The chronic fatigue syndrome (CFS), as defined by recent criteria, is a heterogeneous disorder with a common set of symptoms that often either follows a viral infection or a period of stress. Using indirect immunofluorescence testing for measuring antibody against human herpesvirus 6 (HHV-6), this study investigated the association of CFS with infection by HHV-6. Natural killer cells as defined by CD16, CD56 and CD57 antigens were significantly reduced in CFS. Health-Related Quality of Life (HRQOL). The clinical symptoms and signs of CFS resemble those of infectious mononucleosis, but patients with CFS do not have the severe dysphagia and grey exudative pharyngitis often accompanied by submandibular adenopathy common to primary infection with the gamma subfamily herpesvirus, Epstein-Barr virus (EBV), the prototype virus of the lymphocryptovirus genus. “This is not associated with a new and spreading disease. Seventy-two percent of the CFS patients had elevated serum anti-HHV-6 IgG titers, but active HHV-6 infection was detected in only 38.6% of the cases as identified by ACE, nPCR, and virus isolation.
The World Health Organization (WHO) has classified CFS as a chronic (long-term) neurological condition and this classification has been accepted by the Department of Health. EBV DNA level increased significantly at both stress intervals, while VZV DNA level increased only at low-stress. DNA levels of HSV-1 decreased at low-stress but increased at high-stress. Patients who had a “viral onset” for their CFS. Cortisol concentrations at both stress intervals were significantly higher than those at rest.