Incidence and prevalence of hepatitis c virus infection among persons who inject drugs in New York City: 2006-2013

HCV prevalence and phylogenetic characteristics in a cross-sectional, community study of young people who inject drugs in New York City: Opportunity for and threats to HCV elimination

Background and Aims

In the United States, the opioid epidemic has led many young people who use opioids to initiate injection drug use, putting them at risk for hepatitis C virus (HCV) infection. However, community surveys to monitor HCV prevalence among young people who inject drugs (YPWID) are rare.

Methods

As part of Staying Safe (Ssafe), a trial to evaluate an HCV-prevention intervention, a community-recruited sample of 439 young people who use opioids (ages 18-30) in New York City (NYC) were screened from 2018 to 2021. Screening procedures included a brief verbal questionnaire, a visual check for injection marks, onsite urine drug testing, rapid HCV antibody (Ab) testing, and dried blood spot (DBS) collection. DBS specimens were sent to a laboratory for HCV RNA testing and phylogenetic analysis to identify genetic linkages among HCV RNA-positive specimens. Multivariable logistic regression was used to assess associations between HCV status (Ab and RNA) and demographics and drug use patterns.

Results

Among the 330 participants who reported injecting drugs (past 6 months), 33% (n = 110) tested HCV Ab-positive, 58% of whom (n = 64) had HCV RNA-positive DBS specimens, indicating active infection. In multivariable analysis, visible injection marks (AOR = 3.02; p < 0.001), older age (AOR = 1.38; p < 0.05), and female gender (AOR = 1.69; p = 0.052) were associated with HCV Ab-positive status. Visible injection marks were also associated with HCV RNA-positive status (AOR = 5.24; p < 0.01). Twenty-five percent of RNA-positive specimens (14/57) were genetically linked.

Conclusion

The relatively low prevalence of active infection suggests the potential impact of treatment-as-prevention in reducing HCV prevalence among YPWID. Targeted community serosurveys could help identify actively infected YPWID for treatment, thereby reducing HCV incidence and future transmissions.

Hepatitis C treatment outcomes among people who inject drugs experiencing unstable versus stable housing: Systematic review and meta-analysis

BACKGROUND

The prevalence of hepatitis C virus (HCV) among people who inject drugs (PWID) is between 50-70%. Prior systematic reviews demonstrated that PWID have similar direct acting antiviral treatment outcomes compared to non-PWID; however, reviews have not examined treatment outcomes by housing status. Given the links between housing and health, identifying gaps in HCV treatment can guide future interventions.

METHODS

We conducted a systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched six databases for articles from 2014 onward. Two reviewers conducted title/abstract screenings, full-text review, and data extraction. We extracted effect measures for treatment initiation, adherence, completion, success, and reinfection by housing status. Studies underwent quality and certainty assessments, and we performed meta-analyses as appropriate.

RESULTS

Our search yielded 473 studies, eight of which met inclusion criteria. Only the treatment initiation outcome had sufficient measures for meta-analysis. Using a random-effects model, we found those with unstable housing had 0.40 (0.26, 0.62) times the odds of initiating treatment compared to those with stable housing. Other outcomes were not amenable for meta-analysis due to a limited number of studies or differing outcome definitions.

CONCLUSIONS

Among PWID, unstable housing appears to be a barrier to HCV treatment initiation; however, the existing data is limited for treatment initiation and the other outcomes we examined. There is a need for more informative studies to better understand HCV treatment among those with unstable housing. Specifically, future studies should better define housing status beyond a binary, static measure to capture the nuances and complexity of housing and its subsequent impact on HCV treatment. Additionally, researchers should meaningfully consider whether the outcome(s) of interest are being accurately measured for individuals experiencing unstable housing.

How the rural risk environment underpins hepatitis C risk: Qualitative findings from rural southern Illinois, United States

BACKGROUND

Hepatitis C virus (HCV) infection has increased among persons who inject drugs (PWID) in the United States with disproportionate burden in rural areas. We use the Risk Environment framework to explore potential economic, physical, social, and political determinants of hepatitis C in rural southern Illinois.

METHODS

Nineteen in-depth semi-structured interviews were conducted with PWID from August 2019 through February 2020 (i.e., pre-COVID-19 pandemic) and four with key informants who professionally worked with PWID. Interviews were recorded, professionally transcribed, and coded using qualitative software. We followed a grounded theory approach for coding and analyses.

RESULTS

We identify economic, physical, policy, and social factors that may influence HCV transmission risk and serve as barriers to HCV care. Economic instability and lack of economic opportunities, a lack of physically available HCV prevention and treatment services, structural stigma such as policies that criminalize drug use, and social stigma emerged in interviews as potential risks for transmission and barriers to care.

CONCLUSION

The rural risk environment framework acknowledges the importance of community and structural factors that influence HCV infection and other disease transmission and care. We find that larger structural factors produce vulnerabilities and reduce access to resources, which negatively impact hepatitis C disease outcomes.

Methods and indicators to validate country reductions in incidence of hepatitis C virus infection to elimination levels set by WHO

One of the main goals of the 2016 Global Health Sector Strategy on viral hepatitis is the elimination of hepatitis C virus (HCV) as a public health problem by 2030, defined as an 80% reduction in incidence and 65% reduction in mortality relative to 2015. Although monitoring HCV incidence is key to validating HCV elimination, use of the gold-standard method, which involves prospective HCV retesting of people at risk, can be prohibitively resource-intensive. Additionally, few countries collected quality data in 2015 to enable an 80% decrease by 2030 to be calculated. Here, we first review different methods of monitoring HCV incidence and discuss their resource implications and applicability to various populations. Second, using mathematical models developed for various global settings, we assess whether trends in HCV chronic prevalence or HCV antibody prevalence or scale-up levels for HCV testing, treatment, and preventative interventions can be used as reliable alternative indicators to validate the HCV incidence target. Third, we discuss the advantages and disadvantages of an absolute HCV incidence target and suggest a suitable threshold. Finally, we propose three options that countries can use to validate the HCV incidence target, depending on the available surveillance infrastructure.

The Impact of Direct-Acting Antiviral Therapy on End-Stage Liver Disease Among Individuals with Chronic Hepatitis C and Substance Use Disorders

BACKGROUND AND AIMS

Our aim was to evaluate the impact of direct-acting antivirals (DAAs) on decompensated cirrhosis (DCC) and HCC in patients with chronic HCV and substance use disorder (SUD) compared with those without an SUD.

APPROACH AND RESULTS

This retrospective cohort study used the MarketScan database (2013-2018) to identify 29,228 patients with chronic HCV, where 22% (n = 6,385) had ≥1 SUD diagnosis. The inverse probability of treatment weighted multivariable Cox proportional hazard models were used to compare the risk of developing DCC and HCC. Among the those who were noncirrhotic, treatment reduced the DCC risk among SUD (adjusted hazard ratio [aHR] 0.13; 95% CI, 0.06-0.30) and non-SUD (aHR 0.11; 95% CI, 0.07-0.18), whereas the risk for HCC was not reduced for the SUD group (aHR 0.91; 95% CI, 0.33-2.48). For those with cirrhosis, compared with patients who were untreated, treatment reduced the HCC risk among SUD (aHR, 0.33; 95% CI, 0.13-0.88) and non-SUD (aHR, 0.40; 95% CI, 0.25-0.65), whereas the risk for DCC was not reduced for the SUD group (aHR, 0.64; 95% CI, 0.37-1.13). Among patients with cirrhosis who were untreated, the SUD group had a higher risk of DCC (aHR, 1.52; 95% CI, 1.03-2.24) and HCC (aHR, 1.69; 95% CI, 1.05-2.72) compared with non-SUD group.

CONCLUSIONS

Among the HCV SUD group, DAA treatment reduced the risk of DCC but not HCC for those who were noncirrhotic, whereas DAA treatment reduced the risk of HCC but not DCC for those with cirrhosis. Among the nontreated, patients with an SUD had a significantly higher risk of DCC and HCC compared with those without an SUD. Thus, DAA treatment should be considered for all patients with HCV and an SUD while also addressing the SUD.

