Detection and characterization of hepatitis B virus of anti-hepatitis B core antigen-reactive blood donors in Quebec with an in-house nucleic acid testing assay.
BACKGROUND
Hepatitis B virus (HBV) infection can be detected in blood donations by many serologic markers. Since the introduction of routine anti-hepatitis B core antigen (HBc) donor screening at Héma-Québec in April 2003, a large number of donors have been deferred on the basis of reactive anti-HBc test results. The objective of this study was to evaluate the correlation between the anti-HBc-reactive donations and the detection of HBV DNA with an in-house nucleic acid testing (NAT) assay.


METHODS
The in-house HBV NAT assay is a conventional polymerase chain reaction amplifying part of the viral S gene. From October 2004 to November 2005, a total of 1169 anti-HBc-reactive donations were tested with this in-house assay. The results were correlated with hepatitis B surface antigen (HBsAg) and anti-HBs markers. HBV DNA-positive samples were further investigated by DNA sequencing.


RESULTS
All HBsAg-positive samples were detected by the NAT assay. Overall, 38 (3.25%) of anti-HBc-positive samples were found to be positive for the presence of HBV DNA. Of these 38, a total of 12 donations with a low level of HBV DNA were HBsAg-negative. The sequencing results clearly showed various genotypes and subtypes within a same genotype.


CONCLUSIONS
The 3.25 percent HBV DNA positivity rate among the anti-HBc-reactive donations and more particularly the low level of HBV DNA observed in occult donations underline the importance of the use of a sensitive assay to detect HBV DNA in conjunction with other markers. The HBV genetic diversity found in our donor population reflects the province demographics, particularly in the Montreal area where most of the positive donors were from.
Chevrier
Marie-Claire
MC
Research and Development, Héma-Québec, 1009 route du Vallon, Québec, Canada. Marie-Claire.Chevrier@hema-quebec.qc.ca
St-Louis
Maryse
M
Perreault
Josée
J
Caron
Brigitte
B
Castilloux
Cindy
C
Laroche
Jérôme
J
Delage
Gilles
G
D000595:Amino Acid Sequence; D001782:Blood Donors / Q000706:statistics & numerical data*; D001800:Blood Specimen Collection / Q000379:methods; D001803:Blood Transfusion / Q000592:standards*; D017931:DNA Primers; D004279:DNA, Viral / Q000097:blood / Q000302:isolation & purification; D005838:Genotype; D006511:Hepatitis B Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011792:Quebec; D012367:RNA, Viral / Q000097:blood
D017931:DNA Primers; D004279:DNA, Viral; D006511:Hepatitis B Antigens; D012367:RNA, Viral