Study of insecticide resistance in Anopheles gambiae s.l. (sensu lato) Giles, (1902) and impact on the efficacy of Long-Acting Impregnated Mosquito Nets (LLINs) in Ebebda and Emana-benyada, southern Cameroon. The jury, made up of lecturers from the Department of Animal Biology and Physiology at the University of Douala, approved the scientific nature of the study.
Samuel Ndik with members of the jury.
On Saturday 04th May 2024, Mr Samuel Ndik, a student in Prof. NDO’s team at CRID, successfully defended his Master’s thesis at the Faculty of Science, University of Douala. The aim of his study was to contribute to the fight against malaria in Cameroon by monitoring insecticide resistance in Anopheles gambiae s.l. This important work was carried out in two localities in the Lekié department (Centre-Cameroon region), namely Ebebda (semi-urban facies) and Emana-benyada (rural facies).
A cross-sectional survey was carried out in the two target localities to determine the distribution of species of the Anopheles gambiae complex and to assess their susceptibility to the insecticides used in public health, using the standard protocols recommended by the World Health Organisation (WHO).
The results of this study indicate that Anopheles gambiae is the only species of the gambiae complex present in the two locations surveyed. This vector is sensitive to pirimiphos-methyl but resistant to pyrethroids and carbamates. The strong resistance of this species to insecticides of the pyrethroid class is supported by the combined presence of metabolic mechanisms through the action of Cytochromes P450 and molecular mechanisms due to modification of the target site of the insecticide, in particular the L1014F (kdr-West) mutation which was detected in both populations. This resistance phenomenon poses a serious threat to malaria vector control, as it is associated with a reduction in the effectiveness of long-Lasting Insecticide-treated Nets (LLINs) in these two sites.
This study highlights the persistence of high malaria transmission by insecticide-resistant vectors, due to their ability to fight back against the various control tools. The results call for the urgent implementation of insecticide resistance management strategies in the study localities and surrounding areas.
