Risk factors for hepatitis C seropositivity among young people who inject drugs in New York City: Implications for prevention

Background: Hepatitis C virus (HCV) infection remains a significant problem in the United States, with people who inject drugs (PWID) disproportionately afflicted. Over the last decade rates of heroin use have more than doubled, with young persons (18-25 years) demonstrating the largest increase. Methods: We conducted a cross-sectional study in New York City from 2005 to 2012 among young people who injected illicit drugs, and were age 18 to 35 or had injected drugs for <5 years, to examine potentially modifiable factors associated with HCV among young adults who began injecting during the era of syringe services. Results: Among 714 participants, the median age was 24 years; the median duration of drug injection was 5 years; 31% were women; 75% identified as white; 69% reported being homeless; and 48% [95% CI 44-52] had HCV antibodies. Factors associated with HCV included older age (adjusted odds ratio [AOR], 1.99 [1.52-2.63]; p<0.001), longer duration of injection drug use (AOR, 1.68 [1.39-2.02]; p<0.001), more frequent injection (AOR, 1.26 [1.09-1.45]; p = 0.001), using a used syringe with more individuals (AOR, 1.26 [1.10-1.46]; p = 0.001), less confidence in remaining uninfected (AOR, 1.32 [1.07-1.63]; p<0.001), injecting primarily in public or outdoors spaces (AOR, 1.90 [1.33-2.72]; p<0.001), and arrest for carrying syringes (AOR, 3.17 [1.95-5.17]; p<0.001). Conclusions: Despite the availability of harm reduction services, the seroprevalence of HCV in young PWID in New York City remained high and constant during 2005-2012. Age and several injection behaviors conferred independent risk. Individuals were somewhat aware of their own risk. Public and outdoor injection and arrest for possession of a syringe are risk factors for HCV that can be modified through structural interventions.