Here is a video report on TripAdvisor's survey that lists the "Ten Dirtiest Hotels in America." The report goes on the road to visit some of those hotels. An expert took a UV light and a meter that measured bacteria. They then talked to a TripAdvisor expert about what to look for when you are in a hotel room to find evidence if there are "bedbugs" in the bed. The video does not list the dirtiest hotels, but here is the link to the TripAdvisor list.