Fusarium wilt in my shrivelled Sharry Baby?

[turock]

Hi y'all!

I am new to this forum, though I have been lurking around for some time, learning from your wisdom. I'll make a proper introduction soon, but I needed to post about a more urgent problem first.

I recently purchased a wilted Sharry Baby oncidium at an auction and, despite my best care, its pseudobulbs haven't plumped up at all. I repotted it today, and accidentally divided the plant in the process. I noticed a bit of purple ring in the division point, feared fusarium wilt, and sliced off a bit more to get a better look.

Sure enough, there are purple rings in every rhizome I cut. The plant's mature pseudobulbs are all very shriveled, but it has several healthy-looking new growths with root systems. I've attached some pictures of the purple rings in question, and the new growths from the healthiest divisions. However, I have very little experience with oncidiums, so I need some advice please!

1) Is this purple ring ALWAYS an indicator of fusarium wilt?
2) Is fusarium wilt always fatal, or can it be cured?
3) Is it possible to divide off the brand new growths and get them to survive?
4) How contagious is the disease? Could it spread to another orchid that touches the infected plant or gets water splashed on it from an infected plant?

I really appreciate your help, in advance!