Hepatitis C virus infection in injection drug users in Bavaria: Risk factors for seropositivity

Background: Hepatitis C Virus (HCV) infection is the most common disease among intravenous drug users (IDUs). Patients and method: All patients admitted to the detoxification unit 1991-1997 and meeting ICD-10 diagnosis of opioid dependency were tested for anti-HCV serology. Results: Thousand and forty nine patients were included in the study. About 61.3% of the IDUs were anti-HCV positive. Increasing age (PR: 1.46; 95% CI: 1.34-1.60), living with a significant other drug user (PR: 1.17; 95% CI: 1.05-1.31), history of therapy (PR: 1.62; 95% CI: 1.50-1.74), history of imprisonment (PR: 1.48; 95% CI: 1.36-1.61), history of emergency treatment (PR: 1.23; 95% CI: 1.12-1.35), additional daily consumption of benzodiazepines (PR: 1.10; 95% CI: 1.00-2.21) or alcohol (PR: 1.26; 95% CI: 1.14-1.38), frequency of injecting heroin (daily: PR: 0.86; 95% CI: 0.78-0.96; previously: PR: 1.14; 95% CI: 1.03-1.26) and type of opioid dependency (methadone: PR: 1.26; 95% CI: 1.13-1.41) were significant factors, considered as individual factors, for positive anti-HCV serology. Using multiple logistic regression we found that older age (OR: 3.54, 95% CI: 1.30-9.67), longer duration of opioid use (OR: 5.74; 95% CI: 1.82-18.13), living with a significant other drug user (OR: 1.47; 95% CI: 1.01-2.16), history of therapy (OR: 4.87; 95% CI: 1.67-14.20), history of imprisonment (OR: 1.92; 95% CI: 1.12-3.28), history of emergency treatment (OR: 1.45; 95% CI: 1.06-1.99) and additional daily consumption of alcohol (OR: 1.49; 95% CI: 1.04-2.13) remained independently associated with positive anti-HCV serology. Conclusions: These data support the need for early prevention strategies, namely, education of teachers in schools and further training of counsellors informing IDUs of what they can do to minimise the risk of becoming infected or of transmitting infectious agents to others.