title: Inactivation of hepatitis A virus by heat and high hydrostatic pressure: variation among laboratory strains.
abstract: OBJECTIVE
  Hepatitis A virus (HAV) transmission via contaminated blood products has been reported. Cell-adapted HAV strains are generally used to confirm virus inactivation in manufacturing blood products, but the strains may differ in their sensitivity to inactivation treatment. To select an appropriate cell-adapted HAV strain for virus validation, we compared the inactivation efficiency among four strains under two different physical inactivation treatments: heat and high hydrostatic pressure.
  
  
  METHODS
  The cell-adapted HAV strains used here were KRM238, KRM003 (subgenotype IIIB), KRM031 (IA), and TKM005 (IB). The strains were treated at 60 degrees C for up to 10 h or under high hydrostatic pressure (up to 420 MPa). The reduction in HAV infectivity was measured by an immunofocus-staining method.
  
  
  RESULTS
  The heat treatment at 60 degrees C for 10 h reduced HAV infectivity in the range of 3 to 5 log(10) among the strains; KRM238 and TKM005 were harder to inactivate than the other two. The high hydrostatic pressure treatment at 420 MPa also reduced infectivity in the range of 3 to 5 log(10) among the strains, and KRM031 was easier to inactivate than the other strains.
  
  
  CONCLUSIONS
  Heat treatment and high hydrostatic pressure treatment revealed differences in inactivation efficiencies among cell-adapted HAV strains, and each strain reacted differently depending on the treatment. KRM238 may be the best candidate for virus validation to ensure the safety of blood products against viral contamination, as it is harder to inactivate and it replicates better in cell culture than the other strains.
authors.affiliation: Department of Virology II, Division of Biosafety Control and Research, National Institute of Infectious Diseases, Gakuen, Musashimurayama, Tokoyo, Japan, shima@nih.go.jp
authors.forename: N
authors.initials: N
authors.lastname: Shimasaki
authors.forename: T
authors.initials: T
authors.lastname: Kiyohara
authors.forename: A
authors.initials: A
authors.lastname: Totsuka
authors.forename: K
authors.initials: K
authors.lastname: Nojima
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: J
authors.initials: J
authors.lastname: Kajioka
authors.forename: T
authors.initials: T
authors.lastname: Wakita
authors.forename: T
authors.initials: T
authors.lastname: Yoneyama
mesh_terms: D000818:Animals; D058731:Blood Safety / Q000379:methods*; D002460:Cell Line; D002522:Chlorocebus aethiops; D030041:Hepatitis A virus / Q000145:classification / Q000254:growth & development / Q000502:physiology*; D006358:Hot Temperature; D006874:Hydrostatic Pressure; D007668:Kidney; D013045:Species Specificity; D014776:Virus Cultivation; D038301:Virus Inactivation