Blood transfusion-transmitted infections: A global perspective

Thanks to the many blood-safety interventions introduced since 1984, the overall risk for most transfusion-transmitted infections has become exceedingly small.

In the September 28 issue of the New England Journal of Medicine, Dr. Morris Blajchman, professor of Medicine at McMaster University, and medical director, Canadian Blood Services (Hamilton Centre), with co-author Dr. Eleftherios Vamvakas of Ottawa, puts into perspective the continuing risk of transfusion-transmitted infections as well as the possible safety interventions that might reduce that risk even further, particularly those due to emerging agents including variant Creutzfeldt-Jakob disease (vCJD) the human counterpart to mad cow disease.

With regard to the emerging pathogens, several newly-developed pathogen-reduction technologies have been shown to be effective in destroying most bacteria, viruses and parasites in donated blood, but ineffective against the pathogens that cause neurodegenerative diseases and those viruses that are present in exceedingly high concentrations in blood.

Newer technologies can also have a downside, notes Blajchman. They tend to reduce the effectiveness of the blood components, necessitating the transfusion of greater quantities and thus exposing patients to blood from more donors; thereby increasing the risk of infection transmission by transfusion.

"The possible additional safety interventions that might further reduce the risk of transfusion-transmitted infections will be debated extensively over the next few years," says Blajchman.

"Regardless of the outcomes of these debates it is clear that the risk of transmission is not static. As new agents continue to emerge, old ones change their properties and epidemiologic patterns, and new information and technology become available to change our understanding of that risk."

The commentary by Blajchman and Vamvakas was written in relation to an article in the same issue of the journal concerning the transfusion-transmission of HHV-8, a virus that has the potential to cause skin tumors (Kaposi's Sarcoma) in immunocompromised recipients.Source : McMaster University