Resumen

Objectives: To describe the proportion of persons who inject drugs (PWID) who are not aware of their HIV and Hepatitis C (HCV) infection and to assess factors associated with undiagnosed HIV/ HCV infections among them. Methods: Cross-sectional study among 734 PWID who attended harm reduction centers (HRC) in Catalonia in 2012-13. Anonymous questionnaires and oral fluid samples to determine HIV/HCV prevalences were collected. Those that report “unknown” or “negative” status but test positive on the oral fluid test represent the HIV and HCV undiagnosed groups. Poisson regression models were applied to assess factors associated with undiagnosed HIV/HCV infection. Results: The prevalence of HIV and HCV was 30.6% and 64.9%, respectively. Undiagnosed infection among HIV positive was 25.9% (89.5% reported negative status and 10.5% did not know their status), and among HCV positive was 22.7% (76.4% reported negative status and 23.6% did not know their status). Undiagnosed HIV infection was associated with being male (PR=3.42), having never been in prison (PR=2.31), not having accessed a primary health center in the last 6 months (PR=1.58), and not having used (or used with a low frequency) a drug consumption room in the last 6 months (PR=1.74). Undiagnosed HCV infection was associated with being younger than 30 (PR=1.55), being a migrant (PR=1.66), and having never been in treatment (PR=1.47). Both undiagnosed HIV and HCV infection was higher among those who had never shared syringes (PR=2.90 and 2.09, respectively). Conclusions: A significant proportion of PWID in Catalonia who attended HRC are unaware of their HIV and/or HCV infection. Counseling and testing programs are specially needed for young injectors and migrants. Rapid HIV and HCV tests can play an important role in order to increase the rate of early diagnosis, especially in populations who do not seek conventional medical care.