The USA has ideal conditions for malaria. Washington DC was a giant malarial swamp at one point.

Florida has an abundance of skeeters, but they do not test positive for malaria.

Yes but that was not always the case. Malaria was endemic to North America and existed from Florida all the way up through Minnesota. The CDC was formed as the center for malaria control. I was responding to the point that "pretty much all rich countries" are in areas with climates not conducive to malaria. There are at least a half dozen rich countries that once were endemic to malaria. USA, Hong Kong, Australia, Italy, Singapore, etc.

It seems, then, that we need to figure out how to create more rich people in sub-Saharan Africa. Capitalism isn't the problem. It is the best long-term solution to problems like these.

I should have specified that I was talking about the US. My point was the US markets serve the US's demands very well. And if demand grew to cure malaria, the market would solve it, much like any other demand.