Consider bartonella. Dr. J. Schaller believes that it could potentially be a more widespread infection than borrelia, and being that he is the only physician who has published any kind of decent book on co-infections (ie, The Diagnosis and Treatment of Babesia), I wouldn't be surprised if he knows what he's talking about here. New strains of bartonella are being discovered all the time but it sure as heck ain't common knowledge.
What remains, then, besides obtaining an awareness that co-infections exist more often than not along with Lyme disease and that they may even be even more prevalent than borrelia?
A conviction that they need to be treated would be a good start.
Of course, it would help if testing methods for bartonella and babesia were more accurate. Unfortunately, even the best lab for co-infections--Fry Labs in Arizona--only tests for a few strains of the aforementioned, when dozens of both are thought to exist. Still, it's a place to begin. Rumor has it that a new method is being developed which may eventually be effective for testing for the presence of ALL strains of babesia and bartonella. But it's still in the works.
In the meantime, if you can't afford Fry or you test negative with Fry but yet suspect you are co-infected (yes, please, have heavy suspicions), then seek out a competent muscle test practitioner to ascertain the presence of these infections, especially babesia and bartonella.
Treating co-infections along with Lyme will not only expedite, but make possible your recovery from this oh-so-fun illness!