title: Low transfusion transmission of hepatitis E among 25,637 single-donation, nucleic acid-tested blood donors.
abstract: Hepatitis E virus genotype-3 (HEV-gt-3) causes autochthonous infections in western countries, with a primary reservoir in animals, especially pigs. HEV transfusion transmission has been reported, and HEV-gt-3 prevalence is high in some European countries. The prevalence of HEV RNA was investigated among Danish blood donors, and the prevalence of HEV transfusion-transmitted infection (TTI) was investigated among recipients.
  
  
  
  Samples from 25,637 consenting donors collected during 1 month in 2015 were screened retrospectively using an individual-donation HEV RNA nucleic acid test with a 95% detection probability of 7.9 IU/mL. HEV-positive samples were quantified by real-time polymerase chain reaction and genotyped. Transmission was evaluated among recipients of HEV RNA-positive blood components. Phylogenetic analyses compared HEV sequences from blood donors, symptomatic patients, and swine.
  
  
  
  Eleven donations (0.04%) were confirmed as positive for HEV RNA (median HEV RNA level, 13 IU/mL). Two donations were successfully genotyped as HEV-gt-3. Only one donor had a travel history outside Europe. Nine of 11 donors were male, but the gender ratio was nonsignificant compared with the total donor population. Seven available recipients tested negative for HEV RNA and anti-HEV immunoglobulin M in follow-up samples. One recipient was HEV RNA-negative but anti-HEV immunoglobulin G-positive. HEV TTI was considered unlikely, but a transfusion-induced secondary immune response could not be excluded. Phylogenetic analysis showed relatively large sequence differences between HEV from donors, symptomatic patients, and swine.
  
  
  
  Despite an HEV RNA prevalence of 0.04% in Danish blood donations, all HEV-positive donations carried low viral loads, and no evidence of TTI was found.
authors.affiliation: Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Lene H
authors.initials: LH
authors.lastname: Harritshøj
authors.affiliation: Department of Clinical Immunology, Odense University Hospital, Odense, Denmark.
authors.forename: Dorte K
authors.initials: DK
authors.lastname: Holm
authors.affiliation: Department of Clinical Immunology, Naestved Hospital, Naestved, Denmark.
authors.forename: Susanne G
authors.initials: SG
authors.lastname: Saekmose
authors.affiliation: Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Bitten A
authors.initials: BA
authors.lastname: Jensen
authors.affiliation: Departments of Blood-borne Infections and Virology, Sanquin Research and Diagnostic Services, Amsterdam, the Netherlands.
authors.forename: Boris M
authors.initials: BM
authors.lastname: Hogema
authors.affiliation: Virus Surveillance and Research Section, Statens Serum Institute, Copenhagen, Denmark.
authors.forename: Thea K
authors.initials: TK
authors.lastname: Fischer
authors.affiliation: Virus Surveillance and Research Section, Statens Serum Institute, Copenhagen, Denmark.
authors.forename: Sofie E
authors.initials: SE
authors.lastname: Midgley
authors.affiliation: Section for Diagnostics and Scientific Advice, National Veterinary Institute, Copenhagen, Denmark.
authors.forename: Jesper S
authors.initials: JS
authors.lastname: Krog
authors.affiliation: Department of Clinical Immunology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Erikstrup
authors.affiliation: Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Ullum
mesh_terms: D000328:Adult; D000818:Animals; D001782:Blood Donors / Q000706:statistics & numerical data*; D005260:Female; D005838:Genotype; D016751:Hepatitis E / Q000209:etiology / Q000635:transmission*; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D008297:Male; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D013552:Swine
chemical_list: D012367:RNA, Viral