Hi Jon.
The best thing is to see an immunologist, who will run a full blood panel , along with the viruses you are looking for, ie herpes, varicella shingles, lyme, CMV, MCV, etc.
Immunologist tend to look for infections or viruses, along with the general immune system , and how it functions, also they can find out the cause to the underlying cause sometimes, also they are very clever when it comes to viruses, etc, and if i was in your case, this is the consultant you need.
Good luck
Nicola
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