The use of all-oral direct-acting antivirals in hepatitis C virus-infected patients with substance use disorders

BACKGROUND: There is evidence that barriers exist for the initiation of direct-acting antiviral (DAA) treatment for hepatitis C virus (HCV) for those with substance use disorders (SUDs). However, real world clinical evidence of DAA treatment initiation following receipt of a prescription and continuation among those with SUDs and HCV is lacking. OBJECTIVES: To (1) compare HCV treatment initiation (prescription fill) rates and early discontinuation rates between HCV-infected patients with and without SUDs in the DAA era, and (2) identify patient-level factors associated with HCV treatment initiation and early discontinuation in patients with SUDs. METHODS: A retrospective cohort analysis of the MarketScan databases (January 2012-December 2018) was conducted for newly diagnosed treatment naïve HCV-infected patients (age ≥ 18) with and without SUDs. We used multivariable Cox regression to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals of treatment initiation and early discontinuation in those with SUDs versus those without. RESULTS: We identified a total of 29,228 newly diagnosed HCV-infected patients (6,385 with SUDs and 22,843 without SUDs). Overall, DAA treatment initiation for patients with SUDs was significantly lower than that for those without SUDs (24% vs 34%; P < 0.01). After adjusting for demographics and clinical characteristics, patients with SUDs were less likely to initiate DAA treatments than those without SUDs (aHR, 0.87 [0.82-0.92]). There was no difference in discontinuation of DAA treatment between those with and without SUDs (4% vs 3%: aHR, 1.13 [0.81-1.60]). Among patients with SUDs (n = 6,385), lower rates of initiating DAA treatment was associated with younger age, and comorbidities including alcoholic liver disease (ALD; aHR, 0.44 [0.33-0.57), chronic kidney disease (CKD) (aHR, 0.52 [0.36-0.75]), and hepatitis B virus (HBV; aHR, 0.64 [0.44-0.92]). DAA treatment discontinuation was associated with younger age, ribavirin (RBV) therapy (aHR, 3.78 [2.21-6.47]), and cirrhosis diagnosis (aHR, 2.42 [1.21-4.84]) but not SUD treatment (aHR, 0.68 [0.34-1.34]). CONCLUSIONS: HCV-infected patients with SUDs had significantly lower treatment initiation rates, especially in young females and those with ALD, CKD, and HBV. No difference was found in DAA discontinuation. However, younger patients with RBV treatment and/or cirrhosis were more likely to stop treatment. Interventions directed towards these groups are needed to enhance DAA initiation and treatment maintenance among HCV-infected patients with SUDs. DISCLOSURES: Research reported in this publication was supported in part by the National Institute on Drug Abuse of the National Institutes of Health under award number K01DA045618 (to Park). The other authors have nothing to disclose that may present a potential conflict of interest.

Hepatitis C Virus (HCV) Care Continuum Outcomes and HCV Community Viral Loads Among Patients in an Opioid Treatment Program

BACKGROUND

Hepatitis C virus (HCV) remains endemic among people who use drugs (PWUD). Measures of HCV community viral load (CVL) and HCV care continuum outcomes may be valuable for ascertaining unmet treatment need and for HCV surveillance and control.

METHODS

Data from patients in an opioid treatment program during 2013-2016 were used to (1) identify proportions of antibody and viral load (VL) tested, linked-to-care, and treated, in 2013-2014 and 2015-2016, and pre- and postimplementation of qualitative reflex VL testing; (2) calculate engaged-in-care HCV CVL and "documented" and "estimated" unmet treatment need; and (3) examine factors associated with linkage-to-HCV-care.

RESULTS

Among 11 267 patients, proportions of HCV antibody tested (52.5% in 2013-2014 vs 73.3% in 2015-2016), linked-to-HCV-care (15.7% vs 51.8%), and treated (12.0% vs 44.7%) all increased significantly. Hispanic ethnicity was associated with less linkage-to-care, and Manhattan residence was associated with improved linkage-to-care. The overall engaged-in-care HCV CVL was 4 351 079 copies/mL (standard deviation = 7 149 888); local HCV CVLs varied by subgroup and geography. Documented and estimated unmet treatment need decreased but remained high.

CONCLUSIONS

After qualitative reflex VL testing was implemented, care continuum outcomes improved, but gaps remained. High rates of unmet treatment need suggest that control of the HCV epidemic among PWUD will require expansion of HCV treatment coverage.

Hepatitis C Virus Incidence in a Cohort in Medication-Assisted Treatment for Opioid Use Disorder in New York City

BACKGROUND

Hepatitis C virus (HCV) incidence has increased in the worsening opioid epidemic. We examined the HCV preventive efficacy of medication-assisted treatment (MAT), and geographic variation in HCV community viral load (CVL) and its association with HCV incidence.

METHODS

HCV incidence was directly measured in an open cohort of patients in a MAT program in New York City between 1 January 2013 and 31 December 2016. Area-level HCV CVL was calculated. Associations of individual-level factors, and of HCV CVL, with HCV incidence were examined in separate analyses.

RESULTS

Among 8352 patients, HCV prevalence was 48.7%. Among 2535 patients seronegative at first antibody test, HCV incidence was 2.25/100 person-years of observation (PYO). Incidence was 6.70/100 PYO among those reporting main drug use by injection. Female gender, drug injection, and lower MAT retention were significantly associated with higher incidence rate ratios. Female gender, drug injection, and methadone doses <60 mg were independently associated with shorter time to HCV seroconversion. HCV CVLs varied significantly by geographic area.

CONCLUSIONS

HCV incidence was higher among those with lower MAT retention and was lower among those receiving higher methadone doses, suggesting the need to ensure high MAT retention, adequate doses, and increased HCV prevention and treatment engagement. HCV CVLs vary geographically and merit further study as predictors of HCV incidence.

Acceptability and Effectiveness of Hepatitis C Care at Syringe Service Programs for People Who Inject Drugs in New York City

Introduction/Objectives: The incidence of hepatitis C (HCV) infection is rising among people who inject drugs (PWID). Even in the context of known HCV prevention and treatment strategies, some PWID remain unengaged in HCV care. This study aimed to identify and characterize experiences and perceptions of PWID regarding the acceptability and effectiveness of HCV testing and treatment at a local syringe service program (SSP). Methods: A total of 36 PWID participated in semi-structured interviews at an SSP in New York City. Interviews were audio-recorded, transcribed, and coded by three coders, following a constructivist grounded theory approach. Relevant themes were identified as they emerged from the data. Results: Interviews with PWID revealed three themes related to the impact of SSPs on HCV care: (1) non-stigmatizing SSP environments, (2) the role of SSPs in improving HCV knowledge, and (3) acceptability of SSPs as sites for HCV care among PWID. Discussion: This paper contributes to the ongoing understanding that SSPs provide a well-accepted source of HCV services for PWID. Participants believed that SSPs are accessible and effective sites for HCV care, and suggested that stigma among PWID continues to affect receipt of HCV care in traditional settings. Conclusions: Understanding attitudes and beliefs of PWID regarding the effectiveness of SSPs as sites for HCV care is crucial for the development of focused strategies to reduce HCV transmission, and to ultimately achieve HCV elimination. Given this, further research is warranted investigating how best to improve HCV care at harm reduction sites such as SSPs.

Cost-effectiveness of Direct Antiviral Agents for Hepatitis C Virus Infection and a Combined Intervention of Syringe Access and Medication-assisted Therapy for Opioid Use Disorders in an Injection Drug Use Population

BACKGROUND

There are too many plausible permutations and scale-up scenarios of combination hepatitis C virus (HCV) interventions for exhaustive testing in experimental trials. Therefore, we used a computer simulation to project the health and economic impacts of alternative combination intervention scenarios for people who inject drugs (PWID), focusing on direct antiviral agents (DAA) and medication-assisted treatment combined with syringe access programs (MAT+).

METHODS

We performed an allocative efficiency study, using a mathematical model to simulate the progression of HCV in PWID and its related consequences. We combined 2 previously validated simulations to estimate the cost-effectiveness of intervention strategies that included a range of coverage levels. Analyses were performed from a health-sector and societal perspective, with a 15-year time horizon and a discount rate of 3%.

