Donor exposures in recipients of pooled platelet concentrates: a case-study in arithmetic, logic, "expert opinion",...

Advocacy for single-donor (rather than pooled) platelets has been based on the absolute increase in the risk of transfusion-transmitted infections (TTIs) from pooled (rather than single-donor) platelets in the population of platelet transfusion recipients. A recent study published in a prestigious medical journal advocated for pooled (rather than single-donor) platelets based on the relative increase in the risk of TTIs from pooled (rather than single-donor) platelets in patients transfused with any blood component. If this policy recommendation for use of pooled (rather than single-donor) platelets were followed in the US, there would be an annual increase in the risk of TTIs by 15-20 recipient infections for hepatitis B virus, 85-113 recipient infections for the next "West-Nile-virus-like" pathogen, and 528-704 recipient infections for the next "human-immunodeficiency-virus-like" pathogen to emerge in the future. We present the calculation of the increased risk and discuss the stark contrast between simple arithmetic and logic versus the end result of a process of "expert opinion" and "peer review".