Abstract
The molecular epidemiological and clinical aspects of hepatitis D virus (HDV) in a unique HBV, HCV, and HDV triple virus endemic community in southern Taiwan were investigated. A total of 2,909 residents aged 45 or older were screened for hepatitis B surface antigen (HBsAg), anti‐HCV antibody, and anti‐HDV antibody (specifically for HBsAg‐positive carriers). Factors that might be associated with HDV infection, viral nucleic acid detection, and genotyping of HBV, HCV, and HDV were investigated. The prevalence of HBsAg and anti‐HCV were 12.6% (366/2,909) and 41.6% (1,227/2,909), respectively. For HBsAg carriers, 15.3% (56/366) were positive for anti‐HDV assay. Living in a higher endemic district of HCV infection (odds ratio [OR] = 3.2; 95% confidence interval [CI] = 1.7–6.3), male gender (OR = 1.9; 95% CI = 1.1–3.6) and co‐infection with HCV (OR = 1.8; 95% CI = 1.0–3.3) were significantly independent factors associated with HDV infection. The detection rate of HDV RNA among anti‐HDV‐positive patients was only 12.7% (7/55). The mean HBV titer of triple infection group was significantly lower than in the HBV/HDV co‐infection group (2.23 vs 3.05 in log~10~, copies/ml, P = 0.046). HCV RNA detection among the triple infection group showed 47.4% (9/19) viremia rate and viral loads of 579,121 IU/ml in median (16,803–1,551,190 IU/ml). The prevalent genotype of HBV was type B (23/25); HCV was 1b (7/9) and HDV was IIa/IIb (4/4). Only the presence of HCV RNA predicted the presence of elevated ALT significantly (OR = 25.0; 95% CI = 3.39–184.6). In conclusion, the geographical aggregation of HDV infection paralleled that of HCV infection in this community. HCV suppressed the replication of HBV among triple vital infection patients. HBV and HDV lapsed into a remission or nonreplicative phase in most cases, and HCV acted as a dominant factor in triple viral‐infected individuals. Only the presence of HCV RNA was associated with elevated ALT values, but not HBV or HDV. J. Med. Virol. 70:74–80, 2003. © 2003 Wiley‐Liss, Inc.