RESULTS

From a health-sector perspective (excluding criminal justice system-related costs), 4 potential strategies fell on the cost-efficiency frontier. At 20% coverage, DAAs had an incremental cost-effectiveness ratio (ICER) of $27 251/quality-adjusted life-year (QALY). Combinations of DAA at 20% with MAT+ at 20%, 40%, and 80% coverage had ICERs of $165 985/QALY, $325 860/QALY, and $399 189/QALY, respectively. When analyzed from a societal perspective (including criminal justice system-related costs), DAA at 20% with MAT+ at 80% was the most effective intervention and was cost saving. While DAA at 20% with MAT+ at 80% was more expensive (eg, less cost saving) than MAT+ at 80% alone without DAA, it offered a favorable value compared to MAT+ at 80% alone ($23 932/QALY).

CONCLUSIONS

When considering health-sector costs alone, DAA alone was the most cost-effective intervention. However, with criminal justice system-related costs, DAA and MAT+ implemented together became the most cost-effective intervention.

Hepatitis A virus survival on drug paraphernalia

The ongoing hepatitis A outbreaks in multiple states in the United States have concerned public health authorities since March 2017. The outbreaks have spread throughout 30 states and include primarily persons who use drugs, including persons who inject drugs (PWID) and persons experiencing homelessness. Contaminated drug injection paraphernalia and sharing of these items could potentially aid in transmission of hepatitis A virus (HAV) among these populations. We examined HAV survival on drug paraphernalia frequently shared among PWIDs. The effect of low pH on HAV survival using citric acid, which is frequently used by PWIDs during dose preparation, was investigated. We compared the plaque assay results with those concurrently obtained by qRT-PCR to establish whether HAV RNA levels could be used as surrogates for plaque assay results. HAV suspended in minimal essential media at room temperature infected FRhK4 cells for more than 17 weeks. HAV remained viable in syringes/needles for up to 10 weeks depending on the gauge of the needles and the syringe dead volumes, and on cookers, tourniquets and cotton balls/filter surfaces for up to 4 weeks. HAV retained its infectivity for more than 10 weeks at pH as low as 2. In conclusion, our findings show that HAV survives and remains infective in or on injection drug use equipment for 1 to 10 weeks depending on the type of paraphernalia examined and environmental conditions. These findings suggest that contaminated drug paraphernalia can potentially facilitate the transmission of HAV within populations who share these items.

HCV Genetic Diversity Can Be Used to Infer Infection Recency and Time since Infection

HIV-1 genetic diversity can be used to infer time since infection (TSI) and infection recency. We adapted this approach for HCV and identified genomic regions with informative diversity. We included 72 HCV/HIV-1 coinfected participants of the Swiss HIV Cohort Study, for whom reliable estimates of infection date and viral sequences were available. Average pairwise diversity (APD) was calculated over each codon position for the entire open reading frame of HCV. Utilizing cross validation, we evaluated the correlation of APD with TSI, and its ability to infer TSI via a linear model. We additionally studied the ability of diversity to classify infections as recent (infected for <1 year) or chronic, using receiver-operator-characteristic area under the curve (ROC-AUC) in 50 patients whose infection could be unambiguously classified as either recent or chronic. Measuring HCV diversity over third or all codon positions gave similar performances, and notable improvement over first or second codon positions. APD calculated over the entire genome enabled classification of infection recency (ROC-AUC = 0.76). Additionally, APD correlated with TSI (R² = 0.33) and could predict TSI (mean absolute error = 1.67 years). Restricting the region over which APD was calculated to E2-NS2 further improved accuracy (ROC-AUC = 0.85, R² = 0.54, mean absolute error = 1.38 years). Genetic diversity in HCV correlates with TSI and is a proxy for infection recency and TSI, even several years post-infection.

HIV Pre-Exposure Prophylaxis Prevention Awareness, Willingness, and Perceived Barriers among People Who Inject Drugs in Los Angeles and San Francisco, CA, 2016-2018

BACKGROUND

Pre-exposure prophylaxis (PrEP) for HIV prevention is indicated for people who inject drugs (PWID), yet most studies do not focus on PWID. This study examines factors associated with PrEP awareness and willingness, and identifies perceived barriers to PrEP among PWID. Methods: PWID were interviewed in Los Angeles and San Francisco, CA from 2016 to 2018. We analyzed data from self-reported HIV-negative participants who had injected drugs within the past 6 months (n = 469). Questions on PrEP included awareness, willingness, barriers, and uptake. Multiple logistic regression models of factors associated with awareness of, and willingness to, take PrEP were developed. Descriptive statistics on perceived PrEP barriers are reported. Results: Among HIV-negative PWID, 40% were aware of PrEP, 59% reported willingness to take PrEP, and 2% were currently taking PrEP. In multivariable analysis, PrEP awareness was associated with study site and sexual minority status, higher educational attainment, and HIV testing in the last 6 months. Willingness to take PrEP was associated with self-reported risk (paying sex partner in the last 6 months, sharing drug paraphernalia, and being injected by another PWID) and perceived HIV risk. The most common perceived barriers to PrEP were copays, concerns about increased HIV or sexually transmitted risk with PrEP, and concerns about reduction of medication efficacy without daily use. Conclusion: PrEP awareness among PWID remains inadequate. Willingness to take PrEP was moderate and was most desired by PWID who engaged in high-risk behaviors. Interventions to increase PrEP awareness and willingness, and to facilitate PrEP uptake among PWID are needed.

Global prevalence of HCV and/or HBV coinfections among people who inject drugs and female sex workers who live with HIV/AIDS: a systematic review and meta-analysis

Coinfections of hepatitis C virus (HCV) and/or hepatitis B virus (HBV) with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) are associated with high morbidity and mortality and poor prognosis. The main objective of this study was to evaluate the prevalence of HCV and/or HBV coinfections among people who inject drugs (PWID) and female sex workers (FSWs) who live with HIV/AIDS worldwide. Data sources were searched from January 2008 to October 2018 in different databases, including PubMed, Scopus, Web of Science, Embase, and Ovid. Data were analyzed in Stata 14 software using the Metaprop command. The results showed that the prevalence of HCV among PWID and FSWs with HIV/AIDS was 72% (95% CI: 59%-83%) and 40% (95% CI: 0%-94%), respectively. The prevalence of HBV among PWID and FSWs with HIV/AIDS was 8% (95% CI: 5%-13%) and 2% (95% CI: 0%-7%), respectively, and the prevalence of HCV/HBV in PWID with HIV/AIDS was 11% (95% CI: 7%-15%). The highest prevalence of HCV was observed in PWID in the Eastern Mediterranean and Europe regions, and the lowest was observed in the Africa region. The South-East Asia region had the highest prevalence of HBV among PWID, and the Africa region had the lowest prevalence. The high prevalence of HCV coinfection among PWID and FSWs with HIV/AIDS was an alarming health problem and requires appropriate interventions. Therefore, considering that these populations are key populations for HCV elimination, it is recommended to screen them regularly for HCV. In addition, harm reduction and HBV vaccination should be carefully considered.

Systematic Review and Meta-Analysis of Global Prevalence of HBsAg and HIV and HCV Antibodies among People Who Inject Drugs and Female Sex Workers

The main objective of this study was to evaluate the prevalence of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), hepatitis C virus (HCV) and hepatitis B virus (HBV) and their co-infections among people who inject drugs (PWID) and female sex workers (FSWs). Data sources were searched from January 2008 to October 2018 in different databases. Data were analyzed in Stata 16 software using the Metaprop command. The results showed that the prevalence of HIV, HCV and HBV among PWID was 15%, 60% and 6%, respectively. The prevalence of HIV, HCV and HBV among FSWs was 5%, 1% and 3%, respectively. The prevalence of HIV/HCV, HIV/HBV, HCV/HBV and HIV/HCV/HBV co-infections among PWID was 13%, 2%, 3% and 2%, respectively. The prevalence of HIV/HCV and HIV/HBV co-infections among FSWs was 3% and 1%, respectively. The results show that the prevalence of HCV and HIV infections in PWID and the prevalence of HIV in FSWs is higher than their prevalence in the general population. Interventions for the prevention of HIV and HCV in PWID appear to be poor, and may not be sufficient to effectively prevent HIV and HCV transmission.

