在美国,人群当中一生传染乙型肝炎的危险大约为5％,而在高度危险的人群中可达到100％。估计每年可有100,000名有症状的乙型肝炎病例,大约有16,000名乙肝住院者,190例爆发性病人,其中大约3/4的人死亡。 1982年报告的乙肝病人,在已知其年龄者中有88％是在20岁以上。成人中的乙肝病毒感染6—10％可以成为携带者。而在美国至少有400,000—800,000名携带者。在携带者中有25％以上为慢性活动性肝炎。在美国每年大约有4,000名死于与乙肝有关的肝硬化,800名死于与乙肝有关的肝癌。 In the United States, the risk of transmitting hepatitis B throughout a lifetime is about 5%, while it can reach 100% among people at high risk. An estimated 100,000 cases of symptomatic hepatitis B disease each year, about 16,000 hospitalized hepatitis B patients and 190 explosive cases, about three-quarters of whom died. Of the hepatitis B patients reported in 1982, 88% were known to be over 20 years of age. Hepatitis B virus infection in adults 6-10% can become carriers. In the United States, there are at least 400,000-800,000 carriers. More than 25% of carriers are chronic active hepatitis. About 4,000 people die of cirrhosis associated with hepatitis B every year in the United States, and 800 die of liver cancer related to hepatitis B every year.