Wardrop Nicola A, Kuo Chi-Chien, Wang Hsi-Chieh, Clements Archie C A, Lee Pei-Fen, Atkinson Peter M
Geospat Health. 2013 Nov;8(1):229-39. doi: 10.4081/gh.2013.69.
Scrub typhus is transmitted by the larval stage of trombiculid mites. Environmental factors, including land cover and land use, are known to influence breeding and survival of trombiculid mites and, thus, also the spatial heterogeneity of scrub typhus risk. Here, a spatially autoregressive modelling framework was applied to scrub typhus incidence data from Taiwan, covering the period 2003 to 2011, to provide increased understanding of the spatial pattern of scrub typhus risk and the environmental and socioeconomic factors contributing to this pattern. A clear spatial pattern in scrub typhus incidence was observed within Taiwan, and incidence was found to be significantly correlated with several land cover classes, temperature, elevation, normalized difference vegetation index, rainfall, population density, average income and the proportion of the population that work in agriculture. The final multivariate regression model included statistically significant correlations between scrub typhus incidence and average income (negatively correlated), the proportion of land that contained mosaics of cropland and vegetation (positively correlated) and elevation (positively correlated). These results highlight the importance of land cover on scrub typhus incidence: mosaics of cropland and vegetation represent a transitional land cover type which can provide favourable habitats for rodents and, therefore, trombiculid mites. In Taiwan, these transitional land cover areas tend to occur in less populated and mountainous areas, following the frontier establishment and subsequent partial abandonment of agricultural cultivation, due to demographic and socioeconomic changes. Future land use policy decision-making should ensure that potential public health outcomes, such as modified risk of scrub typhus, are considered.
恙虫病由恙螨幼虫传播。已知包括土地覆盖和土地利用在内的环境因素会影响恙螨的繁殖和生存，进而也影响恙虫病风险的空间异质性。在此，将空间自回归建模框架应用于台湾2003年至2011年期间的恙虫病发病率数据，以增进对恙虫病风险空间模式以及促成该模式的环境和社会经济因素的理解。在台湾观察到恙虫病发病率存在明显的空间模式，且发现发病率与几种土地覆盖类型、温度、海拔、归一化植被指数、降雨量、人口密度、平均收入以及从事农业工作的人口比例显著相关。最终的多元回归模型包括恙虫病发病率与平均收入（负相关）、包含农田和植被镶嵌体的土地比例（正相关）以及海拔（正相关）之间具有统计学意义的相关性。这些结果凸显了土地覆盖对恙虫病发病率的重要性：农田和植被镶嵌体代表了一种过渡性土地覆盖类型，可为啮齿动物以及恙螨提供适宜的栖息地。在台湾，由于人口和社会经济变化，这些过渡性土地覆盖区域往往出现在人口较少的山区，这些区域是在农业开垦前沿建立并随后部分荒废之后形成的。未来的土地利用政策决策应确保考虑潜在的公共卫生结果，例如恙虫病风险的改变。
