Okay, connect these dots: HHV-6, CFS, MS and (drum roll) AIDS.

"MS and CFS/ME are two common conditions with increased prevalence in middle aged females. As the diagnosis of CFS/ME is clinical with no positive clinical signs or investigations; it can be made with difficulty in the presence of another clear explanation for the disabling fatigue. Our results suggest that the two conditions may co-exist. Considering CFS/ME as a potential co-morbidity may lead to more focused and appropriate management."


http://www.ncbi.nlm.nih.gov/pubmed/25238862