Spatial-temporal analysis on the distribution of infected snail at the village level in Anhui province, 2006-2012 / 中华流行病学杂志

Objective The characteristics of spatial-temporal distribution on infected snails were analyzed at the village level in Anhui province,2006-2012.Methods Data on the distribution of infected snails from 2006 to 2012 in Anhui province was collected.Spatial database was established by ArcGIS 9.3.Retrospective spatial-temporal cluster analysis was done by SaTScan 9.1.1 at the village level.Results Eight areas with increased risk and distributed along the upstream to downstream of Yangtze and connecting branch rivers,were found having infected snails,from 2006 through 2012,including one area in 2006,five in 2006-2008,one in 2007-2009 and one in 2009-2011,respectively.Proportion on the number of areas with infected snails decreased from 6.2％ in 2006 to 0.5％ in 2012.Conclusion The spatial-temporal distribution of infected snail was not random but there appeared significant clusters.The trend seemed to be declining in Anhui province,between 2006 and 2012.Areas being detected as smails positive were important for the schistosomiasis control program to be carried out in Anhui province.

Relationship between distribution of infected snails and transmission of acute schistosomiasis in hilly regions / 中国血吸虫病防治杂志

Objective To explore the relationship between the distribution of infected snails and transmission of acute schistosomiasis in hilly regions.Methods The data concerning the distribution of the infected snails and acute schistosomiasis in Shitai County,Anhui Province from 1999 to 2008 were collected and analyzed.Results The sehistosome infection rate of human increased as the distance between the settings with infected snails and activity sites of humans shortened.Conclusions Acute infection of schistosome of human is associated with the distance between the settings with infected snails and activity sites of them.Strengthening the measures of snail control in key regions,protecting key populations and carrying out health education for schistosomiasis control are important approaches to control the transmission of acute schistosomiasis in hilly regions.

Distribution of schistosome infected snails in Anhui Province / 中国血吸虫病防治杂志

Objective To understand the current distribution of infected snails in Anhui Province.Methods The data of snail survey were collected,the database was set up and the position of environments of infected snails were determined with GPS,the E-map was established with ArcGis 9.1 and the distribution of infected snail was analyzed.Results In 2007,331 environments with infected snails were found in Anhui Province,and 62.5% of them were found in the lake regions and 37.5% in the mountainous areas.The infected snail habitat areas were 682.6 hm2,85.5% of them were distributed in the lake regions and 14.5% in the mountainous areas.The river beach and the canal were the main environments with infected snails in the lake regions and mountainous areas,respectively;and 97.2% of the environments with infected snail were distributed in the infection-uncontrolled villages or villages which reached the criteria of infection control of schistosomiasis.Grassland was the main vegetation with infected snails,and the second was the reeds and trees.Conclusions The current endemic situation of the infection-uncontrolled villages or villages which reached the criteria of infection control of schistosomiasis is severe and should be emphasized for schistosomiasis prevention and control.The distribution of infected snail is connected with the river system.In the lake regions,the infected snails are distributed over the bottomlands of the Yangtze River and tributaries and islets and lakes;in the mountainous areas,the infected snails are distributed in the rivers banks and irrigated areas or special environments.