title: Insecticide resistance in malaria vectors in Kumasi, Ghana.
abstract: There have been recent reports of surge in resistance to insecticides in pocketed areas in Ghana necessitating the need for information about local vector populations and their resistance to the insecticides approved by the World Health Organization (WHO). We therefore studied a population of malaria vectors from Kumasi in the Ashanti Region of Ghana and their resistance to currently used insecticides. We conducted susceptibility tests to the four major classes of insecticides by collecting larvae of anopheline mosquitoes from several communities in the region. Surviving adults from these larvae were then subjected to the WHO-approved susceptibility tests and characterization of knockdown resistance and acetylcholinesterase mutant genes.
  
  
  
  Out of 619 Anopheles specimens sampled, 537 (87%) were identified as Anopheles gambiae (sensu stricto), which was also the species with the lowest knockdown resistance mutant gene, 61% (P = 0.017). Knockdown resistance mutant gene was as high as 91% in An. coluzzii. Mosquitoes collected showed susceptibility ranging from 98-100% to organophosphates, 38-56% to carbamates and 15-47% and 38-46% to pyrethroids and organochlorides, respectively. The knockdown resistance mutation frequency of Anopheles gambiae (sensu lato) mosquitoes that were exposed to both pyrethroids and organochlorides was 404 (65%). Acetylcholinesterase mutant gene was not found in this population of vectors.
  
  
  
  Our study shows that pyrethroids have the highest level of resistance in the population of mosquito vectors studied probably due to their frequent use, especially in impregnation of insecticide-treated nets and in insecticides used to control pests on irrigated vegetable farms. We recommend studies to monitor trends in the use of all insecticides and of pyrethroids in particular.
authors.affiliation: Kumasi Centre for Collaborative Research (KCCR), College of Health Sciences, Kumasi, Ghana. mamiboatemah@yahoo.co.uk.|Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana. mamiboatemah@yahoo.co.uk.
authors.forename: Sandra
authors.initials: S
authors.lastname: Baffour-Awuah
authors.affiliation: Kumasi Centre for Collaborative Research (KCCR), College of Health Sciences, Kumasi, Ghana.|Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana.
authors.forename: Augustina A
authors.initials: AA
authors.lastname: Annan
authors.affiliation: Kumasi Centre for Collaborative Research (KCCR), College of Health Sciences, Kumasi, Ghana.|Bernhard-Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany.
authors.forename: Oumou
authors.initials: O
authors.lastname: Maiga-Ascofare
authors.affiliation: Institut de Recherche en Sciences de la Santé (IRSS), Ouagadougou, Burkina Faso.
authors.forename: Soma Diloma
authors.initials: SD
authors.lastname: Dieudonné
authors.affiliation: Kumasi Centre for Collaborative Research (KCCR), College of Health Sciences, Kumasi, Ghana.
authors.forename: Priscilla
authors.initials: P
authors.lastname: Adjei-Kusi
authors.affiliation: Kumasi Centre for Collaborative Research (KCCR), College of Health Sciences, Kumasi, Ghana.|School of Public Health, College of Health Sciences, KNUST, Kumasi, Ghana.
authors.forename: Ellis
authors.initials: E
authors.lastname: Owusu-Dabo
authors.affiliation: Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana.
authors.forename: Kwasi
authors.initials: K
authors.lastname: Obiri-Danso
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D005869:Ghana; D007303:Insect Vectors / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D008288:Malaria / Q000635:transmission*; D059645:Mutation Rate; D011722:Pyrethrins / Q000494:pharmacology
chemical_list: D007306:Insecticides; D011722:Pyrethrins
keywords: Anopheles; Malaria; Resistance; Urban area; Vector control