New tools for malaria control
- Integrated Vector Control Consortium
- Medical Research Council
Current vector control strategies focus largely on indoor measures, such as long-lasting insecticide treated nets (ITNs) and indoor residual spraying (IRS). However, mosquitoes frequently feed on sugar sources outdoors, inviting the possibility of novel control strategies.
One such strategy is the application of attractive toxic sugar baits (ATSB), either sprayed on vegetation or provided in outdoor bait stations. Trials in Mali have shown that this significantly reduces mosquito density. We have developed a simple mathematical model of mosquito sugar-feeding behaviour which was fitted to an ATSB field trial in Mali. Our results suggest that an integrated vector management program including both ATSB and ITNs could substantially reduce mosquito density in this setting, and thereby have a substantial impact on the prevalence of infection and onward transmission.
Similarly, whilst ITNs and IRS have significantly reduced malaria transmission throughout Africa, these vector control methods are almost entirely dependent on a single insecticide class: the synthetic pyrethroids. The exposure of mosquitoes to these molecules through vector control campaigns and agricultural pest management has selected for pyrethroid resistance in a number of mosquito populations. This threatens the sustainability of our most effective and popular vector control interventions. With lack of insecticidal alternatives, operationally practicable ways of resolving this threat are proving elusive. One promising solution involves the co-application of a potent juvenile hormone analogue to surfaces commonly treated only with pyrethroids. Pyriproxyfen (PPF) is a highly potent pupacide and chemosterilant. The exposure of adult mosquitoes to this compound partially sterilises females and may increase mortality.
Marshall JM, White MT, Ghani AC, Schlein Y, Muller GC, Beier JC (2013). Quantifying the mosquito’s sweet tooth: modelling the effectiveness of attractive toxic sugar bait (ATSB) for malaria vector control. Malaria Journal 12 291. Publisher's link.