Indefinite Deferral for History of Chronic Fatigue Syndrome
Canadian Blood Services is undertaking a deferral to protect blood product recipients from any potential risk that could come from a link between Xenotropic Murine Leukemia Virus-Related Virus (XMRV) and Chronic Fatigue Syndrome (CFS). XMRV is a type of retrovirus originating in mice ("murine" relates to mice).
Although the media is reporting that XMRV may be a threat to the blood supply, the deferral Canadian Blood Services is undertaking at this point relates to those patients with a history of CFS only. At this point there is no evidence that XMRV causes any disease in humans. This new information has reported association, but not causality.
Today, donors who have a history of CFS and who are well again are allowed to donate blood. Under the new deferral, it is this group that will no longer be able to donate blood at Canadian Blood Services' clinics. Blood donors with a history of CFS represent a very small segment of Canadian Blood Services' donor base, so the impact on the blood supply will be minimal.
Donors with active cases of CFS don't usually come in to donate blood because they are not feeling well. Historically, however, Canadian Blood Services has allowed people with a history of the illness to donate. This is what will change with the new deferral.
Health Canada, the body that regulates Canadian Blood Services, has approved this deferral. Implementation will occur in late April.
It is important to note that the available data related to the link between XMRV and CFS is conflicting. While it has been reported to have a strong association in American patients, the finding has not been substantiated in patients in the UK or the Netherlands, suggesting some geographic differences in the pattern of virus spread. Furthermore, there are as yet no data confirming that XMRV causes disease. So at this time, it is not possible to quantify the risk a donor with a history of CFS could pose to a blood recipient.
Once the scientific community understands more about the role of XMRV or other viruses in relation to chronic fatigue, Canadian Blood Services will revisit the deferral decision to determine whether the deferral is still warranted. Canadian Blood Services is part of an inter-agency North American task force led by the American Association of Blood Banks (AABB) that is investigating the XMRV issue.
How Canadian Blood Services currently handles potential threats to the blood supply system:
Canadian Blood Services operates one of the safest blood systems in the world. An essential element of our commitment to safety is our multilayered approach to ensuring that our blood products meet the highest level of safety available.
Before they donate, donors are asked an extensive list of questions about their behaviour and about their health status. People, who are unhealthy, including those with symptomatic diseases, are deferred from donation.
The organization then subjects each and every donation to a variety of blood screening tests for pathogens that are known to be transmissible by blood transfusion including HIV and the hepatitis B and C viruses.
Canadian Blood Services also maintains strong international networks with other blood systems to monitor the behaviour of possible pathogenic threats to the blood supply, so that if a new pathogen appears we can be ready to respond to the threat.