Got it three times as I remember. First two times from a snake that came with them, thankfully was in Qt so was easy to get rid of.
The second time I took some of my collection with a local herp group for a event that we were doing. Bearing in mind, I had been doing this for ~3 years with no issues, but one of the people (the people who run it no less) had a Sudanese plated lizard they brought along that was absolutely riddled with mites. I found the mites after we were handling the plated, then my burm.
Found mites on her a couple of weeks later, and infested almost all my collection

Took around four months to get rid of entirely but they've been mite free for a good three months now and I hope they do not come back again.