Sharing of Injection Drug Preparation Equipment Is Associated With HIV Infection: A Cross-sectional Study

Background:

Sharing needles/syringes and sexual transmission are widely appreciated as means of HIV transmission among persons who inject drugs (PWIDs). London, Canada, is experiencing an outbreak of HIV among PWIDs, despite a large needle/syringe distribution program and low rates of needle/syringe sharing.

Objective:

To determine whether sharing of injection drug preparation equipment (IDPE) is associated with HIV infection.

Methods:

Between August 2016 and June 2017, individuals with a history of injection drug use and residence in London were recruited to complete a comprehensive questionnaire and HIV testing.

Results:

A total of 127 participants were recruited; 8 were excluded because of failure to complete HIV testing. The remaining 35 HIV-infected (cases) and 84 HIV-uninfected (controls) participants were assessed. Regression analysis found that sharing IDPE, without sharing needles/syringes, was strongly associated with HIV infection (adjusted odds ratio: 22.1, 95% confidence interval: 4.51 to 108.6, P < 0.001).

Conclusions:

Sharing of IDPE is a risk factor for HIV infection among PWIDs, even in the absence of needle/syringe sharing. Harm reduction interventions to reduce HIV transmission associated with this practice are urgently needed.

Prescription opiate analgesics, heroin, HIV and HCV among persons who inject drugs in New York City, 2016-2018

OBJECTIVES

Assess relationships among non-medical use of prescription opioid analgesics (POAs), heroin use, and HIV and hepatitis C (HCV) infection among persons who inject drugs (PWID) in New York City, 2016-2018.

METHODS

PWID (N = 134) were recruited from Mount Sinai Beth Israel drug treatment programs. HIV seropositive persons were oversampled. A questionnaire was administered, and serum samples were collected for HIV and HCV testing. Analyses were stratified by HIV serostatus and compared those who had used POAs to those who had not used POAs.

RESULTS

Among the participants, 97% reported injecting heroin, 44% reported injecting cocaine, and 47% reported smoking crack cocaine in the 6 months prior to the interview. There were 66% who reported oral non-medical use of POAs, with 42% using oral POAs in the previous 6 months. There was a clear historical pattern in median year of first injection for different groups: HIV seropositive persons (1985), HIV seronegative persons who never used POAs (1999), and HIV seronegative persons who used POAs (2009). By the time of interview (2016-2018), however, almost all participants (97%) reported injecting heroin. All PWID who reported using POAs also reported injecting heroin.

CONCLUSIONS

Non-medical POA use among PWID was very common and should not be considered a separate drug use epidemic, but as an additional component of the continuing heroin/poly-drug use epidemic, itself a part of the syndemic of opioid use, stimulant use, overdose, HCV and HIV occurring in New York City.

Prevalence, estimated incidence, risk behaviours, and genotypic distribution of hepatitis C virus among people who inject drugs accessing harm-reduction services in Kenya: a retrospective cohort study

BACKGROUND

Sub-Saharan Africa has a large population of people with hepatitis C virus (HCV) infection, yet little is known about HCV among people who inject drugs this region. We assessed the prevalence of HCV mono-infection and HIV-HCV co-infection, and the estimated incidence, genotypes, and risk behaviours associated with HCV among people who inject drugs in Kenya.

METHODS

People aged 18 years or older who were living in Nairobi, coastal Kenya, or western Kenya, had a history of injection drug use, and had used any illicit drugs in the past 12 months were recruited at needle and syringe programme sites using respondent-driven sampling. Participants were screened for the presence of an anti-HCV antibody. Those who were anti-HCV positive underwent confirmatory HCV RNA testing, and those with detectable HCV RNA were genotyped. Participants were interviewed regarding parenteral risk behaviours and exposure to services received at the needle and syringe programme sites. We examined correlates of HCV infection and HIV-HCV co-infection using bivariate and multivariate regression, and estimated HCV incidence.

FINDINGS

Of 2188 enrolled participants, 291 (13%) were anti-HCV positive: 183 (22%) of 842 participants in coastal Kenya, 105 (13%) of 817 in Nairobi, and three (1%) of 529 in western Kenya. 284 anti-HCV-positive participants underwent successful HCV RNA testing, of whom 230 (81%) were viraemic. Estimated incidence rates of anti-HCV positivity per 100 person-years were 6·31 in coastal Kenya, 3·19 in Nairobi, and 0·22 in western Kenya. HCV incidence rate was greater in coastal Kenya compared with Nairobi (incidence rate ratio 1·97 [95% CI 1·35-2·93], p=0·0001) and the western region (28·17 [7·55-236·58], p<0·0001). In the coastal region, history of incarceration, more years injecting, more injections in the past month, and receptive cooker sharing were associated with increased risk of HCV, while female sex, more years injecting, more injections in the past month, and regular use of a syringe with a detachable needle were associated with HCV risk in Nairobi. HCV prevalence among HIV-positive participants was 50% (66 of 131 participants) in coastal Kenya, 35% (42 of 121) in Nairobi, and 4% (one of 23) in western Kenya. Risk factors for HIV-HCV co-infection were similar to those observed for HCV mono-infection. The prevailing genotypes were 1a (51%), 4a (47%), and mixed (2%; three 1a/4a and one 1a/2b).

INTERPRETATION

HCV prevalence, estimated incidence, and risk behaviours among people who inject drugs in Kenya vary with region, with the highest estimated incidence observed in coastal Kenya. These findings should be used to inform focused strategies to reduce HCV transmission, such as expansion of needle and syringe programmes, upscaling of opioid agonist therapy, and treatment as prevention in regions affected by injection drug use and HCV.

FUNDING

National Institute on Drug Abuse.

Geographic distribution of risk ("Hotspots") for HIV, HCV, and drug overdose among persons who use drugs in New York City: the importance of local history

AIMS

To identify geographic "hotspots" for potential transmission of HIV and HCV and for drug overdose among persons who use heroin and cocaine in New York City and to examine historical continuities in problem drug use hotspots in the city.

METHODS

A total of 2714 study participants were recruited among persons entering Beth Israel substance use treatment programs. A structured questionnaire was administered and blood samples for HIV and HCV testing were collected. Hotspots for potential virus transmission were defined as ZIP codes with 10+ participants, 2+ persons infected with the virus and engaging in transmission behavior, and 2+ persons not infected and engaging in acquisition behavior. ZIP codes with 3+ persons with previous overdoses were considered potential hotspots for future overdoses.

RESULTS

Participants resided in 166/178 (93%) of the ZIP codes in New York City. Injecting drug use was reported in 150/178 (84%) of the ZIP codes. No zip codes were identified for injecting-related HIV transmission, 5 zip codes were identified for sexual HIV transmission, 3 for HCV transmission, and 8 for drug overdose. Many of the ZIP code potential hotspots were in neighborhoods long associated with drug use: Lower Eastside and Harlem in Manhattan, the South Bronx, and Central Brooklyn.

DISCUSSION

Heroin and cocaine use requiring treatment were reported from almost all ZIP codes in New York City, indicating needs for widely dispersed harm reduction services. Identified hotspots should be targeted for reducing sexual transmission of HIV, transmission of HCV, and drug overdoses. Some of the hotspots have persisted as problem drug use areas for 40 to over 100 years. Monitoring of drug use patterns in historical hotspot neighborhoods may permit early identification of and response to emerging drug use-related health problems. Persistent historical hotspots for problem drug use present a complex problem for implementing harm reduction services that deserve additional research.

Recovery of Infectious Hepatitis C Virus From Injection Paraphernalia: Implications for Prevention Programs Serving People Who Inject Drugs

Background

Controlling hepatitis C virus (HCV) transmission among people who inject drugs (PWID) has focused on preventing sharing syringes and drug preparation paraphernalia, but it is unclear whether HCV incidence linked to sharing paraphernalia reflects contamination of the paraphernalia or syringe-mediated contamination when drugs are shared.

Methods

In experiments designed to replicate real-world injection practices when drugs are shared, the residual contents of HCV-contaminated syringes with detachable or fixed needled were passed through the "cookers" and filters used by PWID in preparing drugs for injection and then introduced into a second syringe. All items were tested for the presence of infectious HCV using a chimeric HCV with a luciferase gene.

Results

Hepatitis C virus could not be recovered from cookers regardless of input syringe type or cooker design. Recovery was higher when comparing detachable needles to fixed needles for residue in input syringes (73.8% vs 0%), filters (15.4% vs 1.4%), and receptive syringes (93.8% vs 45.7%).

