Dynamique Spatiale Et Temporelle De La Sensibilité d’Anopheles Gambiae Sensu Lato Aux Insecticides Utilisés En Santé Publique Au Congo De 2002 À 2018

En depit des methodes de lutte developpees contre le paludisme, l’apparition de la resistance d’Anopheles gambiae s.l. aux insecticides constitue une menace susceptible de conduire a l’echec de la lutte contre cette pathologie. Une etude recapitulative a ete realisee afin de montrer la dynamique spatio-temporelle de la resistance d’Anopheles gambiae s.l. a quelques insecticides utilises au Congo de 2002 a 2018. Les tests de sensibilite ont ete realises avec des femelles adultes âgees de un a cinq jours. Les insecticides testes appartiennent a 4 familles : (1) organochlores : DDT 4%; (2) organophosphores : malathion 5%, pirimiphos-methyl 1,25% ; (3) pyrethrinoides : permethrine 0,75%, deltamethrine 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 ete faits avec les synergistes, l’effet knock-down a ete evalue pendant 60 minutes et la mortalite observee 24 heures apres. Cette etude a montre un developpement de la resistance au DDT, aux pyrethrinoides, l’apparition de la resistance au bendiocarbe et au pirimiphosmethyl et la sensibilite au malathion. Les mutations knockdown resistance (kdr) (L1014F) et (L1014S) sont percues comme responsables de la resistance au DDT et aux pyrethrinoides. Le retablissement de la sensibilite des anopheles a la deltamethrine apres exposition aux synergistes implique une resistance metabolique. L'etude a confirme l’existence de la resistance au DDT, aux pyrethrinoides, au bendiocarbe et au pirimiphos-methyl dans plusieurs departements du pays. Pour garantir l’efficacite des insecticides, il est primordial de surveiller la dynamique de la resistance aux insecticides et eventuellement, identifier les mecanismes impliques dans la resistance. 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.