduction of training to critical life-threatening emergency situations on high-fidelity patient simulators the dentistry curriculum. The impact on clinical practice in the dental office remains to be assessed.

Impact of sex work on risk behaviours and their association with HIV positivity among people who inject drugs in Eastern Central Canada: cross-sectional results from an open cohort study

OBJECTIVES

The objectives of this study were: (1) to examine the correlates of HIV positivity among participants who injected drugs and engaged in sex work (PWID-SWs) in the SurvUDI network between 2004 and 2016, after stratification by sex, and (2) to compare these correlates with those of sexually active participants who did not engage in sex work (PWID non-SWs).

DESIGN AND SETTING

This biobehavioural survey is an open cohort of services where participants who had injected in the past 6 months were recruited mainly through harm reduction programmes in Eastern Central Canada.

PARTICIPANTS

Data from 5476 participants (9223 visits in total; 785 not included in multivariate analyses due to missing values) were included.

METHODS

Participants completed an interviewer-administered questionnaire and provided saliva samples for anti-HIV antibody testing. Generalised estimating equations taking into account multiple participations were used.

RESULTS

Baseline HIV prevalence was higher among SWs compared with non-SWs (women: 13.0% vs 7.7%; P<0.001, and men: 17.4% vs 10.8%; P<0.001). PWID-SWs were particularly susceptible to HIV infection as a result of higher levels of vulnerability factors and injection risk behaviours. They also presented different risk-taking patterns than their non-SWs counterparts, as shown by differences in correlates of HIV positivity. Additionally, the importance of sex work for HIV infection varies according to gender, as suggested by a large proportion of injection risk behaviours associated with HIV among women and, conversely, a stronger association between sexual behaviours and HIV positivity observed among men.

CONCLUSION

These results suggest that sex work has an impact on the risk of HIV acquisition and that risk behaviours vary according to gender. Public health practitioners should take those specificities into account when designing HIV prevention interventions aimed at PWIDs.

Abstract P3-01-02: Trends in positive predictive values following transition from screen film to digital mammography

Purpose

Our health region converted from screen-film mammography (SFM) to digital mammography (DM) in 2005. DM has several advantages over SFM, including superior contrast resolution, less noise, and opportunities for image optimization through post-acquisition processing; although, the spatial resolution of DM is inferior to SFM. We sought to determine what effect this transition may have had on positive predictive values (PPVs) for malignant and premalignant lesions.

Methods

From our institution's breast biopsy database, we retrospectively reviewed core biopsy results for mammographic calcifications performed in the years 2001-2004 (SFM years) and 2009-2012 (DM years). We subsequently determined the PPV3 (detection of malignancy after biopsy) for each group of years (SFM and DM). We then performed subgroup analysis to calculate PPVs for each of ductal carcinoma in-situ (DCIS) without invasion, DCIS with invasion, and premalignant lesions. Premalignant lesions included atypical ductal hyperplasia, atypical lobular hyperplasia, and lobular carcinoma in-situ.

Results

A total of 4787 biopsies in 4633 patients were reviewed. The comparative detection of cancer after biopsy performed for mammographic calcification between SFM and DM was not statistically significant (PPV3 = 23.5% and 24.0%, respectively; P=.71). Upon further analysis, however, PPV for premalignant lesions increased (SFM=6.6% and DM=8.9%; P&lt;.01) and PPV for DCIS without invasion increased (SFM=15.5% and DM=18.2%; P=.015), while PPV for DCIS with invasion decreased (SFM=8.0% and DM=5.8%; P&lt;.01).

Conclusion

We observed no significant impact on PPV3 for calcifications following the transition from SFM to DM; however, our subgroup analysis suggests that with digital mammography we are now detecting a statistically significantly lower proportion of DCIS with invasion but greater proportions of DCIS without invasion and premalignant lesions. As the natural history of these lower-grade lesions, particularly in the premalignant category, is still not entirely understood, the significance of potentially detecting more of these earlier cancers/precancers is uncertain.

