Malaria Management

Recently, a fungus has been discovered that could help reduce malaria-prevalence in endemic regions. The fungus infects mosquitoes, but instead of killing them like a pesticide, it kills the malaria that they carry and could transmit to humans. One biological question that arises is, if this fungus is used, should it be engineered to also kill mosquitoes? A few colleagues and I came up with a model of how this fungus could be used in combating malaria, and through studying a model system of ODEs numerically and analytically, we demonstrated that under certain assumptions on the mosquito carrying capacity and growth rate, the fungus should be engineered to have minimal virulence to mosquitoes to have an optimal effect in reducing malaria. Under other assumptions on the carrying capacity, different behaviour can be observed. Our paper has been published by Malaria Journal.

compartment model of malaria with fungus present
In addition to the usual human-malaria-human cycle, some mosquitoes can become infected by the fungus making them unable to transmit malaria.
optimal fungal virulence
If the mosquito population grows relatively slowly then the endemic level of malaria in the human population decreases as the fungal virulence increases (i.e. becomes more lethal to mosquitoes). But if the mosquito population grows more quickly, there is an optimal virulence as the mosquto-fungus exposure rate increases.