In Europe, injecting drug use is a major transmission route for hepatitis C virus (HCV) infections. Estimates suggest that around 1 million people who have injected drugs may be living with HCV in the EU today. Typically between 40 % and 90 % of injecting drug users are infected, and many contract the disease soon after their first injection. This is due to unsafe injecting practices which include sharing of needles/syringes and other injection materials. The high prevalence of HCV infection among drug injectors represents a serious public health problem for the EU, made worse by the fact that many of those who have contracted the virus are unaware of their infection status. HCV infection may lead to severe chronic liver disease and premature death. This can occur after many years of asymptomatic infection.
IDUs, the largest known transmission group for hepatitis C
In Europe, injecting drug users (IDUs) account for the majority of newly reported cases of hepatitis C infection, where the transmission route is documented. The EMCDDA has been reporting data on hepatitis C notifications since 2003. Although caution is warranted, the data suggest that a large proportion (40 %) of newly infected (acute) cases, and the large majority (80 %) of newly diagnosed (acute and chronic) cases, have been infected by injecting drugs. See this graph (.ppt).
See 'European monitoring of notifications of hepatitis C virus infection in the general population and among injecting drug users (IDUs) – the need to improve quality and comparability' (Eurosurveillance, Volume 13, Issue 21, 22 May 2008).
EMCDDA data on HCV antibody prevalence in samples of IDUs across Europe suggest infection levels of over 40 % generally, with extremes of over 90 %.
Treatment of injecting drug users with chronic hepatitis C
Up to 30 % of patients with untreated chronic hepatitis C will develop liver cirrhosis within 30 years, and the costs incurred in the management of end-stage liver disease are considerable. To reduce the burden of hepatitis C in Europe, it is essential to promote and expand access to treatment. Treatment access for active drug injectors, one of the largest patient groups that could benefit from care, has been very low. This is in part due to the explicit exclusion of injecting drug users from many national treatment guidelines. Although recent data on HCV treatment availability for injectors is currently lacking, the little information that does exist suggests that it remains limited.
See the box 'Treatment of injecting drug users with chronic hepatitis C' (EMCDDA annual report 2009, p. 83).
See also 'The access of injecting drug users to hepatitis C treatment is low and should be improved' (Eurosurveillance, Volume 5, Issue 31, 02 August 2001).
Evidence of effectiveness of HCV prevention in drug injectors
Evidence suggests that opioid substitution treatment (OST) can contribute to reduced transmission of HCV among drug injectors who use heroin and other opioids. There is however still a lack of evidence on whether other prevention (harm reduction) measures are effective in protecting IDUs from HCV infection. These include: needle and syringe programmes (NSPs), pharmacy and vending-machine-based provision of needles/syringes, prison-based NSPs and drug consumption rooms. However, the combined provision of OST and NSPs may be effective if coverage levels are sufficient. See Chapter 5 of the EMCDDA Monograph on harm reduction: Harm reduction among injecting drug users — evidence of effectiveness.
Hepatitis C prevalence as a possible indicator of injection-related HIV risk
A group of modellers and epidemiologists brought together by the EMCDDA has examined the potential for using information on the prevalence of the hepatitis C virus among injecting drug users as an indicator of the population-level HIV transmission risk.
See full article: 'Hepatitis C prevalence as a possible indicator of injection-related HIV risk' (Drugnet 69, January–March 2010).
Other hepatitis viruses are also highly prevalent in IDUs
In addition to high levels of hepatitis C infection, IDUs are often infected with other hepatitis viruses, including the vaccine-preventable hepatitis A, B and D viruses. Levels of hepatitis B antibodies are often very high among injectors. Among notified acute cases of hepatitis B where transmission route is documented, one in five has been infected by injecting drugs. See this graph (.ppt). Large outbreaks of hepatitis A have also been documented among IDUs in several European countries. Having concurrent hepatitis infections greatly increases the risk of death due to sudden liver failure.
Statistics and data
Statistics and data related to viral hepatitis can be found in the following data sets of the EMCDDA's annual statistical bulletin: