Surveillance of infectious diseases in IDUs across the EU: information from the EU expert network

Lucas Wiessing (lucas.wiessing@emcdda.eu.int)¹, Fortune Ncube (fortune.ncube@hpa.org.uk)², and Dagmar Hedrich, Paul Griffiths, Vivian Hope, Noel Gill, Françoise Hamers, Luis de la Fuente, Irena Klavs, Pauli Leinikki, Hans Blystad, Andre Meheus, Giovanni Rezza, Gerry Stimson, David Goldberg, for the EMCDDA expert network on drug related infectious diseases³

¹European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), Lisbon, Portugal;
²Health Protection Agency Communicable Disease Surveillance Centre, London, England;
³EMCDDA expert network on drug related infectious diseases (http://www.emcdda.eu.int/situation/themes/infectious_diseases.shtml).

Infectious diseases associated with injecting drug use (IDU), such as HIV and hepatitis B and C, are an important cause of mortality and morbidity among young people in Europe and cause high costs to society (1-4). Hepatitis B, C and HIV prevalence are highly concentrated among IDUs (5-7), forming a constant threat of transmission to the wider population.

Prevalence of HCV in injecting drug users (IDUs) is high overall in the European Union (30-90%), but may be slowly declining, while HIV shows marked variation in prevalence (1-30%) and trends between countries (5). However, high prevalence in new and young injectors demonstrates recently recent transmission (Figures 1-3) and increases in HIV and HCV prevalence or incidence are again reported in several areas, including some where prevalence was historically low (5,6,8). Absolute numbers are also large, as IDUs may constitute up to a half percent of the adult population in the EU (5).

Drug injecting is the major determinant of bloodborne infections, such as HIV and hepatitis B and C. In IDUs, injecting can also be a major risk factor for transmission of other infections such as tetanus, HTLV, malaria, syphilis, hepatitis A, wound botulism and GBV-C (6, 19). In the EU, drug injecting is mostly associated with problematic opiate use, although Sweden and Finland report large numbers of amphetamine injectors, and cocaine use is increasing among (former) problem opiate users (5). Data from drug treatment suggest that injecting drug use has declined during the 1990s in some countries, but not in others (Fig 4). Recent national estimates of injecting vary from 2 to 6 injectors per 1000 population aged 15 to 64 (5,9). In total there are an estimated 600 000 to 900 000 active IDUs in the 15 EU countries, of whom about two thirds are infected with HCV (5,10). Drug injecting is on the rise in the new EU countries of Central Europe and large HIV outbreaks in IDUs have been reported in the Baltic countries (11,20).

Prevention of infections in IDUs is difficult, but some effective measures exist. Needle exchange and methadone maintenance are cost-effective to prevent HIV (10,12,13) and possibly also HCV (13). These and other measures such as HBV vaccination and HIV testing and counselling are being implemented in all 15 EU countries, but coverage of IDUs by most measures is poor in some countries(5,14), while the situation is worse in most new EU countries (11). Despite rapid improvements in highly active antiviral treatments, access to treatment of IDUs may vary between sub-optimal for HIV (15) to very low in the case of HCV (16).

The EMCDDA is coordinating an EU-wide expert network on drug related infectious diseases. This includes routine collection and analysis of existing data on prevalence and interventions (5), collaboration between existing and new sero-behavioural studies in IDUs (17), as well as early warning in cases of outbreaks of serious illness in IDUs related to injectable drugs (18). Work in close collaboration with national focal points, other partner institutions, and related expert networks has resulted in expanded EU datasets and yearly EU analyses on prevalence and trends of HIV, HCV and HBV in IDUs and IDU-specific interventions (5).

Figure 1. HCV antibody prevalence in IDUs who have been injecting for under 2 years

Figure 2. HIV antibody prevalence in IDUs who have been injecting for under 2 years

Note for figs 1-2
Comparisons should be done with caution, as data are from different study settings and study methods. Brackets indicate the 95% confidence interval of prevalence.

Figure 3. HIV antibody prevalence in IDUs aged less then 25 years

Note: Comparisons should be done with caution, as data are from different study settings and study methods. Data for Belgium, Austria and Portugal, and low figure for Finland include some small sample sizes (<50).

