Most people in the US don't grasp that, without huge public health effort, malaria would be endemic in much of the US. There's a reason the CDC is based in Atlanta. The organization is a direct descendant of the MCWA, founded in 1942 to control malaria in Southern army bases. https://twitter.com/balajis/status/1259483087785783297

In the 1930s, malaria control was also a vital part of the establishment of the TVA, because it affected about a third of the population there. I'm quite sure @rauchway knows way more about this than me.

Anyway, these "tropical" diseases aren't miraculously absent from the US.