已知甲、乙、非甲非乙三型病毒性肝炎中,仅乙型肝炎病毒(HBV)和甲型旰炎病毒具有血清学和形态学特征。众所周知HBV仅有一个型,它具有一种HB_c特异性的核衣壳和一含有S、前S_1及前S_2蛋白的包膜(envelope),包膜表面各亚型有一共同特异性的a和不同亚特异性的d、r、y或w。在HBV感染中,HBsAg和HBeAg在抗-HB_c或临床症状出现前数天到数周一般即可检测。HBV感染始终能检测到抗-HB_c, It is known that only hepatitis B virus (HBV) and type A virus have serological and morphological features among hepatitis A, B and non-B-hepatitis B virus hepatitis. It is well-known that there is only one type of HBV, which has an HB_c-specific nucleocapsid and an envelope containing S, pre-S 1 and pre-S 2 proteins. Each of the subtypes has a common specificity a and different Sub-specific d, r, y or w. In HBV infection, HBsAg and HBeAg can be detected several days to weeks before anti-HBc or clinical symptoms appear. HBV infection can always detect anti-HBc,