There was malaria in Sweden and it was relatively common 250 years ago, especially in the archipelagos around Stockholm. The climate is probably not the best f

There was malaria in Sweden and it was relatively common 250 years ago, especially in the archipelagos around Stockholm. The climate is probably not the best for the parasite, but there was a number of changes that more or less unintentionally helped erradicate the disease. First, there were enormous projects to improve farming. Basically all lakes became regulated and most wetlands were dried out to gain farmland. Before that there was a long period of improvements of living standards and hygiene - as simple as separate and better houses for the people rather than sharing a single house with the kettle. Glass windows got affordable for basically everyone, etc. There are still mosquitos, including those that may transmit malaria, but the breeding opportunities and contamination paths got reduced below a critical level for the parasite. I suspect that having cold winters helps, but I guess that the situation in Africa could be improved too with better houses and better control of potential breeding areas. It took a couple of hundred years in Sweden though..