Résumé
Objective To observe the survival and reproduction of Oncomelania hupensis snails and their susceptibility to schistosome in schistosomiasis non-endemic area of the Yangtze River estuary in Southern Jiangsu.Methods The soil and water from the Yangtze River estuary of Southern Jiangsu were used for the experiment.The snails reproduced in the same year were collected from the upper reaches of the Yangtze River and raised in the laboratory.The snail survival and reproduction rates and schistosome infection of the snails were observed.The soil collected from schistosomiasis endemic area was used in the control group.Results There was no significant difference between the experimental and control groups for the snail survival rates both in 6 and 12 months (X~2= 0.727 8,P > 0.05 and X~2 = 0.416 1,P > 0.05).Each female snail reproduced 67.69 eggs in average (95 % CI:24.026 0-110.097 4).The average hatchability rate of snail eggs was 83.60%,and there was no significant difference between the 2 groups (X~2= 9.131 8,P > 0.05).The schistosome infection rate of the second generation snails was 1.40% (5/356) 60 days after the infection in the laboratory.Conclusions The snails collected from the upper reaches of the Yangtze River marshland can survival and reproduce in the soil and water from schistosomiasis non-endemic area of the Yangtze River estuary of Southern Jiangsu,and the second generation of the snails can be infected with schistosome in the laboratory.
Résumé
Both the snail number and the detection rate of living snails by means of snail screening in soil layer were higher than those of snail survey on soil surface. It is indicated that snail screening in soil layer can make up the shortage of survey on soil surface and improve the efficiency of snail control.