I would be mostly concerned with what fluids have previously coated said tongue ring.
Agreed. Too much is unknown about disease transmission to rule out any possibility of troubles stemming from such contact, and of course we have no idea as to what volume of fluids are accompanying your appetizer as well. A little? A lot? Saliva only, or a bit of blood also? What to do? According to the article, it doesn't appear likely that the offending restaurant(s) will be named, and even if they are, who is to say that similar 'people' work at other places?
The Stoat Solution:
1. Become a good chef! (cooking your own food at home puts you in control of your destiny)
2. When you HAVE to eat out, patronize upscale restaurants or those places where you can SEE the cooks. Do they look scruffy, scummy, unkempt, or hippie-esque? Take your food dollars elsewhere!
Additional suggestions?