They rely on the natural medicines they have always used. When those become ineffective, the people succumb to the mutated disease we have helped to create by taking preventative prophylaxis. With more than 2 billion people exposed to this disease, we all have a responsibility to stop the mutation of Malaria. Using the medicines as a cure after contracting malaria reduces the risk of mutation, as the virus doesn't have as many opportunities to develop a new resistant strain. For us to take prophylaxis regularly, as a preventative is putting the local people's lives at risk.
Most malaria is curable.
The overall result is that we save ourselves from harmful side effects from taking semi-toxic prophylaxis medicines over a significant period of time and we don't generate resistant strains that have significant impact on the native population. Throughout this expedition, we are going to be continuously exposed to malaria. We will often be in very remote areas unable to access any medical facilities. My research has led me to a new type of medicine which we will take as treatment when we contract this disease. I cannot talk from experience yet, but Artenam certainly looks promising.