Methamphetamine injecting is associated with phylogenetic clustering of hepatitis C virus infection among street-involved youth in Vancouver, Canada

Infectious Diseases Among People Experiencing Homelessness: A Systematic Review of the Literature in the United States and Canada, 2003-2022

Homelessness increases the risk of acquiring an infectious disease. We conducted a systematic review of the literature to identify quantitative data related to infectious diseases and homelessness. We searched Google Scholar, PubMed, and SCOPUS for quantitative literature published from January 2003 through December 2022 in English from the United States and Canada. We excluded literature on vaccine-preventable diseases and HIV because these diseases were recently reviewed. Of the 250 articles that met inclusion criteria, more than half were on hepatitis C virus or Mycobacterium tuberculosis. Other articles were on COVID-19, respiratory syncytial virus, Staphylococcus aureus, group A Streptococcus, mpox (formerly monkeypox), 5 sexually transmitted infections, and gastrointestinal or vectorborne pathogens. Most studies showed higher prevalence, incidence, or measures of risk for infectious diseases among people experiencing homelessness as compared with people who are housed or the general population. Although having increased published data that quantify the infectious disease risks of homelessness is encouraging, many pathogens that are known to affect people globally who are not housed have not been evaluated in the United States or Canada. Future studies should focus on additional pathogens and factors leading to a disproportionately high incidence and prevalence of infectious diseases among people experiencing homelessness.

Assessment of factors affecting response of direct-acting antivirals in chronic hepatitis C patients

Background

Hepatitis C virus (HCV) is a universally prevalent pathogen and a major cause of liver-related morbidity and mortality worldwide. The evolution of antiviral therapy for HCV has rapidly progressed from interferon (IFN)-based therapies to IFN-free combinations of direct-acting antivirals (DAAs).

Aims

This study aims to assess the response of DAAs in chronic hepatitis C (CHC) patients and to study the various factors affecting the response of DAAs in CHC.

Settings and Design

This longitudinal observational study spanning over a year was conducted in the Medicine department of a tertiary care teaching hospital.

Materials and Methods

The study was conducted on 400 adult CHC patients, diagnosed by a positive anti-HCV antibody test and a detectable viral load (HCV RNA) by real time polymerase chain reaction (RT-PCR), registered for treatment with DAAs. The first 400 patients satisfying the eligibility criteria were enrolled by non-probability consecutive sampling. All the participants were treated as per the National Viral Hepatitis Control Programme (NVHCP) guidelines. Repeat HCV viral load was done at or after 12 weeks of completion of anti-viral therapy to ascertain sustained virological response (SVR). Various factors which might predict treatment response were analyzed.

Statistical Analysis Used

The continuous variables were expressed as mean and standard deviation, while the categorical variables were summarized as frequencies and percentages. The Student's independent t-test was employed for the comparison of continuous variables. The Chi-square or Fisher's exact test, whichever is appropriate, was employed for the comparison of categorical variables. Multivariate Logistic Regression was used to identify the independent predictors of treatment nonresponse. A P < 0.05 was considered statistically significant.

Results

The mean age of the subjects was 42.3 ± 15.23 years with a male-to-female ratio of 1.96:1. Most of the patients (80.5%) were non-cirrhotic; among 19.5% cirrhotic, 13% were compensated while 6.5% were decompensated cirrhotic. The overall SVR done at or after 12 weeks of completion of treatment was 88.75%. Age, gender distribution, occupation, socioeconomic status, educational status, body mass index, treatment regimen, duration of treatment, and baseline viral load did not alter the treatment response. Among comorbidities, only diabetes mellitus (DM) and human immunodeficiency virus (HIV) co-infection adversely affected the treatment response (P = 0.009 and P < 0.001, respectively). Intravenous (IV) drug abuse was significantly associated with treatment failure (P < 0.001). The presence of liver cirrhosis (P < 0.001), thrombocytopenia (P < 0.001), elevated transaminases (alanine transaminase: P = 0.021, aspartate transaminase: P < 0.001), and previous treatment experience (P = 0.038) were other significant predictors of treatment failure.

Conclusions

DAAs are highly efficacious drugs in the treatment of CHC with a high rate of treatment response. Significant predictors of CHC treatment failure included comorbidities especially DM and HIV co-infection, IV drug abuse, presence of liver cirrhosis, thrombocytopenia, elevated transaminases, and previous treatment experience. However, independent predictors of treatment nonresponse observed in this study were thrombocytopenia, IV drug abuse, and liver cirrhosis.

Associations between prescription stimulant use as prescribed, nonmedical use, and illicit stimulant use among adults evaluated for substance use treatment, 2017-2021

Background

Limited data exist on risk factors for illicit stimulant use, including associations between prescription stimulant use/nonmedical use (NMU) and illicit stimulant use.

Methods

We used 2017-2021 data from adults assessed for substance use disorder (SUD) treatment using the National Addictions Vigilance Intervention and Prevention Program Addiction Severity Index-Multimedia Version® tool. Multivariable Poisson regression models analyzed associations between past 30-day prescription stimulant use as prescribed or NMU and past 30-day illicit stimulant use. Separate models examined past 30-day illicit stimulant, methamphetamine, and cocaine use. We explored problem severity across seven biopsychosocial domains (e.g., drug, psychiatric, family) by past 30-day prescription stimulant use/NMU and illicit stimulant use.

