Tracing the history of hepatitis B virus genotype D in western Japan

Abstract

The major hepatitis B virus (HBV) genotypes in Japan are B and C. HBV genotype D (HBV/D), however, is widespread in a small area of Western Japan, where the Gianotti-Crosti syndrome caused by HBV subtype ayw, which is suspected to be HBV/D, was endemic in the 1970s. The aim of the study was to elucidate its origin, time of transmission, and spread in this area. Genotyping of HBV-DNA was done in 363 patients with HBV infection. The year of birth was checked in patients with HBV/D. The full genome sequences of 20 HBV/D strains, 2 of which were obtained from a single carrier with a 19-yearinterval, were analyzed. An evolutionary rate, the date of the most recent common ancestor, and the effective number of HBV/D infections were calculated. Fifty-two of 363 patients were infected with HBV/D, and 39 were born in 1970s. In a phylogenetic tree, the 20 HBV/D strains produced a definite cluster, and the evolutionary rate was calculated to be 5.4 Â 10 À5 nucleotide substitutions/site/year. The root of the tree was estimated to be in approximately 1,900 and began to spread from the 1940s, leading to a rapid increase of infected patients in the 1970s. From these results, it is suspected that HBV/D was likely transmitted to the area investigated approximately 100 years ago and then spread widely in the 1970s. From the history of the area and the genetic analysis, HBV/ D in this area was speculated to be of Russian origin.

Outbreak of Infections by Hepatitis B Virus Genotype A and Transmission of Genetic Drug Resistance in Patients Coinfected with HIV-1 in Japan

“…To estimate the emergence time of the prevailing genotype A2 strain, we estimated its mutation rate per year and tMRCA. First, the median mutation rate per year was calculated as 3.23 ϫ 10 Ϫ5 (5.62 ϫ 10 Ϫ8 to 9.01 ϫ 10 Ϫ5 ), which is close to those previously reported (10,18). Next, the median tMRCAs of all A strains, A1, A2, and C were determined to be 370.8, 88.9, 184.3, and 494.9 years ago, respectively (Table 4; Fig.…”

Clinical Features and Hepatitis B Virus (HBV) Genotypes in Pregnant Women Chronically Infected with HBV

“…However, in the district where our hospital is situated, the presence of genotype D has also been reported, with a prevalence of genotypes B, C, and D of approximately 5%, 88%, and 6%, respectively (19). The rate of genotype D-infected subjects in the present study was higher than that reported in previous studies, however, another report indicated that the proportion of genotype D in this district is high among HBV carriers born in the 1970s, in which decade the HBV genotype D was supposed to have spread in this area (20). Duong et al investigated the clinical features of patients infected with genotypes C and D in this district, and reported a high virulence of genotype C compared with genotype D, with the rate of anti-HBe state being higher in patients with genotype D than in those with genotype C (21).…”

Virologic characteristics of hepatitis B virus in patients infected via maternal-fetal transmission

“…This deletion mutant has previously been reported in different clinical conditions, especially hepatocellular carcinoma (HCC) and chronic hepatitis B (CHB) infection with genotypes C and D, and fulminant hepatitis B (FHB) with genotype A in Africa. It has also been observed in isolates obtained from nonhuman primates (Table 2) [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] . Interestingly, there are no reports of this deletion mutation in genotypes B, E, F and G. In a heart transplant recipient who died from fulminate hepatitis B transmitted by the donor, the 18bp deletion was detected in the recipient, but not in the donor [20] .…”