OBJECTIVETo investigate drug resistance, genotype and serotype of hepatitis B virus (HBV) in nucleos(t)ide analogue (NA) naive patients with chronic hepatitis B (CHB).

METHODSFull-length reverse transcriptase region of HBV DNA was amplified by semi-nested polymerase chain reaction from 97 NA-naive CHB patients, and the PCR product was sequenced, and analyzed to screen 11 classical antiviral drug resistance mutation sites and to identify HBV genotypes, subgenotypes and serotypes.

RESULTSWild-type sequences were found at all of the 11 classical antiviral drug resistance mutation sites from all samples. The patients were infected with either genotype B (36.1%, 35/97) or C (63.9%, 62/97) HBV. The former were all belonged to subgenotype B2 strain; while the latter were divided further into subgenotype C2 (91.9%, 57/62), subgenotype C1 (6.5%, 4/62) and unknown subgenotype (1.6%, 1/62). The 71.9% (23/32) of HBV genotype B patients were born in southern China, while 81.6% (40/49) of HBV genotype C patients were from northern China, showing a clear geographic distribution (Chi-square test = 23.19, Probability value less than 0.01). Of 97 CHB patients, 59 (60.8%) were serotype adr associated with genotype C, while 37 (38.1%) were adw related to genotype B (subgenotype B2) (Chi-square test = 87.83, P less than 0.01).

CONCLUSIONThe wild-type HBV strains prevail in NA-naive CHB patients, whose HBV genotypes, subgenotypes and serotypes are associated with their places of birth.