To speak to your medical practice is sound advice, but most are likely to consult standard "official" advice and proceed accordingly for fear of otherwise being criticized. This usually results in a degree of over-reaction. Nearly all of the people you are likely to deal with will also never have been beyond the standard tourist destinations in Europe and North America (if that). Provided you take sensible precautions (bottled water only, freshly cooked hot food only, peel-yourself fruit only, no salad trays, take rigorous anti-mosquito measures - see past threads - etc.) then your risk will be quite low. Just to hop onto the parallel thread: I envy those going to Madagascar. It is a lovely place although we were there more than 15 years ago. Take the train south from "Tana" (Antanarivo) to Toamasina if you can, go to places like Pangalanes, Isle Ste Marie, etc. if you can. No doubt it is more developed now, but then it was superbly unspoilt.