It's difficult to say. The organism can flourish even in swimming pools. Other than wearing a nose clip while swimming, and pinching the nose shut with one hand while jumping into the water, I don't know what else can be done.
And wasn't it so very nice of them to push the 'global warming' angle on this story? They're dancing on this kid's grave.
Thank you for providing the CDC link, Blackyce. I deal with diseases for a living, but sometimes I get a "duh" moment.