I remember hearing about this a few years ago. One thing I remember (but can't find any links to
) was that infection was very high in France, and was causing very minor psychological changes in humans. As I recall, the changes were gender based. Women tended to being 'sex kittens', taking more care of appearance and having more lovers than average/before; whilst men tended to become more like tomcats, becoming more surly and less interested in appearance.
As I said, can't find any link for this, but did find this...
http://news.bbc.co.uk/1/hi/sci/tech/850556.stm