title: A strategy for emergency treatment of Schistosoma japonicum-infested water.
abstract: BACKGROUND
  Schistosomiasis japonica, caused by contact with Schistosoma japonicum cercaria-infested water when washing, bathing or production, remains a major public-health concern in China. The purpose of the present study was to investigate the effect of a suspension concentrate of niclosamide (SCN) on killing cercaria of S. japonicum that float on the water surface, and its toxicity to fish, so as to establish an emergency-treatment intervention for rapidly killing cercaria and eliminating water infectivity.
  
  
  RESULTS
  At 30 min after spraying 100 mg/L SCN, with niclosamide dosages of 0.01, 0.02, 0.03, 0.04 g/m², the water infectivity reduced significantly and no infectivity was found at 60 min after spraying SCN. The surface of static water was sprayed with 100 mg/L SCN, the peak concentration was found at 0 min, and the solution diffused to site with a water depth of 10 cm after 10 min. 30 min later, SCN diffused to the whole water body, and distributed evenly. After spraying 100 mg/L SCN onto the surface of the water with a volume of(3.14 × 202 × 50)cm³, with niclosamide dosages of 0.02 g/m², 96 h later, no death of zebra fish was observed.
  
  
  CONCLUSIONS
  By spraying 100 mg/L SCN, with a niclosamide dosage of 0.02 g/m² onto the surface of S. japonicum-infested water, infectivity of the water can be eliminated after 30-60 min, and there is no evident toxicity to fish. This cercaria-killing method, as an emergency-treatment intervention for infested water, can be applied in those forecasting and early warning systems for schistosomiasis.
authors: Jiangsu Institute of Parasitic Diseases, 117 Yangxiang, Meiyuan, Wuxi 214064, Jiangsu Province, People's Republic of China. wxliangyousheng@yahoo.cn
authors: You-Sheng
authors: YS
authors: Liang
authors: Wei
authors: W
authors: Wang
authors: Yun-Tian
authors: YT
authors: Xing
authors: Hong-Jun
authors: HJ
authors: Li
authors: Yong-Liang
authors: YL
authors: Xu
authors: Xue-Hui
authors: XH
authors: Shen
authors: Guo-Li
authors: GL
authors: Qu
authors: You-Zi
authors: YZ
authors: Li
authors: Jian-Rong
authors: JR
authors: Dai
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology* / Q000633:toxicity; D058487:Cercaria / Q000187:drug effects / Q000254:growth & development; D002681:China; D004305:Dose-Response Relationship, Drug; D006801:Humans; D051379:Mice; D009534:Niclosamide / Q000494:pharmacology* / Q000633:toxicity; D010571:Pest Control / Q000379:methods*; D012549:Schistosoma japonicum / Q000187:drug effects* / Q000254:growth & development; D012554:Schistosomiasis japonica / Q000469:parasitology / Q000517:prevention & control*; D012908:Snails / Q000469:parasitology; D014867:Water / Q000469:parasitology*; D015027:Zebrafish
chemical_list: D000871:Anthelmintics; D014867:Water; D009534:Niclosamide