In 2009, a study published in Science by Dr. Judy Mikovits linked chronic fatigue syndrome to a viral infection with XMRV. Two years later, in December of 2011, this original study along with one study that supported the findings were retracted within days of each other, and the viral association was discredited. After the study was published, a number of studies failed to confirm the association, and a critical part of the scientific process, replication, was unable to occur.
Chronic fatigue syndrome is defined by a number of symptoms, the most common being profound exhaustion, swollen lymph nodes, sore throat, and cognitive dysfunction. Up until the publication of Mikovit's study, there was no known cause for CFS. The Center for Disease Control even classifies the syndrome as a psychological disease or a stress-related condition. According to a paper by the CDC, patients' who suffer from CDC tend to disproportionately have "paranoid, schizoid, obsessive-compulsive, avoidant, and depressive personality disorders."
On a side note, following the study's retraction, a legal plague hit the institution and researcher associated with the XMRV study. The main researcher, Dr. Mikovits was jailed for stealing from the lab and charged with being a fugitive. At the same time, the Whittemores, from the Whittemore Peterson Institute for NeuroImmune Disease (the research institution where the original study was performed) are being sued for embezzlement.
The XMRV-CFS association was not the only viral-associated connection that Mikovits proposed. At several conferences, Dr. Mikovits offered the idea that the murine leukemia virus (MLV) is associated with autism.