Recently we saw two patients with acute hepatitis, infected with hepatitis E virus (HEV) of a rare genotype 3f. One patient (Tokyo/2012) had traveled Spain 1 month before developing hepatitis, while the other patient (Saitama/2014) did not have history of traveling abroad. Nearly entire genomic sequence of HEV was recovered from both patients; 7,336 nucleotides (nt) from the Tokyo case in 2012 (isolate name=JAO-SpaTok12, accession=LC055972) and 7,306 nt from the Saitama case in 2014 (JMH-Sai14, LC055973). Phylogenetic analysis revealed that JMH-Sai14 from the Saitama patient, who denied having traveled abroad, could be classified into a subgroup of genotype 3f, together with European isolates as well as an already reported Japanese isolate HE-JA12-0725 (AB850879) from a patient living in Gunma and having never traveled abroad when he/she developed hepatitis in 2012. On the other hand, the Tokyo patient's sequence segregated to a separate branch together with European isolates. Based on these findings it is possible that HEV genotype 3f has already made inroad into Japan as in the case of 3e.