Results

Among 218,981 assessments, 1.8% reported prescription stimulant NMU; 1.6% reported use as prescribed. Past 30-day prescription stimulant NMU (vs. no use) was associated with past 30-day illicit stimulant use (adjusted prevalence ratio [aPR] [95% CI]: 2.67 [2.59, 2.75]), methamphetamine use (aPR: 2.81 [2.71, 2.92]), and cocaine use (aPR: 3.53 [3.33, 3.74]). Prescription stimulant use as prescribed (vs. no use) was associated with lower prevalence of past 30-day illicit stimulant use. Assessments reporting prescription stimulant NMU (vs. no use, or use as prescribed) appeared more likely to have moderate-to-extreme problem scores across biopsychosocial domains, indicating greater need for treatment or assistance. Assessments reporting prescription stimulant use as prescribed or NMU frequently reported opioids, alcohol, or other substances as their primary substance problem.

Conclusions

Adults using illicit stimulants/nonmedically using prescription stimulants may benefit from care addressing polysubstance use, mental health, social, and recovery support services.

Methamphetamine use in the United States: epidemiological update and implications for prevention, treatment, and harm reduction

Recent attention has focused on the growing role of psychostimulants, such as methamphetamine in overdose deaths. Methamphetamine is an addictive and potent stimulant, and its use is associated with a range of physical and mental health harms, overdose, and mortality. Adding to the complexity of this resurgent methamphetamine threat is the reality that the increases in methamphetamine availability and harms are occurring in the midst of and intertwined with the ongoing opioid overdose crisis. Opioid involvement in psychostimulant-involved overdose deaths increased from 34.5% of overdose deaths in 2010 to 53.5% in 2019-an increase of more than 50%. This latest evolution of the nation's overdose epidemic poses novel challenges for prevention, treatment, and harm reduction. This narrative review synthesizes what is known about changing patterns of methamphetamine use with and without opioids in the United States, other characteristics associated with methamphetamine use, the contributions of the changing illicit drug supply to use patterns and overdose risk, motivations for couse of methamphetamine and opioids, and awareness of exposure to opioids via the illicit methamphetamine supply. Finally, the review summarizes illustrative community and health system strategies and research opportunities to advance prevention, treatment, and harm reduction policies, programs, and practices.

Drugs of Abuse and Their Impact on Viral Pathogenesis

Commonly misused substances such as alcohol, cocaine, heroin, methamphetamine, and opioids suppress immune responses and may impact viral pathogenesis. In recent years, illicit use of opioids has fueled outbreaks of several viral pathogens, including the human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). This review focuses on the myriad of mechanisms by which drugs of abuse impact viral replication and disease progression. Virus–drug interactions can accelerate viral disease progression and lead to increased risk of virus transmission.

Adverse childhood experiences and stimulant use disorders among adults in the United States

Recent data indicate a resurgence of stimulant use and harms in the United States; thus, there is a need to identify risk factors to inform development of effective prevention strategies. Prior research suggests adverse childhood experiences (ACEs) are common among individuals using stimulants and may be an important target for prevention. National Epidemiological Survey on Alcohol and Related Conditions was used to estimate prevalence of ACEs among U.S. adults using amphetamine-type stimulants (ATS), cocaine, or both. Multivariable logistic regression examined associations between ACEs and stimulant use and use disorders. Among adults reporting lifetime ATS use, 22.1% had ≥4 ACEs, 24.9% had 2-3 ACEs, 22.4% had 1 ACE, 30.6% reported no ACEs. Among adults with lifetime ATS use disorder, 29.3% reported ≥4 ACEs, 28.7% reported 2-3 ACEs, 21.6% reported 1 ACE, and 20.4% reported no ACEs. Multivariable logistic regression found a significant relationship between number of ACEs and stimulant use and use disorders. In conclusion, we found a strong relationship between increasing ACE exposures and stimulant use and use disorders. Advancing comprehensive strategies to prevent ACEs and treating underlying trauma among those using stimulants holds great promise to reduce stimulant use and its health and social consequences in the United States.

A prospective cohort study of risk behaviours, retention and loss to follow-up over 5 years among women and men in a needle exchange program in Stockholm, Sweden

BACKGROUND

Needle exchange programs (NEP) are important in reducing risk behaviours among people who inject drugs (PWID), also exposed to HIV and hepatitis C (HCV) through injecting drug use (IDU). Women (WWID) compared to men who inject drugs (MWID), are particularly vulnerable with complex needs, however less is known about their risk determinants and NEP outcomes.

METHODS

In an open prospective NEP cohort, 697 WWID and 2122 MWID were followed, 2013-2018. Self-reported socio/drug-related determinants for receptive injection (needle/syringe and paraphernalia) and sexual risk behaviours at enrolment, lost to follow-up (LTFU) and probability of retention, were assessed for both groups. Multivariable logistic regression (adjusted odds ratios, aOR) for enrolment and Poisson regression (adjusted incidence rate ratios, aIRR) for LTFU, were used. Cumulative NEP-retention probability was analysed using a six- and 12-month scenario.

RESULTS

At NEP enrolment, injection risk behaviours among WWID were associated with: younger age; homelessness; amphetamine-IDU; non-participation in opioid substitution therapy (OST); history of custody and among MWID: lower education level; cohabitation; homelessness, being a tenant; amphetamine-IDU; non-participation in OST; history of being sectioned, HIV-negative and HCV-positive. Condomless sex among WWID was associated with: younger age; lower education-level; cohabitation; having a partner; amphetamine-IDU; non-participation in OST; being HIV-negative and HCV-positive and among MWID: younger age; married; cohabitation; having a partner; amphetamine-IDU; non-participation in OST; history of custody, prison and being HIV-negative. WWID had higher NEP-retention levels compared to MWID over time. Being LTFU among WWID was associated with being HIV-negative and reporting injection risk behaviours and among MWID, younger age, non-participation in OST, being HIV-negative and having protected sex.

