Sector News

  1. How does a Positive or Negative Hepatitis C Virus Test Impact Behavior?

    Background

    • Worldwide, Hepatitis C virus (HCV) prevalence among injection drug users is estimated between 50% and 90%.
    • HCV testing and counselling can be used as an opportunity to influence behaviour and transmission of HCV at the time of test notification. For example, a study conducted in Montreal showed a decrease in syringe sharing after participants were made aware of both positive and negative HCV test results in an addition to a reduction of alcohol use. However the results were limited due to a small sample size.

    Approach

    • The authors used data from the International Collaboration of Incident HIV and HCV Infection in Injecting Cohorts (InC3 Study), which is a multicohort study of pooled data from prospective studies of people who inject drugs (PWID) in Canada, USA, The Netherlands, and Australia. Participants were recruited and followed between 1985 and 2011. The sample included 829 people who inject drugs.

    Findings

    • Notification of a HCV test result showed a reduction in recent injection drug use and recent syringe sharing for both those who received a positive and negative HCV test result (5% and 3% reduction, respectively). There were no significant differences between the two groups.
    • Recent Australian and Canadian data show some sustained behavioural changes associated with the notification process.
    • The proportion of participants using alcohol increased among those who received a positive HCV test
    • Younger (under 25 years) PWID populations who received a positive HCV test significantly increased alcohol consumption in comparison to the HCV-negative group.

    Conclusion

    Timely notification of HCV test results is a key opportunity for risk behavior reduction counseling. In addition, there is need to expand post-test counseling services and monitoring in order to address post-diagnosis alcohol use.

    Spelman, T., Morris, M.D., and Zang, G. (2015). A longitudinal study of hepatitis C virus testing and infection status notification on behavior change in people who inject drugs. J Epidemiol Community Health. 69(8): 745–752.

  2. Crack-Cocaine Abuse: Overview of Interventions

    Background

    • Globally, approximately 14-21 million (0.3-0.5%) are cocaine users.
    • The prevalence of cocaine use is estimated to be highest in the Americas as it is the second most common illicit drug used.
    • Crack-cocaine makes up an extensive proportion of cocaine use and is the most commonly used non-injection drug among street drug user populations.
    • Psychiatric problems, HCV, HIV, and tuberculosis are higher among crack-users. Also, mortality rates are 4-8 times higher when compared to the general population.
    • Many crack users are socially and economically marginalized, which results in limited social, health, and/or treatment services.
    • Due to a lack of targeted prevention and treatment specifically for crack use, the authors provide a comprehensive overview of secondary prevention and treatment interventions with a specific focus on crack-cocaine misuse.

    Findings

    Diverse Psycho-social treatment

    • A large body of evidence shows that psycho-social treatment (e.g. cognitive/behavioural therapy, peer-delivered interventions) can reduce drug use, as well as the negative health impacts associated with it. Though limited, it may, be the best treatment currently available for cocaine/crack.
    • Psycho-social treatment that incorporates Contingency Management (e.g. housing contingent on drug abstinence, vouchers for cocaine-free urine samples) may be the primary reason for the effectiveness of psycho-social treatment. Contingency Management shows greater efficacy in achieving periods of drug abstinence in crack user populations.

    Pharmaceutical treatment

    • Many studies explored pharmacotherapy treatment options for cocaine/crack-dependence, however, despite the multiple drugs tested, studies have shown no pharmacological treatments to be overall effective. At this point, the most promising options are glutamatergic and GABA (e.g. topiramate) as well as dexamphetine formulations.
    • Immunotherapy is considered a promising preventative-therapeutic approach, however so far the effects appear to be short lived and only in very specific populations. A new vaccine compound shows a reduction in cocaine seeking in animal studies, but it has not yet been studied in humans.

    Conclusion

    Even though crack use is as common as opioid and injection drug use, currently, there is no  ‘gold standard’ prevention and treatment intervention for crack abuse.  Further research is vital in order to develop treatments for crack/cocaine comparative to the effectiveness of other interventions such as needle exchange services and opioid maintenance treatment.

    Fischer, B., Blanken, P. and Da Silveira, D. et al. (2015). Effectiveness of secondary prevention and treatment interventions for crack-cocaine abuse: A comprehensive narrative overview of English-language studies. International Journal of Drug Policy. Vol. 26. Pp. 352-363.