Recent hepatitis C virus infections in HIV-infected patients in Taiwan: incidence and risk factors

Abstract

Outbreaks of sexually transmitted hepatitis C virus (HCV) infections have been recently reported in HIV-infected men who have sex with men (MSM) in Europe, Australia, and North America. Little is known concerning whether this also occurs in other Asia-Pacific countries. Between 1994 and 2010, a prospective observational cohort study was performed to assess the incidence of recent HCV seroconversion in 892 HIV-infected patients (731 MSM and 161 heterosexuals) who were not injecting drug users. A nested case-control study was conducted to identify associated factors with recent HCV seroconversion, and phylogenetic analysis was performed using NS5B sequences amplified from seroconverters. During a total followup duration of 4,270 person-years (PY), 30 patients (3.36%) had HCV seroconversion, with an overall incidence rate of 7.03 per 1,000 PY. The rate increased from 0 in 1994 to 2000 and 2.29 in 2001 to 2005 to 10.13 per 1,000 PY in 2006 to 2010 (P < 0.05). After adjustment for age and HIV transmission route, recent syphilis remained an independent factor associated with HCV seroconversion (odds ratio, 7.731; 95% confidence interval, 3.131 to 19.086; P < 0.01). In a nested case-control study, seroconverters had higher aminotranferase levels and were more likely to have CD4 ≥ 200 cells/μl and recent syphilis than nonseroconverters (P < 0.05). Among the 21 patients with HCV viremia, phylogenetic analysis revealed 7 HCV transmission clusters or pairs (4 within genotype 1b, 2 within genotype 2a, and 1 within genotype 3a). The incidence of HCV seroconversion that is associated with recent syphilis is increasing among HIV-infected patients in Taiwan.

Fig 1

Phylogenetic analysis of NS5B sequences amplified from HCV seroconverters. The 21 HCV sequences amplified from seroconverters are labeled in yellow. The 96 prevalent HCV sequences amplified from men who have sex with men (n = 33), heterosexuals (n = 8), and injecting drug users (IDUs) (n = 55) are labeled in blue, green, and red, respectively (see Fig. S1 in the supplemental material). Some HCV sequences from IDUs were excluded from analysis due to the size of the phylogenetic tree; such exclusion did not have any impact on the outcomes (data not shown). Only the HCV genoytypes with clusters/pairs are shown. Panels A, B, and C represent HCV genotypes 1b, 2a, and 3a, respectively. The horizontal branch was drawn in accordance with relative genetic distances. Bootstrap values of greater than 700 of 1,000 replicates were considered significant and are indicated at the nodes of the corresponding branches. The brackets at the right of the panels indicate the major sequence genotypes.