100-150 cases a year according to the article but I wonder how many are contracted from the hobby. But the article also states that it can be contracted by "handling, cleaning and processing fish" and "swimming or working in fresh or salt water." From the sounds of it the chances are pretty low.
I scraped my hand the day before this thread opened..
i was thinking... wow.. that stinks.. (for her).. the next day.. where I scraped my hand on the liverock.. I had a large puss filled (mmmm, yummy) boil and my hand felt just like the article said, like I had arthritis..
luckily, now.. it's almost healed.. but I was a little concerned for a couple hours there..