Rise of multiple insecticide resistance in Anopheles funestus in Malawi: a major concern for malaria vector control
Top Cited Papers
Open Access
- 15 September 2015
- journal article
- research article
- Published by Springer Science and Business Media LLC in Malaria Journal
- Vol. 14 (1), 1-9
- https://doi.org/10.1186/s12936-015-0877-y
Abstract
Deciphering the dynamics and evolution of insecticide resistance in malaria vectors is crucial for successful vector control. This study reports an increase of resistance intensity and a rise of multiple insecticide resistance in Anopheles funestus in Malawi leading to reduced bed net efficacy. Anopheles funestus group mosquitoes were collected in southern Malawi and the species composition, Plasmodium infection rate, susceptibility to insecticides and molecular bases of the resistance were analysed. Mosquito collection revealed a predominance of An. funestus group mosquitoes with a high hybrid rate (12.2 %) suggesting extensive species hybridization. An. funestus sensu stricto was the main Plasmodium vector (4.8 % infection). Consistently high levels of resistance to pyrethroid and carbamate insecticides were recorded and had increased between 2009 and 2014. Furthermore, the 2014 collection exhibited multiple insecticide resistance, notably to DDT, contrary to 2009. Increased pyrethroid resistance correlates with reduced efficacy of bed nets (® net), which can compromise control efforts. This change in resistance dynamics is mirrored by prevalent resistance mechanisms, firstly with increased over-expression of key pyrethroid resistance genes (CYP6Pa/b and CYP6M7) in 2014 and secondly, detection of the A296S-RDL dieldrin resistance mutation for the first time. However, the L119F-GSTe2 and kdr mutations were absent. Such increased resistance levels and rise of multiple resistance highlight the need to rapidly implement resistance management strategies to preserve the effectiveness of existing insecticide-based control interventions.Keywords
Funding Information
- Wellcome Trust (WT101893MA)
This publication has 38 references indexed in Scilit:
- Dissecting the mechanisms responsible for the multiple insecticide resistance phenotype in Anopheles gambiae s.s., M form, from Vallée du Kou, Burkina FasoGene, 2013
- Genetic mapping identifies a major locus spanning P450 clusters associated with pyrethroid resistance in kdr-free Anopheles arabiensis from ChadHeredity, 2013
- Directionally selected cytochrome P450 alleles are driving the spread of pyrethroid resistance in the major malaria vector Anopheles funestusProceedings of the National Academy of Sciences of the United States of America, 2012
- Entomological indices of malaria transmission in Chikhwawa district, Southern MalawiMalaria Journal, 2012
- Impact of pyrethroid resistance on operational malaria control in MalawiProceedings of the National Academy of Sciences of the United States of America, 2012
- Identification and validation of a gene causing cross-resistance between insecticide classes inAnopheles gambiaefrom GhanaPublished by Proceedings of the National Academy of Sciences ,2012
- Identification and distribution of a GABA receptor mutation conferring dieldrin resistance in the malaria vector Anopheles funestus in AfricaInsect Biochemistry and Molecular Biology, 2011
- Insertion polymorphisms of SINE200 retrotransposons within speciation islands of Anopheles gambiae molecular formsMalaria Journal, 2008
- Analyzing real-time PCR data by the comparative CT methodNature Protocols, 2008
- Detection of knockdown resistance (kdr) mutations in Anopheles gambiae: a comparison of two new high-throughput assays with existing methodsMalaria Journal, 2007