日本血吸虫毛蚴对不同密度和距离湖北钉螺易感性的初步实验观察

摘要

To investigate the susceptibility of Oncomelania snails at different densities and to miracidium of Schistosomajaponicum, snails at 1, 2, 3 and 5 m, each with densities of 5, 10, 50 and 100 per package were infected with 20 000 freshly hatched miracidia in the field, and transferred to laboratory 4 h post-infection. All snails were dissected for infection eight weeks later. At sites of 1, 2, 3 and 5 m, the infection rates of snails were 7.06%, 4.35%, 2.47% and 1.23%, 4.55%, 4.44%, 4.11% and 2.27%, 2.62%, 1.58%, 1.29% and 1.1%, 2.36%, 4.04%, 2.73% and 1.5%, respectively for snail densities of 5, 10, 50 and 100 per package. It is indicated that the infection rates of snails are inversely proportional to the distances from the miracidium-disposal sites, but no linear relation between snail infection rate and snail density.%为探讨日本血吸虫（Schistosoma japonicum）毛蚴对不同密度、不同距离湖北钉螺（Oncomelania hupensis）易感性，在现场环境下，采用20000条新鲜孵化出的日本血吸虫毛蚴分别感染1、2、3、5m处的湖北钉螺，每处钉螺分为5、10、50、100只／袋4个密度组，感染4h后带回实验室饲养，8周后解剖观察钉螺感染情况。结果发现，距离1、2、3、5m，密度5、10、50、100只／袋4个组钉螺感染率分别为7．06％、4.35％、2．47％和1．23％：4．55％、4．44％、4．11％和2．27％：2．62％、1．58％、1．29％和1．1％：2．36％、4．04％、2．73％和1．5％。研究表明，钉螺感染概率与距毛蚴投放的距离成反比；但是，未得出钉螺感染率与钉螺密度之间的线性关系。