ABSTRACT
Objectives To know the affecting degree of snail status by the flood in schistosomiasis epdemic areas.Methods The eight embankments suffered from disasterous floods and collapsed were selected in Dongting Lake; the changes of snail states and snail-killed etc.Before and after disasterous floods were surveyed by retrospectively. Results In the eight embankments, the snail areas inside embankment increased at different degree except two embankments where snail was not found after disaster, it was 10.8 times of that before disaster; Furthermore, after disaster the snail was found in the embankment enclosing village areas inside where it was not found before disaster; in most of embankments collapsed, the mean density of living snail inside embankment and mean density of infected snail and positive rates of snail outside embankment descended at different degree after disaster. Conclusions Inside embankment, the disastrous floods could lead to snails speading in most of embankments collapsed. Otherwise, outside embankment the flood led to reduce the mean density of infected snail and positive rates of snail in most of embankments collapsed, and the degree of snails spreading was affected by the factors such as the snail states at the collapsed place, mean density of living snail,immersed area by water, mud and sand ect.