Citation Format: Motiuk DA, Dahl P, Roy E, Docktor B-J, Burrowes P. Trends in positive predictive values following transition from screen film to digital mammography [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-01-02.

Tobacco Use Among Adolescents Entering Quebec Youth Protection Centers

BACKGROUND: Every year between 4,000 and 5,000 adolescents reside in Quebec Youth Protection Centers (YPCs). Many of these adolescents use tobacco products and other psychotropic substances that impact their present and future well-being.

OBJECTIVES: Document the prevalence of tobacco use among youth residing in YPCs and identify associated factors. Describe the measures taken to implement policies for smoke-free environments in YPCs and promote smoking cessation counseling for youth in care.

DESIGN/METHODS: Between July 2008 and May 2009, adolescents aged 14-17 living in six YPCs across Quebec were recruited on a volunteer basis to participate in a surveillance study on health risk behaviors. Data on socio-demographics, lifetime substance use and sexual risk behaviors, as well as certain health consequences related to these behaviors were obtained during structured, face-to-face interviews. An analysis of factors associated with daily tobacco use was carried out.

RESULTS: Data regarding behaviors reported during the year prior to admission were collected among 499 participants (boys: 59%; median age: boys: 16; girls: 15). Lifetime tobacco use was reported by 93% of girls and 91% of boys (median age at first cigarette was 12 years). During the year prior to admission, 15% of youth reported no tobacco use, and 20% smoked occasionally. Two thirds (65%) reported daily tobacco use, with 36% of girls and 43% of boys smoking 10 or more cigarettes a day. In univariate analysis, factors significantly (p&lt;0.05) associated with daily smoking were: school failure or dropping out; family history of problematic alcohol or drug use; precocious initiation of alcohol use before age 13; history of regular use of alcohol or cannabis; problematic drug use (measured by DEP-ADO scale); having 6 or more lifetime sexual partners. Following dissemination of these results, measures were taken to develop a smoke-free policy and implementation plan for YPCs. Health professionals were trained to do brief interventions with all youth smokers entering care. In 2015 the YPC presented a brief to the provincial parlimentary committee on the Tobacco Act to support adoption of smoke-free policies for all health establishments in Québec.

CONCLUSION: Daily tobacco use is very prevalent among adolescents entering YPCs and the majority report problematic use of other psychoac-tive substances. Youth entering care merit screening for tobacco and drug use so that appropriate counseling can be initiated. Promoting policies that encourage smoke-free environments in child protection centers for both youth and the professionals working with them may greatly improve the chances for youth to live tobacco-free.

Prevalence of Anaplasma phagocytophilum in small rodents in France

Anaplasma phagocytophilum is an emerging zoonotic tick-borne pathogen affecting a wide range of mammals. Rodents are suspected to be natural reservoirs for this bacterium, but their role in the epidemiologic cycles affecting domestic animals and wild ungulates has not been demonstrated. This study aimed to improve our knowledge on A. phagocytophilum prevalence in Apodemus sylvaticus, A. flavicollis and Myodes glareolus using data collected in 2010 in one area in eastern France and in 2012-2013 in two others areas in western France. Rodents were captured in each site and infection was tested using qualitative real-time PCR assays on either blood or spleen samples. Prevalence showed high variability among sites. The highest prevalence was observed in the most eastern site (with an average infection rate of 22.8% across all species), whereas no rodent was found to be PCR positive in the south-west site and only 6.6% were positive in the north-west of France. Finally, a significant increase in prevalence was observed in autumn samples compared to spring samples in the north-west, but no change was found in the other two sites.

