Surveillance and risk assessment system of schistosomiasis in Jiangsu Prov-inceⅢRisk of schistosomiasis transmission in the area along the Yangtze River in Yang-zhou City / 中国血吸虫病防治杂志

Objective To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City,so as to provide evidences for establishing a post?transmission surveillance system for schistosomiasis in marsh?land regions. Methods The water infectivity,floating boatmen and fishermen infection,reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City,including Guangling,Hanji?ang,Jiangdu,Yizheng and Development Zone,and the transmission factors and risky characteristics were assessed after inter?ruption of schistosomiasis transmission in marshland regions. Results A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed,after breeding,their overall sur?vival rate was 99.33%;1 490 were dissected,with no schistosome infection. Of the 5 576 floating boatmen and fishermen exam?ined,no schistosome infection was observed,and among the 3 566 domestic animals(including 171 cattle,1 895 sheep and 1 500 pigs),no infections were detected. During the period between January and March,2016,there were 3 200 mouse traps placed on 8 marshlands,and 62 wild mice were captured from 6 marshlands,with a capture rate of 1.94%,and no schistosome?infected wild mice were seen. In addition,there were 35 pieces of fresh wild feces captured from 7 marshlands,including 11 pieces of bovine feces(31.43%),17 pieces of sheep feces(48.57%),2 pieces of dog feces(5.71%)and 5 pieces of other feces (14.29%),and no infections were detected. Conclusions There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However,the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.

Integration and demonstration of key techniques in surveillance and fore-cast of schistosomiasis in Jiangsu Province III Development of a machine simulta-neously integrating mechanized environmental cleaning and automatic mollusciciding / 中国血吸虫病防治杂志

Objective To develop a machine simultaneously integrating mechanized environmental cleaning and automatic mollusciciding and to evaluate its effectiveness of field application,so as to provide a novel Oncomelania hupensis snail control technique in the large?scale marshlands. Methods The machine simultaneously integrating mechanized environmental clean?ing and automatic mollusciciding,which was suitable for use in complex marshland areas,was developed according to the mech?anization and automation principles,and was used for O. hupensis snail control in the marshland. The effect of the machine on environmental cleaning and plough was evaluated,and the distribution of living snails was observed at various soil layers follow? ing plough. The snail control effects of plough alone and plough followed by mollusciciding were compared. Results The ma?chine could simultaneously complete the procedures of getting vegetation down and cut vegetation into pieces,plough and snail control by spraying niclosamide. After plough,the constituent ratios of living snails were 36.31% ,25.60% ,22.62% and 15.48% in the soil layers at depths of 0-5,6-10,11-15 cm and 16-20 cm respectively,and 61.91% living snails were found in the 0-10 cm soil layers. Seven and fifteen days after the experiment,the mortality rates of snails were 9.38% and 8.29% in the plough alone group,and 63.04% and 80.70% in the plough + mollusciciding group respectively(c27 d = 42.74,c215 d =155.56,both P values < 0.01). Thirty days after the experiment,the densities of snails were 3.02 snails/0.1 m2 and 0.53 snails/0.1 m2 in the soil surface of the plough alone group and the plough + mollusciciding group,which decreased by 64.92% and 93.60% ,respectively,and the decrease rate of snail density was approximately 30% higher in the plough + mollusciciding group than that in the plough alone group. Conclusions The machine simultaneously integrating mechanized environmental cleaning and automatic mollusciciding achieves the integration of mechanical environmental cleaning and automatic niclosamide spraying in the complex marshland areas,which provides a novel technique of field snail control in the large?scale setting in Chi?na.

Surveillance of Oncomelania hupensis snails in source areas of east route of South-to-North Water Diversion Project / 中国血吸虫病防治杂志

Objective To understand the distribution of Oncomelania hupensis snails in source areas of the east route of Southto-North Warter Diversion Project and evaluate the effects of the snails on the safety of water transfer.Methods The investigation of snail distribution was carried out in the source areas of the east route of South-to-North Warter Diversion Project every spring.The method of the random sample combined with environmental sample was used for the field investigation.The beach land in the stilling pool of Jiangdu Pumping Station was selected as a surveillance site to observe the snail spread.Results The areas of the snail habitats and infected snails were 256.11,184.55,164.92,121.16 hm~2 and 8.27,1.0,1.0,0 hm~2 respectively in the source areas of the east route of South-to-North Wafter Diversion Project from 2006 to 2009.The densities of living snails had a downtrend,too.Google Earth showed that the areas of snail habitats distributed mainly in the Jiajiang River and Mangdao River in the source areas.The snail habitats were detected in the beach land in the stilling pool of Jiangdu Pumping Station.The research results showed that the snail spread related to the wastes from the river of drawing water.Conclusion There are the risks of snail spread in the source areas of the east route of South-to-North Wafter Diversion Project,so that the long-term surveillance and control on the snails is very necessary.