Substance Use & Misuse, Early Online:1–6, 2013 ISSN: 1082-6084 print / 1532-2491 online DOI: 10.3109/10826084.2013.793356

ORIGINAL ARTICLE

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Hepatitis C Among Injecting Drug Users Is Two Times Higher in Stockholm, Sweden than in Rotterdam, the Netherlands Lillebil Norden1 , Maaike van Veen2 , Christer Lidman3 , Ivo Todorov4 , Bruno Guarita5 , Mirjam Kretzschmar6 and Lucas Wiessing5 1

Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Addiction Centre, Stockholm, Sweden; Center for Infectious Disease Control, RIVM, Bilthoven, the Netherlands; 3 Department of Medicine, Karolinska Institutet, Stockholm, Sweden; 4 Department of Psychology, Stockholm University, Stockholm, Sweden; 5 European Monitoring Centre for Drugs and Drug Addiction, Lisbon, Portugal; 6 Center for Infectious Disease Control, RIVM, Bilthoven, the Netherlands and Julius Centre for Health Sciences and Primary Care, University Medical Centre, Utrecht, the Netherlands 2

RR VS.

This study assessed risk behavior and preventive measures for hepatitis C among injecting drug users in Rotterdam, the Netherlands (452 participants, 2002–2003) and Stockholm, Sweden (310 participants, 2004–2006), two cities with contrasting drug policies. Uni- and multivariate logistic regression models were used. We found that the prevalence of hepatitis C was almost two times higher in participants from Stockholm than in participants from Rotterdam, even after adjustment for sex sharing paraphernalia (adjusted relative risk: 1.92, 95% confidence interval: 1.60–2.29). Follow-up comparative studies are needed to determine if policies with structured health programs can decrease transmission of hepatitis C.

DEFINITIONS

Paraphernalia: needles and syringes Other paraphernalia: filters, rinse water, cookers and drug mixtures INTRODUCTION

Risk factors for acquiring hepatitis C virus (HCV) infection among injecting drug users (IDUs) include sharing needles, syringes, and other paraphernalia (filters, rinse water, cookers, and drug mixtures) (Bruandet et al., 2006; Lucidarme et al., 2004; Maher, Li, Jalaludin, Chant, & Kaldor, 2007). HCV prevalence is generally high among IDUs across Europe. However, there are large differences in prevalence rates between the European countries, varying from 20% to 90% in subnational data (EMCDDA, 2008–2009). The Netherlands and Sweden report different strategies to decrease the number of HCV cases among IDUs. This is most notable in their drug policies, which differ with regard to the acceptance of the harm reduction concept and the implementation of preventive measures such as well-developed opiate substitution treatment (OST) and needle and syringe programs (NSPs) (EMCDDA, 2010). In 1995, the Dutch government published a paper entitled

Keywords injecting drug users, sharing needles or syringes or other paraphernalia, needle and syringe exchange programs, opiate substitution treatment.

ABBREVIATIONS AND DEFINITIONS

aRR CI HCV HIV IDUs NSP OST

Risk ratio Versus

Adjusted risk ratio Confidence interval Hepatitis C virus Human immunodeficiency virus Injecting drug users Needles and syringes program Opiate substitution treatment

The authors would like to thank the following colleagues for their contributions to the work here described: Jeanelle Breemer, Charmaine Kerr, Manel Dulioust, Alfonso the Great, and Linn Anderson Konke. This study contributes to the work of the “European Study Group for Mathematical Modelling and Epidemiological Analysis of Drug-Related Infectious Diseases,” coordinated by EMCDDA and RIVM, with funding from WHO/Europe and the Government of the Netherlands. Address correspondence to Lillebil Norden, PhD student, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm S-141 86, Sweden; E-mail: [email protected]

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L. NORDEN ET AL.

“Drug policy: continuity and change” (Ministry of Health, Welfare and Sport, 2010), which formulated the basic principles of the Dutch drug policy, including a distinction between “soft” and “hard” drugs. The main feature of the Dutch prevention policy is a strong focus on health promotion and harm reduction in general. Facilities for needle and syringe exchange exist for more than 20 years and are available in all major Dutch cities (EMCDDA, 2010; van den Berg, Smit, Van Brussel, Coutinho, & Prins, 2007). In addition, drug users in OST are routinely offered testing for infectious diseases on a yearly basis (Schreuder et al., 2010). The “Swedish National Action Plan on Drugs (2006–2010)” does not use the term harm reduction measures and overall follows a restrictive policy with regard to drug use. The drug action plan is comprehensive, focuses on illegal drugs and covers prevention, treatment and rehabilitation, and supply reduction (EMCDDA, 2010; Swedish Government Proposition, 2005). Access to testing and counseling for blood borne infections is offered in Sweden, and there is access to OST. Access to NSPs is limited to only three cities in the whole of Sweden and Stockholm is not one of them. However, an action program for STI/HIV prevention in Stockholm County (2009–2013) favored NSPs, and in June 2010 a decision was taken to implement a 4-year trial of NSPs. In this study, we used data from two surveys regarding risk behavior, HCV infection, and preventive measures in Rotterdam, the Netherlands, and in Stockholm, Sweden, two cities with contrasting preventive policies regarding HCV infection among IDUs. The total number of IDUs in Rotterdam is estimated to be around 1,200 in a city with 600,000 inhabitants (2/1000 inhabitants) and in Stockholm around 5,000 in a city with 2 million inhabitants (2.5/1000 inhabitants) (D. Svensson, personal communication, October 28, 2010; M. van Veen, personal communication, September 10, 2010. The HCV infection among IDUs might be associated with different factors in high- and low-prevalence countries, and IDUs may have different risky injecting behaviors in those countries. This study aims to provide some insights on the association between prevention policy, risk behavior, and the prevalence of HCV infection among IDUs. METHODS

Data from two cross-sectional studies among IDUs from different recruitment sites were used. The first study was carried out in Rotterdam, the Netherlands, by RIVM, with 452 participants recruited in 2002–2003 (de Boer et al., 2004), and the second in Stockholm, Sweden, by Karolinska Institutet, with 310 participants recruited during 2004–2006 (Lidman et al., 2009). Participants in Rotterdam were recruited at “user venues” such as methadone treatment and user rooms, participants in Stockholm were recruited from units and settings that provide care for IDUs but not units specialized in methadone treatment. The inclusion criteria in both studies were participants

older than 18 years and who reported ever having injected drugs. Participants were interviewed about demographic characteristics and risk behavior in the last 6 months. Exclusion criteria were in Stockholm; HIV positive drug users and previous participation in this study. The data from the two data sets were not collected at the same time and have a limited number of comparable variables. However, risk behavior data were collected in very similar format and may be well comparable. The first study was carried out in Rotterdam, the Netherlands, by RIVM, with 452 participants recruited in 2002–2003 (de Boer et al., 2004), and the second in Stockholm, Sweden, by Karolinska Institutet, with 310 participants recruited during 2004–2006 (Lidman et al., 2009). R software version 9.0 (SAS Institute, Cary, NC, JMP R USA) and Stata 12.0 (StataCorp LP, College Station, TX, USA) were used for statistical analyses. A univariate logistic regression model was used to analyze risk factors for HCV infection. Positive HCV antibody test was used as the outcome variable. Variables tested one by one in univariate models were city (Rotterdam vs. Stockholm), age (in years), sex, and age at first injection (in years), duration of injection (in years), sharing needles and syringes (in last 6 months), and sharing other paraphernalia (in last 6 months). In the multivariate logistic regression model, where all variables must have a value of p