Conclusions

Our results, consistent with the hypothesis that sharing paraphernalia does not directly result in HCV transmission but is a surrogate for transmissions resulting from sharing drugs, have important implications for HCV prevention efforts and programs that provide education and safe injection supplies for PWID populations.

Hepatitis C transmission in young people who inject drugs: Insights using a dynamic model informed by state public health surveillance

Increasing injection of heroin and prescription opioids have led to increases in the incidence of hepatitis C virus (HCV) infections in US young adults since the early 2000s. How best to interrupt transmission and decrease HCV prevalence in young people who inject drugs (PWID) is uncertain. We developed an age-stratified ordinary differential equation HCV transmission model of PWID aged 15-64, which we fit to Michigan HCV surveillance data among young PWID aged 15-29. We used Latin hypercube sampling to fit to data under 10,000 plausible model parameterizations. We used the best-fitting 10% of simulations to predict the potential impact of primary (reducing injection initiation), secondary (increasing cessation, reducing injection partners, or reducing injection drug use relapse), and tertiary (HCV treatment) interventions (over the period 2017-2030) on acute and chronic HCV cases by the year 2030. Treating 3 per 100 current and former PWID per year could reduce chronic HCV by 27.3% (range: 18.7-30.3%) and acute HCV by 23.6% (range: 6.7-29.5%) by 2030 among PWID aged 15-29 if 90% are cured (i.e. achieved sustained virologic response [SVR] to treatment). Reducing the number of syringe sharing partners per year by 10% was predicted to reduce chronic HCV by 15.7% (range: 9.4-23.8%) and acute cases by 21.4% (range: 14.2-32.3%) among PWID aged 15-29 by 2030. In simulations of combinations of interventions, reducing injection initiation, syringe sharing, and relapse rates each by 10% while increasing cessation rates by 10% predicted a 27.7% (range: 18.0-39.7%) reduction in chronic HCV and a 38.4% (range: 28.3-53.3%) reduction in acute HCV. Our results highlight the need for HCV treatment among both current and former PWID and the scale up of both primary and secondary interventions to concurrently reduce HCV prevalence and incidence in Michigan.

Combination interventions for Hepatitis C and Cirrhosis reduction among people who inject drugs: An agent-based, networked population simulation experiment

Hepatitis C virus (HCV) infection is endemic in people who inject drugs (PWID), with prevalence estimates above 60% for PWID in the United States. Previous modeling studies suggest that direct acting antiviral (DAA) treatment can lower overall prevalence in this population, but treatment is often delayed until the onset of advanced liver disease (fibrosis stage 3 or later) due to cost. Lower cost interventions featuring syringe access (SA) and medically assisted treatment (MAT) have shown mixed results in lowering HCV rates below current levels. However. little is known about the potential cumulative effects of combining DAA and MAT treatment. While simulation experiments can reveal likely long-term effects, most prior simulations have been performed on closed populations of model agents—a scenario quite different from the open, mobile populations known to most health agencies. This paper uses data from the Centers for Disease Control’s National HIV Behavioral Surveillance project, IDU round 3, collected in New York City in 2012 to parameterize simulations of open populations. To test the effect of combining DAA treatment with SA/MAT participation, multiple, scaled implementations of the two intervention strategies were simulated. Our results show that, in an open population, SA/MAT by itself has only small effects on HCV prevalence, while DAA treatment by itself can lower both HCV and HCV-related advanced liver disease prevalence. More importantly, the simulation experiments suggest that combinations of the two strategies can, when implemented together and at sufficient levels, dramatically reduce HCV incidence. We conclude that adopting SA/MAT implementations alongside DAA interventions can play a critical role in reducing the long-term consequences of ongoing HCV infection.

Modelling the impact of a national scale-up of interventions on hepatitis C virus transmission among people who inject drugs in Scotland

BACKGROUND AND AIMS

To reduce hepatitis C virus (HCV) transmission among people who inject drugs (PWID), Scottish Government-funded national strategies, launched in 2008, promoted scaling-up opioid substitution therapy (OST) and needle and syringe provision (NSP), with some increases in HCV treatment. We test whether observed decreases in HCV incidence post-2008 can be attributed to this intervention scale-up.

DESIGN

A dynamic HCV transmission model among PWID incorporating intervention scale-up and observed decreases in behavioural risk, calibrated to Scottish HCV prevalence and incidence data for 2008/09.

SETTING

Scotland, UK.

PARTICIPANTS

PWID.

MEASUREMENTS

Model projections from 2008 to 2015 were compared with data to test whether they were consistent with observed decreases in HCV incidence among PWID while incorporating the observed intervention scale-up, and to determine the impact of scaling-up interventions on incidence.

FINDINGS

Without fitting to epidemiological data post-2008/09, the model incorporating observed intervention scale-up agreed with observed decreases in HCV incidence among PWID between 2008 and 2015, suggesting that HCV incidence decreased by 61.3% [95% credibility interval (CrI) = 45.1-75.3%] from 14.2/100 person-years (py) (9.0-20.7) to 5.5/100 py (2.9-9.2). On average, each model fit lay within 84% (10.1/12) of the confidence bounds for the 12 incidence data points against which the model was compared. We estimate that scale-up of interventions (OST + NSP + HCV treatment) and decreases in high-risk behaviour from 2008 to 2015 resulted in a 33.9% (23.8-44.6%) decrease in incidence, with the remainder [27.4% (17.6-37.0%)] explained by historical changes in OST + NSP coverage and risk pre-2008. Projections suggest that scaling-up of all interventions post-2008 averted 1492 (657-2646) infections over 7 years, with 1016 (308-1996), 404 (150-836) and 72 (27-137) due to scale-up of OST + NSP, decreases in high-risk behaviour and HCV treatment, respectively.

CONCLUSIONS

Most of the decline in hepatitis C virus (HCV) incidence in Scotland between 2008 and 2015 appears to be attributable to intervention scale-up (opioid substitution therapy and needle and syringe provision) due to government strategies on HCV and drugs.

Prevalence of hepatitis C viral infection among injecting drug users in a Saudi Arabian hospital: A point cross sectional survey

Hepatitis C Virus is an important cause of preventable morbidity and mortality among Injecting Drug Users worldwide. The aim of this study is to determine the prevalence and correlations of HCV infection among IDUs in Saudi Arabia. A point cross-sectional survey was conducted between May 2012 and Nov 2012 to determine hepatitis C viral antibodies serological status using venous blood among IDUs (N=300) accessing care at Al-Amal Hospital in the Kingdom of Saudi Arabia, as well as to determine clinical correlates of hepatitis C infection among the Injecting Drug Users. There was an overall HCV prevalence of 42.7% among IDUs studied. Low level primary education, single marital status, being unemployed and commencing Injecting Drugs beyond the age of 15 years have higher specific prevalence of HCV among IDUs population. There was statistically significant association between clinical assessments of the participants who were abusing drugs generally, dependent on drugs, specifically abusing cocaine, amphetamines, opioids, cannabinoids and alcohol with HCV antibodies seropositivity. There was no statistical significant relationship between drug induced sleep/sexual disorder and psychosis/delusion with HCV seropositivity. This study demonstrated a relatively high prevalence of HCV among IDUs in KSA. Targeted public health preventive strategies are necessary to halt the spread of HCV among IDUs in KSA. The resultant benefits of these will include reduction in morbidity and mortality as well as improved socioeconomic wellbeing of the IDU's population.

The Syndemic of Opioid Misuse, Overdose, HCV, and HIV: Structural-Level Causes and Interventions

PURPOSE OF REVIEW

This article reviews the case for recognizing (1) the epidemics of opioid misuse, overdose, hepatitis C virus, and HIV as a syndemic and (2) the importance of examining and addressing structural factors in responses to this syndemic. We focus on the current syndemic in the US, but also consider data from other locations to highlight the issues existing and arising in various contexts.

