感染性钉螺在北方水域对动物宿主的易感性

Infectivity of infected Oncomelania snails to reservoir hosts of Schistosoma japonicum in northern China

目的探索输入性感染性钉螺在北方非疫区水域感染人畜的可能性。方法选择南水北调水利枢纽微山湖区作为研究现场,以南水北调东线工程干渠南端取水口地区江滩的感染性钉螺,感染动物宿主小白鼠30只和家兔3只;采用毛蚴孵化法粪检和解剖实验动物,观察肝脏虫卵结节的方法以确定感染情况。结果感染后第2～4周,存活的19只小白鼠肝脏均有虫卵结节,感染成功率为100%;感染后第7周,家兔毛蚴孵化法粪检血吸虫卵均为阳性,解剖见肝脏均有虫卵结节。结论输入性感染性钉螺在北方非疫区自然水域具有逸出尾蚴并感染动物宿主的能力。

Dushan Island in the Weishan Lake area which was the hydro-junction of the South-to-North Water Diversion Project was selected as a study site to study the infection probability of imported infected Oncomelania snails to reservoir hosts of Schistosoma japonicum in a non-endemic area. Thirty mice and 3 rabbits were infected with cercaria of Schistosoma japonicum from Oncomelania snails at the water intake area in the south of the main canal of the project, and the status of infection was determined by using the miracidum hatching method and counting the number of egg tubercles in the liver after anatomy. The results showed that 11 mice died from the second to forth week after the infection, egg tubercles were found in the livers of the other 19 mice, and the infection rate was 100%. In the seventh week after the infection, the egg positive of the rabbits were 100%, and egg tubercles were found in the livers of all of them. It is indicated that the importted infected Oncomelania snails have the ability to infect the reservoir hosts of Schistosoma japonicum.