Hepatitis E virus in patients with unexplained hepatitis in Finland

BackgroundHepatitis E virus (HEV) is an important cause of enterically transmitted viral hepatitis, especially in developing countries. Recently, HEV isolates have been identified in humans also in industrialized countries, where it has been considered nonendemic.ObjectivesTo investigate whether HEV is a cause of unexplained hepatitis in humans in Finland.Study designThe prevalence of anti-HEV IgM and IgG and HEV RNA was determined in 105 serum samples from 97 patients diagnosed with acute unexplained hepatitis. Partial nucleotide sequences of the HEV isolates obtained were compared with reported sequences in GenBank.ResultsAnti-HEV IgM and/or IgG by both ELISA test and immunoblotting were detected in 29 serum samples (27.6%) from 22 patients (22.7%). HEV RNA was detected in eight patient samples (8.2%) and partial nucleotide sequences were present in five of these. All five viruses belonged to HEV genotype 1, and three of them were from patients who had traveled to Asia.ConclusionThese preliminary results indicate that HEV must be considered a possible cause of acute hepatitis in Finland.