CONCLUSIONS

Despite better NEP compliance among WWID, high injection and sexual risk behaviours in both gender-subgroups, especially in intimate relationships, suggests ongoing HCV and HIV-infection risks. Subgroup-variation in the NEP continuum of care warrants more gender-disaggregated research and tailoring gender-sensitive services may improve prevention, health and retention outcomes.

Residential eviction predicts initiation of or relapse into crystal methamphetamine use among people who inject drugs: a prospective cohort study

Reports of increasing methamphetamine use among vulnerable populations may be attributed in part to the adaptive use of stimulants in response to the loss of stable housing through residential eviction. We employed multivariable recurrent event extended Cox regression to examine the independent association between recent evictions and initiation of or relapse into crystal methamphetamine use among people who inject drugs in Vancouver, Canada enrolled in two prospective cohort studies. In a multivariable analysis, eviction remained independently associated with methamphetamine initiation or relapse (adjusted hazard ratio = 1.90; 95% confidence interval: 1.31-2.75). Findings demonstrate the need to secure tenancies for drug-using populations to reduce harms.

Treatment of stimulant use disorder: A systematic review of reviews

AIMS

Stimulant use disorder contributes to a substantial worldwide burden of disease, although evidence-based treatment options are limited. This systematic review of reviews aims to: (i) synthesize the available evidence on both psychosocial and pharmacological interventions for the treatment of stimulant use disorder; (ii) identify the most effective therapies to guide clinical practice, and (iii) highlight gaps for future study.

METHODS

A systematic database search was conducted to identify systematic reviews and meta-analyses. Eligible studies were those that followed standard systematic review methodology and assessed randomized controlled trials focused on the efficacy of interventions for stimulant use disorder. Articles were critically appraised using an assessment tool adapted from Palmeteer et al. and categorized for quality as 'core' or 'supplementary' reviews. Evidence from the included reviews were further synthesized according to pharmacological or non-pharmacological management themes.

RESULTS

Of 476 identified records, 29 systematic reviews examining eleven intervention modalities were included. The interventions identified include: contingency management, cognitive behavioural therapy, acupuncture, antidepressants, dopamine agonists, antipsychotics, anticonvulsants, disulfiram, opioid agonists, N-Acetylcysteine, and psychostimulants. There was sufficient evidence to support the efficacy of contingency management programs for treatment of stimulant use disorder. Psychostimulants, n-acetylcysteine, opioid agonist therapy, disulfiram and antidepressant pharmacological interventions were found to have insufficient evidence to support or discount their use. Results of this review do not support the use of all other treatment options.

CONCLUSIONS

The results of this review supports the use of contingency management interventions for the treatment of stimulant use disorder. Although evidence to date is insufficient to support the clinical use of psychostimulants, our results demonstrate potential for future research in this area. Given the urgent need for effective pharmacological treatments for stimulant use disorder, high-quality primary research focused on the role of psychostimulant medications for the treatment of stimulant use disorder is needed.

Examining risk behavior and syringe coverage among people who inject drugs accessing a syringe services program: A latent class analysis

INTRODUCTION

Injection drug use (IDU) remains a significant public health problem. IDU has been associated closely with the opioid crisis; driving overdose, HIV, and Hepatitis C (HCV) infection nationwide. Syringe services programs (SSPs) remain pivotal evidence-based interventions to reduce harm and engage subgroups of people who inject drugs (PWID). This study aims to provide policy considerations from the IDEA SSP, the first legal SSP in the state of Florida.

METHODS

We performed a latent class analysis on patterns of substance use among participants (N = 982) newly enrolled in a syringe services program (SSP). Associations between classes of substance use and sociodemographic variables, risky injection and sex behaviors, HIV/HCV status and syringe coverage were analyzed using the R3STEP and BCH 3-step procedures in latent class regression.

RESULTS

We found a three-class solution: Heroin-Dominant class (73.9%), Methamphetamine-Dominant class (9.5%) and Heroin/Cocaine class (16.6%). Compared to Heroin-Dominant class, the Heroin/Cocaine class were more likely to report homelessness, sharing works, unprotected sex, public injection, and to be HCV positive. Compared to both Heroin-Dominant and Heroin/Cocaine classes, the Methamphetamine-Dominant class were more likely to be male, Hispanic, gay or bisexual orientation, HIV positive, to report unprotected sex and sex with PWID. In addition, the lowest and highest syringe coverage were among those in the Heroin/Cocaine and Methamphetamine-Dominant classes, respectively.

CONCLUSION

Existing interventions among this population to mitigate infectious disease risk, such as SSPs, can be a used to engage differing PWID populations. However, multi-component, targeted preventive interventions and need-based syringe distribution policies are required to further reduce HIV and HCV risk among various PWID populations.

