Methods A total of 1214 serum samples from patients with chronic HBV infection were collected in 11 cities of China,including Beijing,Qingyuan, Shenzhen,Shijiazhuang,Hanchuan,Nanjing,Changchun,Liaocheng,Jinan,Ningbo and Wenzhou.

• 方法收集北京、清远、深圳、石家庄、汉川、南京、长春、济南、聊城、宁波和温州市共1214份HBV DNA阳性的慢性HBV感染者血清样本,用型特异性引物聚合酶链反应法(PCR)进行基因型测定,并对其中部分样本以PCR产物直接测序验证。