NEW THIS MONDAY: QUANTIFYING THE MOSQUITO SWEET TOOTH

Saturday, 31st of August 2013

QUANTIFYING THE MOSQUITO SWEET TOOTH: MODELLING THE EFFECTIVENESS OF ATTRACTIVE TOXIC SUGAR BAITS (ATSB) FOR MALARIA VECTOR CONTROL

John M Marshall1*, Michael T White1, Azra C Ghani1, Yosef Schlein2, Gunter C Muller2 and John C Beier3

* Corresponding author: John M Marshall john.marshall@imperial.ac.uk

1 Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK

2 Department of Parasitology, Kuvin Center for the Study of Tropical and Infectious Diseases, Hadassah Medical School, Hebrew University, Jerusalem, Israel

3 Department of Epidemiology and Public Health, Miller School of Medicine, University of Miami, Miami, Florida, USA

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Malaria Journal 2013, 12:291 doi:10.1186/1475-2875-12-291

The electronic version of this article is the complete one and can be found online at: http://www.malariajournal.com/content/12/1/291

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract below; full text is at http://www.malariajournal.com/content/12/1/291

Background

Current vector control strategies focus largely on indoor measures, such as long-lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS); however mosquitoes frequently feed on sugar sources outdoors, inviting the possibility of novel control strategies. Attractive toxic sugar baits (ATSB), either sprayed on vegetation or provided in outdoor bait stations, have been shown to significantly reduce mosquito densities in these settings.

Methods

Simple models of mosquito sugar-feeding behaviour were fitted to data from an ATSB field trial in Mali and used to estimate sugar-feeding rates and the potential of ATSB to control mosquito populations. The model and fitted parameters were then incorporated into a larger integrated vector management (IVM) model to assess the potential contribution of ATSB to future IVM programmes.

Results

In the Mali experimental setting, the model suggests that about half of female mosquitoes fed on ATSB solution per day, dying within several hours of ingesting the toxin. Using a model incorporating the number of gonotrophic cycles completed by female mosquitoes, a higher sugar-feeding rate was estimated for younger mosquitoes than for older mosquitoes. Extending this model to incorporate other vector control interventions suggests that an IVM programme based on both ATSB and LLINs may substantially reduce mosquito density and survival rates in this setting, thereby substantially reducing parasite transmission. This is predicted to exceed the impact of LLINs in combination with IRS provided ATSB feeding rates are 50% or more of Mali experimental levels. In addition, ATSB is predicted to be particularly effective against Anopheles arabiensis, which is relatively exophilic and therefore less affected by IRS and LLINs.

Conclusions

These results suggest that high coverage with a combination of LLINs and ATSB could result in substantial reductions in malaria transmission in this setting. Further field studies of ATSB in other settings are needed to assess the potential of ATSB as a component in future IVM malaria control strategies.