A microfluidic electrochemical biosensor based on multiwall carbon nanotube/ferrocene for genomic DNA detection of Mycobacterium tuberculosis in clinical isolates

Herein we present a microfluidic-multiplexed platform that integrates electrochemical sensors based on carbon nanotubes associated with ferrocene as redox marker (carbon nanotube (CNT)/ferrocene) for direct detection of pathogenic viral DNA from Hepatitis C and genomic DNA from Mycobacterium tuberculosis in clinical isolates. By operating the fluidic device under high flow (150 μl/min), the formation of a very thin depletion layer at the sensor surface (δS = 230 nm) enhances the capture rate up to one DNA strand per second. By comparison, this capture rate is only 0.02 molecule/s in a static regime without flow. This fluidic protocol allows thus enhancing the limit of detection of the electrochemical biosensor from picomolar in bulk solution to femtomolar with a large dynamic range from 0.1 fM to 1 pM. Kinetics analysis also demonstrates an enhancement of the rate constant of electron transfer (kS) of the electrochemical process from 1 s(-1) up to 6 s(-1) thanks to the geometry of the miniaturized fluidic electrochemical cell. This microfluidic device working under high flow allows selective direct detection of a Mycobacterium tuberculosis (H37Rv) rpoB allele from clinical isolate extracted DNA. We envision that a microfluidic approach under high flow associated with a multiwall CNT/ferrocene sensor could find useful applications as the point-of-care for multi-target diagnostics of biomarkers in real samples.

Exploration of a crack use setting and its impact on drug users' risky drug use and sexual behaviors: the case of piaules in a Montréal neighborhood

From July 2011, a one-year study based on ethnographic methodology was carried out in "crack houses" in the neighborhood of Hochelaga-Maisonneuve in Montréal, Canada. The study aimed to explore the operational style of a specific indoor drug use setting and its impact on users' risky sexual and drug use behaviors in a context of drug market change. A thematic analysis of observational and interview notes was conducted. This study stresses the importance to examine the role of environmental factors in relation to crack smoking's health-related risks and to complement individual-based interventions with structural strategies. The study's limitations are noted.

Transition to injection drug use: the role of initiators

Data are limited about the role of initiators in the transition to injection drug use. We examined the prevalence and predictors of giving someone their first injection using baseline data from a study involving 98 injection drug users (IDUs) in Toronto, Canada. Participants were recruited in 2011 using respondent-driven sampling. Findings revealed that 27.4 % (95 % CI 14.7-42.2) of IDUs had ever given anyone their first injection. In the logistic regression analysis, being unemployed and having ever spoken positively about injecting to a non-injector were associated with giving someone their first injection. Furthermore, the odds of initiating non-IDUs increased with the number of years that IDUs had been injecting. Our results provide support for interventions that aim to reduce the initiation of non-IDUs; however, further research is needed to shed light on the link between unemployment and initiation of non-injectors.

Sustained drug use changes after hepatitis C screening and counseling among recently infected persons who inject drugs: a longitudinal study

BACKGROUND

Notification of hepatitis C virus (HCV) positive status is known to have short-term impacts on subsequent alcohol, drug use and injection behaviors among persons who inject drugs (PWID). It remains to be established whether postscreening behavioral changes extend over time for PWID and whether screening test notification has behavioral impacts among HCV-negative PWID. This study sought to longitudinally assess substance use and injection behaviors after HCV status notification among HCV seroconverters and HCV-negative PWID.

METHODS

Initially HCV-seronegative PWID (n = 208) were followed prospectively between 2004 and 2011 in Montreal, Canada. Semiannual screening visits included blood sampling and an interview-administered questionnaire assessing substance use and injection behaviors. Multivariable generalized estimating equation analyses were conducted to assess substance use and behavior changes over time and compare changes between HCV seroconverters and HCV-seronegative participants while adjusting for baseline characteristics.

RESULTS

Of the 208 participants (83% male; mean age, 34.7 years, mean follow-up time, 39 months), 69 (33.2%) seroconverted to HCV. A linear decrease in syringe sharing behavior was observed over time after HCV and status notification, whereas a 10% decrease for each additional 3 months of follow-up was observed for injection cocaine and heroin use among HCV seroconverters but not among HCV-seronegative PWID (P < .05). No significant changes were observed in alcohol use.

