Insecticide resistance in Anopheles arabiensis from Ethiopia (2012–2016): a nationwide study for insecticide resistance monitoring

Malaria Journal

Research

Robert A. Wirtz¹  Louisa A. Messenger¹  Seth R. Irish¹  Mekonnen Yohannes²  Hiwot Solomon Taffese³  Aklilu Seyoum⁴  Dereje Dengela⁴  Alemayehu Getachew Tesfaye⁵  Yemane Ye-Ebiyo⁵  Gedeon Yohannes Anshebo⁵  Josephat Shililu⁵  Kristen George⁶  Christen Fornadel⁶  Estifanos Kebede⁷  Endalew Zemene⁷  Abebe Asale⁷  Delenasaw Yewhalaw⁸  Gunawardena Dissanayake⁹  Sheleme Chibsa⁹ 

[1] Entomology Branch, Centers for Disease Control and Prevention, 1600 Clifton Road, 30329-4027, Atlanta, GA, USA;Medical and Entomology Unit, Institute of Bio-Medical Sciences, College of Health Sciences, Mekelle University, Mek’ele, Ethiopia;National Malaria Control Programne, Federal Ministry of Health, Addis Ababa, Ethiopia;President’s Malaria Initiative Africa Indoor Residual Spraying Project, Abt Associates, 4550 Montgomery Ave., Suite 800 North, 20814, Bethesda, MD, USA;President’s Malaria Initiative Africa Indoor Residual Spraying Project, Abt Associates, Gerji Road, Sami Building, 1st Floor, Addis Ababa, Ethiopia;President’s Malaria Initiative, United States Agency for International Development, Bureau for Global Health, Office of Infectious Disease, 2100 Crystal Drive, 22202, Arlington, VA, USA;Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia;Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia;Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia;U.S. Agency for International Development (USAID), Entoto Street, Addis Ababa, Ethiopia;

关键词: Insecticide resistance;    Anopheles arabiensis;    Resistance mechanisms;    Intensity assays;    Malaria;    kdr;    Ethiopia;   

DOI  :  10.1186/s12936-017-2115-2

 received in 2017-07-01, accepted in 2017-11-10,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundIndoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) remain the cornerstones of malaria vector control. However, the development of insecticide resistance and its implications for operational failure of preventative strategies are of concern. The aim of this study was to characterize insecticide resistance among Anopheles arabiensis populations in Ethiopia and describe temporal and spatial patterns of resistance between 2012 and 2016.MethodsBetween 2012 and 2016, resistance status of An. arabiensis was assessed annually during the long rainy seasons in study sites from seven of the nine regions in Ethiopia. Insecticide resistance levels were measured with WHO susceptibility tests and CDC bottle bioassays using insecticides from four chemical classes (organochlorines, pyrethroids, organophosphates and carbamates), with minor variations in insecticides tested and assays conducted between years. In selected sites, CDC synergist assays were performed by pre-exposing mosquitoes to piperonyl butoxide (PBO). In 2015 and 2016, mosquitoes from DDT and deltamethrin bioassays were randomly selected, identified to species-level and screened for knockdown resistance (kdr) by PCR.ResultsIntense resistance to DDT and pyrethroids was pervasive across Ethiopia, consistent with historic use of DDT for IRS and concomitant increases in insecticide-treated net coverage over the last 15 years. Longitudinal resistance trends to malathion, bendiocarb, propoxur and pirimiphos-methyl corresponded to shifts in the national insecticide policy. By 2016, resistance to the latter two insecticides had emerged, with the potential to jeopardize future long-term effectiveness of vector control activities in these areas. Between 2015 and 2016, the West African (L1014F) kdr allele was detected in 74.1% (n = 686/926) of specimens, with frequencies ranging from 31 to 100% and 33 to 100% in survivors from DDT and deltamethrin bioassays, respectively. Restoration of mosquito susceptibility, following pre-exposure to PBO, along with a lack of association between kdr allele frequency and An. arabiensis mortality rate, both indicate metabolic and target-site mutation mechanisms are contributing to insecticide resistance.ConclusionsData generated by this study will strengthen the National Malaria Control Programme’s insecticide resistance management strategy to safeguard continued efficacy of IRS and other malaria control methods in Ethiopia.

【 授权许可】

CC BY   
© The Author(s) 2017