Resurgent Methamphetamine Use at Treatment Admission in the United States, 2008-2017

Objectives. To evaluate trends and correlates of methamphetamine use in the United States.Methods. Data are from 15 747 334 drug-related treatment admissions among persons aged 12 years or older in the 2008-2017 Treatment Episode Data Set. We analyzed trends and used multivariable logistic regression.Results. Methamphetamine-related admissions increased from 15.1% of drug-related treatment admissions in 2008 to 23.6% in 2017. Increases occurred among nearly all demographic groups. Methamphetamine injection increased from 17.5% of admissions in 2008 to 28.4% in 2017. Among methamphetamine-related admissions, heroin use increased from 5.3% of admissions in 2008 to 23.6% in 2017. Characteristics associated with increased odds of reporting methamphetamine use at admission included female sex; admissions aged 35 to 44 years; admissions in the Midwest, South, and West; unemployment; not in labor force; living dependent; living homeless; and having a referral from criminal justice, a health care provider, or other community treatment source.Conclusions. Treatment admissions involving methamphetamine use increased significantly over the past decade and appear to be linked to the ongoing opioid crisis in the United States. Efforts to mobilize public health prevention, treatment, and response strategies to address rising methamphetamine use and overdose are needed.

Increases in methamphetamine use among heroin treatment admissions in the United States, 2008-17

BACKGROUND AND AIMS

Due to their small sample sizes, geographic specificity and limited examination of socio-demographic characteristics, recent studies of methamphetamine use among people using heroin in the United States are limited in their ability to identify national and regional trends and to characterize populations at risk for using heroin and methamphetamine. This study aimed to examine trends and correlates of methamphetamine use among heroin treatment admissions in the United States.

DESIGN

Longitudinal analysis of data from the 2008 to 2017 Treatment Episode Data Set. Descriptive statistics, trend analyses and multivariable logistic regression were used to examine characteristics associated with methamphetamine use among heroin treatment admissions.

SETTING

United States.

PARTICIPANTS

Treatment admissions of people aged ≥ 12 years whose primary substance of use is heroin.

MEASUREMENTS

Primary measurement was heroin treatment admissions involving methamphetamine. Secondary measurements were demographics of sex, age, race/ethnicity, US census region, living arrangement and employment status.

FINDINGS

The percentage of primary heroin treatment admissions reporting methamphetamine use increased each year from 2.1% in 2008 to 12.4% in 2017, a relative percentage increase of 490% and an annual percentage change (APC) of 23.4% (P < 0.001). During the study period, increases were seen among males and females and among all demographic and geographic groups examined. Among primary heroin treatment admissions reporting methamphetamine use in 2017, 47.1% reported injecting, 46.0% reported smoking, 5.1% reporting snorting and 1.8% reported oral/other as their usual route of methamphetamine use.

CONCLUSIONS

Methamphetamine use among heroin treatment admissions in the United States increased from one in 50 primary heroin treatment admissions in 2008 to one in 8 admissions in 2017.

Social values for health technology assessment in Canada: a scoping review of hepatitis C screening, diagnosis and treatment

Background

Health care system decision makers face challenges in allocating resources for screening, diagnosis and treatment of hepatitis C. Approximately 240,000 individuals are infected with the hepatitis C virus (HCV) in Canada. Populations most affected by HCV include Indigenous people, people who inject drugs, immigrants and homeless or incarcerated populations as well as those born between 1946 and 1965. Curative but expensive drug regimens of novel direct acting antivirals (DAAs) are available. We aim to identify social values from academic literature for inclusion in health technology assessments.

Methods

We conducted a scoping review of academic literature to identify and analyze the social values and evidence-based recommendations for screening, diagnosis and treatment of HCV in Canada. After applying inclusion/exclusion criteria, we abstracted: type of intervention(s), population(s) affected, study location, screening methods, diagnostics and treatments. We then abstracted and applied qualitative codes for social values. We extracted social value statements and clustered them into one of 4 categories: (1) equity and justice, (2) duty to provide care, (3) maximization of population benefit, and (4) individual versus community interests.

Results

One hundred and eighteen articles met our inclusion criteria on screening, diagnosis and treatment of HCV in Canada. Of these, 54 (45.8%) discussed screening, 4 (3.4%) discussed diagnosis and 60 (50.8%) discussed treatment options. Most articles discussed the general population and other non-vulnerable populations. Articles that discussed vulnerable populations focused on people who inject drugs. We coded 1243 statements, most of which fell into the social value categories of equity and justice, duty to provide care and maximization of population benefit.

Conclusion

The academic literature identified an expanded set of social values to be taken into account by resource allocation decision makers in financially constrained environments. In the context of hepatitis C, authors called for greater consideration of equity and justice and the duty to provide care in making evidence-based recommendations for screening, diagnosis and treatment for different populations and in different settings that also account for individual and community interests.

Direct-acting antiviral treatment for hepatitis C, reinfection and mortality among people attending an inner-city community health centre in Victoria, Canada

BACKGROUND

Direct-acting antiviral (DAA) treatment for hepatitis C virus (HCV) has been shown to be effective among PWID, but more real-world data on treatment outcomes is needed. The aim of this analysis was to assess the efficacy of DAA therapy, and the rate of reinfection and mortality among people attending an inner-city community health centre in Victoria, Canada.

METHODS

In this retrospective study, patients treated with DAA therapy between November 2014 and Dec 31, 2017 were included. Retrospective chart review was performed to assess recent injecting drug use (IDU, previous six months) or receipt of opioid agonist treatment (OAT). The primary endpoint was Sustained Virologic Response (SVR12). Secondary endpoints included HCV reinfection and mortality.

