Does varicella-zoster virus infection of the peripheral ganglia cause Chronic Fatigue Syndrome?

SummaryThis article posits that infection of the peripheral ganglia causes at least some cases of Chronic Fatigue Syndrome (CFS), with a neurotropic herpesvirus, particularly varicella-zoster virus (VZV), as the most likely cause of the infection. Virtually all CFS symptoms could be produced by an infection of the peripheral ganglia, with infection of the autonomic ganglia causing fatigue, postural hypotension, and sleep disturbances, and infection of the sensory ganglia causing sensory symptoms such as chronic pain. Furthermore, infections of the peripheral ganglia are known to cause long-term nerve dysfunction, which would help explain the chronic course of CFS. Herpesviruses have long been suspected as the cause of CFS; this theory has recently been supported by studies showing that administering antiherpes agents causes substantial improvement in some CFS patients. VZV is known to frequently reactivate in the peripheral ganglia of previously healthy adults and cause sudden, debilitating illness, making it a likely candidate as a cause of CFS. Moreover, many of the symptoms of CFS overlap with those of herpes zoster (shingles), with the exception that painful rash is not one of the symptoms of CFS. A model is therefore proposed in which CFS is one of the many manifestations of zoster sine herpete; that is, herpes zoster without rash. Furthermore, re-exposure to VZV in the form of chickenpox has become less common in the past few decades; without such re-exposure, immunity to VZV drops, which could explain the increased incidence of CFS. Co-infection with multiple herpesviruses is a possibility, as some CFS patients show signs of infection with other herpesviruses including Epstein-Barr, Cytomegalovirus, and HHV6. These three herpesviruses can attack immune cells, and may therefore promote neurotropic herpesvirus reactivation in the ganglia. The possibility of VZV as the causal agent in CFS has previously received almost no attention; the possibility that CFS involves infection of the peripheral ganglia has likewise been largely overlooked. This suggests that the search for a viral cause of CFS has been far from exhaustive. Several antiherpes drugs are available, as is a vaccine for VZV; more research into such agents as possible treatments for CFS is urgently needed.