OBJECTIVETo determine the rate and type of "a" dominant mutation of hepatitis B virus (HBV) in community-based population of Shandong province and the possible effect of hepatitis B vaccination upon "a" dominant mutation.

METHODSThe anticipants aged 1-59 years were selected by multi-stage random sampling from the general population of Shandong province. Hepatitis B vaccination status was obtained by inquisition (for those over 15 years old) or immunization record (for those under 14 years old). The blood samples were collected and detected for HBsAg by ELISA. HBV DNA was extracted from the sera with positive HBsAg and S gene was amplified by nested-PCR. The PCR produce was sequenced and compared with the standard sequence.

RESULTSOverall, 7601 anticipants were investigated. HBV DNA was successfully amplified and sequenced in 102 of 239 samples with positive HBsAg. 14.70% sera samples mutated in HBV "a" determinant region and 13 mutation types were detected. There were no statistically differences in the mutation rate by age groups (born before or after national universal infant hepatitis B vaccination) and hepatitis B vaccination status.

CONCLUSIONThe "a" determinant mutation seemed to be uncommon in community-based population of Shandong province and the mutation sites were relatively scattered. Hepatitis B vaccination has no effect on "a" dominant mutation of hepatitis B virus.