title: Hepatitis E virus: seroprevalence and frequency of viral RNA detection among US blood donors.
abstract: BACKGROUND
  Hepatitis E virus (HEV) is a nonenveloped emerging virus of increasing worldwide interest. Antibody prevalence, RNA frequencies, and transfusion transmissions have been reported. We investigated the HEV RNA and antibody frequencies in US blood donors.
  
  
  METHODS
  Individual-donation HEV RNA testing was performed on 18,829 donations from six US geographic regions using a CE-marked nucleic acid test (95% limit of detection, 7.9 IU/mL). Repeat-reactive donations were confirmed by in-house, real-time polymerase chain reaction (PCR; 10.3 IU/mL). Total HEV seroprevalence in a randomly selected subset of donations (n = 4499) was assessed by a direct, double-antigen sandwich assay; reactives were further tested for immunoglobulin (Ig)G and IgM. As part of the total antibody confirmatory algorithm, the cutoff was adjusted.
  
  
  RESULTS
  Two donations tested confirmed-positive for RNA (PCR not quantifiable, IgM/IgG positive; and 14 IU/mL, antibody negative) for a frequency of 1 in 9500 (95% confidence interval [CI], 1:2850-1:56,180) and 99.96% specificity (95% CI, 99.92%-99.98%); both donors were from the Midwest United States. Antibody prevalence was 9.5% (95% CI, 8.7-10.5) before the cutoff adjustment and 7.7% (95% CI, 7.0%-8.5%) after adjustment; 0.58% (95% CI, 0.39%-0.85%) were IgM positive.
  
  
  CONCLUSIONS
  We confirmed comparatively low rates and low viral loads of HEV RNA in US blood donors indicating the need for individual-donation testing if screening is implemented. Antibody prevalence rates were comparable to those reported by one US study using a different assay, but lower than those reported in another study using yet a third assay. We did not answer the question of whether US blood donation screening is warranted. Selective strategies involving providing HEV-negative blood to severely immunosuppressed patients at risk of developing hepatitis may be considered.
authors.affiliation: Scientific Support Office, American Red Cross, Gaithersburg, Maryland.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Stramer
authors.affiliation: Scientific Support Office, American Red Cross, Gaithersburg, Maryland.
authors.forename: Erin D
authors.initials: ED
authors.lastname: Moritz
authors.affiliation: Scientific Support Office, American Red Cross, Gaithersburg, Maryland.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Foster
authors.affiliation: Hologic, Inc., San Diego, California.
authors.forename: Edgar
authors.initials: E
authors.lastname: Ong
authors.affiliation: Hologic, Inc., San Diego, California.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Linnen
authors.affiliation: Department of Blood-Borne Infections, Virology Diagnostic Services, Sanquin Blood Supply Foundation, Amsterdam, the Netherlands.
authors.forename: Boris M
authors.initials: BM
authors.lastname: Hogema
authors.affiliation: MP Biomedicals Asia Pacific Pte. Ltd., Singapore.
authors.forename: Matthew
authors.initials: M
authors.lastname: Mak
authors.affiliation: MP Biomedicals Asia Pacific Pte. Ltd., Singapore.
authors.forename: Chee Poh
authors.initials: CP
authors.lastname: Chia
authors.affiliation: North Potomac, Maryland.
authors.forename: Roger Y
authors.initials: RY
authors.lastname: Dodd
mesh_terms: D000465:Algorithms; D000914:Antibodies, Viral / Q000097:blood; D001782:Blood Donors; D046148:Donor Selection / Q000379:methods*; D005260:Female; D016751:Hepatitis E / Q000097:blood / Q000453:epidemiology; D016752:Hepatitis E virus; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D012367:RNA, Viral / Q000097:blood*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D016036:Seroepidemiologic Studies; D014481:United States
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D012367:RNA, Viral