alt Hacker NewsNo. Malaria epidemics occurred in medieval Europe, both in warmer countries (Italy, Greece) and in France, Germany and England. It was also common in portions of the US until large-scale eradication efforts.
It's unlikely to become a problem again because the climate is not optimal and these countries are wealthy, have advanced healthcare systems, and can spray everything with DDT again if they feel like doing it.
Yes to everything but "the climate is not optimal". The climate was not optimal. I expect this year's weather in most of Europe must have been pretty spectacular for mosquitoes; if it becomes a regular occurrence, as scientists suggest, things might get pretty spicy. Places like Milan are already massive breeding grounds for the most aggressive types of mosquitoes.