流动水和静态水体中尾蚴感染力的比较观察

Comparative Study on Infectivity of Schistosome Cercaria in Flowing and Static Water

目的通过流动水和静态水体中尾蚴感染力的比较研究 ,探索尾蚴在流动水中感染力的规律。方法将逸出的尾蚴定量投入尼龙绢包绕的铁丝筐内 ,在不同水体、不同时段投放哨鼠 ,使其在流动水和静态水体两种状态中被感染。 3 5 d后解剖全部哨鼠 ,检获、计数血吸虫成虫 ,观察不同时间段哨鼠感染率 ,以推断尾蚴在流动水和静态水体中的感染力及其变化情况。结果流水组实验中 ,第 1组 (刚逸出尾蚴 )有 1只哨鼠被感染 ,哨鼠感染率为 1 .1 1 % ( 1 /90 )。静水组实验中 ,有 8组 (刚逸出至逸出 8h前组 ) 1 2只哨鼠被感染 ,感染率为 1 7.65 % ( 1 2 /68)。两组哨鼠感染率经统计学检验 ,( P<0 .0 0 5 ) ,差异有显著性 ,表明静水组哨鼠感染率显著高于流水组。结论实验表明尾蚴在流动水中的感染力明显减弱 ,而静态水中尾蚴的感染力较强。同时随着时间的延长 。

Objective To explore the infectivity of Schistosoma japonicum cercaria in flowing and static water. Method Special cages made with 260 aperture/cm 2 nylon were placed in the flowing (0.53 m/s) or static water. The mice were put into the cages which had been put into quntitative cercariae at different period of time. 35 days after infection, all the mice were anatomized to determine the infection. Result The infection rates of mice in flowing and static water were 1.11% (1/90) and 17.65% (12/68) respectively (P<0.005). The infection rate of mice decreased along with the time went by. Conclusion The study revealed that the infectivity of cercaria in flowing water was obviously weaker than that in static water. Meanwhile, it was deduced that the infectivity would loss gradually with the passing of time.