ABSTRACT
Objective To explore the enrichment technique of Schistosoma japonicum cercariae on the water surface,so as to establish a new method combined with the existing technology to detect the cercarial infested water body quickly and sensitive-ly. Methods Soybean oil,gasoline,kerosene and isophorone were screened as expanding agents. The cercariae were enriched by the thrust of the expanding agents when diffusing on the water surface,and PE adsorption film and C-6 film were applied to seize them so as to determine the infectivity of the water quickly. The relationship between the dose of expanding agents and dif-fusion radius were explored. Results Gasoline,kerosene and isophorone were suitable expanding agents,and the diffusion ef-fect of isophorone was the best. After the enrichment by the expanding agents,the detection rate of cercariae of the method seiz-ing cercariae with the film significantly improved in the water. Conclusion This new method could effectively improve the de-tection rate of the cercarial infested water and is suitable for the low-degree infested water.
ABSTRACT
The C -6 film for adsorbing cercariae of Schistosoma japonicum on water surface were in-vestigated experimentally and in the field. The experimental results demonstracted that the average recovery rate of cercariae of the C -6 film adsorbing technique was about 40% while the traditional nylon tissue adsorbing precipitation method was about 3% ,which was signifi-cantly lower than the former. In some of the fields where oncomelania snails bred, the film adsorbing techinque could discover cercariae which usually could not be discovered with con-ventional methods. The study also showed that the film adsorbing technique was simple in operation,low in cost,and could obtain detection results promply within one day.