[Survey on Oncomelania snail distribution in sluices in Dongting Lake region].

Objective: To investigate the distribution, classification and reformation of all sluices located in the Dongting Lake region, and found out the relationship between irrigation and Oncomelania snail diffusion.
Methods: The information of sluices and their reformation were collected from the local Department of Water Resources and the information of snail conditions collected from the Department of Schistosomiasis Control. The latitude and longitude of each sluice were pinpointed and record with GPSmap76. All the data were analyzed statistically.
Results: There were a total of 589 sluices in the Dongting Lake region including 190 Kejinluo sluices (snails might enter through the sluice, 69 were reformed) and 49 Jinluo sluices (snails could enter through the sluice, 8 were reformed). The occurrence rate of snails was higher in water sluice than in drain sluice, and there was a significant difference between them (P < 0.05); the occurrence rate of snails in the sluice was higher when there were snails outside the sluice than when there was no snails outside the sluice, and there was a significant difference between them(P < 0.05).
Conclusions: The main source of snails in the sluice is from the outside of the sluice and irrigation is the main way that snails spread into sluice. The sluices should be reformed effectively, and the snails inside and outside sluice should also be destroyed effectively in order to consolidate the effect of snail control inside the embankment.