SI17 What Diseases Should We Test For and Which Ones Should We Not Test For
Authors: Reesink H. W. 
Published: September 2006

The safety of the blood supply in high income countries has very high standards. New technical developments allow even further improvement of the safety margin, although at very high costs. From the perspective of health care budget at large, the costs for screening the blood supply for viral infectious agents are unprecedented high, compared to the benefit the recipients of blood products may experience. Moreover, the majority of fatal transfusion reactions are due to other causes, like TRALI, haemolytic transfusion reactions and sepsis by bacterial contaminated blood products, as was mentioned in a recently published International Forum [Vox Sanguinis (2006) 90: 207–241]. Fatal viral infections are at present a minority of all fatalities caused by transfusion of blood! What tests can we add in the (near) future to further safeguard the blood supply for infectious diseases? Bacterial testing of all labile blood components, and especially platelet concentrates stored at room temperature may be a sensible approach when these tests become less labour intensive and more sensitive. Prototype NAT tests have shown proof of principle and have great promise to fulfil the above criterions, although many problems have to be solved yet. Improvement of tests to detect donors with malaria parasites is welcomed. When more sensitive tests are implemented, the rejection of a substantial proportion of donors who travelled or stayed in endemic areas may be avoided in the future. With respect to viral screening pressure from the industry is building up to test for HBV‐DNA, offering only multiplex (HIV, HCV, HBV) formatted NAT tests for their second generation automates. If we follow the industry (and I am afraid we do not have much choice), the pool size should be diminished to <8 donors to make HBV‐NAT screening significant. Eventually we may end by testing individual donor samples, as is already the case in some countries like South‐Africa. When sensitive and specific vCJD tests will become available, it is clear that all donors will be screened in the future. Tendencies from the plasma industry to test for Parvo B19 DNA and HAV by NAT should only be done as internal control tests for plasma derivates and not be used as release criterion for labile blood components. What screening tests may be omitted in the future? In countries who have implemented anti‐HBc (anti‐HB‐core) screening HBsAg, like HIV p24 antigen test, may be superfluous when (ID) HBV‐NAT is in place. However, much water has to flow through the Thames River before we dare to omit such an old and reliable screening test as HBsAg ! From a cost benefit point of view all NAT screening tests may be omitted, taking into consideration their low yield to detect extra infected donations. Especially when pathogen inactivation may become state‐of‐the‐art in the future, this option becomes more realistic. Next to screening, it is important that a continuous monitoring system for new infectious agents or variants of old ones, within the population at large is warning the blood transfusion organizations in the various countries for new threats. BOTIA, a consortium sponsored by the European Commission, is an example of such a monitoring system. In conclusion, screening for infectious agents in donor blood will be in the future as dynamic as it was for the last 3 decades.