Abstract:

Objective  To analyze the dynamic changes of schistosomiasis infection and Oncomelania snails before and after the twice rebounds in history of schistosomiasis endemic in Liling county, in order to find the prevalence rules for scientific evidence in following prevention and control of schistosomiasis. Methods  Retrospective investigation was conducted through collection and review of the schistosomiasis endemic data in Liling county from 1960 to 2013. Then the database was established for analysis of the trends and rules of changes of snail status and infections in humans and cattle. Results  Twice rebounds of schistosomiasis endemic in history in Linli county were associated with rebounded snail prevalence, and positively correlated with snail density, infection rate in population and cattle(1982~1997: rhuman=0.879, P<0.01; rcattle=0.898, P<0.01; 2003-2013: rhunan=0.791, P<0.01; rcattle=0.845, P<0.01). Conclusion  Snail prevalence status can be critical indicators for estimation of epidemic situation, and effective control of snails may reduce the schistosomiasis transmission. Nevertheless, prevention and control of schistosomiasis should be long-term efforts, and monitoring and warning systems should be strengthened to prevent the endemic schistosomiasis from rebounding even the endemic remains in lower level.

Key words: Schistosomiasis, Retrospective investigation, Epidemic situation, Linli County