[Survey of causes of infected Oncomelania snails and infectious sources of schistosomiasis in marshland and lake region of Jingzhou City].

Objective: To explore the causes of infected Oncomelania snails and the sources of infection of schistosomiasis in marshland and lake regions of Jingzhou City, so as to provide the evidence for the establishment of control strategy.

Methods: The snail environments in villages with or without cattle in Gong'an and Jianli counties, Hubei Province were selected, the snail status, infection status of people and livestock and wildlife reservoir host (mice), as well as the contamination status of wild faeces were surveyed, and the infectivity of water in investigated villages without cattle were detected by sentinel mice. The correlation between the densities of infected snails and positive faeces were tested by the rank correlation method.

Results: In villages without cattle, there were no positive faeces and infected sentinel mice discovered, while in the villages with cattle, 374 pieces of wild faeces were collected, the densities of wild faeces were 0.02 - 0.29 pieces/100 m2, and those of the positive ones were 0 - 0.01 pieces/100 m2, and the densities of infected snails were 0.001 - 0.040 snails /0.1 m2. The distribution of infected snails was consistent with that of the positive faeces, but the correlation coefficient between their densities had no statistical significance (r(s) = 0.123 5, P > 0.05). The average infection rates of human in villages with cattle inside embankment of Gong'an and Jianli counties were 2.87% and 1.37%, respectively, while that of the villages outside embankment of Gong'an County was 1.23%, and all the infection rates of cattle were 0. No infected wild mice were discovered.

Conclusions: Human and cattle are the main sources of schistosome infection in the local areas, the possibility of wild mice as source of infection is low, and cattle is an important cause of infected snails in marshland and lake regions in Jingzhou City.