上海市1988年甲型肝炎暴发的血清流行病学研究

本文以人群为基础,调查了上海市长宁区居民1649人。结果显示甲型肝炎(简称甲肝)罹患率为5.76％,发病以青壮年为主,男女性别无显著差別(p>0.05)。调查人群中食毛蚶者甲肝罹患率为15.86％,未食者为0.64％。相对危险度(RR)为24.78,特异危险度(AR)为15.22％,特异危险度百分比(AR％)为95.96％,人群特异危险度(PAR)为5.12％,人群特异危险度百分比(PAR％)为88.89％。甲肝发病与食蚶量及食蚶方式有关(p<0.0001)。对1649名居民采血470份,检测抗HA和抗HAIgM。血清学调查结果显示人群对甲肝易感性随年龄的增加而降低。人群的甲肝易感性平均为30.21％。抗HA阴性易感者食毛蚶的甲肝罹患率为29.41％,感染率为38.24％;未食蚶易感者甲肝罹患率分别为1.35％和5.41％。RR分别为21.79和7.07。本次甲肝流行隐性传染率为1.91％。

SEROEPIDEMIOLOGICAL SURVEY OF VIRAL HEPATITIS A DURING AN EPIDEMIC IN SHANGHAI

In order to investigate the characteristics of an epidemic hepatitis A in Shanghai which occurred in the early spring of 1988, 1 649 residents of Ohangning district were surveyed. The investigation revealed that the attack rate of hepatitis A was 5.76%, and the sufferers were mainly limited to the age group of 20-39 with no difference between males and females. For those having eaten a species of clam Area (Anadara) subcrenata, the attack rate was 15.86%, while for those without 0.64%. The relative risk (RR) was found to be 24.78, the attributable risk (AR) 15.22%, the attributable risk percentage (AR%) 95.96, the population attributable risk (PAR) 5.12% and the population attributable risk percentage (PAR%) 88.89. The attack rate of hepatitis A was closely related to quantity of the clams and ways of eating them (p<0.0001). Taking Wood samples of 470 among 1649 residents who had been examined for anti-HA and anti-HA IgM revealed that the number of persons susceptible to hepatitis A in the population fell gradually as the ago increased. Tho average susceptibility of this, group was 30.21%. In the Anti-HA negative group, for those who had eaten the clams, the attack rate was 29.41 % and the infective rate was 38.24%, while for those who had not eaten the clams, the attack rate was 1.35% and the infective rate was 5.41%. The relative risk was 21.79 and 7.07 respectively. The overall inapparent infection rate of hepatitis A in this outbreak was 1.91 %.