Do Viral Infections Cause Chronic Fatigue Syndrome?

virusChronic fatigue syndrome (CFS) is a debilitating medical condition that is characterized by persistent, unexplained fatigue, insomnia, and pain which not relieved by rest and sleep. The cause of CFS is unclear, but infections have been associated with this illness.  For example, in 2009 a study linked CFS to XMRV (xenotropic murine leukemia virus (MLV)-related virus)1 infection but subsequent investigations were unable to replicate this finding, Overall, no single infectious source  including viruses has been consistently identified in CFS patients.

Since the 2009 report linking the mouse retrovirus XMRV to CFS, much work has been done on the topic. In 2010, a study found that 86.5% of CFS participants carried a MLV-like virus sequence, but not the XMRV itself.2 This study was not reproducible and later retracted by the authors. More recently, investigators at the University of South Florida’s Morsani College of Medicine suggested that the common Human Herpesvirus 6 (HHV-6) is the cause of CFS in some patients.3 Thus, it appears possible that viruses may at least contribute to CFS and its symptoms.

In order to definitively determine the role of viral infections in CFS, Dr. Ian Lipkin, the director of the Center for Infection and Immunity at Columbia University, is leading a large scale investigation of possible virus infection in CFS. Dr. Lipkin has become known as a prolific virus hunter who has discovered over 400 new viruses in the past decade. In addition to discovering new viruses, Dr. Lipkin has helped disprove viral links for autism in children, specifically those related to the MMR vaccine. Using highly sophisticated techniques in large numbers of CFS patients, Dr. Lipkin hopes to provide definitive answers as to whether CFS is linked to viral infections.

Despite the lack of consistent findings, many investigators and patients believe that viruses are the cause of CFS. Some physicians even prescribe antiretroviral drugs for the management of CFS. However, only empirical evidence will tell us whether we viral or other infections are the cause for CFS.

Meriem Mokhtech, BS
Senior Laboratory Technician
UF Center for Musculoskeletal Pain Research


  1. Lombardi VC, Ruscetti FW, Gupta JD, Pfost MA, Hagen KS, Peterson DL, Ruscetti SK, Bagni BK, Petrow-Sadowski C, Gold B, Dean M, Silverman RH, Mikovits JA.  Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome. Science 2009.
  2. Lo, SC, Pripuzovaa N, Lia B, Komaroff, AL, Hunga GC, Wangc R, Alterc HJ. Detection of MLV-related virus gene sequences in blood of patients with chronic fatigue syndrome and healthy blood donors. PNAS 2010.
  3. Pantry SN, Medveczky MM, Arbuckle JA, Luka J, Montoya JG, Hu J, Renne R, Peterson D, Pritchett JC, Ablashi DV, Medveczky PG. Persistent human herpesvirus-6 infection in patients with an inherited form of the virus. Journal of Medical Virology 2013.