甲型肝炎疫苗免疫前后发病情况分析

Analysis of the Incidence of Hepatitis A Around Immunity

为比较沙县在甲型肝炎（甲肝）疫苗免疫前后甲肝的发病情况，对本站疫情定收集的1990～1997年报告的882例甲肝病例进行了分析。结果表明，疫苗免疫前甲肝发病率在63.36／10万～99.90／10万，免疫后为16.20／10万～21.87／10万，免疫前后平均发病率之比为422：1。按＜15岁、15～44岁和≥45岁分组，发病率下降最明显的是＜15岁，其次是15～44岁和≥45岁，依次下降了91.9％、70.1％和37.1％．工人、农民、学生（大、小、小学生）不同职业人群，以学生下降最明显，农民下降不明显，存在差别的原因可能是甲肝疫苗接种率的高低。甲肝疫苗接种的成本效益为1：953．

In the next half year of 1993, a wide range vaccination of hepatitis A (HA)vaccine had been launched in Sha County of Fujian Province. In order to investigatethe change of HA incidence around immunity, we took 882 HA cases reported in1990- 1997 in the county for study. The results showed that HA incidence before HAvaccination (1990 ~ 1993) was 63.36/100000 ~ 99.0/100000 (X2= 28.07, P= 0.000009) andthat after HA vaccination (1994 ~ 1997) was 16.20/100 000 ~ 21 .87/100 000 (x2= 2.31,P=0.000000). If compared HA incidence by age groups, it decreased by 91 .9%, 70.5% and37.1 % in < 15, 15 ~44, >45 year old cases respectively, and if compared by occupations, theincidence ranged from 62.67% ~ 91 '67%(X2 = 32. 72, P= 0.00000428), that was to say, HAincidence was the lowest in students from universities, theddle and primary schools, the highestin peasants. The difference may be re1ated to inununization coverage rate in populationsengaging different occupations. The cost benefit of HA vaccine was in the ratio of 1 to 9.53.