Hepatitis E virus HEV has been detected in Spain among patients with acute hepatitis swine livestock wild fauna and urban sewage but prospective studies have been scarce The incidence of the infection among humans and the mechanisms for acquisition of local HEV strains are unknown Serum samples from prospectively selected patients displaying liver alterations were tested for IgG and IgM antibody to HEV anti HEV and for HEV RNA HEV RNA was investigated in stool samples from piglets and in sewage samples from a single region and anti HEV was tested in serum samples from piglets from the same farms Acute HEV infection was identified in six patients and evidence of contact with HEV in the past but unrelated to the ongoing liver alterations was obtained in eight Two imported and four autochthonous cases of acute infection were recorded Most autochthonous cases were found in the Basque Country where swine livestock is not of economic importance HEV RNA was detected in stool samples from three piglets aged weeks from a single farm and anti HEV was found among piglets from all farms at rates ranging overall from to but from to among the oldest ones weeks old All sewage samples tested negative for HEV RNA The results show that locally acquired human HEV infection might be significantly more frequent in the Northern regions of Spain and that swine livestock might not be in the origin of most of these infections
