There is another disease threatening our nation, brought here by refuges from he Middle East. It is Cutaneous leishmaniasis, a flesh eating disease caused by a parasite in the blood stream transmitted through sand fly bites. The disease can result in horrible open sores as well as disfiguring skin lesions, nodules or papules. If this disease can be hosted by other insect carriers, like fleas, ticks, or, God help us, mosquitoes, we will be spending billions to counter that menace.
Typically, multi-host parasites take advantage of specific host biologies in order to propagate. That means that the chance of leish being spread by vectors unrelated to sand flies is quite low.
Are there close relatives of sand flies in the US, or any US species of sand fly, that have similar biting behaviors? Those are the insects I would look at, in trying to determine whether leish could spread endemically in the US.