[Causation of Oncomelania snail recurrence in water-net areas of Jiaxing City].

From 2004 to 2012, fourteen Oncomelania snail remaining spots with an area of 31.954 hm2 were found in the historical snail areas of Xiuzhou District, Jiaxing City. The recurrence time of snails was 5-39 years. These spots were mainly distributed in the complex breeding environments, such as paddy fields (37.15%), nursery stock fields (36.93%), mulberry fields (16.09%), and ditches (6.82%). A total of 8 370 snails were dissected and no infected ones were found. It suggests that the nursery stock fields should be included in the key points for snail surveillance in water-net areas where schistosomiasis transmission has been interrupted.