Résumé
<p><b>OBJECTIVE</b>Occult hepatitis B infection of voluntary blood donors has been plagued in the serum screening. Determined the OBI through the highly sensitive detection methods Nest-PCR among the blood donors, and then learned occult HBV infection and analysed the genotypes of this area.</p><p><b>METHODS</b>10 080 serums of donors were determined respectively by the imported Abbott HBsAg kit and Beijing Wantai anti-HBc and anti-HBs reagents, obtained the gene and detected DNA sequences by the high sensitive Nest-PCR method.</p><p><b>RESULTS</b>Among 10 080 cases of unpaid blood donors, 108 cases were detected HBsAg positively by Abbott sensitivity kit (positive rate of 1.07%), 767 cases were anti-HBc single - positive (positive rate of 7.67%). 25 patients screened blood donors who tested negative for serum HBsAg and positive for HBV DNA in the 10 080 cases. Occult HBV infection incidence rate was 0.25%. 12 cases were HBV genotype C (48%), 13 cases were genotype B (52%), and no other genotypes. Genotype B has no statistically significant difference to genotype C (P > 0.05). Sequence analysis showed that 5 patients in the HBsAg epitope "a" (aa124 - aa147) have mutation (20%).</p><p><b>CONCLUSION</b>The high proportion of occult hepatitis B infected among voluntary blood donors in our country. Also genotype and mutation was differences in different regions.</p>