人工感染钉螺尾蚴得量的研究

目的 探讨大量人工感染钉螺的尾蚴收集及逸蚴得量。方法 在实验室条件下，用日本血吸虫毛蚴人工感染钉螺，60d后把全部感染钉螺分7份，每天逸1份，每10天对各份钉螺进行1轮逸蚴，用低速离心方法收集尾蚴，以沉淀尾蚴的重量作为尾蚴得量。结果 1900g贵池江滩钉螺，感染后经120d常规实验室饲养，感染率为36．00％，存活率为51．58％，经6轮40个逸蚴日的逸蚴，共收集尾蚴10．5g，经推算逸蚴期每1000只阳性钉螺1次逸蚴可获得尾蚴0.2573g。

STUDIES ON QUANTITY OF CERCARIAE SHEDDING FROM ARTIFICIAL INFECTED SNAILS

Objective To explore the Schistosoma japonicum cercariae collected method and the quantity of cercariae obtained from a great quantity artificial infected snails. Methods In laboratory condition, Oncomelania snails were infected with schistosome miracidia. Sixty days post-infection all snails were divided into 7 shares. Cercariae shed from 1 share snails every day and the number of all shedding days were 40. Cercariae shed from snails were collected with low-velocity centrifuge and the cercariae sediment were weighted. Results One thousand and nine hundred g snails bred for 120 days post-infection, the infection and survival rates were 36. 00% and 51. 58%. Cercariae col-lected were 10. 5 g from 40 days collection. Cercariae quantity of shedding from 1 000 positive snails per day was 0. 257 4 g.