Ferreira de Souza Rodrigo Augusto, Andreoli Rita Valéria, Toshie Kayano Mary, Lima Carvalho Afrânio
Universidade do Estado do Amazonas, Escola Superior de Tecnologia, Manaus, AM.
Geospat Health. 2015 May 18;10(1):314. doi: 10.4081/gh.2015.314.
A temporal series of the normalized difference vegetation index (NDVI) and other environmental parameters covering the years 2002- 2009 was used for the study of the potential association between the climate and the number of cases of American cutaneous leishmaniasis (CL) in Manaus Metropolitan Region (MMR), State of Amazonas, Brazil. The results show that CL has a marked seasonality and a strong linkage with local climate conditions. Dry and warm conditions favor the vector, while the maximum number of CL cases occurs during the following wet season. This has a clear relation to the El Niño/La Niña Southern Oscillation (ENSO) and the results presented here show that uncharacteristic dry conditions in the MMR follow El Niño after a lag period of 3 months, while wet conditions follow La Niña, again after a lag period of 3 months. El Niño brings dry conditions with warming of the land surface leading to increased growth of trees and bushes as indicated by rising NDVI values, eventually producing increased numbers of CL cases, with a peak of new cases occurring 4 to 5 months later. La Niña, on the other hand, produces wet and cool weather, which is less favorable for the leishmaniasis vector and therefore results in comparatively lower number of CL cases. Since these seasonal climate changes affect the dynamics of the CL vector, and thus the number of CL cases, a close watch of the ENSO phenomenon and the weather type it brings should be useful for monitoring and control of CL in the MMR.
利用2002年至2009年期间归一化植被指数（NDVI）和其他环境参数的时间序列，研究了巴西亚马孙州马瑙斯大都市区（MMR）气候与美洲皮肤利什曼病（CL）病例数之间的潜在关联。结果表明，CL具有明显的季节性，且与当地气候条件密切相关。干燥温暖的条件有利于传播媒介，而CL病例数最多的情况出现在随后的雨季。这与厄尔尼诺/拉尼娜南方涛动（ENSO）有明显关系，此处给出的结果表明，MMR地区非典型的干燥条件在厄尔尼诺现象出现3个月的滞后期后出现，而潮湿条件则在拉尼娜现象出现3个月的滞后期后出现。厄尔尼诺现象带来干燥条件，陆地表面升温，导致树木和灌木丛生长增加，如NDVI值上升所示，最终导致CL病例数增加，新病例数高峰在4至5个月后出现。另一方面，拉尼娜现象产生潮湿凉爽的天气，对利什曼病传播媒介不利，因此导致CL病例数相对较少。由于这些季节性气候变化影响CL传播媒介的动态，进而影响CL病例数，密切关注ENSO现象及其带来的天气类型，对于MMR地区CL的监测和控制应该是有用的。
