Chronic Fatigue Syndrome (CFS) is a disorder characterized by extreme tiredness that does not go away with bed rest, lasts for about 6 months in adults. Some of its many other symptoms include cognitive problems, headaches and vertigo. A study in the Journal of Health Psychology also found a high mortality level (12.5%) in CFS patients over the course of 10 years.
Experts believe that CFS has many root causes including psychological factors, pathogens and genetic predisposition. Recently, a study led by the University of South Florida published under the Journal of Medical Virology suggests that Human Herpesvirus 6 (HHV-6), a common virus, may be a culprit behind some CFS cases.
HHV-6 infects almost everyone by the age of 3, but becomes inactive in people with normal immune systems. In patients with compromised immune systems, however, HHV-6 can reactivate. This reactivation occurs in different parts of the body and is associated with various clinical conditions such as cognitive dysfunction (known as brain fog), pain and seizures.
Unlike other types of human herpesvirus, HHV-6 can also be inherited from parent to child––A condition often referred to as "chromosomally integrated HHV-6 (CIHHV-6)”––by integrating its DNA into human chromosome. This happens in its inactive state. Medveczky, the principal investigator of the study, reports that the prevalence of CIHHV-6 in CFS patients with serious neurological symptoms is over twice the level found in the general public. The HHV-6 was also found to be actively replicating in untreated CFS patients with CIHHV-6. This HHV-6 activity was determined by the presence of its messenger RNA (mRNA) – a molecule in the cell that carries and sends protein-building messages.
According to Medveczky, patients with CFS-like conditions can benefit from the application of this research. After 6 weeks of undergoing anti-herpesvirus drug treatment, the HHV-6 mRNA in the patients disappeared, resulting in an improvement in the severe neurological symptoms they had been experiencing. Nevertheless, as CFS is a complex disorder that is not yet fully understood, further studies would be needed to confirm that the persisting presence of HHV-6, in addition to having a compromised immune system, actually causes CFS-related symptoms.