Distribution of Anopheles vectors and potential malaria transmission stability in Europe and the Mediterranean area under future climate change

Abstract

Background: In the scope of climate change the possible recurrence and/or expansion of vector-borne diseases poses a major concern. The occurrence of vector competent Anopheles species as well as favorable climatic conditions may lead to the re-emergence of autochthonous malaria in Europe and the Mediterranean area. However, high-resolution assessments of possible changes of Anopheles vector distributions and of potential malaria transmission stability in the European-Mediterranean area under changing climatic conditions during the course of the 21st century are not available yet. Methods: Boosted Regression Trees are applied to relate climate variables and land cover classes to vector occurrences. Changes in future vector distributions and potential malaria transmission stability due to climate change are assessed using state-of-the art regional climate model simulations. Results: Distinct changes in the distributions of the dominant vectors of human malaria are to be expected under climate change. In general, temperature and precipitation changes will lead to a northward spread of the occurrences of Anopheles vectors. Yet, for some Mediterranean areas, occurrence probabilities may decline. Conclusions: Potential malaria transmission stability is increased in areas where the climatic changes favor vector occurrences as well as significantly impact the vectorial capacity. As a result, vector stability shows the highest increases between historical and future periods for the southern and south-eastern European areas. Anopheles atroparvus, the dominant vector in large parts of Europe, might play an important role with respect to changes of the potential transmission stability.