Overlap and discrepancy between tests for anti-C100, anti-GOR and anti-CP9 in patients with chronic liver disease and inhabitants in Saga, Japan

Phylogenetic tree-based epidemiological analysis of hepatitis C virus transmission in a region of Japan with a high prevalence of infection

Local clustering of hepatitis C virus (HCV) infection has been demonstrated in various regions in Japan. HCV genotypes have now been compared between infected individuals from districts of Saga prefecture with either a high (H district) or low (L district) prevalence of HCV-seropositivity. The prevalence of HCV genotype 1b was significantly higher (P < 0.001) in the H district (45/50; 90%) than in the L district (19/36; 52.8%). A phylogenetic tree was constructed based on the genomic sequences of viral isolates from 20 patients infected with genotype 1b in the H district. Almost all these HCV strains clustered in the same regions of the tree. With regard to risk factors for HCV transmission, the percentage of patients with a history of surgery was significantly higher in the H district than in the L district (58 versus 33.3%; P < 0.05). Of 20 patients infected with similar strains of HCV in the H district, 16 (80%) had at least one parenteral risk factor associated with medical care. These results indicate an increased transmission of similar strains of HCV in the H district as a result of nosocomial infection.

Analysis of nucleotide sequences of hepatitis C virus isolates from husband-wife pairs

To identify the route of hepatitis C virus (HCV) transmission, we investigated the sexual transmission of HCV by examining HCV markers among spouses of patients with chronic liver disease (CLD) due to HCV. Of 83 spouses, 14 (16.9%) had elevated serum aspartate aminotransferase or alanine aminotransferase, 20 (24.1%) had detectable anti-HCV antibodies, and 17 (20.5%) had measurable HCV-RNA in serum. However, the seropositivity rate of anti-HCV antibodies (24.1%) of patients' spouses was not significantly higher than that (15.4-27.5%) of an unselected population in the same district. Ten patient-spouse pairs underwent nucleotide sequence analysis of the HCV core and envelope genes. Overall the sequence homology of 10 couples (91.1%) was not significantly higher than that of 10 randomly chosen unrelated pairs (88.2%). As reported earlier, in an age and sex matched case-control study of HCV transmission, a history of surgery is a prominent HCV risk factor. These results suggest that sexual transmission of HCV is rare.