Abstract:

Objective  To investigate and analyze the characteristics of Oncomelania hupensis distribution in the hilly and mountain areas in Jiangning district  for the evidence to plan the strategy for transmission interruption in this area. Methods  Retrospective analysis was performed on the data summarized from the work reports on schistosomiasis control in Jiangning district between 2004 and 2013, with respect to the changes of infected areas with snails in different years and the snail index in mountainous endemic region in 10 years. Results  The snail-ridden areas in the hilly mountain areas in Jiangning district were 760.4562 hm2 in history, and were decreased from . The areas were decreased gradually, from 23.3765hm2 in 2004 to 10.3025hm2 in 2013, and the average annual decline was 5.59%. The average density of snails was decreased from 23.38hm2 in 2004 to 10.30hm2 in 2013, with an average decrease of 5.59% by each year. Snail density was also decreased from 0.7362 snail/frame in 2004 to 0.03 snail/frame in 2013. No infected snails were found except for one emerging snail region and two reemerging snail regions, which only amounted to a total area of 0.56hm2. Conclusion  Snail infected area and snail density tend to decline in the hilly mountain areas in Jiangning district. In order to achieve the target of transmission interruption, following control of schistosomiasis should be focused on these area.

Key words: Schistosomiasis, Oncomelania hupensis, hilly and mountain areas