Processes that reduce or abolish the infectivity of microrganisms in blood components offer an additional level of security against transfusion transmissible infections, including those for which screening tests are not currently available. (19304113).

Plasma

Several processes are available that have been shown to cause substantial reductions in infectivity while causing only moderate reduction in activity of fibrinogen and other plasma proteins. These processes utilise methylene blue, amotosalen, or riboflavin (single donor units), or a solvent detergent treatment (applied to pool of multiple units). An alternative approach is the use of quarantined plasma (PMID 18583192).

Platelets

Platelets pose a risk of bacterial contamination because they are stored at 22°C. Bacterial culture of platelets during the storage period is used by some organisations to minimise this risk. A process for pathogen inactivation of platelets is now CE marked and in use in several countries. A further large clinical trial of efficacy and safety is due to report its findings.

Red cells

Processes for pathogen reduction of red cell components have not completed clinical trials.