Autochthonous infection with hepatitis E virus related to subtype 3a, France: a case report

Hepatitis E virus (HEV) recently emerged in Europe as a cause of autochthonous acute hepatitis and a porcine zoonosis. European autochthonous cases almost exclusively involved viruses of genotype 3, subtype 3a being only recently reported in France, from farm pigs. We report an autochthonous human infection with a HEV related to subtype 3a in Southeastern France. A 55-year-old human immunodeficiency virus-infected man presented liver cytolysis in June 2014. HEV RNA was detected in serum and three months later, anti-HEV IgM and IgG were positive whereas HEV RNA was no more detectable in serum. No biological or clinical complication did occur. HEV phylogeny based on two capsid gene fragments showed clustering of sequences obtained from the case-patient with HEV-3a, mean nucleotide identity being 91.7 and 91.3% with their 10 best GenBank matches that were obtained in Japan, South Korea, USA, Canada, Germany and Hungria from humans, pigs and a mongoose. Identity between HEV sequence obtained here and HEV-3a sequences obtained at our laboratory from farm pigs sampled in 2012 in Southeastern France was only 90.2-91.4%. Apart from these pig sequences, best hits from France were of subtypes 3i, 3f, or undefined. The patient consumed barely cooked wild-boar meat; no other risk factor for HEV infection was documented. In Europe, HEV-3a has been described in humans in England and Portugal, in wild boars in Germany, and in pigs in Germany, the Netherlands, and, recently, France. These findings suggest to gain a better knowledge of HEV-3a circulation in France.