Insecticide resistance evolution with mixtures and sequences: a model-based explanation

Abstract Background Insecticide resistance threatens effective vector control, especially for mosquitoes and malaria. To manage resistance, recommended insecticide use strategies include mixtures, sequences and rotations. New insecticides are being developed and there is an opportunity to develop us...

Full description

Bibliographic Details
Main Authors: Andy South, Ian M. Hastings
Format: Article
Language:English
Published: BMC 2018-02-01
Series:Malaria Journal
Subjects:
Online Access:http://link.springer.com/article/10.1186/s12936-018-2203-y
_version_ 1818955156609302528
author Andy South
Ian M. Hastings
author_facet Andy South
Ian M. Hastings
author_sort Andy South
collection DOAJ
description Abstract Background Insecticide resistance threatens effective vector control, especially for mosquitoes and malaria. To manage resistance, recommended insecticide use strategies include mixtures, sequences and rotations. New insecticides are being developed and there is an opportunity to develop use strategies that limit the evolution of further resistance in the short term. A 2013 review of modelling and empirical studies of resistance points to the advantages of mixtures. However, there is limited recent, accessible modelling work addressing the evolution of resistance under different operational strategies. There is an opportunity to improve the level of mechanistic understanding within the operational community of how insecticide resistance can be expected to evolve in response to different strategies. This paper provides a concise, accessible description of a flexible model of the evolution of insecticide resistance. The model is used to develop a mechanistic picture of the evolution of insecticide resistance and how it is likely to respond to potential insecticide use strategies. The aim is to reach an audience unlikely to read a more detailed modelling paper. The model itself, as described here, represents two independent genes coding for resistance to two insecticides. This allows the representation of the use of insecticides in isolation, sequence and mixtures. Results The model is used to demonstrate the evolution of resistance under different scenarios and how this fits with intuitive reasoning about selection pressure. Using an insecticide in a mixture, relative to alone, always prompts slower evolution of resistance to that insecticide. However, when resistance to both insecticides is considered, resistance thresholds may be reached later for a sequence relative to a mixture. Increasing the ability of insecticides to kill susceptible mosquitoes (effectiveness), has the most influence on favouring a mixture over a sequence because one highly effective insecticide provides more protection to another in a mixture. Conclusions The model offers an accessible description of the process of insecticide resistance evolution and how it is likely to respond to insecticide use. A simple online user-interface allowing further exploration is also provided. These tools can contribute to an improved discussion about operational decisions in insecticide resistance management.
first_indexed 2024-12-20T10:33:35Z
format Article
id doaj.art-fabdd7ddf58d4cefbef0c8c1461b0b9c
institution Directory Open Access Journal
issn 1475-2875
language English
last_indexed 2024-12-20T10:33:35Z
publishDate 2018-02-01
publisher BMC
record_format Article
series Malaria Journal
spelling doaj.art-fabdd7ddf58d4cefbef0c8c1461b0b9c2022-12-21T19:43:41ZengBMCMalaria Journal1475-28752018-02-0117112010.1186/s12936-018-2203-yInsecticide resistance evolution with mixtures and sequences: a model-based explanationAndy South0Ian M. Hastings1Department of Parasitology, Liverpool School of Tropical MedicineDepartment of Parasitology, Liverpool School of Tropical MedicineAbstract Background Insecticide resistance threatens effective vector control, especially for mosquitoes and malaria. To manage resistance, recommended insecticide use strategies include mixtures, sequences and rotations. New insecticides are being developed and there is an opportunity to develop use strategies that limit the evolution of further resistance in the short term. A 2013 review of modelling and empirical studies of resistance points to the advantages of mixtures. However, there is limited recent, accessible modelling work addressing the evolution of resistance under different operational strategies. There is an opportunity to improve the level of mechanistic understanding within the operational community of how insecticide resistance can be expected to evolve in response to different strategies. This paper provides a concise, accessible description of a flexible model of the evolution of insecticide resistance. The model is used to develop a mechanistic picture of the evolution of insecticide resistance and how it is likely to respond to potential insecticide use strategies. The aim is to reach an audience unlikely to read a more detailed modelling paper. The model itself, as described here, represents two independent genes coding for resistance to two insecticides. This allows the representation of the use of insecticides in isolation, sequence and mixtures. Results The model is used to demonstrate the evolution of resistance under different scenarios and how this fits with intuitive reasoning about selection pressure. Using an insecticide in a mixture, relative to alone, always prompts slower evolution of resistance to that insecticide. However, when resistance to both insecticides is considered, resistance thresholds may be reached later for a sequence relative to a mixture. Increasing the ability of insecticides to kill susceptible mosquitoes (effectiveness), has the most influence on favouring a mixture over a sequence because one highly effective insecticide provides more protection to another in a mixture. Conclusions The model offers an accessible description of the process of insecticide resistance evolution and how it is likely to respond to insecticide use. A simple online user-interface allowing further exploration is also provided. These tools can contribute to an improved discussion about operational decisions in insecticide resistance management.http://link.springer.com/article/10.1186/s12936-018-2203-yInsecticide resistancePublic healthMosquitoesVector-borne diseasesInfectious diseasesMalaria
spellingShingle Andy South
Ian M. Hastings
Insecticide resistance evolution with mixtures and sequences: a model-based explanation
Malaria Journal
Insecticide resistance
Public health
Mosquitoes
Vector-borne diseases
Infectious diseases
Malaria
title Insecticide resistance evolution with mixtures and sequences: a model-based explanation
title_full Insecticide resistance evolution with mixtures and sequences: a model-based explanation
title_fullStr Insecticide resistance evolution with mixtures and sequences: a model-based explanation
title_full_unstemmed Insecticide resistance evolution with mixtures and sequences: a model-based explanation
title_short Insecticide resistance evolution with mixtures and sequences: a model-based explanation
title_sort insecticide resistance evolution with mixtures and sequences a model based explanation
topic Insecticide resistance
Public health
Mosquitoes
Vector-borne diseases
Infectious diseases
Malaria
url http://link.springer.com/article/10.1186/s12936-018-2203-y
work_keys_str_mv AT andysouth insecticideresistanceevolutionwithmixturesandsequencesamodelbasedexplanation
AT ianmhastings insecticideresistanceevolutionwithmixturesandsequencesamodelbasedexplanation