Application of geographic information system in surveillance of snail in Zhejiang province

Abstract

Objective To analyze the spatial distribution and trends of schistosomiasis intermediate host oncomelania snail in Zhejiang using geographic information systems (GIS). Methods The data gained from sampling surveys on schistosomiasis surveillance from 2005 to 2009 in Zhejiang were collected. The GIS database was created with these data. The distribution and variance map of spatial status of oncomelania snail was analyzed with spatial analyst extension of ArcGIS 9.2. Results Between 2005 and 2009, 28 residual snails conuties were found. The cumulate number of residual snails villages was 1580, and the cumulate residual snails area was 513.28 hm2 in 5 years. GIS database of oncomelania snails spatial distribution during 2005-2009 in Zhejiang was established, which made the snailsurvey information electronic. Compared to the years 2005 in Zhejiang, the variance map showed the county of snail areas compression and increasing accounted for 48.0% (12/25) and 52.0% (13/25) separately. The environmental satellite snail superposition map was established in national schistosomiasis surveillance site of Zhejiang. There were 17 snail spots in the map, and every spots showed the relevant information of snail situation. Conclusions The distribution and variance maps of oncomelania snail generated from GIS can eventually provide more scientific information for the situation of schistosomiasis, and help to provide the base of schistosomiasis control in Zhejiang. Key words: Geographic information system; Snails; Database