Dr Magellan Tchouakui, Research Scientist
Randomised cluster control trials conducted in Benin and Tanzania provide compelling evidence of the epidemiological impact of using dual active ingredient insecticide-treated nets (dual AI ITNs) treated with chlorfenapyr (CFP) and alpha-cypermethrin in malaria control . The results of these trials indicate that the public health value of dual AI ITNs significantly exceeds that of pyrethroid-only ITNs, which is not surprising given the widespread and often intense pyrethroid resistance in the Anopheles populations in these areas.
Similarly, pilot evaluations performed by PMI indicate that universal coverage campaigns using dual AI ITNs, including CFP-alpha-cypermethrin ITNs, are more effective at reducing malaria transmission than campaigns using pyrethroid-only ITNs. However, these differences in effect may be less pronounced in Cameroon and Burkina Faso (analysis ongoing), where pyrethroid resistance intensity is high, and laboratory and semi-field experiments (experimental hut trials (EHTs)) show that the impact of CFP-pyrethroid ITNs is variable between sites and mosquito populations.
Understanding the characteristics of mosquito populations that impact CFP-pyrethroid ITN performance is crucial for predicting epidemiological efficacy and making informed decisions on net deployment and effectiveness prolongation. The current project was initiated to investigate the causes of lower-than-expected susceptibility to CFP and reduced efficacy of IG2 nets in Cameroon and Burkina Faso. Funded by Global Funds for $ 599,456.00, it is expected to run from 2023-2024. The team at CRID working under this project comprises Prof. Charles Wondji as Principal Investigator, assisted by Dr Tchouakui as Co-PI.
They will be conducting the following studies:
Study 1: Uptake/metabolism/excretion analysis to explore biological explanations for variable results
Study 2: Monitoring for phenotypic and genotypic evidence of emerging resistance and cross resistance in Cameroon and Burkina Faso
Study 3: Assess efficacy of CFP-based ITNs in areas where reduced susceptibility is seen to CFP or with low CFP-pyrethroid ITN efficacy
