Your doctor might have said 16 months, because spirochetes are known to have an 8 month lifecycle. Therefore 2 lifecycles of treatment might get rid of them. However, it might not. Read up on what Horowitz has said about dapsone. Wouldn't hurt to read his latest book.
re: 8 month lifecycle of spirochetes - where did you read this? Or...did your LLMD tell you?
I've not heard this before.