RECENT FINDINGS

Advances in multi-level theory and statistical methods allow sound ecologic and multi-level analyses of the impact of structural factors on the syndemic. Studies of opioid misuse, overdoses, hepatitis C virus, and HIV demonstrate that area-level access to healthcare, medication-assisted treatment of opioid use disorders, sterile injection equipment, and overdose prevention with naloxone, as well as factors such as opioid marketing, income inequality, intensity of policing activities, and health care policies, are related to the prevalence of substance misuse, overdoses, infection risk, and morbidity. Structural variables can predict area-level vulnerability to the syndemic. The implementation of combined prevention and treatment interventions can control and reverse components of the syndemic. Recognizing and monitoring potent structural factors can facilitate the identification of areas at risk of vulnerability to the syndemic. Further, many structural factors are modifiable through intervention and policy to reduce structural vulnerability and create health-enabling environments. Evidence supports the immediate implementation of broader HCV and HIV testing and substance use screening, medication-assisted treatment, needle/syringe exchange programs, naloxone programs, increased population-level implementation of HCV treatment, and further attention to structural-level factors predicting, and contributing to, area-level vulnerability, such as degrees of opioid marketing, distribution, and prescribing.

Potential geographic "hotspots" for drug-injection related transmission of HIV and HCV and for initiation into injecting drug use in New York City, 2011-2015, with implications for the current opioid epidemic in the US

OBJECTIVE

We identified potential geographic "hotspots" for drug-injecting transmission of HIV and hepatitis C virus (HCV) among persons who inject drugs (PWID) in New York City. The HIV epidemic among PWID is currently in an "end of the epidemic" stage, while HCV is in a continuing, high prevalence (> 50%) stage.

METHODS

We recruited 910 PWID entering Mount Sinai Beth Israel substance use treatment programs from 2011-2015. Structured interviews and HIV/ HCV testing were conducted. Residential ZIP codes were used as geographic units of analysis. Potential "hotspots" for HIV and HCV transmission were defined as 1) having relatively large numbers of PWID 2) having 2 or more HIV (or HCV) seropositive PWID reporting transmission risk-passing on used syringes to others, and 3) having 2 or more HIV (or HCV) seronegative PWID reporting acquisition risk-injecting with previously used needles/syringes. Hotspots for injecting drug use initiation were defined as ZIP codes with 5 or more persons who began injecting within the previous 6 years.

RESULTS

Among PWID, 96% injected heroin, 81% male, 34% White, 15% African-American, 47% Latinx, mean age 40 (SD = 10), 7% HIV seropositive, 62% HCV seropositive. Participants resided in 234 ZIP codes. No ZIP codes were identified as potential hotspots due to small numbers of HIV seropositive PWID reporting transmission risk. Four ZIP codes were identified as potential hotspots for HCV transmission. 12 ZIP codes identified as hotspots for injecting drug use initiation.

DISCUSSION

For HIV, the lack of potential hotspots is further validation of widespread effectiveness of efforts to reduce injecting-related HIV transmission. Injecting-related HIV transmission is likely to be a rare, random event. HCV prevention efforts should include focus on potential hotspots for transmission and on hotspots for initiation into injecting drug use. We consider application of methods for the current opioid epidemic in the US.

A Bayesian evidence synthesis approach to estimate disease prevalence in hard-to-reach populations: hepatitis C in New York City

Existing methods to estimate the prevalence of chronic hepatitis C (HCV) in New York City (NYC) are limited in scope and fail to assess hard-to-reach subpopulations with highest risk such as injecting drug users (IDUs). To address these limitations, we employ a Bayesian multi-parameter evidence synthesis model to systematically combine multiple sources of data, account for bias in certain data sources, and provide unbiased HCV prevalence estimates with associated uncertainty. Our approach improves on previous estimates by explicitly accounting for injecting drug use and including data from high-risk subpopulations such as the incarcerated, and is more inclusive, utilizing ten NYC data sources. In addition, we derive two new equations to allow age at first injecting drug use data for former and current IDUs to be incorporated into the Bayesian evidence synthesis, a first for this type of model. Our estimated overall HCV prevalence as of 2012 among NYC adults aged 20-59 years is 2.78% (95% CI 2.61-2.94%), which represents between 124,900 and 140,000 chronic HCV cases. These estimates suggest that HCV prevalence in NYC is higher than previously indicated from household surveys (2.2%) and the surveillance system (2.37%), and that HCV transmission is increasing among young injecting adults in NYC. An ancillary benefit from our results is an estimate of current IDUs aged 20-59 in NYC: 0.58% or 27,600 individuals.

Trends in HIV and HCV Risk Behaviors and Prevalent Infection Among People Who Inject Drugs in New York City, 2005-2012

BACKGROUND

We assess trends in HIV and hepatitis C virus (HCV) risk behaviors and prevalent infection among people who inject drugs (PWID) in New York City (NYC).

METHODS

PWID in NYC were sampled using respondent-driven sampling in 2005, 2009, and 2012 (serial cross sections) for the Centers for Disease Control and Prevention-sponsored National HIV Behavioral Surveillance study. Participants were interviewed about their current (≤12 months) risk behaviors and tested for HIV and HCV. The crude and adjusted risk ratio (RR) and 95% confidence interval (95% CI) for linear time trends were estimated using generalized estimating equations regression with a modified Poisson model.

RESULTS

The sample comprised 500, 514, and 525 participants in 2005, 2009, and 2012, respectively. Significant (P < 0.05) linear trends in risk behaviors included a decline in unsafe syringe sources (60.8%, 31.3%, 46.7%; RR = 0.86, 95% CI: 0.81 to 0.92), an increase in all syringes from syringe exchanges or pharmacies (35.4%, 67.5%, 50.3%; RR = 1.15, 95% CI: 1.09 to 1.22), and an increase in condomless vaginal or anal sex (53.6%, 71.2%, 70.3%; RR = 1.14, 95% CI: 1.09 to 1.19). Receptive syringe sharing (21.4%, 27.0%, 25.1%), sharing drug preparation equipment (45.4%, 43.4%, 46.7%), and having ≥2 sex partners (51.2%, 44.0%, 50.7%) were stable. Although HIV seroprevalence declined (18.1%, 12.5%, 12.2%), HCV seroprevalence was high (68.2%, 75.8%, 67.1%). In multivariate analysis, adjusting for sample characteristics significantly associated with time, linear time trends remained significant, and the decline in HIV seroprevalence gained significance (adjusted RR = 0.76, 95% CI: 0.64 to 0.91, P = 0.003).

CONCLUSIONS

This trend analysis suggests declining HIV prevalence among NYC PWID. However, HCV seroprevalence was high and risk behaviors were considerable. Longitudinal surveillance of HIV and HCV risk behaviors and infections is needed to monitor trends and for ongoing data-informed prevention among PWID.

Development and validation of a novel scale for measuring interpersonal factors underlying injection drug using behaviours among injecting partnerships

BACKGROUND

People who inject drugs with sexual partners or close friends have high rates of syringe/ancillary equipment sharing and HIV and hepatitis C virus (HCV) infection. Although evidence suggests that interpersonal factors underlie these higher risk profiles, there is no quantitative measure of how interpersonal factors operate within injecting relationships. We aimed to develop and validate a quantitative scale to assess levels of injecting drug-related interpersonal factors associated with risky injecting behaviours within injecting partnerships.

METHODS

We conducted qualitative interviews with 45 people who inject drugs (PWID) who reported having injecting partners to inform item development, and tested these items in a quantitative study of 140 PWID from San Francisco, USA, to assess internal reliability (Cronbach's alpha) and validity (convergent, and discriminant validity).

RESULTS

With results from the qualitative interview data, we developed the Interpersonal Dynamics in Injecting Partnerships (IDIP) scale with 54 final items for 5 subscales of injecting-related interpersonal factors. Exploratory factor analysis revealed 5 factors ("trust", "power", "risk perception", "intimacy", and "cooperation") with eigenvalues of 14.32, 6.18, 3.55, 2.46, and 2.14, explaining 57% of the variance, and indicating good internal reliability (alpha: 0.92-0.68). Strong convergent validity was observed in bivariate logistic regression models where higher levels of trust, intimacy, and cooperation within partnerships were positively associated with partners sharing needles and injecting equipment, whereas higher levels of power and risk perception were negatively associated with partners sharing needles and injecting equipment.

