ABSTRACT
Objective To study the compliance of forbidden depasturing livestock on the marshland with Oncomelania snails in schistosomiasis endemic areas. Methods According to 3 levels of human infection rates as > 10% ,5%-10% and <5% , 2 204 residents selected randomly from the schistosomiasis endemic villages were sampled with the stratified cluster sampling method in Hunan, Hubei, Jiangxi, Anhui, Jiangsu, Sichuan and Yunnan provinces, and investigated by questionnaire. The contents of the questionnaire included the recognition and implementation of forbidden depasturing livestock on marshland with Oncomelania snails and breeding livestock in bam. Results A total of 78.4% residents agreed forbidden depasturing livestock on marshland with snails, but 3. 7% residents disagreed it. A total of 83. 9% residents considered the relationship between breeding livestock in bam and schistosomiasis control, but 3. 1% residents thought that it was no relationship. The main reasons of depasturing livestock on marshland with Oncomelania snails were the high cost of breeding livestock in bam (36. 2% ) , unaccustomed (26.4% ) and no room for breeding livestock in bam (25.4% ). Conclusion Forbidden depasturing livestock on the marshland with Oncomelania snails should be strengthened according to the local economic, nature environment, agriculture, residents'culture degree and agriculture habit.
ABSTRACT
Objective To observe the influence of suspension concentrate of niclosamide on the enzyme activity of Oncomelania hupensis in order to explore its molluscicidal mechanism. Methods Oncomelania hupensis snails were collected in the habitates of river marshland in Dantu District, Zhenjiang City, Jiangsu Provence and were divided into 2 groups. The snails of the treated group were sprinkled with 25% suspension concentrate of niclosamide. The snails of the control group were sprinkled with distilled water. The soft body tissue of the snail was separated and the sections of snail tissue were made in the Cryostat Microtome. The stain of enzyme-histochemistry showed CCO, LDH, SDH, CHE and NOS had been done, and then the staining block was made by routine method. The staining reaction in the snail tissue and the average gray density were observed with the image analysis system of biomicroscope. Results The enzyme activity of CCO, LDH, SDH, CHE and NOS located in the mouth, muscle fiber, tegumentary membrane, ganglia, liver and pharyngeal cavity of Oncomelania hupensis snails. The enzyme activities of CCO, LDH, SDH, CHE and NOS in the treated group were significantly lower than that in the control group. Conclusions Niclosamide can affect the transmitting of neurohypophysis and obstruct the energy and result in the disorder of the physiological functions in Oncomelania hupensis. It is one of the reasons of Oncomelania hupensis death.