Wow this is really close to home. Here is the orgional link. It seems that some of this is how she reacted to it, it is rare because most people's immune system would take care of it. I've used river water to wash off cuts before, nothing near this serious though.
The rivers that far north in the state are concidered clean because they are upstream of the major cities. You don't think of this happening like you would south on the Chattahoochee.
http://www.ajc.com/news/gwinnett-woman-improving-in-1434554.html