Dynamic modelling of hepatitis C virus transmission among people who inject drugs: a methodological review

Equipment sharing among people who inject drugs (PWID) is a key risk factor in infection by hepatitis C virus (HCV). Both the effectiveness and cost-effectiveness of interventions aimed at reducing HCV transmission in this population (such as opioid substitution therapy, needle exchange programs or improved treatment) are difficult to evaluate using field surveys. Ethical issues and complicated access to the PWID population make it difficult to gather epidemiological data. In this context, mathematical modelling of HCV transmission is a useful alternative for comparing the cost and effectiveness of various interventions. Several models have been developed in the past few years. They are often based on strong hypotheses concerning the population structure. This review presents compartmental and individual-based models in order to underline their strengths and limits in the context of HCV infection among PWID. The final section discusses the main results of the papers

Impact of a treatment as prevention strategy on hepatitis C virus transmission and on morbidity in people who inject drugs

Background: Highly effective direct-acting antiviral (DAA) regimens (90% efficacy) are becoming available for hepatitis C virus (HCV) treatment. This therapeutic revolution leads us to consider possibility of eradicating the virus. However, for this, an effective cascade of care is required. Methods: In the context of the incoming DAAs, we used a dynamic individual-based model including a model of the people who inject drugs (PWID) social network to simulate the impact of improved testing, linkage to care, and adherence to treatment, and of modified treatment recommendation on the transmission and on the morbidity of HCV in PWID in France. Results: Under the current incidence and cascade of care, with treatment initiated at fibrosis stage $\ge$F2, the HCV prevalence decreased from 42.8% to 24.9% [95% confidence interval 24.8%--24.9%] after 10 years. Changing treatment initiation criteria to treat from F0 was the only intervention leading to a substantial additional decrease in the prevalence, which fell to 11.6% [11.6%--11.7%] at 10 years. Combining this change with improved testing, linkage to care, and adherence to treatment decreased HCV prevalence to 7% [7%--7.1%] at 10 years and avoided 15.3% [14.0%-16.6%] and 29.0% [27.9%--30.1%] of cirrhosis complications over 10 and 40 years respectively. Conclusion: A high decrease in viral transmission occurs only when treatment is initiated before liver disease progresses to severe stages, suggesting that systematic treatment in PWID, where incidence remains high, would be beneficial. However, eradication will be difficult to achieve

Distributive sharing among HIV-HCV co-infected injecting drug users: the preventive role of trust in one's physician

International audienceThis study, based on data from the MANIF 2000 cohort study, investigates the relationship between the lending of injecting equipment, drug use and experience with HIV care. The sample comprised 224 HIV-HCV-coinfected patients who reported having injected drugs in the previous 6 months and their 538 visits to clinical services. Longitudinal data were collected for medical status, and self-reported risk behaviors. A logistic regression GEE model was used to identify correlates of distributive sharing. After multiple adjustment, patients who reported trust in physicians were significantly less likely to report lending injection equipment while cocaine users were at increased risk. Promoting dialogue between physicians and IDUs may play an important role in HIV-HCV positive prevention

The fast and furious

Cocaine and amphetamines (‘stimulants’) are distinct central nervous system stimulants with similar effects (Pleuvry, 2009; Holman, 1994). Cocaine is a crystalline tropane alkaloid extracted from coca leaves. Amphetamines are a subclass of phenylethylamines with primarily stimulant effects, including amphetamine, methamphetamine, methcathinone and cathinone and referred to as ‘amphetamines’ in this review (Holman, 1994). MDMA (3,4-methylenedioxy-N-methamphetamine or ecstasy) is a substituted amphetamine known for its entactogenic, psychedelic, and stimulant effects (Morgan, 2000). Stimulants can produce increased wakefulness, focus and confidence, elevated mood, feelings of power, and decreased fatigue and appetite; stimulants also produce nervousness or anxiety and, in some cases, psychosis and suicidal thoughts (Holman, 1994; EMCDDA, 2007f; Hildrey et al., 2009; Pates and Riley, 2009). Although there is little evidence that stimulants cause physical dependence, tolerance may develop upon repetitive use and withdrawal may cause discomfort and depression (EMCDDA, 2007f; Pates and Riley, 2009). Users may engage in ‘coke or speed binges’ alternated with periods of withdrawal and abstinence (Beek et al., 2001)