RESULTS

Of 270 patients who initiated DAA treatment (31% female), 20% (n=54) had HIV/HCV coinfection, 32% (n=84) had cirrhosis, 67% (n=181) had genotype 1, 6% (n=15) had genotype 2, 26% (n=69) had genotype 3. 46% (n=125) of patients were receiving OAT and 49% (n=132) reported recent IDU. 98% (n=265) completed treatment; two people stopped due to mental health, two people died, and one was non-adherent. 92% (249 of 270) achieved SVR12. 16 patients with End of Treatment (EOT) response did not have a SVR12; 7 were lost to follow-up; 2 people refused bloodwork; 2 people died; 1 had reinfection; and 4 had viral relapse. There was no difference in SVR12 by OAT (OAT, 93% vs. no OAT, 91%, P=0.435), recent injecting drug use (yes, 92% vs. no, 92%, P=0.904), or HIV status (HIV, 92% vs. no HIV, 94%, P=0.498). Eight cases of HCV reinfection were observed over 253 person-years of follow up (3.2 cases per 100 person-years; 95% CI 1.6-6.3). Twenty people died (6.3 per 100 person-years; 95% CI 3.9-10.3), including two during therapy (drug overdose, n=2) and 18 following therapy completion (drug overdose, n=7).

CONCLUSION

This study demonstrates that DAA treatment is effective among a marginalized population receiving care in an inner-city community health centre. The high mortality in this study highlights the importance of integrating HCV care within a framework addressing drug-related harms, preventing overdose mortality, addressing social inequalities, and improving the health of PWID.

Role of HCV Viremia in Corroborated HCV Transmission Events Within Young Adult Injecting Partnerships

Background

Hepatitis C virus (HCV), a major cause of morbidity and mortality, is common and rising among young persons who inject drugs (PWID). Reducing the level of viremia may be an intervention, yet the impact of viremia on HCV transmission is unknown.

Methods

We conducted a prospective study of injecting partnerships (Partner Study) of young adult (age < 30 years) PWID within the UFO Study, which enrolled those at risk for HCV or with seronegative viremic infection and up to 3 HCV RNA-positive regular injecting partners. We examined the level of HCV viremia and stage of infection in the HCV-positive partner in regression analyses of HCV transmission events that were corroborated via HCV phylogenetic linkage analyses.

Results

We enrolled 69 at-risk/acutely infected PWID. There were 25 new HCV infections (incidence rate, 35.9 per 100 person-years; 95% confidence interval [CI], 24.3-53.2 per 100 person-years); 12/25 (48%) were phylogenetically linked to at least 1 partner. We found no association between the infected partner's quantitative level of HCV viremia and likely transmission in multivariate analyses (adjusted odds ratio [AOR], 0.90; 95% confidence interval [CI], 0.55-1.46); however, seronegative viremic infection in the infected partner was associated with increased transmission (AOR, 28.02; 95% CI, 5.61-139.95).

Conclusions

The HCV viremia level was not associated with increased odds of transmission, yet acute HCV infection (seronegative viremic) was. Explanations include high-risk behavior during acute infection or missed fluctuations in viremia during acute infection. Both point to the need for frequent testing to detect new infection and attempt to prevent onward transmission.

Inconsistent temporal patterns of genetic variation of HCV among high-risk subjects may impact inference of transmission networks

Hepatitis-C Virus (HCV) sequences are often used to establish networks of people who inject drugs (PWID). However, the degree to which within-host evolutionary dynamics affect those inferences has not been carefully studied. Here, we analyzed 702 longitudinally-sampled HCV E1 sequences from 88 HCV+ people who inject drugs (PWID) in the Baltimore Before and After Acute Study of Hepatitis (BBAASH) cohort. Individuals were tested for HCV RNA over multiple visits to the clinic, and the HCV E1 gene was sequenced for HCV+ samples. Genetic clustering was performed on the full set of sequences using a 3% genetic distance threshold to define epidemiological linkage. Maximum-likelihood (ML) phylogenies were inferred to assess evolutionary relationships. We found 22 clusters containing sequences sampled over five or more years (long-term clusters, LTC), of which 17 had >1 subject. In six of the multi-subject LTC, one subject had a sequence sampled >3 years earlier or later than the next-closest subject in the cluster (time-gap LTC). ML trees showed that, in three of the time-gap LTC, two subjects had identical sequences despite 7-10 years separating the sampling times. In four of the time-gap LTC for whom additional data were available, the subject with the later detected shared variant had both different variants and visits with no detectable HCV RNA (RNA-) prior to the appearance of the shared variant. In the subject with the earlier detection of the shared variant, different variants and RNA- visits were also detected in multiple cases subsequent to appearance of the shared variant. Complex patterns of shared viral variation among PWID reflect on-going re-infection, multiple transmission partners, and/or inconsistent detection of viral variants. Our results suggest that transmission events are currently underestimated by analysis of sequences at a single point in time.

Direct-Acting Antiviral Treatment Failure Among Hepatitis C and HIV-Coinfected Patients in Clinical Care

Background

There are limited data on the real-world effectiveness of direct-acting antiviral (DAA) treatment in patients coinfected with hepatitis C virus (HCV) and HIV—a population with complex challenges including ongoing substance use, cirrhosis, and other comorbidities. We assessed how patient characteristics and the appropriateness of HCV regimen selection according to guidelines affect treatment outcomes in coinfected patients.

