Graduate School of Environmental Sciences and Global Center of Excellence Program on Integrated Field Environmental Science, Hokkaido University, Sapporo, Japan.
J Infect Dis. 2012 Jun 15;205(12):1885-91. doi: 10.1093/infdis/jis289. Epub 2012 Apr 5.
Patterns of concerted fluctuation in populations-synchrony-can reveal impacts of climatic variability on disease dynamics. We examined whether malaria transmission has been synchronous in an area with a common rainfall regime and sensitive to the Indian Ocean Dipole (IOD), a global climatic phenomenon affecting weather patterns in East Africa.
We studied malaria synchrony in 5 15-year long (1984-1999) monthly time series that encompass an altitudinal gradient, approximately 1000 m to 2000 m, along Lake Victoria basin. We quantified the association patterns between rainfall and malaria time series at different altitudes and across the altitudinal gradient encompassed by the study locations.
We found a positive seasonal association of rainfall with malaria, which decreased with altitude. By contrast, IOD and interannual rainfall impacts on interannual disease cycles increased with altitude. Our analysis revealed a nondecaying synchrony of similar magnitude in both malaria and rainfall, as expected under a Moran effect, supporting a role for climatic variability on malaria epidemic frequency, which might reflect rainfall-mediated changes in mosquito abundance.
Synchronous malaria epidemics call for the integration of knowledge on the forcing of malaria transmission by environmental variability to develop robust malaria control and elimination programs.
种群协同波动模式——同步性，可以揭示气候变异性对疾病动态的影响。我们研究了在一个具有共同降雨模式且对影响东非天气模式的全球气候现象印度洋偶极子（IOD）敏感的地区，疟疾传播是否具有同步性。
我们研究了维多利亚湖流域约 1000 至 2000 米海拔高度范围内的 5 个 15 年长（1984-1999 年）的月度时间序列中的疟疾同步性。我们量化了不同海拔高度和研究地点海拔梯度范围内的降雨和疟疾时间序列之间的关联模式。
我们发现降雨与疟疾呈正季节性关联，这种关联随海拔高度的增加而减弱。相比之下，IOD 和年际降雨对年际疾病周期的影响随海拔高度的增加而增加。我们的分析显示，疟疾和降雨的同步性具有相似的非衰减幅度，这与 Moran 效应一致，支持气候变异性对疟疾流行频率的影响，这可能反映了降雨介导的蚊子数量变化。
同步性疟疾流行呼吁整合环境变异性对疟疾传播的驱动力的知识，以制定稳健的疟疾控制和消除计划。