CONCLUSIONS

These findings offer strong evidence that the IDIP scale provides a psychometrically sound measure of injecting drug-related interpersonal dynamics. This measurement tool has the potential to facilitate additional investigations into the individual and collective impact of trust, intimacy, power, cooperation, and risk perception on injection drug using behaviours and engagement in HIV and HCV testing and treatment among PWID in a variety of settings.

Cost-effectiveness of subdermal implantable buprenorphine versus sublingual buprenorphine to treat opioid use disorder

AIMS

Subdermal implantable buprenorphine (BSI) was recently approved to treat opioid use disorder (OUD) in clinically-stable adults. In the pivotal clinical trial, BSI was associated with a higher proportion of completely-abstinent patients (85.7% vs 71.9%; p = .03) vs sublingual buprenorphine (SL-BPN). Elsewhere, relapse to illicit drug use is associated with diminished treatment outcomes and increased costs. This study evaluated the cost-effectiveness of BSI vs SL-BPN from a US societal perspective.

METHODS

A Markov model simulated BSI and SL-BPN cohorts (clinically-stable adults) transiting through four mutually-exclusive health states for 12 months. Cohorts accumulated direct medical costs from drug acquisition/administration; treatment-diversion/abuse; newly-acquired hepatitis-C; emergency room, hospital, and rehabilitation services; and pediatric poisonings. Non-medical costs of criminality, lost wages/work-productivity, and out-of-pocket expenses were also included. Transition probabilities to a relapsed state were derived from the aforementioned trial. Other transition probabilities, costs, and health-state utilities were derived from observational studies and adjusted for trial characteristics. Outcomes included incremental cost per quality-adjusted-life-year (QALY) gained and incremental net-monetary-benefit (INMB). Uncertainty was assessed by univariate and probabilistic sensitivity analysis (PSA).

RESULTS

BSI was associated with lower total costs (-$4,386), more QALYs (+0.031), and favorable INMB at all willingness-to-pay (WTP) thresholds considered. Higher drug acquisition costs for BSI (+$6,492) were outpaced, primarily by reductions in emergency room/hospital utilization (-$8,040) and criminality (-$1,212). BSI was cost-effective in 89% of PSA model replicates, and had a significantly higher NMB at $50,000/QALY ($20,783 vs $15,007; p < .05).

CONCLUSIONS

BSI was preferred over SL-BPN from a health-economic perspective for treatment of OUD in clinically-stable adults. These findings should be interpreted carefully, due to some relationships having been modeled from inputs derived from multiple sources, and would benefit from comparison with outcomes from studies that employ administrative claims data or a naturalistic comparative design.

Risk factors for hepatitis C seropositivity among young people who inject drugs in New York City: Implications for prevention

Background

Hepatitis C virus (HCV) infection remains a significant problem in the United States, with people who inject drugs (PWID) disproportionately afflicted. Over the last decade rates of heroin use have more than doubled, with young persons (18–25 years) demonstrating the largest increase.

Methods

We conducted a cross-sectional study in New York City from 2005 to 2012 among young people who injected illicit drugs, and were age 18 to 35 or had injected drugs for ≤5 years, to examine potentially modifiable factors associated with HCV among young adults who began injecting during the era of syringe services.

Results

Among 714 participants, the median age was 24 years; the median duration of drug injection was 5 years; 31% were women; 75% identified as white; 69% reported being homeless; and 48% [95% CI 44–52] had HCV antibodies. Factors associated with HCV included older age (adjusted odds ratio [AOR], 1.99 [1.52–2.63]; p<0.001), longer duration of injection drug use (AOR, 1.68 [1.39–2.02]; p<0.001),more frequent injection (AOR, 1.26 [1.09–1.45]; p = 0.001), using a used syringe with more individuals (AOR, 1.26 [1.10–1.46]; p = 0.001), less confidence in remaining uninfected (AOR, 1.32 [1.07–1.63]; p<0.001), injecting primarily in public or outdoors spaces (AOR, 1.90 [1.33–2.72]; p<0.001), and arrest for carrying syringes (AOR, 3.17 [1.95–5.17]; p<0.001).

Conclusions

Despite the availability of harm reduction services, the seroprevalence of HCV in young PWID in New York City remained high and constant during 2005–2012. Age and several injection behaviors conferred independent risk. Individuals were somewhat aware of their own risk. Public and outdoor injection and arrest for possession of a syringe are risk factors for HCV that can be modified through structural interventions.

HCV reinfection incidence among individuals treated for recent infection

One challenge to HCV elimination through therapeutic intervention is reinfection. The aim of this analysis was to calculate the incidence of HCV reinfection among both HIV-positive and HIV-negative individuals treated for recent HCV infection (estimated infection duration <18 months). Individuals with recent HCV infection who achieved an end-of-treatment response in four open-label studies between 2004 and 2015 in Australia and New Zealand were assessed for HCV reinfection, confirmed by sequencing of the Core-E2 and/or NS5B regions. Reinfection incidence was calculated using person-time of observation. Exact Poisson regression analysis was used to assess factors associated with HCV reinfection. The cohort at risk for reinfection (n=120; 83% male; median age 36 years) was composed of HIV-positive men-who-have-sex-with-men (53%) and people who inject drugs (current 49%, ever 69%). Total follow-up time at risk was 135 person-years (median 1.08 years, range 0.17, 2.53). Ten cases of HCV reinfection were identified, for an incidence of 7.4 per 100 py (95% CI 4.0, 13.8). Reinfection incidence was significantly higher among participants who reported injection drug use at end of or post-treatment, irrespective of HIV status (15.5 per 100 py, 95% CI 7.8, 31.1). In adjusted analysis, factors associated with reinfection were older age (aIRR 5.3, 95% CI 1.15, 51.5, P=.042) and injection drug use at end of or post-treatment (aIRR 7.9, 95% CI 1.6, 77.2, P=.008). High reinfection incidence following treatment for recent HCV infection in individuals with ongoing risk behaviour emphasizes the need for post-treatment surveillance, harm reduction strategies and education in at-risk populations.

The cost impact of outreach testing and treatment for hepatitis C in an urban Drug Treatment Unit

BACKGROUND & AIMS

In developed countries persons who inject drugs (PWID) represents a significant risk for chronic hepatitis C virus (HCV). It is reported that up to half of persons with chronic HCV remain undiagnosed and reliance on attendance to specialist clinics remain a barrier to treatment. This study assesses the feasibility and cost-effectiveness of outreach screening and treatment within a Drug Treatment Unit (DTU).

METHODS

All persons attending a London DTU were offered HCV testing, and where appropriate follow-up and treatment by a specialist nurse at the DTU. Three years of data informed a cost-effective-analysis using a validated Markov model. A hypothetical scenario in which only direct acting antiviral (DAA) treatments were used was also assessed.

RESULTS

Of 321 persons eligible, 216 were screened, 89 were HCV positive and 66 had confirmatory evidence of viraemia. All were infected with either HCV genotype 1 or 3. Treatment was initiated in 29 persons, 22 with interferon based and 7 DAA only regimens. Following initial treatment 21 (72%) achieved SVR12. It is estimated that this programme represents an average per-patient cost-saving of £2498 and a quality-adjusted life year (QALY) gain of 4.10 over a lifetime. In a hypothetical scenario of all oral DAA treatment, an incremental cost per QALY of £1029 was estimated.

CONCLUSION

This study demonstrates feasibility and cost effectiveness of outreach testing and treatment of hepatitis C within comparable DTU settings. Additional costs of newer DAA therapies would not be prohibitive when considering willingness-to-pay thresholds commonly used by policy makers.