'My first 48 hours out' : drug users’ perspectives on challenges and strategies upon release from prison

Background Prisoners report much higher prevalence rates of drug use and more harmful consumption patterns than the general population. People who use drugs have above-average experiences with the criminal justice system in general, and the prison system and subsequent release situations in particular. Release from prison is associated with increased mortality rates among drug users due to the risk of overdose. The EU-funded project 'My first 48 hours out' aimed to address the gaps in continuity of care for long-term drug users in prison and upon release, with a special focus on drug user's perspectives on needs and challenges upon release. Methods A multi-country (Belgium, France, Germany and Portugal) qualitative study was set up to explore drug users' perceptions of drug use and risk behaviour upon prison release, experiences of incarceration and release, and strategies to avoid risks when being released. In total, 104 prisoners and recently released persons with a history of drug use participated in semi-structured interviews and focus groups discussions on these topics. Results Respondents pointed out that there are numerous challenges for people who use drugs when released from prison. Lack of stable housing and employment support were frequently mentioned, as well as complex administrative procedures regarding access to services, health insurance and welfare benefits. Besides structural challenges, individual issues may challenge social reintegration like 'old habits', mental health problems and disrupted social networks. As a result, (ex-)prisoners adopt individual strategies to cope with the risks and challenges at release. Conclusion Measures to prepare prisoners for release often do not focus on the individual and specific challenges of persons who use drugs. Psychosocial and medical support need to be improved and adjusted to drug users' needs inside and outside prison. To improve the quality and continuity of care around release, the perspectives and coping strategies of people who use drugs should be used to better address their needs and barriers to treatment

Insufficient access to harm reduction measures in prisons in 5 countries (PRIDE Europe): a shared European public health concern

Background: Prisoners constitute a high-risk population, particularly for infectious diseases. The aim of this study was to estimate the level of infectious risk in the prisons of five different European countries by measuring to what extent the prison system adheres to WHO/UNODC recommendations. Methods: Following the methodology used in a previous French survey, a postal/electronic questionnaire was sent to all prisons in Austria, Belgium, Denmark and Italy to collect data on the availability of several recommended HIV-HCV prevention interventions and HBV vaccination for prisoners. A score was built to compare adherence to WHO/UNODC recommendations (considered a proxy of environmental infectious risk) in those 4 countries. It ranged from 0 (no adherence) to 12 (full adherence). A second score (0 to 9) was built to include data from a previous French survey, thereby creating a 5-country comparison. Results: A majority of prisons answered in Austria (100 %), France (66 %) and Denmark (58 %), half in Belgium (50 %) and few in Italy (17 %), representing 100, 74, 89, 47 and 23 % coverage of the prison populations, respectively. Availability of prevention measures was low, with median adherence scores ranging from 3.5 to 4.5 at the national level. These results were confirmed when using the second score which included France in the inter-country comparison. Overall, the adherence score was inversely associated with prison overpopulation rates (p = 0.08). Conclusions: Using a score of adherence to WHO/UNODC recommendations, the estimated environmental infectious risk remains extremely high in the prisons of the 5 European countries assessed. Public health strategies should be adjusted to comply with the principle of equivalence of care and prevention with the general community

Limited access to HIV prevention in French prisons (ANRS PRI2DE): implications for public health and drug policy

