If I've learned one thing from this, it's that the worst places on Earth are in Sub-Saharan Africa. That's some staggering poverty which has really resisted major change after what appears to be a major shift in the early 80's.

Guinea worm is a great victory, but like Smallpox it's not emblematic of a general trend. You should not look at a chart of guinea worm infections and draw conclusions about rates of Malaria, VHF's, HIV, etc.

What has clearly and drastically improved is the standard of living in the US and Western Europe, which should shock no one at all.