While new and exotic diseases are frightening, the ones to worry about are the ones we already well know, based on this article (Global health: Developing diseases | The Economist) and this chart:
I suspect as the developing world gets richer, mortality due to non-communicable diseases (NCD) will grow to become a greater cause of death. And yet this is a partially a good thing, because when it comes to NCDs, each of us can take action to delay or deflect or prevent some of them. Much more so than poor people in developing countries struggling with communicable diseases, I suspect.
(Found via Andrew Sullivan’s blog. Thanks!)