CONCLUSIONS

Our results indicate that notification of HCV-positive status is associated with reduced injection drug use among seroconverters. Among PWID deemed seronegative after screening, there is no sustained trend for change in risk behavior.

Prevalence and temporal trends of crack injection among injection drug users in eastern central Canada

BACKGROUND

Little is known about crack injection and its temporal trends in North America. This article describes the extent of crack injection and examines temporal trends among injection drug users (IDUs) recruited from 2003 to 2010 in the SurvUDI network.

METHODS

IDUs who injected recently (past 6 months) were recruited in harm reduction and health programs in eastern central Canada. Trend analyses were performed using generalized estimating equations. Some IDUs participated multiple times; first interview was retained for the descriptive analyses, while first interview per year was retained for the trend analyses.

RESULTS

Of the 4088 IDUs recruited, 15.2% (621) reported crack injection; large variations across sites were noted (range: 0.3-39.5%). Trend analyses were limited to Ottawa (449 crack injectors) and Montréal (121). For Ottawa, a significant decline was observed, from 48.3% to 36.9%, with a prevalence ratio (PR) of 0.97 per year (95% CI: 0.94-0.99). For Montréal, a significant rise was observed, from 6.0% to 18.4%, with a PR of 1.29 per year (95% CI: 1.19-1.40).

CONCLUSIONS

Strong variations in crack injection exist throughout the SurvUDI network, and reversed temporal trends have been observed in Ottawa and Montréal. These data will be useful to local harm reduction programs to evaluate the need to distribute items required by crack injectors and to develop prevention messages.

Changing patterns of first injection across key periods of the French Harm Reduction Policy: PrimInject, a cross sectional analysis

BACKGROUND

Monitoring of emerging modes of drug consumption in France has identified new patterns of injection among youths with diverse social backgrounds, which may explain the persistence of high rates of hepatitis C virus infection. The circumstances surrounding the first injection have been poorly documented in the group of heavy drug users and in the context of the French opioid substitution treatment (OST) policy that provides expanded access to high-dosage buprenorphine (BHD) METHODS: An Internet survey (Priminject) was conducted from October 2010 to March 2011 with French drug users. Four time periods were compared based on critical dates throughout the implementation of the Harm Reduction Policy in France.

RESULTS

Compared with drug users who injected for the first time prior to 1995, the aspects of drug use for users who recently injected for the first time were as follows: (1) experimentation with miscellaneous drugs before the first injection; (2) an older age at the time of first injection; (3) heroin as the drug of choice for an individual's first injection, notwithstanding the increased usage of stimulant drugs; (4) BHD did not appear to be a pathway to injection; and (5) an increased number of users who injected their first time alone, without the help or presence of another individual.

CONCLUSION

The PrimInject study showed that there is a group of injection drug users that is larger than the group of injection drug users observed in previous studies; therefore, it is necessary to diversify programs to reach the entire spectrum of high-risk users.

The rising prevalence of prescription opioid injection and its association with hepatitis C incidence among street-drug users

AIMS

  To examine trends in prescription opioid (PO) injection and to assess its association with hepatitis C virus (HCV) seroconversion among injection drug users (IDUs).

DESIGN

  Prospective cohort study.

SETTING

  Montreal, Canada.

PARTICIPANTS

  HCV-negative IDUs at baseline, reporting injection in the past month.

MEASUREMENTS

  Semi-annual visits included HCV antibody testing and an interview-administered questionnaire assessing risk behaviours. HCV incidence rate was calculated using the person-time method. Time-updated Cox regression models were conducted to examine predictors of HCV incidence.

FINDINGS

  The proportion of IDUs reporting PO injection increased from 21% to 75% between 2004 and 2009 (P < 0.001). Of the 246 participants (81.6% male; mean age 34.5 years; mean follow-up time 23 months), 83 seroconverted to HCV [incidence rate: 17.9 per 100 person-years; 95% confidence interval (CI) 14.3, 22.1]. Compared to non-PO injectors, PO injectors were more likely to become infected [adjusted hazard ratio (AHR): 1.87; 95%CI:1.16, 3.03]. An effect modification was also found: PO injectors who did not inject heroin were more likely to become infected (AHR: 2.88; 95%CI: 1.52, 5.45) whereas no association was found for participants using both drugs (AHR: 1.19; 95% CI: 0.61, 2.30). Other independent predictors of HCV incidence were: cocaine injection, recent incarceration and >30 injections per month.

