Unfortunately, it comes down to risk vs benefit.
The good old mossie remains the biggest killer of man.
9 people in the UK died of malaria last year.
Most were returning from Africa.
Larium (mefloquine), is the most effective preventative drug, but, as BM points out, has an undesirable side effect profile. (According to my source it is contra-indicated in those performing "precision activities" including pilots.)
There is an alternative, called "Malarone" which is, I think, less effective, and costs about £70 for 1-2 weeks.
Don't forget the non-drug measures (see
here )
Cheers