"The phrase 'I don't know' is not something easy for some doctors to say. But when it comes to Lyme disease, Specter says, that might be the most apt description of current understanding." NPR expands on Michael Specter's article from The New Yorker:
http://www.npr.org/2013/06/26/195223507/the-lyme-wars-that-tiny-ticks-have-wrought