Effect of schistosomiasis control in Bianmin River of Nanjing City / 中国血吸虫病防治杂志

ABSTRACT

Objective To evaluate the effect of comprehensive control for schistosomiasis with emphasis on environmental modification in the Bianmin River water system of Nanjing City.so as to provide scientific evidence for making up further control measures in this water system.Methods Schistosome infections of Oncomelania snails in the waterway.sentinel mice in water and neighbouring human were investigated longitudinally from 1998 to 2007,and the changes of huaman infection rates in differentyears,the infection rates of sentinel mice and snails in different settings were analyzed and compared.Results A total of 77 395 snails collected from the Bianmin River water system were dissected from 1998 to 2007,and among them,27 snails were infected with Schistosoma japonicum,with a total snail infection rate of 0.03%.A total of 61 039 snails collected from the neighbouring marshland which connected to the Yangtze River wore dissected,and among them,257 were infected with S.japonicum,with a total snail infection rate of 0.42%,and there was a significant difference compared with that in the water system(χ~2=248.55,P<0.01).After the protection works in the waterway,the infection rates of sentinel mice in the water system decreased from 69.68% in 1998 to 17.50% in 2001.with a reduction rate of 74.89%.Two years afterthe clearance ofmarshlandinthewaterway,no infected sentinel mouse was found.The infection rates of residents from 1998 to 2007 were 1.96%,1.37%,1.34%,1.60%,0.30%, 0.26%,0.16%,0.10%,0.04% and 0,respectively,andthe rates declined year by year afterthecomprehensive control.Conclusions The control measures based on the elimination of snail habitats in the waterway that is connected to the Yangtze River have achieved obvious effect.However,the clearance of the re-emerging snail habitats should be carried out termly to consolidate the control effect.