2004~2011年湖南省感染性钉螺时空分布规律的研究

【摘要】 目的  了解湖南省感染性钉螺时空分布特征和变化规律，评估以传染源控制为主的防治策略实施的效果，探索防控重点区域，为血吸虫病防治提供科学依据。方法 收集以乡镇为单位的2004~2011年连续8年的感染性钉螺面积资料，绘制乡镇尺度电子地图，建立空间数据库，用螺情数据的总体指标、乡镇百分位数及空间自相关和扫描统计量分析研究时空分布特征。 结果  2004~2011年湖南省感染性钉螺面积下降明显，2004年为2 627.9hm2，至2011年下降至664.6hm2；乡镇感染性钉螺面积P50、P75、P90下降明显，2011年感染性钉螺面积P90为5.9hm2，分布示意图显示沿垸外有螺水系乡镇感染螺分布相对严重。期间各年感染性钉螺全局Moran’s I指数均大于期望值指数，位于0.13~0.28之间，经统计学检验均有统计学意义（Z>3.77，P<0.05）。局部H-H聚集区域（P<0.05）主要分布在洞庭湖沿岸，年聚集区域包括乡镇数在23~41之间。 结论  2004~2011年湖南省感染性钉螺面积明显下降，以控制传染源为主的防治策略和措施行之有效；感染性钉螺面积的空间正向聚集性明显，2011年个别乡镇感染性钉螺分布面积较大，仍需进一步强化防治，应加强联防联控，突出H-H聚集区域血吸虫病防治工作。

Spatial-temporal variation pattern of infected snails in Hunan Province from 2004 to 2011

【Abstract】 Objective To investigate the spatial-temporal variation pattern of infected snails in Hunan province in order to evaluate the effects of the integrated control strategies on prevention and control of schistosomiasis for scientific evidence in following plan decision. Methods  Data on the areas with infected snails were collected on town basis from 2004 to 2011. The electric map was prepared on town polygon, and spatial database was developed to match the polygon. The total index ,the spatial autocorrelation and spatial scan statistics at town level were included to quantify the spatial-temporal characteristics in the endemic areas. Results  The areas with infected snails tended to decline in general between 2004 and 2011. The decrease was from 2 627.9hm2 in 2004 to 664.6hm2 in 2011, and the corresponding P50, P75 and P90 was decreased sharply. However, the P90 was still at high level in 2011(5.9 h㎡), and the high level areas were associated with towns near the rivers with infected snails. Simulation analysis of the spatial weight matrix by Moran’s I between 20014 and 2011 indicated the index was greater than the expected one, which fell in 0.13-0.28, and the difference was statistically significant(Z>3.77, P<0.05). The number of towns, clustered primarily along the banks of Dongting Lake, with H-H types of auto-correlation was between 23-41. Conclusion  The areas with infected snails were significantly reduced in Hunan Province from 2004 through 2011, suggesting that the integrated measures with emphasis on infectious sources control appear effective for schistosomiasis control. However, distribution of the areas with infected snails tends to be positive auto-correlation, and the snail burden is still heavy in some towns in 2011. This needs further consolidated comprehensive prevention and control, particularly in areas with H-H types of distribution.