The potential persistence of ancient malaria through the Quaternary period in Europe

Abstract

Several members of the Mediterranean mosquito fauna are the potential vectors of Plasmodium vivax malaria. Although it is known that such primates as Macaca populated the Old Continent at least from the late Miocene era, the possible continuity of the Mediterranean mosquito fauna in Europe previously were not studied. In this study, the potential summer generation number of a Plasmodium vivax-like malaria protozoon and the suitability patterns of the Mediterranean mosquito fauna were modelled for 2 latest Neogene and 10 Quaternary periods. In addition, the mid-Pliocene and mid-Pleistocene Macaca distributions were also modelled. The model results show that the mid-Pliocene and mid-Pleistocene potential range of the Mediterranean mosquito fauna was much more extensive than the present days, covering the western and central parts of Europe. The mid-Pliocene and mid-Pleistocene Macaca populations lived in such areas where the Mediterranean Anopheles species could exist, and the potential summer generation number of Plasmodium vivax-like protozoon could be 3–4. During the Pleistocene interglacials and the Holocene era, many ancient human populations lived under such mild climatic conditions where the Mediterranean malaria mosquitoes and the malaria parasites could persist. In the Last Glacial Maximum, the members of the Mediterranean fauna were restricted to small refugia, which gradually increased in the last 21 ka reaching the present-day conditions. The Atlantic coasts of western Europe, the North Pontic area – and to a lesser extent-the Carpathian Basin seems to be sensitive to climatic changes related to the spread of Mediterranean mosquito vectors. The results support the permanent survival of P. vivax-like parasites throughout the Quaternary Period in Europe.