Methods

We included all patients who initiated DAA treatment between November 2013 and July 2017 in the Canadian Co-Infection Cohort. Sustained virologic response (SVR) was defined as an undetectable HCV RNA measured between 10 and 18 weeks post-treatment. We defined treatment failure as virologic failure, relapse, or death without achieving SVR. Bayesian logistic regression was used to estimate the posterior odds ratios (ORs) associated with patient demographic, clinical, and treatment-related risk factors for treatment failure.

Results

Two hundred ninety-five patients initiated DAAs; 31% were treatment-experienced, 29% cirrhotic, and 80% HCV genotype 1. Overall, 92% achieved SVR (263 of 286, 9 unknown), with the highest rates in females (97%) and lowest in cirrhotics (88%) and high-frequency injection drug users (89%). Many patients (38%) were prescribed regimens that were outside current clinical guidelines. This did not appreciably increase the risk of treatment failure—particularly in patients with genotype 1 (prior odds ratio [OR], 1.5; 95% credible interval [CrI], 0.38–6.0; posterior OR, 1.0; 95% CrI, 0.40–2.5).

Conclusions

DAAs were more effective than anticipated in a diverse, real-world coinfected cohort, despite the use of off-label, less efficacious regimens. High-frequency injection drug use and cirrhosis were associated with an increased risk of failure.

A latent class approach to identify multi-risk profiles associated with phylogenetic clustering of recent hepatitis C virus infection in Australia and New Zealand from 2004 to 2015

INTRODUCTION

Over the last two decades, the incidence of hepatitis C virus (HCV) co-infection among men who have sex with men (MSM) living with HIV began increasing in post-industrialized countries. Little is known about transmission of acute or recent HCV, in particular among MSM living with HIV co-infection, which creates uncertainty about potential for reinfection after HCV treatment. Using phylogenetic methods, clinical, epidemiological and molecular data can be combined to better understand transmission patterns. These insights may help identify strategies to reduce reinfection risk, enhancing effectiveness of HCV treatment as prevention strategies. The aim of this study was to identify multi-risk profiles and factors associated with phylogenetic pairs and clusters among people with recent HCV infection.

METHODS

Data and specimens from five studies of recent HCV in Australia and New Zealand (2004 to 2015) were used. HCV Core-E2 sequences were used to infer maximum likelihood trees. Clusters were identified using 90% bootstrap and 5% genetic distance threshold. Multivariate logistic regression and latent class analyses were performed.

RESULTS

Among 237 participants with Core-E2 sequences, 47% were in a pair/cluster. Among HIV/HCV co-infected participants, 60% (74/123) were in a pair/cluster, compared to 30% (34/114) with HCV mono-infection (p < 0.001). HIV/HCV co-infection (vs. HCV mono-infection; adjusted odds ratio (AOR), 2.37, 95% confidence interval (CI), 1.45, 5.15) was independently associated with phylogenetic clustering. Latent class analysis identified three distinct risk profiles: (1) people who inject drugs, (2) HIV-positive gay and bisexual men (GBM) with low probability of injecting drug use (IDU) and (3) GBM with IDU & sexual risk behaviour. Class 2 (vs. Class 1, AOR 3.40; 95% CI, 1.52, 7.60), was independently associated with phylogenetic clustering. Many clusters displayed homogeneous characteristics, such as containing individuals exclusively from one city, individuals all with HIV/HCV co-infection or individuals sharing the same route of acquisition of HCV.

CONCLUSIONS

Clusters containing individuals with specific characteristics suggest that HCV transmission occurs through discrete networks, particularly among HIV/HCV co-infected individuals. The greater proportion of clustering found among HIV/HCV co-infected participants highlights the need to provide broad direct-acting antiviral access encouraging rapid uptake in this population and ongoing monitoring of the phylogeny.

Interventions to address substance use and sexual risk among gay, bisexual and other men who have sex with men who use methamphetamine: A systematic review

BACKGROUND

Methamphetamine use is common among some populations of gay, bisexual and other men who have sex with men (gbMSM). This study reviewed the status of research on the efficacy of interventions that address harms among gbMSM who use methamphetamine.

METHODS

We searched MEDLINE, PsycINFO, CINAHL, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar to identify publications from inception to October 23, 2017, that assessed an intervention addressing methamphetamine use among gbMSM.

RESULTS

Of 1896 potential studies and 935 unique articles screened for inclusion, 28 eligible studies assessed 26 different interventions in the following categories: pharmacological (n = 5); psychosocial (n = 20); harm reduction (n = 1). Given that outcome variables were measured in highly variable ways, we were unable to conduct a meta-analysis of intervention effects. However, 22 studies reported a statistically significant effect on one or more methamphetamine-related outcomes. Among 21 studies that included measures of sexual health-related outcomes, 18 reported a significant effect on one or more sexual health-related outcomes, and 15 of those reported a concurrent effect on both drug- and sexual health-related outcomes.

CONCLUSIONS

This is the first review to provide compelling evidence that integrating interventions to address both drug- and sexual-related harms for gbMSM who use methamphetamine can be efficacious. Future research should focus on identifying differential effects of various intervention approaches by social positioning, as well as prioritize future evaluations of integrated harm reduction interventions (e.g., the distribution of harm reduction kits within sexual health care settings).

The role of prevention strategies in achieving HCV elimination in Canada: what are the remaining challenges?

BACKGROUND

The worldwide economic, health, and social consequences of drug use disorders are devastating. Injection drug use is now a major factor contributing to hepatitis C virus (HCV) transmission globally, and it is an important public health concern.

