Just from the video, it seems that the bacteria that causes Lyme disease is older than humans but the disease itself was basically unknown until the lab started messing around, at which points locals started getting sick.

It's interesting to note that there's a second bacteria that often appears in conjunction with the first that is linked to chronic Lyme disease (which was denied by the medical "experts" for decades), so it's totally possible that some sort of symbiotic gain of function occured, maybe not even intentionally.