流行趋势最近的20多年中,一些国家的病毒肝炎有上升趋势。1967年世界卫生组织统计,病毒肝炎的发病率为0～9/10万者有14个国家;发病率为100～219/10万者有10个国家。从一些国家的历年发病曲线看来,似有周期性现象。Rowland等报告,在美国可以看出每7年上升一次的周期:1954年和1961年各有一次高峰,于1968年又呈回升,发病率为22.3/10万,1971年又有一次高峰,发病率为 Trend In recent 20 years, the viral hepatitis in some countries has been on the rise. According to the statistics of the World Health Organization in 1967, the incidence of viral hepatitis is 0 to 9 per 100,000 people in 14 countries; the incidence rate is 100 to 219 per 100,000 people and 10 countries. From the history of some countries incidence curve appears to be a cyclical phenomenon. Rowland et al. Reported that in the United States, there is a cycle of rising once every seven years: a peak in 1954 and 1961, a rise again in 1968 with a prevalence of 22.3 / 100 000 and a peak in 1971 with onset Rate is