title: New Introductions, Spread of Existing Matrilines, and High Rates of Pyrethroid Resistance Result in Chronic Infestations of Bed Bugs (Cimex lectularius L.) in Lower-Income Housing.
abstract: Infestations of the common bed bug (Cimex lectularius L.) have increased substantially in the United States in the past 10-15 years. The housing authority in Harrisonburg, Virginia, conducts heat-treatments after bed bugs are detected in a lower-income housing complex, by treating each infested unit at 60°C for 4-6 hours. However, a high frequency of recurrent infestations called into question the efficacy of this strategy. Genetic analysis using Bayesian clustering of polymorphic microsatellite loci from 123 bed bugs collected from 23 units from May 2012 to April 2013 in one building indicated that (a) 16/21 (73%) infestations were genetically similar, suggesting ineffective heat-treatments or reintroductions from within the building or from a common external source, followed by local spread of existing populations; and (b) up to 5 of the infestations represented new genotypes, indicating that 5 new populations were introduced into this building in one year, assuming they were not missed in earlier screens. There was little to no gene flow among the 8 genetic clusters identified in the building. Bed bugs in the U.S. often possess one or both point mutations in the voltage-gated sodium channel, termed knockdown resistance (kdr), from valine to leucine (V419L) and leucine to isoleucine (L925I) that confer target-site resistance against pyrethroid insecticides. We found that 48/121 (40%) bed bugs were homozygous for both kdr mutations (L419/I925), and a further 59% possessed at least one of the kdr mutations. We conclude that ineffective heat treatments, new introductions, reintroductions and local spread, and an exceptionally high frequency of pyrethroid resistance are responsible for chronic infestations in lower-income housing. Because heat treatments fail to protect from reintroductions, and pesticide use has not decreased the frequency of infestations, preventing new introductions and early detection are the most effective strategies to avoid bed bug infestations in multistory apartment buildings.
authors.affiliation: College of Integrated Science and Technology, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Raab
authors.affiliation: SRI International, Center for Immunity and Infectious Diseases, Harrisonburg, Virginia, United States of America.
authors.forename: Julia E
authors.initials: JE
authors.lastname: Moore
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Edward L
authors.initials: EL
authors.lastname: Vargo
authors.affiliation: Harrisonburg High School, Harrisonburg, Virginia United States of America.
authors.forename: Lucy
authors.initials: L
authors.lastname: Rose
authors.affiliation: Harrisonburg High School, Harrisonburg, Virginia United States of America.
authors.forename: Julie
authors.initials: J
authors.lastname: Raab
authors.affiliation: Harrisonburg High School, Harrisonburg, Virginia United States of America.
authors.forename: Madeline
authors.initials: M
authors.lastname: Culbreth
authors.affiliation: Harrisonburg High School, Harrisonburg, Virginia United States of America.
authors.forename: Gracie
authors.initials: G
authors.lastname: Burzumato
authors.affiliation: Harrisonburg High School, Harrisonburg, Virginia United States of America.
authors.forename: Aurvan
authors.initials: A
authors.lastname: Koyee
authors.affiliation: College of Integrated Science and Technology, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Brittany
authors.initials: B
authors.lastname: McCarthy
authors.affiliation: College of Integrated Science and Technology, James Madison University, Harrisonburg, Virginia, United States of America.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Raffaele
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Coby
authors.initials: C
authors.lastname: Schal
authors.affiliation: SRI International, Center for Immunity and Infectious Diseases, Harrisonburg, Virginia, United States of America.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Vaidyanathan
mesh_terms: D000818:Animals; D001511:Bedbugs / Q000187:drug effects*; D004478:Ectoparasitic Infestations / Q000635:transmission; D006798:Housing; D007305:Insecticide Resistance / Q000187:drug effects; D007306:Insecticides / Q000494:pharmacology*; D011203:Poverty; D011722:Pyrethrins / Q000494:pharmacology*; D014481:United States
chemical_list: D007306:Insecticides; D011722:Pyrethrins