2004-2008年江苏省钉螺分布动态分析

Dynamic analysis of Oncomelania snail distribution in Jiangsu Province,2004-2008

目的分析江苏省不同流行类型和流行程度地区钉螺分布特点及变化规律,为采取因地制宜、分类指导的防治策略与措施提供依据。方法采取回顾性调查方法,收集江苏省2004-2008年螺点卡报表和血吸虫病防治(血防)工作报表资料,建立江苏省5年的Excel螺情数据总库,分析不同年份钉螺面积、感染性钉螺面积和钉螺感染率的变化趋势,比较流行类型和程度不同的地区上述指标的年间变化。结果2004-2008年期内实有钉螺面积和感染性钉螺面积分别减少了3799.86hm2和2006.35hm2,年平均降幅为9.64%和18.83%,其中江湖滩、水网和山丘型地区期内实有钉螺面积分别减少了3546.10、209.19hm2和44.57hm2,年平均降幅为9.59%、10.29%和11.18%。5年间共新查出钉螺面积22.02hm2,其中水网地区占89.24%。2004-2008年期内实有钉螺面积占历史有螺面积的2.77%～5.36%,其中未传播控制、传播控制和传播阻断地区期内实有钉螺面积占历史累计钉螺面积的百分比分别为13.29%～22.82%、0.88%～3.54%和0.14%～0.32%,3组间差异均有统计学意义(P均(0.01)。2004-2008年江湖滩、水网和山丘型地区期内实有钉螺面积的构成比分别为93.79%～95.60%、3.67%～5.45%和0.73%～1.01%。2004-2008年全省钉螺感染率由0.15%下降到0.02%,下降了85.50%(P<0.01),其中未传播控制、传播控制和传播阻断地区查出感染性钉螺面积的构成比分别为98.15%～100%、0～0.81%和0～1.43%。结论江苏省钉螺面积和感染性钉螺面积总体呈下降趋势,传播阻断地区螺情逐步得到巩固,有效控制江湖滩地区钉螺面积和未传播控制地区感染性钉螺面积是下阶段血防工作的重点。

Objective To analyze the characteristics and changes of Oncomelania snail distribution in regions with different epidemic types and degrees of Jiangsu Province, so as to provide the evidence for implementing the feasible schistosomiasis control strategy. Methods A retrospective survey was performed, and the 5-year database of snail status in Jiangsu Province was estab- lished based on the collected reports of snail habitat cards and schistosomiasis control in Jiangsu Province from 2004 to 2008. The changes of snail areas, infected snail areas, infection rates of snails in different years were analyzed, and the annual variations of snail areas, infected snail areas and infection rates of snails in areas with different epidemic types and degrees were compared. Results The actual snail areas and infected snail areas decreased by 3 799.86 hm^2 and 2 006.35 hm^2 , respectively in Jiangsu Province, 2006 -2008, with the annual mean decreasing rates of 9.64% and 18.83%. Among them, the actual snail areas in marshland and lake regions, water net regions and mountainous regions decreased by 3 546.10,209.19 hm^2 and 44.57 hm^2 , respectively, with the annual mean decreasing rates of 9.59%, 10.29% and 11.18%, respectively. An area of 22.02 hm^2 of new snail habitats was detected during the 5 years, and the water net regions accounted for 89.24%. The proportions of actual snail areas in historical snail areas were between 2.77% and 5.36%. Among them, the proportions of actual snail areas in historical accumulative snail areas in transmission-uncontrolled, transmission-controlled and transmission-interrupted areas were 13.29% - 22.82% , 0.88% - 3.54% and 0.14% - 0.32% , respectively, and there were significant differences among them （ P 〈 0.01 ）. The constituent ratios of the actual snail areas were 93.79% -95.60% , 3.67% -5.45% and 0.73% - 1.01% , respectively in marshland and lake regions, water net regions and mountainous regions from 2004 to 2008. The infection rate of snails in Jiangsu Province reduced from 0.15% in 2004 1o 0.02% in 2008, with a reduction rate of 85.50% （ P 〈 0. 01 ）. The constituent ratios of infected snail areas in transmission-uncontrolled, transmission-controlled and transmission-interrupted areas were 98. 15% - 100% , 0 -0.81% , and 0 - 1.43% , respectively. Conclusions As a whole, there is a decreasing tendency of snail areas and infected snail areas in Jiangsu Province, and the snail control has been consolidated step by step in transmission-interrupted areas. The effective control of snails in marshland and lake regions and infected snails in transmission-uncontrolled areas are the key points in the future schistosomiasis control of Jiangsu Province.