Dynamique Spatiale Et Temporelle De La SensibilitÃ© dâ€™Anopheles Gambiae Sensu Lato Aux Insecticides UtilisÃ©s En SantÃ© Publique Au Congo De 2002 Ã€ 2018
Authors: Tainsie Nianga Bikouta GrÃ¢ce OdÃ©ra , Bitsindou Patrick , Lenga ArsÃ¨ne 
Published: February 2021

En dÃ©pit des mÃ©thodes de lutte dÃ©veloppÃ©es contre le paludisme, lâ€™apparition de la rÃ©sistance dâ€™Anopheles gambiae s.l. aux insecticides constitue une menace susceptible de conduire Ã  lâ€™Ã©chec de la lutte contre cette pathologie. Une Ã©tude rÃ©capitulative a Ã©tÃ© rÃ©alisÃ©e afin de montrer la dynamique spatio-temporelle de la rÃ©sistance dâ€™Anopheles gambiae s.l. Ã  quelques insecticides utilisÃ©s au Congo de 2002 Ã  2018. Les tests de sensibilitÃ© ont Ã©tÃ© rÃ©alisÃ©s avec des femelles adultes Ã¢gÃ©es de un Ã  cinq jours. Les insecticides testÃ©s appartiennent Ã  4 familles : (1) organochlorÃ©s : DDT 4%; (2) organophosphorÃ©s : malathion 5%, pirimiphos-mÃ©thyl 1,25% ; (3) pyrÃ©thrinoÃ¯des : permÃ©thrine 0,75%, deltamÃ©thrine 0,05% et 0,5%, European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 245 lambdacyhalothrine 0,05 %; (4) carbamates : bendiocarbe 0,1% et 0,5%. Les tests ont Ã©tÃ© faits avec les synergistes, lâ€™effet knock-down a Ã©tÃ© Ã©valuÃ© pendant 60 minutes et la mortalitÃ© observÃ©e 24 heures aprÃ¨s. Cette Ã©tude a montrÃ© un dÃ©veloppement de la rÃ©sistance au DDT, aux pyrÃ©thrinoÃ¯des, lâ€™apparition de la rÃ©sistance au bendiocarbe et au pirimiphosmÃ©thyl et la sensibilitÃ© au malathion. Les mutations knockdown resistance (kdr) (L1014F) et (L1014S) sont perÃ§ues comme responsables de la rÃ©sistance au DDT et aux pyrÃ©thrinoÃ¯des. Le rÃ©tablissement de la sensibilitÃ© des anophÃ¨les Ã  la deltamÃ©thrine aprÃ¨s exposition aux synergistes implique une rÃ©sistance mÃ©tabolique. L'Ã©tude a confirmÃ© lâ€™existence de la rÃ©sistance au DDT, aux pyrÃ©thrinoÃ¯des, au bendiocarbe et au pirimiphos-mÃ©thyl dans plusieurs dÃ©partements du pays. Pour garantir lâ€™efficacitÃ© des insecticides, il est primordial de surveiller la dynamique de la rÃ©sistance aux insecticides et Ã©ventuellement, identifier les mÃ©canismes impliquÃ©s dans la rÃ©sistance.
Despite control methods developed against malaria, the emergence of Anopheles gambiae s.l. resistance to insecticides constitutes a threat that could lead to the failure of the fight against this pathology. A summary study was carried out in order to show the spatio-temporal dynamic of resistance of European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 246 Anopheles gambiae s.l. to some insecticides used in Congo from 2002 to 2018. Sensitivity tests were carried out with two to five days old adult females. The insecticides tested belonged to 4 families: (1) organochlorines: DDT 4%; (2) organophosphates: malathion 5%, pirimiphos-methyl 1.25%; (3) pyrethroids: permethrin 0.75%, deltamethrin 0.05% and 0.5%, lambdacyhalothrin 0.05%; (4) carbamates: bendiocarb 0.1% and 0.5%. Tests were done with synergists. The knock-down effect was evaluated for 60 minutes and mortality 24 hours later. This study showed the existence of resistance to DDT, pyrethroids, development of resistance to bendiocarb and pirimiphos-methyl and sensitivity to malathion in several departments of the country. The knockdown resistance (kdr) mutations (L1014F) and (L1014S) are responsible for DDT resistance. Restoration of Anopheles' sensitivity to deltamethrin after exposure to synergists involves metabolic resistance. The study confirmed the development susceptibility to DDT, pyrethroids, bendiocarb and pirimiphos-methyl. To ensure the effectiveness of insecticides, it is essential to monitor the periodically susceptibility tests to insecticides and to identify the possible resistance mechanisms involved.