METHODS

This article presents a narrative review of scientific evidence on public health strategies for HCV prevention among people who inject drugs (PWID) in Canada.

RESULTS

A combination of public health strategies including timely HCV detection and harm reduction (mostly needle and syringe programmes and opioid substitution therapy) have helped to reduce HCV transmission among PWID. The rising prevalence of pharmaceutical opioid and methamphetamine use and associated HCV risk in several Canadian settings has prompted further innovation in harm reduction, including supervised injection facilities and low-threshold opioid substitution therapies. Further significant decreases in HCV incidence and prevalence, and in corresponding disease burden, can only be accomplished by reducing transmission among high-risk persons and enhancing access to HCV treatment for those at the greatest risk of disease progression or viral transmission. Highly effective and tolerable direct-acting antiviral therapies have transformed the landscape for HCV-infected patients and are a valuable addition to the prevention toolkit. Curing HCV-infected persons, and thus eliminating new infections, is now a real possibility.

CONCLUSIONS

Prevention strategies have not yet ended HCV transmission, and sharing of injecting equipment among PWID continues to challenge the World Health Organization goal of eliminating HCV as a global public health threat by 2030. Future needs for research, intervention implementation, and uptake in Canada are discussed.

Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods

One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.

Drug use and phylogenetic clustering of hepatitis C virus infection among people who use drugs in Vancouver, Canada: A latent class analysis approach

This study estimated latent classes (ie, unobserved subgroups in a population) of people who use drugs in Vancouver, Canada, and examined how these classes relate to phylogenetic clustering of hepatitis C virus (HCV) infection. HCV antibody-positive people who use drugs from two cohorts in Vancouver, Canada (1996-2012), with a Core-E2 sequence were included. Time-stamped phylogenetic trees were inferred, and phylogenetic clustering was determined by time to most common recent ancestor. Latent classes were estimated, and the association with the phylogenetic clustering outcome was assessed using an inclusive classify/analyse approach. Among 699 HCV RNA-positive participants (26% female, 24% HIV+), recent drug use included injecting cocaine (80%), injecting heroin (70%), injecting cocaine/heroin (ie, speedball, 38%) and crack cocaine smoking (28%). Latent class analysis identified four distinct subgroups of drug use typologies: (i) cocaine injecting, (ii) opioid and cocaine injecting, (iii) crack cocaine smoking and (iv) heroin injecting and currently receiving opioid substitution therapy. After adjusting for age and HIV infection, compared to the group defined by heroin injecting and currently receiving opioid substitution therapy, the odds of phylogenetic cluster membership was greater in the cocaine injecting group (adjusted OR [aOR]: 3.06; 95% CI: 1.73, 5.42) and lower in the crack cocaine smoking group (aOR: 0.06; 95% CI: 0.01, 0.48). Combining latent class and phylogenetic clustering analyses provides novel insights into the complex dynamics of HCV transmission. Incorporating differing risk profiles associated with drug use may provide opportunities to further optimize and target HCV treatment and prevention strategies.

Longitudinal analysis of change in individual-level needle and syringe coverage amongst a cohort of people who inject drugs in Melbourne, Australia

BACKGROUND

Needle and syringe program (NSP) coverage is often calculated at the individual level. This method relates sterile needle and syringe acquisition to injecting frequency, resulting in a percentage of injecting episodes that utilise a sterile syringe. Most previous research using this method was restricted by their cross-sectional design, calling for longitudinal exploration of coverage.

METHODS

We used the data of 518 participants from an ongoing cohort of people who inject drugs in Melbourne, Australia. We calculated individual-level syringe coverage for the two weeks prior to each interview, then dichotomised the outcome as either "sufficient" (≥100% of injecting episodes covered by at least one reported sterile syringe) or "insufficient" (<100%). Time-variant predictors of change in recent coverage (from sufficient to insufficient coverage) were estimated longitudinally using logistic regression with fixed effects for each participant.

RESULTS

Transitioning to methamphetamine injection (AOR:2.16, p=0.004) and a newly positive HCV RNA test result (AOR:4.93, p=0.001) were both associated with increased odds of change to insufficient coverage, whilst change to utilising NSPs as the primary source of syringe acquisition (AOR: 0.41, p=0.003) and opioid substitution therapy (OST) enrolment (AOR:0.51, p=0.013) were protective against a change to insufficient coverage.

CONCLUSIONS

We statistically tested the transitions between time-variant exposure sub-groups and transitions in individual-level syringe coverage. Our results give important insights into means of improving coverage at the individual level, suggesting that methamphetamine injectors should be targeted, whilst both OST prescription and NSP should be expanded.

Methamphetamine use and dependence in vulnerable female populations

PURPOSE OF REVIEW

The study reviews recent publications on methamphetamine use and dependence women in term of their epidemic, physical health impact, psychosocial impacts, and also in the identified vulnerable issues.

RECENT FINDINGS

Studies of vulnerable populations of women are wide ranging and include sex workers, sexual minorities, homeless, psychiatric patients, suburban women, and pregnant women, in which amphetamine type stimulants (ATSs) are the most commonly reported illicit drug used among them. The prenatal exposure of ATS demonstrated the small for gestational age and low birth weight; however, more research is needed on long-term studies of methamphetamine-exposed children. Intimate partner violence (IPV) is commonly reported by female methamphetamine users as perpetrators and victims. However, statistics and gendered power dynamics suggest that methamphetamine-related IPV indicates a higher chance of femicide. Methamphetamine-abusing women often have unresolved childhood trauma and are introduced to ATS through families or partners.

