That's a good question to ask.
For malaria, you are right and should not use prophylactics. I still carry Coartem. The trick is to get tested for malaria at first symptoms and then treat it with the Coartem. Malaria IS a killer but is mostly treatable. It kills those who either can't afford treatment or leave it too late.
For advice I would always choose a Dr who lives in a malarial area over one that doesn't. My knowledge is not current and others may have more up to date advice.
I visited a hospital in Cameroon and wouldn't choose to stay in one unless I was desperate. That said, some time spent on a drip can help with staying hydrated in the case of severe vomiting and diarrea.