Background: Numerous epidemiologic studies have shown the high prevalence and incidence of hepatitis C viral (HCV) infection in drug users. This association has been related to injecting drug use and has been attributed to the sharing of injecting equipment.
Objective: To review the literature on the prevalence and incidence of HCV infection and to determine the risk factors for HCV infection in drug users.
Methods: Relevant literature was identified from PubMed and Medline databases using key words of hepatitis C, drug use, injecting, prevalence, and incidence.
Results: Sixteen studies of the prevalence of HCV in drug users were identified, reporting a prevalence of 4.4% in non-injecting drug users (IDUs) and 81.6% in street-recruited IDUs. The prevalence rates for HCV infection were related to injecting behavior, sharing of injecting equipment, older age, increased duration of injecting, cocaine use, and incarceration. Fewer studies of incidence (8 studies) reported a range of 0.4% per 100 person-years in non-IDUs to 41.8% in new IDUs not engaged in treatment. Higher incidence rates were related to injecting behavior, greater frequency of injecting, sharing of injecting equipment, younger age, cocaine use, and attending needle exchange schemes and nonengagement in treatment.
Conclusions: The high prevalence rates of HCV infection in IDUs and the identification of risk factors of HCV infection calls for the universal screening of IDUs in health care settings, which will enable the identification of those with HCV infection and their referral for treatment. For IDUs who are HCV seronegative, the identification of risk factors for contracting HCV infection suggests approaches for prevention of HCV infection, including the provision of treatment of their drug addiction and the administration of specific interventions to minimize the risk for contracting HCV, including prevention counselling and needle exchange schemes.