Collaboration between Texas A&M's Center for Urban & Structural Entomology and the University of Arkansas Insect Genetics laboratory is revealing important clues concerning the reasons for the current resurgence of bed bugs around the world and here in the United States......
....In our preliminary investigations we have found
significant populations occurring in poultry facilities in Arkansas and Texas, and we suspect that resistant populations of bed bugs have slowly increased in numbers in facilities such as these, and have subsequently been transported from poultry workers to other areas where they have subsequently spread. Population genetic studies of both mitochondrial and nuclear DNA reveal no genetic bottlenecks, yet significant variation with no apparent geographic structure with 19 distinct mt DNA halophytes from only 50 populations from throughout the United States (see below). For this reason, we believe that populations never truly died out in the United States, but were forced to alternate their hosts. Ongoing research on host identification from blood meals of bed bugs is currently being investigated to support this hypothesis.
http://urbanentomology.tamu.edu/bedbugs/bedbugs.cfm