Laboratory tests that had helped establish the link were based on uncertain data.
Last Thursday, the journal Science reported that researchers had removed the original study the part about the virus because a laboratory that had participated in the analysis found that some of its samples were contaminated.
In 2009, researchers from Nevada had announced the discovery of a virus related to murine leukemia virus xenotropic (XMRV), normally found in mice, in the blood of people with chronic fatigue syndrome. Suggesting that the cause of the mysterious disease was last found.
Blood banks began to refuse donations from people suffering from chronic fatigue syndrome, believing that they could be infected with XMRV. Several other studies have failed to confirm this finding. Last spring the journal Science published an information to the effect that the supposed presence of the virus in the blood could only be the result of contamination from the laboratory.
The most recent study, also reported in the journal Science, was commissioned by the government to check whether the XMRV or other similar viruses could have affected the quality of the blood. The study concluded that there was no cause for concern.
Nine laboratories repeated the analysis of blood samples from 30 people, some have been identified as carriers of XMRV and suffering from chronic fatigue syndrome, other perfectly healthy
Only two laboratories that had previously found a link to the XMRV noted traces of the virus in some blood samples, but some of them were from well people. Further analysis failed to confirm the initial findings.
“It does not seem to be a clear correlation between XMRV and chronic fatigue syndrome,” said for his part Dr. Harvey Klein, who was not involved in the latest research, but has followed up on behalf American Association of Blood Banks. However, some blood banks can continue to refuse patients with chronic fatigue syndrome because of the potential consequences of blood loss on their physical condition.
The controversy is not resolved. In a joint statement, researchers at the Whittemore Peterson Institute of Nevada indicated that they continued their research on the virus despite the withdrawal of the 2009 study.