Environmental effects on parasitic disease transmission exemplified by schistosomiasis in western China
Environmental effects on parasitic disease transmission exemplified by schistosomiasis in western China
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DOI：
10.1073/pnas.0701878104
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发表时间：
2007-04-24
影响因子：
11.1
通讯作者：
Spear, Robert C.
中科院分区：
文献类型：
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作者：
Liang, Song;Seto, Edmund Y. W.;Spear, Robert C.
环境对许多寄生虫病传播的影响已广为人知，但气候和农业实践等特定因素在调节传播方面的作用却很少被定量描述。基于对中国西部灌溉农业环境中日本血吸虫传播的研究，采用数学模型量化了环境对传播强度的影响。该模型使用三个村庄干预研究的现场数据进行校准，并进行模拟以预测替代控制方案的效果。这些干预措施的结果和早期的流行病学发现都证实了环境因素的核心作用，特别是与蜗牛栖息地以及农业和卫生实践相关的因素。此外，研究结果表明，目前的氯硝柳胺-吡喹酮策略不足以在某些流行地区实现可持续的传播阻断。更一般地说，分析提出了特定于村庄的传播潜力指数，以及这种潜力如何受到时变因素（包括气候变量、季节性水接触模式和灌溉实践）的调节。这些随时间变化的因素、村庄的内部潜力及其与邻居的联系，为评估血吸虫病持续传播的可能性提供了一个框架，并提出了一种量化环境因素对其他寄生虫病的作用的方法。
Environmental effects on the transmission of many parasitic diseases are well recognized, but the role of specific factors like climate and agricultural practices in modulating transmission is seldom characterized quantitatively. Based on studies of Schistosoma japonicum transmission in irrigated agricultural environments in western China, a mathematical model was used to quantify environmental impacts on transmission intensity. The model was calibrated by using field data from intervention studies in three villages and simulated to predict the effects of alternative control options. Both the results of these interventions and earlier epidemiological findings confirm the central role of environmental factors, particularly those relating to snail habitat and agricultural and sanitation practices. Moreover, the findings indicate the inadequacy of current niclosamide-praziquantel strategies alone to achieve sustainable interruption of transmission in some endemic areas. More generally, the analysis suggests a village-specific index of transmission potential and how this potential is modulated by time-varying factors, including climatological variables, seasonal water-contact patterns, and irrigation practices. These time-variable factors, a village's internal potential, and its connectedness to its neighbors provide a framework for evaluating the likelihood of sustained schistosomiasis transmission and suggest an approach to quantifying the role of environmental factors for other parasitic diseases.