SUMMARY

Vulnerable populations of women at risk of methamphetamine abuse and dependence. Impacts on their physical and mental health, IPV, and pregnancy have been reported continuing, which guide that empowering and holistic substance abuse are necessary for specific group.

The association between residential eviction and syringe sharing among a prospective cohort of street-involved youth

BACKGROUND

Syringe sharing is a high-risk practice associated with the transmission of infectious diseases, such as HIV and HCV. While youth who contend with housing instability are known to be more likely to engage in high-risk substance use, the potential relationship between being evicted from housing and syringe sharing has not been examined. This study assessed whether residential eviction was associated with syringe sharing among street-involved youth in Vancouver, Canada.

METHODS

Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort of street-involved youth who use drugs age 14-26 in Vancouver, Canada. The study period was June 2007 to May 2014, and the potential relationship between residential eviction and syringe sharing was analyzed using multivariable generalized estimating equations (GEE) logistic regression.

RESULTS

Among 405 street-involved youth who injected drugs, 149 (36.8%) reported syringe sharing, defined as borrowing or lending a syringe, at some point during the study period. In a multivariable GEE analysis, recent residential eviction remained independently associated with syringe sharing (adjusted odds ratio (AOR) = 1.72, 95% confidence interval (CI): 1.16-2.57), after adjusting for potential confounders.

CONCLUSIONS

Syringe sharing was significantly elevated among youth who had recently been evicted from housing. These findings indicate that policy and programmatic interventions that increase housing stability may help mitigate high-risk substance use practices among vulnerable youth.

Transmission of hepatitis C virus infection among younger and older people who inject drugs in Vancouver, Canada

BACKGROUND & AIMS

Understanding HCV transmission among people who inject drugs (PWID) is important for designing prevention strategies. This study investigated whether HCV infection among younger injectors occurs from few or many transmission events from older injectors to younger injectors among PWID in Vancouver, Canada.

METHODS

HCV antibody positive participants at enrolment or follow-up (1996-2012) were tested for HCV RNA and sequenced (Core-E2). Time-stamped phylogenetic trees were inferred using Bayesian Evolutionary Analysis Sampling Trees (BEAST). Association of age with phylogeny was tested using statistics implemented in the software Bayesian Tip Significance (BaTS) testing. Factors associated with clustering (maximum cluster age: five years) were identified using logistic regression.

RESULTS

Among 699 participants with HCV subtype 1a, 1b, 2b and 3a infection (26% female, 24% HIV+): 21% were younger (<27years), and 10% had recent HCV seroconversion. When inferred cluster age was limited to <5years, 15% (n=108) were in clusters/pairs. Although a moderate degree of segregation was observed between younger and older participants, there was also transmission between age groups. Younger age (<27 vs. >40, AOR: 3.14; 95% CI: 1.54, 6.39), HIV (AOR: 1.97; 95% CI: 1.22, 3.18) and subtype 3a (AOR: 2.12; 95% CI: 1.33, 3.38) were independently associated with clustering.

CONCLUSIONS

In this population of PWID from Vancouver, HCV among young injectors was seeded from many transmission events between HCV-infected older and younger injectors. Phylogenetic clustering was associated with younger age and HIV. These data suggest that HCV transmission among PWID is complex, with transmission occurring between and among older and younger PWID.

HIV infection and hepatitis C virus genotype 1a are associated with phylogenetic clustering among people with recently acquired hepatitis C virus infection

The aim of this study was to identify factors associated with phylogenetic clustering among people with recently acquired hepatitis C virus (HCV) infection. Participants with available sample at time of HCV detection were selected from three studies; the Australian Trial in Acute Hepatitis C, the Hepatitis C Incidence and Transmission Study - Prison and Community. HCV RNA was extracted and Core to E2 region of HCV sequenced. Clusters were identified from maximum likelihood trees with 1000 bootstrap replicates using 90% bootstrap and 5% genetic distance threshold. Among 225 participants with available Core-E2 sequence (ATAHC, n=113; HITS-p, n=90; and HITS-c, n=22), HCV genotype prevalence was: G1a: 38% (n=86), G1b: 5% (n=12), G2a: 1% (n=2), G2b: 5% (n=11), G3a: 48% (n=109), G6a: 1% (n=2) and G6l 1% (n=3). Of participants included in phylogenetic trees, 22% of participants were in a pair/cluster (G1a-35%, 30/85, mean maximum genetic distance=0.031; G3a-11%, 12/106, mean maximum genetic distance=0.021; other genotypes-21%, 6/28, mean maximum genetic distance=0.023). Among HCV/HIV co-infected participants, 50% (18/36) were in a pair/cluster, compared to 16% (30/183) with HCV mono-infection (P=<0.001). Factors independently associated with phylogenetic clustering were HIV co-infection [vs. HCV mono-infection; adjusted odds ratio (AOR) 4.24; 95%CI 1.91, 9.39], and HCV G1a infection (vs. other HCV genotypes; AOR 3.33, 95%CI 0.14, 0.61).HCV treatment and prevention strategies, including enhanced antiviral therapy, should be optimised. The impact of targeting of HCV treatment as prevention to populations with higher phylogenetic clustering, such as those with HIV co-infection, could be explored through mathematical modelling.