Passive Haemovigilance Fails to Adequately Assess the Scope of Bacterial Contamination Risks in Platelet Transfusions

The January 2016 issue of Blood featured the results of a study by Hong et al., comparing active and passive surveillance for bacterially contaminated platelets. From 2007 to 2013, platelet aliquots were cultured at the time of transfusion and reported transfusion reactions were reviewed. Sensitivity and specificity of five different sets of Septic Transfusion Reactions (STRs) criteria were evaluated, as well as detection by active and passive surveillance.

Cultured 24 hours after collection, all 51,400 platelet units came out negative. Active surveillance showed bacterial contamination in 0.004% of the transfused platelet units, resulting in the occurrence of five STRs 9 to 24 hours after transfusion in neutropenic patients transfused with high bacterial loads. Although passive surveillance reported a total of 284 transfusion reactions, these five STRs were not included. Moreover, although 2.1% to 32.7% of these 284 reactions met one or more STR criteria, the sensitivity of these criteria varying from 5.1% to 45.5%, none of these patients had received contaminated platelets.

These results confirm that STRs due to bacterially contaminated platelets remain a major hazard, show how passive surveillance fails to detect STRs, and illustrate the lack of specificity of STR criteria. Consequently, reported national STR data based on passive surveillance can be considered to be flawed and these findings underscore the need to implement additional blood safety measures such as secondary testing or pathogen reduction technologies.

Hong H., et al., Detection of septic transfusion reactions to platelet transfusions by active and passive surveillance, Blood (2016) 127(4), 496-502 (http://www.ncbi.nlm.nih.gov/pubmed/26598718)