Evidence is mounting that a retrovirus called XMRV is not a new human pathogen infecting millions, as was feared, but rather was a laboratory contaminant, the Chicago Tribune reported.
The original finding had prompted some chronic fatigue sufferers to begin taking potent anti-HIV drugs, the newspaper said.
Cancer biologist Robert Silverman at the Cleveland Clinic's Lerner Research Institute who worked on the study that linked XMRV to chronic fatigue said his lab had stored a cell line known to harbor XMRV and he was working to determine if contamination occurred.
"I am concerned about lab contamination, despite our best efforts to avoid it," Silverman said.
This week a European research team reported being unable to find any evidence of XMRV in the blood samples from people diagnosed with chronic fatigue syndrome.
The original study, published in 2009, was led by retroviral immunologist Judy Mikovits of the private Whittemore Peterson Institute for Neuro-Immune Disease in Reno, Nev.
Mikovits has made increasingly broad statements about XMRV, connecting it to a list of frustrating medical conditions like ALS, Parkinson's disease, multiple sclerosis, dementia and even autism, the Tribune reported.
"It is clearly a human infection," Mikovits told a presentation hosted by a California alternative medical practice in January. "It is clearly circulating through the population as is our fear and your fear."
Scientists say there is no evidence to support her statement.
"Saying that is just inciting fear," Columbia University virologist Vincent Racaniello said.
This month, 4,000 scientists and clinicians gathered in Boston for a retroviral conference that included 10 presentations offering evidence that XMRV is a lab contaminant. Mikovits did not attend.