在我国甲型病毒性肝炎(甲肝)是严重的传染病之一,感染率和发病率均比较高。如浙江省调查,40岁以上的成年人中,甲肝抗体阳性率达90%以上,1978～1987年平均年发病率高达300/10万,1988年春上海甲肝特大流行,罹患率高达4000/10万,患病人数约34万。本病在高年龄组表现为很高的既往感染率;在青、少年中又表现为很高的发病率。主要原因 In our country, type A viral hepatitis (hepatitis A) is one of the serious infectious diseases, the infection rate and the incidence rate are relatively high. For example, in Zhejiang Province, among the adults over the age of 40, the positive rate of HAV antibody was over 90%, and the average annual incidence rate was as high as 300 / 100,000 in 1978-1987. In the spring of 1988, the Shanghai HAV pandemic reached as high as 4000 / 100,000 , The number of sick about 34 million. The disease in the high age group showed a high rate of past infection; in youth, juvenile and showed a high incidence. main reason