Only 90% dies? That means there are still 700 million people left, which was about the world population in the 17th~18th century. On top of that, it's still enough to be able to maintain the society as it is established now and within 300 years we'd probably be back with the world population to almost 7 billion.
So I don't think 90% of the world population dying is gonna change much on the long run. Sure there will be a shock and some chaos afterwards, but I bet fairly quickly people will gather and start building a society similar to how it is now.