CONCLUSIONS

  Prescription opioid injectors who do not inject heroin are at greater risk for HCV seroconversion than are those injecting both heroin and prescription opioids. Important differences in age, behaviour and social context suggest a need for targeted outreach strategies to this population.

GM130 gain-of-function induces cell pathology in a model of lysosomal storage disease

Cell pathology in lysosomal storage diseases is characterized by the formation of distended vacuoles with characteristics of lysosomes. Our previous studies in mucopolysaccharidosis type IIIB (MPSIIIB), a disease in which a genetic defect induces the accumulation of undigested heparan sulfate (HS) fragments, led to the hypothesis that abnormal lysosome formation was related to events occurring at the Golgi level. We reproduced the enzyme defect of MPSIIIB in HeLa cells using tetracycline-inducible expression of shRNAs directed against α-N-acetylglucosaminidase (NAGLU) and addressed this hypothesis. HeLa cells deprived of NAGLU accumulated abnormal lysosomes. The Golgi matrix protein GM130 was over-expressed. The cis- and medial-Golgi compartments were distended, elongated and formed circularized ribbons. The Golgi microtubule network was enlarged with increased amounts of AKAP450, a partner of GM130 controlling this network. GM130 down-regulation prevented pathology in HeLa cells deprived of NAGLU, whereas GM130 over-expression in control HeLa cells mimicked the pathology of deprived cells. We concluded that abnormal lysosomes forming in cells accumulating HS fragments were the consequence of GM130 gain-of-function and subsequent alterations of the Golgi ribbon architecture. These results indicate that GM130 functions are modulated by HS glycosaminoglycans and therefore possibly controlled by extracellular cues.

Residential trajectory and HIV high-risk behaviors among Montréal street youth--a reciprocal relationship

Evidence has linked residential instability and engagement in high-risk behaviors. This paper longitudinally examines the relationship between changes in residential stability and changes in HIV risk behaviors among Montréal street youth (SY). Between April 2006 and May 2007, 419 SY (18-25 years old) were recruited in a cohort study. SY (using Montréal street youth agencies services) were eligible if they had had at least one 24-hour episode of homelessness in the previous 30 days. Baseline and follow-up interviews, carried out every 3 months, included completion of a questionnaire (based on Life History Calendar Technique) assessing daily sleeping arrangements since the last interview, and monthly sexual and drug use behaviors. Using mixed-effects logistic regression method, we examined the association between various risk behaviors and residential stability, reached when a youth resided in any of the following settings for a whole month: own place; friends'/partner's/parent's place; any types of housing service (excluding emergency shelters). Analyses were carried out controlling for gender, age, education level, lifetime duration of homelessness, childhood sexual trauma, and lifetime mental health disorders. As of January 2009, 360 SY (79% boys) had completed at least one follow-up interview, representing 4,889 months of follow-up. Residential stability was significantly associated with the following: sex exchange (adjusted odd ratio [AOR], 0.25; 95% confidence interval [CI], 0.14-0.37), drug injection (AOR, 0.55; CI, 0.33-0.76), daily alcohol consumption (AOR, 0.58; CI, 0.42-0.74), polydrug consumption (AOR, 0.61; CI, 0.50-0.73), polydrug consumption excluding marijuana (AOR, 0.55; CI, 0.45-0.65), and multiple sex partners (≥3 partners; AOR, 0.57; CI, 0.40-0.74). Our results suggest a reciprocal relationship between residential instability and HIV risk behaviors. This calls for more integrated services combining both individual and structural-level interventions to improve the health of street youth.

