Molecular epidemiological study of occult hepatitis B virus infection in blood donors / 中华传染病杂志

ABSTRACT

ObjectiveTo evaluate the prevalence of occult hepatitis B infection in blood donors and to explain the possible molecular mechanfism of occult hepatitis B infection.Methods Enzyme linked immunosorbent assay (ELISA) method was used for detection of hepatitis B virus (HBV)markers in serum samples of 594 donors which were collected from blood bank with HBsAg negative results.Nested-polymerase chain reaction (PCR) was performed to detect serum HBV DNA.In donors with occult HBV infection,the serum HBV markers were quantitatively detected by Abbott nested-PCR kit.The PCR products of S region were sequenced and sequence alignment was performed to analyze relevant virus mutations.Eleven HBsAg positive patients were randomly recruited as positive controls and S region was amplified and sequenced.The difference of S region sequences was compared between patients with occult HBV infection and HBsAg positive HBV infection.ResultsAmong 594 HBsAg negative donors,15 were diagnosed with occult HBV infection with the incidence of 2.5 ％.No correlation was found between results of serum HBV markers and occult HBV infection.Sequencing results of HBV S region were obtained from 10 cases,which revealed mutations of HBV.The amino acid mutations in the “a” determinant cluster were found in three patients,which were I126T,T140I and T140I,respectively.On the contrast,mutation in the “a” determinant cluster of T131 N was only found in one positive control.ConclusionsThe occult HBV infection exists in blood donors with negative results for HBsAg test.Genetic mutation may play a role in the occult HBV infection.