It may indeed be true that Lyme cannot claim PEM as a symptom; however, I would be reluctant to base that determination on the voracity of studies published to date.
Most of the recent studies designed to drill down on Bb sensu lato (certainly most of those emanating from the U.S.) have de-emphasized the degree to which patients are afflicted post-acute Lyme. These studies as a whole seem to suggest cognitive issues and pain and weakness and exhaustion etc, are not that severe outside of acute cases.
They seem to be exercises in a) denying any illness exist post-treatment, or,b) deriding the severity of symptoms post-treatment, or, c) ignoring the numbers of late stage patients, and, accordingly, the nature of their sufferings, and the peculiar difficulties presented in trying to eradicate the spirochetal disease once it has progressed this far (not unlike syphilis).
I can tell you with a high level of certitude based on my conversations with Lyme patients that that is simply an inaccurate representation of patients' experience. If anything, once the disease progresses beyond febrile involvement, and enters the realm of Late Stage or chronic or PTLDS, the symptoms are different than those when the disease was acute. The character of the illness evolves.
The degrees of involvement of different organs and tissues and muscles etc are different, too. Literature - by virtue of mistake or design - seems to omit this, or at best, minimize it.
And it's not as if the literature will be improving anytime soon. There are no meaningful studies I can see on the NIH agenda that are specific to Late Stage Lyme, and what efforts are underway for PTLDS or chronic Lyme seem disjointed and insincere.
So if PEM is ever to be recognized as belonging to the symptom pantheon of Lyme, it's probably not going to happen soon.
I also recognize that PEM is supposed to be unique to ME. That may be correct. If so, then I am face with an odd dilemma of allegiance, for lack of a better word. Or I simply have to get used to dual citizenship. But then, I suppose that's why I am here along with the rest of you.
So, I would not base my belief in that on the studies done to date by IDSA supporters, or even ILADS advocates since they have their hands full and coffers empty. Studies that were supposed to identify Bb symptoms and evaluate their impact through the three widely acknowledged Stages, and the curious enigma of PTLDS , imo only take the community so far, and then all too often, come up short.