Modeling neuronal defects associated with a lysosomal disorder using patient-derived induced pluripotent stem cells

By providing access to affected neurons, human induced pluripotent stem cells (iPSc) offer a unique opportunity to model human neurodegenerative diseases. We generated human iPSc from the skin fibroblasts of children with mucopolysaccharidosis type IIIB. In this fatal lysosomal storage disease, defective α-N-acetylglucosaminidase interrupts the degradation of heparan sulfate (HS) proteoglycans and induces cell disorders predominating in the central nervous system, causing relentless progression toward severe mental retardation. Partially digested proteoglycans, which affect fibroblast growth factor signaling, accumulated in patient cells. They impaired isolation of emerging iPSc unless exogenous supply of the missing enzyme cleared storage and restored cell proliferation. After several passages, patient iPSc starved of an exogenous enzyme continued to proliferate in the presence of fibroblast growth factor despite HS accumulation. Survival and neural differentiation of patient iPSc were comparable with unaffected controls. Whereas cell pathology was modest in floating neurosphere cultures, undifferentiated patient iPSc and their neuronal progeny expressed cell disorders consisting of storage vesicles and severe disorganization of Golgi ribbons associated with modified expression of the Golgi matrix protein GM130. Gene expression profiling in neural stem cells pointed to alterations of extracellular matrix constituents and cell-matrix interactions, whereas genes associated with lysosome or Golgi apparatus functions were downregulated. Taken together, these results suggest defective responses of patient undifferentiated stem cells and neurons to environmental cues, which possibly affect Golgi organization, cell migration and neuritogenesis. This could have potential consequences on post-natal neurological development, once HS proteoglycan accumulation becomes prominent in the affected child brain.

Drug use patterns in the presence of crack in downtown Montréal

INTRODUCTION AND AIMS

A study was undertaken to verify reports of an increasing presence of crack in downtown Montréal, and to investigate the influence of crack availability on current drug use patterns among street-based cocaine users.

DESIGN AND METHODS

The study combined both qualitative and quantitative methods. These included long-term intensive participant observation carried out by an ethnographer familiar with the field and a survey. The ethnographic component involved observations and unstructured interviews with 64 street-based cocaine users. Sampling was based on a combination of snowballing and purposeful recruitment methods. For the survey, structured interviews were conducted with a convenience sample of 387 cocaine users attending HIV/HCV prevention programs, downtown Montréal.

RESULTS

A gradual shift has occurred in the last 10 years, with the crack street market overtaking the powder cocaine street market. Although the data pointed to an increase in crack smoking, 54.5% of survey participants both smoked and injected cocaine. Drug market forces were major contributing factors to the observed modes of cocaine consumption. While the study focused primarily on cocaine users, it became apparent from the ethnographic fieldwork that prescription opioids (POs) were very present on the streets. According to the survey, 52.7% of participants consumed opioids, essentially POs, with 88% of them injecting these drugs.

DISCUSSION AND CONCLUSIONS

Despite the increased availability of crack, injection is still present among cocaine users due at least in part to the concurrent increasing popularity of POs.

Initiation to drug injection among street youth: a gender-based analysis

OBJECTIVE(S)

To estimate the incidence rate of initiation into drug injection and to identify predictors of initiation into drug injection separately among street girls and boys.

DESIGN

Data from two consecutive prospective street youth cohort studies (1995-2001 and 2001-2005) were used to conduct these analyses, stratified by gender.

METHODS

Data were collected using semi-annual interviewer-administered questionnaires. Variables from the following domains were considered in Cox regression models: socio-demographic characteristics, early and current substance abuse, marginalization, childhood traumatic sexual events and injection exposure.

