The Genus Cimex has several species. Most are bat bugs and bugs that infests birds’ nests. There are two species of bed bugs, Cimex lectularius and Cimex hemipterus. The latter being the tropical bed bug. As the name implies, it lives in the tropical regions. The main difference in all the species is where they live. Cimex lectularius is the one that has spread all over the world. In the United States, you will find the tropical bed bug in Florida.
Bed bugs belong to the Order of True Bugs. Aphids, cicadas, and stinkbugs are examples. These have piercing/ sucking mouthparts. Most True Bugs feed on plant juices. Kissing bugs and bed bugs are an example true bugs adapting to feed on animals. 
Other species may bite you when their normal host also lives in the building. For example, if you have bats in your attic bat bugs can come down into your room to feed on you. Although these other bugs may feed on humans, they are host specific. Meaning that bat bugs could not sustain themselves long term on human blood.
When the State of Ohio does their trainings, they report that many of their bed bug cases end up being bat bugs. I would guess that this could be true in rural areas where bats are more prolific. The solution for bed bug look-a-likes would be to remove the host (birds/ bats) from the building.