Xu Z Y, Li Z H, Wang J X, Xiao Z P, Dong D X
Department of Epidemiology, School of Public Health, Shanghai Medical University, People's Republic of China.
Vaccine. 1992;10 Suppl 1:S67-8. doi: 10.1016/0264-410x(92)90547-w.
During a shellfish-borne hepatitis A outbreak in Shanghai during the first quarter of 1988, 300,000 cases were reported in two months. Using cell culture and experimental infection of marmosets, hepatitis A virus (HAV) was isolated from clams collected from the market and the sea bed during the epidemic. A dose-response curve correlating the quantity of clams consumed to the attack rate of hepatitis A was well documented. The occurrence of the epidemic was associated with a good harvest of clams in a new area, serious pollution of this area with sewage and importation of the clams in large quantities into Shanghai where most young adults were susceptible. Clams can apparently be decontaminated by using a continuous water flow. In this way, HAV titres can be reduced by 90% in one day and by 99.9% in two weeks. An attenuated live HAV vaccine which has been developed in China has been shown to be safe and immunogenic and may be used for prevention of such epidemics in the future.
1988年第一季度，上海发生了一起由甲肝病毒引起的食源性疾病暴发，两个月内报告了30万病例。通过细胞培养和对狨猴进行实验性感染，从疫情期间市场和海床采集的蛤蜊中分离出了甲型肝炎病毒（HAV）。食用蛤蜊数量与甲型肝炎发病率之间的剂量反应曲线得到了充分记录。此次疫情的发生与一个新地区蛤蜊丰收、该地区受到污水严重污染以及大量蛤蜊被运往上海有关，而上海的大多数年轻人对此易感。显然，通过持续水流冲洗可以对蛤蜊进行净化。这样，甲型肝炎病毒滴度在一天内可降低90%，两周内可降低99.9%。中国研制的一种甲型肝炎减毒活疫苗已被证明是安全且具有免疫原性的，未来可用于预防此类疫情。
