Assessment and Projection of Climate Change Impacts on Malaria Distribution in Ethiopia

Abstract

The dynamics of Earth’s climate system have been affecting human life. In particular, climate change has a significant impact on the environment, socio-economic as well as on public health, especially on the transmission of malaria disease. Some sources of facts display that while no precisely defined limit exists beyond which malaria will not be found, recently a malaria distribution case has been seen in high land areas of Ethiopian. Thus, the objective of this research is to assess the impact of climate change on elevation-dependent malaria distribution temporally over Combolcha and Debark districts which are high lands of Ethiopia where there was no the case in history. The method applied for assessment and projection of climate variability is statistical approach, in general. And for assessment and projection of climate driven malaria distribution, the method used was based on the intersection of the favorable climate parameters (RTH) with the suitable threshold values. Thus, gradual malaria expansion to higher altitudes is justified in association to climate change and variability. In the result, we determine that the change and variability in precipitation was more significant (0.64 correlation) in controlling malaria transmission than the temperature over relative lower elevation areas (Combolcha). On the reverse, the change and variability in temperature (0.53 correlation) takes the first place in controlling malaria transmission over Debark. Moreover, the result indicates that the climate change and variability allowed malaria transmission site potentially tending to elevate/upraise to the high lands of Ethiopia like Debark district, recently. In this climate malaria suitability assessment, the altitude 2,800 meter above mean sea level was determined to be the demarcation point-level above which the disease malaria could not existed in Debark woreda for the period (1986-2016). Finally, this assessment result (2,800m) better demonstrated malaria transmission site with respect to elevation as compared with the result obtained using MARA13 malaria projection model output (2,500 m), for 2015. And, due to the present and future climate change malaria occurred on recent-time over new places of Ethiopia, in particular over high lands of Debark district; and in future, there is an indication to malaria persist over 2,800m elevation and incident on beyond this topographical height. Generally, we conclude that in the face of climate change malaria is climbing above the theoretical limit that nearly 2,000 m was the elevation beyond which malaria was believed unlikely to exist.