An autochthonous case of acute hepatitis E in Mie, Japan who was infected with a rare hepatitis E virus strain of subgenotype 3F

In 2015, we saw a 67-year-old Japanese man with autochthonous acute hepatitis E living in the northern district of Mie prefecture, Japan. He had no history of travel abroad and blood transfusion. A rare HEV strain of subgenotype 3f was recovered from his serum. He was a job hunter engaged in wild boar hunting and processed captured boars with his naked hands. Although subgenotype 3b HEV strain was recovered from stored meat of captured wild boars, it seemed likely that he was infected with 3f HEV via exposure to meat and viscera of HEV-infected wild boars. Up to the present, at least four cases of autochthonous acute hepatitis E infected with 3f HEV have been identified in four prefectures in Japan. Further studies are warranted to clarify whether 3f HEV strains have been indigenized and domestic pigs and wild boars are infected with 3f HEV strains in Japan.