Two cases of acute hepatitis E infected with descendant strains of hepatitis E virus genotype 3 strain isolated from swine herd in Miyazaki Prefecture 12 years ago - One case had acute facial paralysis

We experienced two cases of acute hepatitis E in Miyazaki Prefecture in the same period. The patients were unknown to each other and did not have any clear causes or common risk factors of hepatitis E virus (HEV) infection. Nucleotide sequences of the HEV isolates revealed that the two isolates were closely related but with different HEV genotype 3 strains. The two cases appeared to be infected from unknown and different sources. Molecular phylogenetic analysis indicated that the strains were probably descendants of the strains which had been isolated from swine herd in Miyazaki Prefecture 12 years previously. This result indicates that the strains persisted in pig farms, in wild life, or in the natural environment in this region. The source should be identified, and efforts should be made to prevent of the spread of the infection. One of the cases had acute facial paralysis, which might be an extra-hepatic manifestation of HEV infection.