SOunds like a good thing/law............. would you want your fishin lake to be decimated by disease just b/c you felt the need to catch your minnows and use them on another body of water.
We have that here, some lakes have a no live bait reg and some don't. I would catch my minnows in the same ponds and creeks as the local bait guy......... but I can't use them unless I buy them? Thats what gets me. In a lake where I am allowed to legally use live (and that means anything not artificial here) I am allowed to catch and use livebait from that body of water. Its just to stop tranmitting ANY disease. If I had my way live bait would be even more restricted.
You don't say how the disease is transmitted? Do some species of fish recieve/transmit the disease easier than others? Round here most limitations are put on trout ponds/lakes and rivers. My thinking is that trout being thinner skinned than most fish are more likely to contract disease. Although it could be that deep hokked trout (caught on live bait) stand a smaller chance to survive than say walleye and pike...... I don't know