International audienceABSTRACT: BACKGROUND: Overpopulation, poor hygiene and disease prevention conditions in prisons are major structural determinants of increased infectious risk within prison settings but evidence-based national and WHO guidelines provide clear indications on how to reduce this risk. We sought to estimate the level of infectious risk by measuring how French prisons adhere to national and WHO guidelines. METHODS: A nationwide survey targeting the heads of medical (all French prisons) and psychiatric (26 French prisons) units was conducted using a postal questionnaire and a phone interview mainly focusing on access to prevention interventions, i.e. bleach, opioid substitution treatment (OST), HBV vaccination and post-exposure prophylaxis (PEP) for French prisoners. Two scores were built reflecting adherence to national and WHO international guidelines, ranging from 0 (no adherence) to 10 (maximum adherence) and 0 to 9 respectively. RESULTS: A majority (N=113 (66%)) of the 171 prisons answered the questionnaires, representing 74% coverage (46,786 prisoners) of the French prison population: 108 were medical units and 12 were psychiatric units. Inmate access to prevention was poor. The median[IQR] score measuring adherence to national guidelines was quite low (4.5[2.5; 5.5]) but adherence to WHO guidelines was even lower 2.5[1.5; 3.5]; PEP was absent despite reported risky practices. Unsuitable OST delivery practices were frequently observed. CONCLUSIONS: A wide gap exists between HIV prevention policies and their application in prisons. Similar assessments in other countries may be needed to guide a global policy reform in prison settings. Adequate funding together with innovative interventions able to remove structural and ideological barriers to HIV prevention are now needed to motivate those in charge of prison health, to improve their working environment and to relieve French prisoners from their currently debilitating conditions

The Hep-CORE policy score: A European hepatitis C national policy implementation ranking based on patient organization data.

BACKGROUND content: New hepatitis C virus (HCV) treatments spurred the World Health Organization (WHO) in 2016 to adopt a strategy to eliminate HCV as a public health threat by 2030. To achieve this, key policies must be implemented. In the absence of monitoring mechanisms, this study aims to assess the extent of policy implementation from the perspective of liver patient groups. - Label: METHODS content: "Thirty liver patient organisations, each representing a country, were surveyed in October 2018 to assess implementation of HCV policies in practice. Respondents received two sets of questions based on: 1) WHO recommendations; and 2) validated data sources verifying an existing policy in their country. Academic experts selected key variables from each set for inclusion into policy scores. The similarity scores were calculated for each set with a multiple joint correspondence analysis. Proxy reference countries were included as the baseline to contextualize results. We extracted scores for each country and standardized them from 0 to 10 (best)." - Label: RESULTS content: Twenty-five countries responded. For the score based on WHO recommendations, Bulgaria had the lowest score whereas five countries (Cyprus, Netherlands, Portugal, Slovenia, and Sweden) had the highest scores. For the verified policy score, a two-dimensional solution was identified; first dimension scores pertained to whether verified policies were in place and second dimension scores pertained to the proportion of verified policies in-place that were implemented. Spain, UK, and Sweden had high scores for both dimensions. - Label: CONCLUSIONS content: Patient groups reported that the European region is not on track to meet WHO 2030 HCV goals. More action should be taken to implement and monitor HCV policies

The Harms of Constructing Addiction as a Chronic, Relapsing Brain Disease.

As an international network of historians and social scientists who study approaches to the management of drugs across time and place, we have noticed the effort to redefine addiction as a chronic, relapsing brain disease (CRBD). The CRBD model is promoted as a route to destigmatize addiction and to empower individuals to access treatment that works within that model’s terms.1 CRBD usefully recognizes that brain-based neural adaptations place individual brains in chronic states of readiness to relapse. But brains are housed inside of people. Substance use is biological, social, and political; our concepts and approaches to complex questions surrounding substance use must be, too.2,3 By overlooking the sociopolitical dynamics and inequalities bound up with substance use, the CRBD model can paradoxically further marginalize people who use drugs by positing them as neurobiologically incapable of agency or choice. We are concerned that the CRBD model paints drug users as individuals whose exclusion from social, economic, and political participation is justified by their biological flaws and damaged brains