[Evaluation of molluscicidal effects of contracted responsibility system in Changshan County].

OBJECTIVE: To explore a new molluscicidal pattern suitable for the complicated environments in hilly regions, so as to provide the evidence for making the strategy of Oncomelania snail control. METHODS: The contracted responsibility system for snail control was implemented by government. The quality of control work was evaluated in the same year and the recent molluscicidal effect was assessed in the next spring. RESULTS: After the intervention, the decline rate of snail areas increased from 53.4% to 100%; the compression rate of snail spots increased from 54.6% to 100%; the input of fund for snail control decreased from 2.03 Yuan/m2 to 0.69 Yuan/m2; the cost of snail control decreased from 3.73 Yuan/m2 to 0.75 Yuan/m2; the work efficiency increased from 12.0 m2/(man x day) to 36.7 m2/(man x day); the molluscicide decreased from 7.50 tons/year to 3.20 tons/year and the decline rate was 57.3%. The awareness rate and recognized rate of the contracted responsibility system for snail control were both 92.5%. CONCLUSION: The contracted responsibility system for snail control can increase financing efficiency, molluscicidal quality and work efficiency, and save molluscicide in complicated environments of hilly regions.