日本血吸虫尾蚴钻穿不同宿主皮肤时新转变童虫的死亡情况

日本血吸虫尾蚴在钻穿7种哺乳动物宿主皮肤而转变为童虫时,均发生了自然死亡,而且童虫的死亡率依宿主种类或同一种类的不同品系而异。它们皮肤内平均童虫死亡率分别为:小鼠3.7—7.2％、大鼠6.3％、金黄仑鼠7.0％、长爪沙鼠5.1％、豚鼠6.9％、兔4.9％、恒河猴12.8％。实验证明日本血吸虫尾蚴亦能钻入不易感的鸟类——鸽的皮肤,虽有1/4童虫立即在其皮肤内发生死亡,但部分童虫可移行至肺,然后在肺中消亡。

DEATH OF NEWLY TRANSFORMED SCHISTOSOMULA DURING PENETRATION OF SCHISTOSOMA JAPONICUM CERCARIAE INTO DIFFERENT HOST SKIN

The present study was made in order to determine whether cercariae of Schistosoma ja-ponicum die during penetration of different species of host skin. A small area of abdominal shaved skin infected with 300 cercariae was taken at different time intervals and recovery of schis-tosomula from skin was according to the method described by Clegg and Smithers (1968). Then the schistosomula were stained by 0.05% neutral red-potassium hydroxide to determine their viability.Our resoults showed that some schistosomula newly transformed from cercariae of S. ja-ponicum died during penetration of 7 species of mammalian skin and the mortality of schistosomula in skin varied with the host species. Approximately 3.7-7.2% of schistosomula died in various strains of mouse skin, 6.3% in rat, 7.0% in hamster, 5.1% in jird, 6.9% in guinea pig, 4.9% in rabbit and 12.8% in rhesus monkey, respectively. The number of death of schistosomula which newly transformed from cercariae during penetration of mouse abdominal skin was affect by the age of cercariae following emergence from the snail. Experiment was also designed to compare the mortality of the cercariae of S. japonicum to penetrate the skin of a non-susceptible host, the pigeon, a large numbers of schistosomula were recovered after they had entered the skin. Approximately one-fourth of these schistosomula died soon but some were recovered from the lungs on day 6 after penetvation and then attrition occurred.