Anopheles gambiae (s.l.) exhibit high intensity pyrethroid resistance throughout Southern and Central Mali (2016–2018): PBO or next generation LLINs may provide greater control

Parasites & Vectors

Arthur Sovi¹  Elie Bankineza²  Richard M. Oxborough²  Chitan Keita²  Dereje Dengela²  Cecilia Flatley²  Youssouf Sinaba²  Abdourhamane Dicko³  Christen Fornadel⁴  Jules Mihigo⁴  Allison Belemvire⁴  Jenny Carlson⁴  Moussa B. M. Cisse⁵  Ousmane Koita⁵  Ibrahim Traore⁵ 

[1] Faculty of Agronomy, University of Parakou;PMI VectorLink Project, Abt Associates;Programme National de Lutte contre le Paludisme (PNLP), Ministère de la Santé;U.S. President’s Malaria Initiative, U.S. Agency for International Development;Université des Sciences, des Techniques, et des Technologies de Bamako (USTTB);

关键词: Susceptibility test;    Resistance intensity;    WHO tube test;    CDC bottle bioassay;    Piperonyl butoxide;    Vector control;   

DOI  :  10.1186/s13071-020-04100-7

来源: DOAJ

【 摘 要 】

Abstract Background Millions of pyrethroid LLINs have been distributed in Mali during the past 20 years which, along with agricultural use, has increased the selection pressure on malaria vector populations. This study investigated pyrethroid resistance intensity and susceptible status of malaria vectors to alternative insecticides to guide choice of insecticides for LLINs and IRS for effective control of malaria vectors. Methods For 3 years between 2016 and 2018, susceptibility testing was conducted annually in 14–16 sites covering southern and central Mali. Anopheles gambiae (s.l.) were collected from larval sites and adult mosquitoes exposed in WHO tube tests to diagnostic doses of bendiocarb (0.1%) and pirimiphos-methyl (0.25%). Resistance intensity tests were conducted using CDC bottle bioassays (2016–2017) and WHO tube tests (2018) at 1×, 2×, 5×, and 10× the diagnostic concentration of permethrin, deltamethrin and alpha-cypermethrin. WHO tube tests were conducted with pre-exposure to the synergist PBO followed by permethrin or deltamethrin. Chlorfenapyr was tested in CDC bottle bioassays at 100 µg active ingredient per bottle and clothianidin at 2% in WHO tube tests. PCR was performed to identify species within the An. gambiae complex. Results In all sites An. gambiae (s.l.) showed high intensity resistance to permethrin and deltamethrin in CDC bottle bioassay tests in 2016 and 2017. In 2018, the WHO intensity tests resulted in survivors at all sites for permethrin, deltamethrin and alpha-cypermethrin when tested at 10× the diagnostic dose. Across all sites mean mortality was 33.7% with permethrin (0.75%) compared with 71.8% when pre-exposed to PBO (4%), representing a 2.13-fold increase in mortality. A similar trend was recorded for deltamethrin. There was susceptibility to pirimiphos-methyl, chlorfenapyr and clothianidin in all surveyed sites, including current IRS sites in Mopti Region. An. coluzzii was the primary species in 4 of 6 regions. Conclusions Widespread high intensity pyrethroid resistance was recorded during 2016–2018 and is likely to compromise the effectiveness of pyrethroid LLINs in Mali. PBO or chlorfenapyr LLINs should provide improved control of An. gambiae (s.l.). Clothianidin and pirimiphos-methyl insecticides are currently being used for IRS as part of a rotation strategy based on susceptibility being confirmed in this study.

【 授权许可】

Unknown