What the heck,
I had such good fortune with the other book, so why not take a shot trying to find this story as well.
Not sure where the virus came from, but there is a virus that is begining to infect humankind. Humans go thru metamorposis and turn into a kangaroo-like creature that sees by sonar/sound waves. The virus spreads like wildfire, and whole planets are being converted. Until these creatures become the new dominant species, and human kind must flee in spaceships avoiding any contact. One contact, and everyone becomes converted which would be end of human species. The story is told from point of view of someone that just got converted, and experiences he has, meeting other "people", having kangaroo sex, etc. Forgot how story ended, but basically thats it.
This story was long long time ago, so think at least 20 years ago, when I READ it, so may have been written before that.
Thanks for any help you can provide.