, and its prevalence differed by geographic region (6 to 25%), with a higher rate in the northern part of Japan. At admission, the 11 patients with HEV-associated hepatitis had elevated alanine aminotransferase levels of 914 to 4,850 IU/liter, and all but 1 had elevated bilirubin levels of 1.5 to 24.0 mg/dl. The 11 HEV isolates were of genotype III or IV and were segregated into three groups with intergroup nucleotide differences of 9.5 to 22.0%. Phylogenetic analysis revealed that four isolates of genotype III were closely related to a Japanese isolate, while the other four isolates of the same genotype were nearest those from the United States. The remaining three isolates were close to known isolates of genotype IV in China and Taiwan but shared less than 88% identity with them. These results indicate that multiple genotypes of HEV cocirculate in Japan and contribute to the development of sporadic acute hepatitis, with the prevalence differing by age, sex, and geographic region.

The outcome of acute hepatitis B virus (HBV) infection is variable, influenced by host and viral factors. From 1982 through 2004, 301 patients with acute HBV infection entered a multi-center cross-sectional study in Japan. Patients with fulminant hepatitis (n ‫؍‬ 40) were older (44.7 ؎ 16.3 vs. 36.0 ؎ 14.3 years, P < .0017), less predominantly male (43% vs. 71%, P ‫؍‬ .0005), less positive for hepatitis B e antigen (HBeAg) (23% vs. 60%, P < .0001), less infected with subgenotype Ae (0% vs. 13%, P < .05), and more frequently with Bj (30% vs. 4%, P < .0001) than those with acute self-limited hepatitis (n ‫؍‬ 261). Precore (G1896A) and core-promoter (A1762T/G1764A) mutations were more frequent in patients with fulminant than acute self-limited hepatitis (53% vs. 9% and 50% vs. 17%, P < .0001 for both). HBV infection persisted in only three (1%) patients, and they represented 2 of the 23 infected with Ae and 1 of the 187 with the other subgenotypes (9% vs. 0.5%, P ‫؍‬ .032); none of them received antiviral therapy. In multivariate analysis, age 34 years or older, Bj, HBeAg-negative, total bilirubin 10.0 mg/dL or greater, and G1896A mutation were independently associated with the fulminant outcome. In in vitro transfection experiments, the replication of Bj clone was markedly enhanced by introducing either G1896A or A1762T/G1764A mutation. In conclusion, persistence of HBV was rare (1%) and associated with Ae, whereas fulminant hepatitis was frequent (13%) and associated with Bj and lack of HBeAg as well as high replication due to precore mutation in patients with acute HBV infection.

We have identified four new hepatitis C virus (HCV) isolates whose genomic RNA could be amplified by PCR using primers from the 5' untranslated region (UTR), but the RNA could not be detected with genotype I to IV (or types la, lb, 2a and 2b respectively)-specific core region-derived primers. We compared the nucleotide sequences of the new isolates from positions 65 to 1850 (3' end of 5' UTR, C, E1 and 5' end of E2/NS1) and 8276 to 9394 (3' end of NS5 and 3' UTR) with those for genotypes I to IV. The four isolates had the following characteristics: (i) the overall nucleotide sequence similarity between the four isolates was 95 to 96 %, compared to 73 to 74 %, 73 %, 70 % or 69 to 70 % against genotypes I, II, III or IV, respectively; (ii) the sequence similarity to other reported 'type V (3a)' isolates was 88 to 100 %; (iii) the hypervariable region 1 [(HVR)-I] was present but HVR-2 was absent within the E2/NS1 region; (iv) only one in-frame termination codon was present for the presumed polyprotein; (v) the 3' UTR preceding a terminal poly(U) stretch was significantly shorter than in genotype I to IV isolates.We classified the four isolates as genotype V (3a), and

Thirty-four (41%) of 83 hepatitis C virus (HCV) isolates from commercial blood donors in Vietnam were not classifiable into genotype I/la, H/lb, HI/2a, IV/2b, or

Hepatitis C virus (HCV) isolates from 126 hepatitis patients in Jakarta, Indonesia were genotyped by PCR with genotype-specific primers deduced from the HCV core gene. Fifty-five isolates (44%) were classified as genotype II/lb, 15 (12 %) as lc, 33 (26 %) as III/2a, and 1 (1%) as V/3a, while the remaining 22 (17 %) were not classifiable into any of the five common genotypes (I/la, II/lb, III/2a, IV/2b and V/3a) or lc. Sequences of a part of the NSSb region [1093 bp (nucleotides 8279-9371)] of the 22 isolates of unclassifiable genotype were subjected to pair-wise comparison and phylogenetic analysis along with those of 62 isolates of 25 genotypes in nine genetic groups. Seven of the isolates were classified into 2e and two into 2f, representing novel genotypes in genetic group 2, while ten and three were classified into two new genetic groups, l0 and 11, respectively, and their genotypes were provisionally designated 10a and l la. The isolates of genotype 10a (JK049) and 1 la (JK046) were sequenced in full. Comparison of 24 HCV genomes including those of JK049 and JK046, over the entire genome and subgenomic regions, supported the classification of HCV into 11 genetic groups.