Figure 4. Trends in injecting drug use in EU Member States 1990–2001 - % current injectors among heroin users in drug treatment

Note
Data represent several thousands of cases per country per year and in most countries include almost all treated cases at national level (Treatment Demand Indicator).
** Data for France 1998 are not available; figure is based on interpolation of 1997 and 1999.

References:

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4. Postma M J, Wiessing LG, Jager JC. Pharmaco-economics of drug addiction: estimating the costs of hepatitis C virus, hepatitis B virus and human immunodeficiency virus infection among injecting drug users in member States of the European Union. Bull Narc 2001; 53: 79–89. (http://www.unodc.org/unodc/en/bulletin/bulletin_2001-01-01_1_page008.html) [accessed 22 January 2004]

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7. Semaille C, Alix J, Downs AM, Hamers FF. The HIV infection in Europe: large East-West disparity. Euro Surveill 2003; 8(3):57-64. (http://www.eurosurveillance.org/em/v08n03/0803-221.asp)

8. Judd A, Hickman M, Jones S, Parry J. (2003) Prevalence and incidence of hepatitis C and HIV among injecting drug users in London - evidence for increasing transmission, 14th international conference on the reduction of drug related harm, Chiang Mai, 2003.

9. Kraus L, Augustin R, Frischer M, Kümmler P, Uhl A, Wiessing L. Estimating prevalence of problem drug use at national level in countries of the European Union and Norway. Addiction 2003; 98: 471-85.

10. Jager J, Limburg W, Kretzschmar M, Postma M, Wiessing L (eds.). Hepatitis C and injecting drug use: impact, costs and policy options, Scientific Monograph no 7. Lisbon: EMCDDA. In press, 2004.

11. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). The state of the drugs problem in the acceding and candidate countries to the European Union. Lisbon; EMCDDA; 2003. (http://candidates.emcdda.eu.int/)

12. Hurley SF, Jolley DJ, Kaldor JM. Effectiveness of needle-exchange programmes for prevention of HIV infection. Lancet 1997; 349: 1797-800.

13. Commonwealth of Australia. Return on Investment in Needle and Syringe Programs in Australia. Canberra: Commonwealth Department of Health and Ageing, Commonwealth of Australia; 2002. (http://www.health.gov.au/pubhlth/publicat/document/roireport.pdf)

14. Wiessing LG, Denis B, Guttormsson U, Haas S, Hamouda O, Hariga F et al. Estimating coverage of harm reduction measures for injection drug users in the European Union. In: Proceedings of 2000 Global Research Network Meeting on HIV Prevention in Drug-Using Populations. Third Annual Meeting, Durban South-Africa, 5-7 July 2000. National Institute on Drug Abuse - National Institutes of Health - U.S. Department of Health and Human Services, 2001. (http://www.emcdda.org/situation/themes/infectious_diseases.shtml)

15. Van Asten LC, Boufassa F, Schiffer V, Brettle RP, Robertson JR, Hernandez Aguado I, et al. Limited effect of highly active antiretroviral therapy among HIV-positive injecting drug users on the population level. Eur J Public Health 2003; 13: 347-9.

16. Wiessing L. The access of injecting drug users to hepatitis C treatment is low and should be improved. Eurosurveillance Weekly 2001; 5(31): 02/08/2001. (http://www.eurosurveillance.org/ew/2001/010802.asp)

17. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). Expert meeting: Surveillance of drug-related infectious diseases in the European Union: routine data and seroprevalence studies. Lisbon, 29 November–1 December 2001. Final meeting report. Lisbon: EMCDDA; 2002. (http://www.emcdda.eu.int/situation/themes/infectious_diseases.shtml)

18. McMenamin J Goldberg D, Gill N, Wiessing L. Outbreak of serious illness related to contaminated heroin: European network helps improve surveillance of acute serious health events. Eurosurveillance Weekly 2001; 5(41): 11/10/2001. (http://www.eurosurveillance.org/ew/2001/011011.asp)

19. Brettle RP. Infection and injection drug use. J Infect 1992; 25: 121-31.

20. Hamers FF, Downs AM. HIV in central and eastern Europe. Lancet 2003; 361: 1035-44. Published on line February 18, 2003. (http://image.thelancet.com/extras/02art6024web.pdf)

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