I live in Florida and spend most of my time crawling around where wild animals are... I’ve seen nasty bugs of all kinds and lots of parasitic critters... but I have yet to see a bedbug. Not even in my birds’ nest boxes outside. Worst thing in those are seed beetles, which are annoying to look at, but they don’t bite and the larvae make good chicken and fish food.
Now, I have a relative who is a stewardess who says the darn things are everywhere the airline workers go as some of the stewards and stewardesses are constantly transporting them around. When she travels she won’t even bring luggage or clothes into the house... every stitch of clothes goes into the laundry while the luggage gets stuffed in giant garbage bags and gets fumigated.
It does seem unlikely that the wild could be a primary source of these bugs.
A secondary source maybe, after having been infested from people. Anyhow, the environment needs to be considered. It seems hard to believe that people alone could be sustaining such colonies of bedbugs. They’d be dying of blood loss. Do these bugs somehow supplement their diets?