Probably the fact that in the US any malaria patient would be quickly diagnosed, isolated and treated plays a big role? It makes it a lot less likely that they

Probably the fact that in the US any malaria patient would be quickly diagnosed, isolated and treated plays a big role? It makes it a lot less likely that they would transmit it to the next mosquito. Also in poor countries most people also get bitten in their house at night, with not screend doors or quality windows. I would assume this is pretty rare in well developed countries in comparison.