[Surveillance and forecast system of schistosomiasis in Jiangsu Province. VI. Detection technology of water infectivity based on enrichment of Schistosoma japonicum cercariae on water surface].

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 sensitively. 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 diffusion radius were explored. RESULTS: Gasoline, kerosene and isophorone were suitable expanding agents, and the diffusion effect of isophorone was the best. After the enrichment by the expanding agents, the detection rate of cercariae of the method seizing cercariae with the film significantly improved in the water. CONCLUSION: This new method could effectively improve the detection rate of the cercarial infested water and is suitable for the low-degree infested water.