title: Monitoring field susceptibility to imidacloprid in the cat flea: a world-first initiative twelve years on.
abstract: In 2001, an international surveillance initiative was established, utilising a validated larval development inhibition assay to track the susceptibility of cat flea isolates to imidacloprid. In 2009, an Australian node was incorporated into the programme, joining laboratories in the United States and Europe. Field isolates of Ctenocephalides felis eggs were submitted to participating laboratories and, where egg quantity and quality was sufficient, were placed in the imidacloprid discriminating dose bioassay for evaluation. Between 2002 and 2012, a total of 2,307 cat flea isolates were received across all sites; 1,685 submissions (73 %) were suitable for placement into the bioassay. In the Northern Hemisphere, isolate submission rate was influenced by season, with highest numbers submitted between June and October. In Australia, pets with flea infestations could be sourced year-round, and submission rate was largely influenced by programme factors and not climate. A total of 1,367 valid assays were performed between 2002 and 2012 (assay validity data was not recorded in 2001); adult flea emergence 5 % or greater at 3 ppm imidacloprid was observed in 38 of these assays (2.8 %). For these isolates that reached the threshold for further investigation, re-conduct of the assay using either a repeat challenge dose of 3 ppm of imidacloprid or a dose response probit analysis confirmed their susceptibility to imidacloprid. From 2009 to 2012, the Australian node performed valid assays on 97 field isolates from a total of 136 submissions, with no adult emergence observed at the 3-ppm imidacloprid discriminating dose. In addition to reviewing the data generated by this twelve-year initiative, this paper discusses lessons learned from the coordination and evolution of a complex project across geographically dispersed laboratories on three continents.
authors.affiliation: University of Queensland, Gatton, QLD, Australia. s.kopp@uq.edu.au
authors.forename: Steven
authors.initials: S
authors.lastname: Kopp
authors.forename: Byron
authors.initials: B
authors.lastname: Blagburn
authors.forename: Glen
authors.initials: G
authors.lastname: Coleman
authors.forename: Wendell
authors.initials: W
authors.lastname: Davis
authors.forename: Ian
authors.initials: I
authors.lastname: Denholm
authors.forename: Chris
authors.initials: C
authors.lastname: Field
authors.forename: Joe
authors.initials: J
authors.lastname: Hostetler
authors.forename: Norbert
authors.initials: N
authors.lastname: Mencke
authors.forename: Robert
authors.initials: R
authors.lastname: Rees
authors.forename: Michael
authors.initials: M
authors.lastname: Rust
authors.forename: Iris
authors.initials: I
authors.lastname: Schroeder
authors.forename: Kathrin
authors.initials: K
authors.lastname: Tetzner
authors.forename: Martin
authors.initials: M
authors.lastname: Williamson
mesh_terms: D000818:Animals; D001315:Australia; D002371:Cat Diseases / Q000469:parasitology*; D002415:Cats; D058251:Ctenocephalides / Q000187:drug effects*; D004351:Drug Resistance; D062665:Epidemiological Monitoring; D005060:Europe; D058267:Flea Infestations / Q000469:parasitology*; D007093:Imidazoles / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000494:pharmacology*; D015995:Prevalence; D014481:United States
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid