Mathematical models of malaria control with artificial feeders, odorants and bed nets
University of New Brunswick
Vector behaviour influences the speed of disease spread in populations. The presence of vector bias towards hosts with special characteristics suggests the need for new or tactical disease-control approaches. Malaria parasites produce volatile mosquito attractants. As a result, mosquitoes have bias towards malaria-infected humans. The control of mosquito-borne diseases can be improved by targeting mosquito bias. The attractiveness of humans to mosquitoes can be masked using appropriate odorants. Further, vectors can be artificially blood-fed using simplified devices to prevent infectious bites. In this study, we focus on the use of mosquito feeders, mosquito attractants, repellents and bed nets, knowing that such a multifaceted approach has not been explored previously using mathematical models. Three models of malaria control are developed using systems of nonlinear differential equations. The models are based on the Ross-Macdonald Theory and recent studies of vector-host interactions. In the artificial-feeder model, all infected humans acquire protective odorants at the onset of the infectious stage. The model is analyzed to examine the effect of repellents and artificial feeders on disease transmission and spread. The second model is without artificial feeders and assumes that infected individuals are recruited to use protective odorants during the infectious stage. The resulting mosquito-bias model is analyzed to examine how the recruitment rate affects disease spread. The third model combines the use of artificial feeders and protective odorants with the use of bed nets. The resulting bed-net model is analyzed to examine the effect of bed nets and protective odorants on disease transmission and spread in the presence of artificial feeders. The results of this study suggest that artificial feeders can slow disease spread, but eradication is easily done if mosquito bias is increased towards uninfected individuals. Increasing repellent-usage during the infectious stage decreases disease spread. The disease persists if mosquitoes are less attracted to bed-net users than to non-users. The conclusion is that the transmission and spread of mosquito-borne pathogens can be stopped by using artificial feeders that are attractive to mosquitoes, by increasing repellent-usage throughout the infectious stage, and by ensuring optimal bed-net coverage with protective odorants for all bed-net non-users.