流行病学 A.年龄和职业: 年龄特异性发病率(age specific morbidityrates)在年龄组0—4岁中一般是低的,但在5—9和10—14岁组是最高,年龄增长时则逐渐下降。过去报告病例的半数见于20岁以下的人群中,最近在美国和瑞典有关年龄分布方面起了一种变化,60—70％的病例发生于成人。虽然死亡率在5岁以下的儿童要比5—14岁儿童高得多,许多作者认为在婴儿和较小儿童中傅染性肝炎是典型无黄胆型而且常常不具有任何的症状。在利比锡(Leipzig)医院医务人员中傅染性肝炎传播的危险性要比其他人群中高20倍。有人报告了2918例医师和医助人员与对照组中的工程 Epidemiology A. Age and Occupation: Age-specific morbidityrates are generally low in the 0-4 age group, but are highest in the 5-9 and 10-14 age groups, decreasing gradually. Half of the reported cases in the past have been found in people under the age of 20 and have recently taken a change in age distribution in the United States and Sweden, with 60-70% of cases occurring in adults. Although children under 5 years of age have a much higher mortality rate than children aged 5-14 years, many authors believe that fulminant hepatitis is typically cholestatic and often has no symptoms in infants and younger children. The risk of f to hepatitis spread among healthcare workers in Leipzig hospital is 20 times greater than in other populations. It was reported that 2918 physicians and medical staff and control group in the project