Abstract
Background: This study investigated the association between drug use and Hepatitis C Virus (HCV) infection in HIV-negative men who have sex with men (MSM) who reported drug use but not injection drug use. Methods: This cross-sectional study analyzed the data of 118 HIV-negative MSM who reported drug use but not injection drug use recruited from two inner-city communities between 2004 and 2007. Latent class analysis (LCA) was used to identify drug use latent classes. Multinomial logistic regression analysis was used to evaluate the association between drug use latent class and HCV infection. Results: Four distinct latent classes of drug use were identified: (1) persons >=42 years old who used only crack cocaine, (2) persons about 42 years old who used >2 drugs, (3) persons <42 years old who used >5 drugs, and (4) persons >=42 years old who used >6 drugs. Class 4, persons >= 42 years old who used >6 drugs were significantly associated with HCV infection. Compared with persons about 42 years old who used >2 drugs, persons >=42 years old who used >6 drugs had more than 16 times the odds of having HCV infection (adjusted OR = 16.9, 95%CI: 1.4-205.4), and compared with persons <42 years old who used >5 drugs, persons >=42 years old who used >6 drugs were about 22 times as likely to have HCV infection (adjusted OR=21.8, 95%CI: 1.5-322.8). Conclusions: The subgroup of MSM >=42 years old with non-injection but multiple use of heroin, speedball, and methamphetamine, in addition to crack cocaine and marijuana, had high probability of HCV infection. Public health and education programs, as well as drug treatment and rehabilitation programs, should be developed for this high-risk subgroup to prevent HCV acquisition and transmission.