RESULTS

Of the 946 youth who had never injected drugs at study entry, 86.4% completed at least two questionnaires representing 243 girls and 574 boys. Incidence rates of injection of 7.0 and 5.9 per 100 person-years were observed among these girls and boys respectively. Among girls, cocaine or crack use (adjusted hazard ratio (AHR)=1.97), heroin use (AHR=2.86), homelessness (AHR=2.49) and hanging out regularly with people who inject (AHR=4.46) all independently increased risk of first injection. Among boys, age decreased risk of initiating injection (AHR=0.90/year), while cocaine or crack use (AHR=2.14), heroin use (AHR=3.56), homelessness before age 16 (AHR=1.68), incest or rape before age 14 (AHR=1.98) and hanging out regularly with people who inject (AHR=1.66) all independently increased this risk.

CONCLUSIONS

Our findings suggest similar rates of initiation among girls and boys; however, factors associated with initiation vary by gender. This might lead to the design of more effective programs to prevent initiation into drug injection.

Modeling initiation into drug injection among street youth

This study aimed at examining the predictors of initiation into drug injection among street youth using social cognitive theory framework. A prospective cohort study based on semi-annual interviews was carried out. Psychosocial determinants referred to avoidance of initiation. Other potential predictors were: sociodemographic characteristics, relationships with injectors, parent's substance misuse, drug use patterns, homelessness, survival sex, sexual abuse. Independent predictors were identified using Cox proportional hazards regression models. Among the 352 participants, high control beliefs about avoidance of initiation was protective while younger age, daily alcohol consumption, heroin use, cocaine use, and survival sex all increased risk of initiation. Preventive strategies targeting street youth should both enhance youth's control beliefs and actual control over their substance use and improve their life conditions.

The growing popularity of prescription opioid injection in downtown Montréal: new challenges for harm reduction

Starting in 2007, a 2-year study based on ethnographic methodology was carried out downtown Montréal, Canada. A thematic analysis of observational and interview-based notes was conducted. Illicit prescription opioid (PO) use was widespread among street-based participants. Injection was the main mode of PO administration observed among users. Some injection practices such as "doing a wash" could pose new challenges in terms of prevention of infections. More research is needed to examine the role of illicit PO use in the development of opiate addiction and to better understand drug-using contexts that put PO users at risk of infections. The study's limitations are noted.

Predictors of crack cocaine initiation among Montréal street youth: a first look at the phenomenon

BACKGROUND

Crack cocaine use is increasing in Montréal. However, initiation risk factors among street youth are unknown. The goal of this project is to estimate the incidence of first crack cocaine use among these youth and to identify the associated risk factors.

METHODS

A prospective cohort study of HIV and hepatitis C incidence was conducted among street youth from 2001 to 2005. A questionnaire on sexual and drug use behaviours was administered every 6 months. Incidence was estimated (a) for youth who had never used crack cocaine at recruitment (n=203) and, among them, (b) for those who had snorted cocaine before (n=122). The risk factors for initiation of crack use as well for initiation into a new route of cocaine administration among youth who had snorted cocaine before were determined using Cox regression.

RESULTS

Incidence rates for crack cocaine use were (a) 136.6/1000 person-years (p-y) (95% confidence interval [CI]: 104.5-175.5) and (b) 205.8/1000 p-y (95% CI: 150.2-275.3). The number of substance types used recently increased the risk of initiating crack use (adjusted hazard ratio [AHR]=1.84 per substance type, 95% CI: 1.55-2.18), whereas having a parent with a substance abuse problem decreased that risk (AHR=0.48, 95% CI: 0.26-0.89). The risk factors were identical among youth who had snorted cocaine before.

CONCLUSIONS

Our analyses show a high incidence of crack use among street youth. It is important to delve more deeply into the phenomenon of initiation if we wish to develop effective prevention measures for these young people.

