Malaria in Southern Europe: resurgence from the past?

Malaria is an ancient diseasFe with historic records of high endemicity in southern Europe. With the exception of Turkey, the disease was eliminated from this region in the 20(th) Century by a mixture of targeted control, habitat modification and improvements in general living standards. Here we examine whether the disease might resurge in southern Europe under the environmental and climatic changes anticipated for the future. Populations of malaria vectors remain high in many countries of the continent, and their presence poses a risk of renewed transmission, should infected human hosts be available. The great plains of many southern European countries provide ideal habitats for malaria vectors. In the past 50 years, particularly in Italy, Greece and Turkey, the expansion of rice cultivation has resulted in great increases of the population densities of potential malaria vectors and current environmental conditions are suitable for malaria transmission. In addition, malaria remains endemic in the coastal and internal plains of the Asian parts of Turkey. This region also boarders on malaria-endemic countries such as Syria, Iran, Azerbaijan and Armenia. The increased agricultural activities and associated human migration in search of labour may serve to spread malaria across Europe and into currently malaria-free zones. This concerns mostly the upsurge of Plasmodium vivax, currently the only malaria parasite causing autochthonous cases in southern Europe. Increased international travel has caused an upsurge in cases of imported malaria in all European regions. However, the high level of health care and tendency of people to settle in urban areas, where malaria vector densities are low, are likely to prevent renewed outbreaks. Records of autochthonous transmission of (imported) malaria are rare and unlikely to cause renewed epidemics. It is concluded that under environmental and climate change the southern European region remains vulnerable to malaria transmission, and that locally outbreaks of malaria may occur, favoured by conditions that promote transmission of the disease. It remains to be seen whether the vector-parasite system is capable to adapt to the predicted changes and can adjust with evolutionary changes.