HEV identified in serum from humans with acute hepatitis and in sewage of animal origin in Spain

Background/Aims: Hepatitis E virus (HEV) is an enterically transmitted pathogen that appears sporadically in non-endemic countries. We studied HEV as a causal agent of acute hepatitis cases in the Spanish population, and the role of pigs as an animal reservoir. Methods: The presence of HEV-RNA was analysed by nested polymerase chain reaction in 37 serum samples from patients with acute viral hepatitis, 48 porcine serum samples, 6 pig faecal samples and 12 slaughterhouse sewage samples. Presence of antibodies was also tested in porcine sera. Results: HEV-RNA was found in 3 human serum samples from patients presenting IgG anti-HEV antibodies. Nucleotide sequence analysis identified 2 straiFns with 93.4% identity, phylogenetically most closely related to the Greece1 isolate, and more closely related to North American and other European strains than to those from endemic regions. HEV-RNA was also detected in slaughterhouse sewage mainly from pigs, presenting 92–94% nucleotide similarity compared to the strains detected in the human sera. Twenty-five per cent of the pigs tested presented IgG anti-HEV antibodies. Conclusions: These data suggest that the HEV could be more widespread than previously thought, and present new evidence of the close relationship between HEV strains detected in pigs and those from acute hepatitis patients.