With the jury still out on the connection between XMRV and human disease, experts this week called for more research into the potential risk that the retrovirus poses to blood banks.

Last year, officials in Canada, Australia and New Zealand all recommended that individuals with chronic fatigue syndrome should not donate blood for fear of transmitting the suspected virus. In December, the American Red Cross followed suit, and two weeks later an advisory panel to the US Food and Drug Administration similarly urged blood banks to turn away prospective donors with the disease. But now, in a pair of policy documents published in the journal Transfusions, taskforces for the US Department of Health and Human Services (HHS) and the US American Association of Blood Banks (AABB) say that these bans may have been premature, and they are calling for more studies before making definitive recommendations.

The reports come at the heels of a quartet of studies published late last year in the journal Retrovirology in which independent research teams described ways in which XMRV could have been accidentally introduced during sample analysis. And last month, researchers from University College London suggested in the same journal that the likely culprit of contamination is a commonly used prostate cancer cell line characterized simultaneously in the original studies.

To settle the controversy, the HHS task force recommended conducting a large-scale epidemiological study to determine whether or not there is a link between blood transfusions and chronic fatigue syndrome.

Meanwhile, the AABB is taking a precautionary approach. Until a scientific consensus is reached, the organization is sticking by its June 2010 recommendation barring people with a diagnosis of chronic fatigue syndrome from donating blood.

Image: CDC