The challenge of understanding mortality changes among street youth

According to a cohort study conducted in Montréal, Québec from 1995 to 2000, the mortality rate among street youth was 921/100,000 person-years. Several new community initiatives aiming to increase access to housing and to social and health services for the homeless were implemented in the city between 2000 and 2003. This study aims to update the mortality rate estimate for the period 2001-2006 and to examine factors that could explain a difference between rates, if any. A second cohort study was conducted between 2001 and 2006. The Cohort 2 mortality rate was computed and compared with the Cohort 1 rate. Several analyses were then carried out: (1) mortality rates in the general population were compared with street youth rates using standardized mortality ratios (SMR); (2) Cohorts 1 and 2 distributions of risk factors for mortality were examined, and their effects were assessed using multivariate proportional hazards regression analyses carried out on a combined Cohorts 1 and 2 dataset. Mortality rate among street youth decreased by 79% while it declined by only 19% in the general population; the SMR for Cohort 1 was higher than for Cohort 2 (11.6 versus 3.0). Multivariate proportional hazards regression analyses yielded estimates that were close to the model's estimates based on Cohort 1 data only, and participation in Cohort 1 was an independent predictor of mortality, with an adjusted hazard ratio of 9.0. The mortality decline cannot be completely explained by a similar decrease among the general population or by a difference in distribution of risk factors for mortality between the two cohorts. Field workers suggested that the decrease in heroin consumption they had observed in the streets might have contributed to the mortality decline. We then performed additional analyses which showed that even though the proportion of street youth currently using heroin decreased significantly between 1995 and 2005, the association between heroin use and mortality was not significant (adjusted hazard ratio of 0.9; 95% CI, 0.4 to 2.3). It seems that various factors could have contributed to the decline in mortality rates among street youth, one plausible factor being the implementation of new services for the homeless. This study underscores the importance of monitoring risky behaviors among vulnerable populations to ensure that morbidity and mortality data among these populations is correctly interpreted. Setting up a system to monitor the drug market could improve the quality of information collected.

Hepatitis C virus incidence among young street-involved IDUs in relation to injection experience

BACKGROUND

Young injection drug users (IDUs) are at very high risk of hepatitis C virus (HCV) infection. Using a time scale starting at first injection, we studied the period of HCV susceptibility after initiation into drug injection among street-involved IDUs.

METHODS

A prospective cohort study was carried out among street youth from 2001 to 2005. Semiannual interviews included completion of an interviewer-administered questionnaire and collection of blood samples for HCV antibody testing. HCV-negative subjects currently injecting drugs (last six months) were included in the analyses. Follow-up started at first questionnaire where current injection was reported and ended at seroconversion or at last questionnaire. Poisson regression was used to assess the predictive power of time elapsed since initiation on incidence rate. Kaplan-Meier technique was used to estimate cumulative infection probabilities.

RESULTS

Among the 858 cohort participants, 145 were injecting at baseline and 60 were injecting at a subsequent questionnaire (45 youth had started injection and 15 had resumed injection). Mean age was 20 years and 62% were males. In the 395 person-years of follow-up, 61 subjects contracted HCV. The HCV incidence rate increased from 16.1/100 person-years during the first year following first injection to 22.4 in the third year, and then decreased to 7.2 in years 7-13 (p=0.02). Median time to seroconversion after first injection was 3.3 years.

CONCLUSION

The first years after first injection is the period during which vulnerability to HCV is greatest. Our results show the importance of intervening with new IDUs to optimize the chances to successfully prevent infection.

Access to sterile injecting equipment is more important than awareness of HCV status for injection risk behaviors among drug users

Awareness of hepatitis C virus (HCV) infection status is expected to influence risk behaviors. In 2004-2005, injection drug users (IDUs) recruited from syringe exchange programs (SEPs) and methadone clinics in Montreal, Canada, were interviewed on drug use behaviors (past 6 months) and HCV testing. Subjects (n = 230) were classified as low/intermediate risk (20.4% borrowed drug preparation equipment only) and high risk (19.6% borrowed syringes), and 54.5% reported being HCV positive. Logistic regression modeling showed that compared to no risk (60% borrowed nothing), low/intermediate risk was associated with fewer noninjecting social network members, poor physical health, and problems obtaining sterile injecting equipment. High risk was associated with all of these factors except social networks. HCV status was not associated with any level of risk. Improved access to sterile injecting equipment may be more important than knowledge of HCV status in reducing injection risks among this IDU population. The study limitations are noted and recommendations discussed.