Incidence and risk factors of hepatitis C virus infection among human immunodeficiency virus (HIV) patients in a large HIV clinic in South Korea

Background/Aims: Increasing incidences of hepatitis C virus (HCV) infection in human immunodeficiency virus (HIV)-infected men who have sex were reported in the United States and Europe. However, few studies regarding the epidemiology of HCV infection in HIV-infected patients in Asian countries have been reported. Methods: To determine the prevalence and incidence of HCV infection in HIV-infected patients, a retrospective cohort study was conducted. All HIV-infected patients who visited a tertiary care hospital in Korea from 2000 to 2013 were identified. Patients with ${\geq}1HCV$ antibody (Ab) test were included and observed until December 2014. Results: Among 996 HIV-infected patients, 790 patients (79%) had baseline HCV Ab tests and 41 (5.2%) were positive at baseline and four at follow-up. Experience of injecting drug use (IDU; adjusted odds ratio, 16.20; 95% confidence interval [CI], 1.56 to 167.89; p < 0.01) was significantly associated with prevalent HCV infection. Conversion to HCV Ab positivity was observed in four of 384 included patients, with an incidence rate of 2.22 (95% CI, 0.60 to 5.80)/1,000 person-years (PYs); 164.89 (95% CI, 34.00 to 481.88)/1,000 PYs in patients with IDU, and 1.40 (95% CI, 0.35 to 7.79)/1,000 PYs in men who have sex with men who denied IDU. There was no significant increase in incidence rate of HCV in HIV-infected patients from 2009 to 2014 (p = 0.119). Among 19 patients who were positive for HCV RNA, genotype 1b (73%) was the most common following 2a/2c (20%). Conclusions: IDU was an independent risk factor for prevalent HCV infection. Prevalence of HCV infection was low and incidence of HCV infection was not significantly increased in HIV-infected patients in South Korea.