title: Hepatitis B viral DNA among HBs antigen negative healthy blood donors.
abstract: BACKGROUND
  Presence of occult hepatitis B infection (OBI) renders HBs antigen (HBsAg) undetectable by ELISA. Therefore it is valuable to evaluate the frequency of OBI among healthy blood donors to improve and perhaps change the strategies of blood screening to reduce the risk of HBV transmission.
  
  
  OBJECTIVE
  The aim of this study was to determine the presence of HBcAb and HBV DNA among Iranian HBsAg negative healthy blood donors who donated their blood to the Tehran Blood Transfusion Center during 2011.
  
  
  METHODS
  1000 serum specimens negative for HBsAg, HCV antibody and HIV antibody were collected from healthy blood donors and tested for HBcAb. Presence of hepatitis B viral DNA was checked in HBcAb positive samples by nested PCR with two sets of primers to amplify part of HBV S gene.
  
  
  RESULTS
  There were 64 women and 936 men in the population under study. The mean ± SD age of the donors was 38 ± 11 years. 80 out of 1000 samples (8%) were found to be positive for HBcAb. HBV DNA was detected in 50% of HBcAb positive specimens. The mean ± SD age of donors without HBV DNA was 37.7 ± 10.5 years and for donors with HBV DNA was 40.9 ± 11.2 years (P = 0.05).
  
  
  CONCLUSIONS
  OBI was prevalent among 50% of HBcAb positive healthy blood donors. The frequency of positive HBcAb among healthy HBsAg negative blood donors was comparable to previous studies reported from Iran. On the other hand, the frequency of HBV DNA in HBsAg negative blood donors was higher than previous reports.
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran ; Department of Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Vaezjalali
authors.forename: Shabnam
authors.initials: S
authors.lastname: Rashidpour
authors.forename: Hanieh
authors.initials: H
authors.lastname: Rezaee
authors.forename: Bashir
authors.initials: B
authors.lastname: Hajibeigi
authors.forename: Majid
authors.initials: M
authors.lastname: Zeidi
authors.forename: Latif
authors.initials: L
authors.lastname: Gachkar
authors.forename: Shadi
authors.initials: S
authors.lastname: Aghamohamad
authors.forename: Ronak
authors.initials: R
authors.lastname: Najafi
authors.forename: Hossein
authors.initials: H
authors.lastname: Goudarzi
keywords: Blood Donors; Hepatitis B Surface Antigens; Hepatitis B virus; Polymerase Chain Reaction