Prevalence of hepatitis C virus infection among HIV+ men who have sex with men: a systematic review and meta-analysis

Since 2000, an increase in hepatitis C virus infection among HIV-infected (HIV+) men who have sex with men has been observed. Evidence points to blood exposure during sex as the medium of hepatitis C virus transmission. Hepatitis C virus prevalence among HIV + MSM overall and in relation to injection drug use is poorly characterized. In this study, a systematic review and meta-analysis examining global hepatitis C virus antibody prevalence and estimating active hepatitis C virus prevalence among HIV + MSM were conducted; 42 reports provided anti-hepatitis C virus prevalence data among HIV + MSM. Pooled prevalence produced an overall anti-hepatitis C virus prevalence among HIV + MSM of 8.1%; active HCV prevalence estimate was 5.3%-7.3%. Anti-hepatitis C virus prevalence among injection drug use and non-injection drug use HIV + MSM was 40.0% and 6.7%, respectively. Among HIV + MSM, hepatitis C virus prevalence increased significantly over time among the overall and non-injection drug use groups, and decreased significantly among injection drug use HIV + MSM. We identified a moderate prevalence of hepatitis C virus among all HIV + MSM and among non-injection drug use HIV + MSM; for both, prevalence was observed to be increasing slightly. Pooled prevalence of hepatitis C virus among HIV + MSM was higher than that observed in the 1945-1965 US birth cohort. The modest but rising hepatitis C virus prevalence among HIV + MSM suggests an opportunity to control HCV among HIV + MSM; this combined with data demonstrating a rising hepatitis C virus incidence highlights the temporal urgency to do so.

Racial Differences in HIV and HCV Risk Behaviors, Transmission, and Prevention Knowledge among Non-Treatment-Seeking Individuals with Opioid Use Disorder

In light of New York's recently reinforced strategy to end the AIDS epidemic by expanding testing, treatment, and access to pre-exposure prophylaxis (PrEP), we assessed drug use and sexual risk behaviors, along with HIV/Hepatitis C virus (HCV) transmission and prevention knowledge among non-treatment-seeking adults with opioid use disorder (OUD) in New York City. Over the course of 18 months, volunteers screening for research studies in the Opioid Laboratory at the New York State Psychiatric Institute completed a locally developed self-assessment questionnaire. A total of 138 adults with OUD (24 female, 114 male) with a mean age of 46.5 years (SD = 9.5 yrs) were assessed. Significant differences among the four racial/ethnic subgroups (n = 65 African-Americans, n = 34 Hispanics, n = 31 Caucasians or Whites, n = 8 Multiracial) were found. Whites were the youngest (p = 0.001), most frequently injecting drugs (p < 0.001), and engaged more often in risky drug use and sexual behaviors, although their virus transmission knowledge was comparable to that of the other subgroups. Few participants had heard about PrEP. White opioid users showed the most risk behaviors among races/ethnicities, despite comparable prevention knowledge. Better HIV/HCV prevention interventions targeting individuals with opioid use disorders who are not currently in treatment would be desirable, given their large health burden.

Outcomes of Patients in Long-Term Opioid Maintenance Treatment

BACKGROUND

Despite the importance of duration of opioid maintenance treatment (OMT), only few studies have reported outcomes of long-term OMT.

OBJECTIVES

To describe outcomes of long-term (> 5 years) OMT patients with respect to substance use, physical and mental health, and socioeconomic characteristics.

METHODS

Patients (n = 160) were recruited from 15 OMT offices in different regions of Germany. Data were collected using a structured interview at baseline, and clinical recordings, including urine drug screenings, during 12 monhts follow-up.

RESULTS

Patients had a mean age of 44 years. During follow-up, 23% of patients showed indications of an alcohol problem. Cannabis was used by 56%, often frequently. Heroin was used by 28%, mostly infrequently. Three quarters of patients either had a non-substance related mental disorder (48.1%, most frequently affective and anxiety disorders) or somatic diagnosis (61.3%, frequently hepatitis C, HIV, or cardiovascular diseases), or both. Unemployment rate was 43.1% at baseline (27% for patients without comorbidity) and remained generally stable during follow-up. No arrests or incarcerations were recorded. During follow-up, 2.5% of patients prematurely terminated OMT, 2.5% regularly completed OMT.

CONCLUSIONS

The sample as a whole was characterized by stable living conditions, high unemployment, low illicit opiate use, and a high retention rate. Continuation of OMT could enable further treatment of comorbidity and prevent resumption of a drug-dominated lifestyle. But it may well be asked how within the context of OMT further improvements can be achieved, especially with regard to further decrease of alcohol use and the treatment of depression.

Spontaneous viral clearance of hepatitis C virus (HCV) infection among people who inject drugs (PWID) and HIV-positive men who have sex with men (HIV+ MSM): a systematic review and meta-analysis

Background

Hepatitis C virus (HCV) infection causes significant morbidity and mortality among people who inject drugs (PWID) and HIV+ men who have sex with men (MSM). Characterizing spontaneous viral clearance of HCV infection among PWID and HIV+ MSM is important for assessing the burden of disease and treatment strategies in these populations.

Methods

Electronic and other searches of medical literature were conducted. Reports were eligible if they presented original data from upper-middle- and high-income countries on laboratory-confirmed HCV infection and spontaneous viral clearance among PWID or HIV+ MSM. Pooled estimates of spontaneous viral clearance were generated using fixed-effect and random-effects models. Meta-regression examined potential predictors related to individual characteristics and research methodology.

Results

The meta-analysis estimated that spontaneous viral clearance occurs in 24.4 % of PWID and 15.4 % of HIV+ MSM. In univariate meta-regression among PWID, male sex and age were significantly associated with spontaneous viral clearance, and in multivariate analysis, male sex and HIV positivity were predictors of spontaneous viral clearance; among HIV+ MSM no variables were found to affect spontaneous viral clearance.

Conclusion

The variability in estimates of spontaneous viral clearance between HIV+ MSM and PWID suggests the impact of HIV co-infection and HCV re-infection. Due to limited data on additional factors that may affect the natural history of HCV, more research is needed to further understand spontaneous viral clearance in these risk groups.

Protocol registration

The protocols for the PWID and HIV+ MSM research were registered with PROSPERO (CRD42014008805; CRD42013006462).

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1807-5) contains supplementary material, which is available to authorized users.

Benzodiazepine Use and Hepatitis C Seroconversion in a Cohort of Persons Who Inject Drugs

OBJECTIVES

To examine the relationship between benzodiazepine (BZD) use and HCV seroconversion in 2 linked prospective cohorts of persons who inject drugs (PWID).

METHODS

We examined prospective cohorts of 440 PWID (baseline BZD users: n = 102; 23.2%) from the AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS) and the Vancouver Injection Drug Users Study (VIDUS) cohorts, followed-up from 1996 to 2013 in Vancouver, Canada.

RESULTS

At baseline, the prevalence of HCV was higher among those who used BZD (80.5% vs 61.5%; P < .001). After adjustment, BZD use remained independently associated with increased rates of HCV seroconversion (adjusted rate ratio = 1.67; 95% confidence interval = 1.05, 2.66).

CONCLUSIONS

BZD use is independently associated with HCV seroconversion in a population of PWID.

HIV Prevalence, Estimated Incidence, and Risk Behaviors Among People Who Inject Drugs in Kenya

OBJECTIVE

HIV infection in sub-Saharan Africa increasingly occurs among people who inject drugs (PWID). Kenya is one of the first to implement a national needle and syringe program. Our study undertook a baseline assessment as part of evaluating needle and syringe program in a seek, test, treat, and retain approach.

METHODS

Participants enrolled between May and December 2012 from 10 sites. Respondent-driven sampling was used to reach 1785 PWID for HIV-1 prevalence and viral load determination and survey data.

RESULTS

Estimated HIV prevalence, adjusted for differential network size and recruitment relationships, was 14.5% in Nairobi (95% CI: 10.8 to 18.2) and 20.5% in the Coast region (95% CI: 17.3 to 23.6). Viral load (log10 transformed) in Nairobi ranged from 1.71 to 6.12 (median: 4.41; interquartile range: 3.51-4.94) and in the Coast from 1.71 to 5.88 (median: 4.01; interquartile range: 3.44-4.72). Using log10 viral load 2.6 as a threshold for HIV viral suppression, the percentage of HIV-infected participants with viral suppression was 4.2% in Nairobi and 4.6% in the Coast. Heroin was the most commonly injected drug in both regions, used by 93% of participants in the past month, typically injecting 2-3 times/day. Receptive needle/syringe sharing at last injection was more common in Nairobi (23%) than in the Coast (4%). Estimated incidence among new injectors was 2.5/100 person-years in Nairobi and 1.6/100 person-years in the Coast.

CONCLUSIONS

The HIV epidemic is well established among PWID in both Nairobi and Coast regions. Public health scale implementation of combination HIV prevention has the potential to greatly limit the epidemic in this vulnerable and bridging population.