That's the latest I've personally heard of. As far as being worried, unfortunately that may depend on you. I can imagine how distressing it might be. The only advice I can give you is what is give anyone else is to not fighting it and accept it may be a new part of you but nothing else has to change. The important thing is to continue to not let it stop you from doing your job or talking. You might just have to do it with the occasional disfluency. The more you fight against or try to control the stutterers, the more control you give them so my advice is when they happen, let them happen as naturally as they would. You have the advice of not unconsciously learning a bunch of bad avoidance behaviors as a kid, something most of us have to work quite hard to unlearn, as well as work on our shame/embarrassment related to the stutter.