Detection of septic transfusion reactions to platelet transfusions by active and passive surveillance

Abstract

• Bacterial sepsis from contaminated platelet transfusions continues to occur despite recent interventions; additional measures are needed.• STR to platelet transfusion is frequently not recognized or reported; use of recent AABB criteria showed highest diagnostic sensitivity.Septic transfusion reactions (STRs) resulting from transfusion of bacterially contaminated platelets are a major hazard of platelet transfusion despite recent interventions. Active and passive surveillance for bacterially contaminated platelets was performed over 7 years (2007)(2008)(2009)(2010)(2011)(2012)(2013) by culture of platelet aliquots at time of transfusion and review of reported transfusion reactions. All platelet units had been cultured 24 hours after collection and released as negative. Five sets of STR criteria were evaluated, including recent AABB criteria; sensitivity and specificity of these criteria, as well as detection by active and passive surveillance, were determined. Twenty of 51 440 platelet units transfused (0.004%; 389 per million) were bacterially contaminated by active surveillance and resulted in 5 STRs occurring 9 to 24 hours posttransfusion; none of these STRs had been reported by passive surveillance. STR occurred only in neutropenic patients transfused with high bacterial loads. A total of 284 transfusion reactions (0.55%) were reported by passive surveillance. None of these patients had received contaminated platelets. However, 6 to 93 (2.1%-32.7%) of these 284 reactions met 1 or more STR criteria, and sensitivity of STR criteria varied from 5.1% to 45.5%. These results document the continued occurrence of bacterial contamination of platelets resulting in STR in neutropenic patients, failure of passive surveillance to detect STR, and lack of specificity of STR criteria. These findings highlight the limitations of reported national STR data based on passive surveillance and the need to implement further measures to address this problem such as secondary testing or use of pathogen reduction technologies. (Blood. 2016;127(4):496-502)

Late sampling for automated culture to extend the platelet shelf life to 5 days in Germany

“…Many countries routinely implemented bacterial screening of PCs early in the shelf life (within 24 hr after production) with highly sensitive cultivation methods . Nonetheless, fatalities were still reported, most likely due to sampling errors at this sampling time point. Recent studies revealed that the increase of sample volume and prolongation of the sampling period from 24 hours to 36 or 48 hours after production improved platelet safety .…”

“…We observed failure or prolonged proliferation kinetics for mostly low‐pathogenic species with only low levels of bacterial contamination. It has been shown that the presence of low‐level bacterial loads most likely does not lead to TTS . Likewise, the implemented strategies of primary bacterial screening with delayed sampling support the extension of platelet shelf life to 7 days, but very low bacterial levels could still be missed .…”

Implications of the US Food and Drug Administration draft guidance for mitigating septic reactions from platelet transfusions

“…3 Recent data using prospective testing report 20 per 51 400 (1/2570) platelet products contaminated resulting in 4 per 51 400 (1/12 800) reactions (1 being fatal [1/51 400]). 4 PRT decreases most bacteria load by .4 logs. Hemovigilance data have not reported septic transfusion cases with pathogen-reduced (PR) platelets.…”

Microbiological Screening of Platelet Concentrates in Europe

“…However, it is assumed that the incidence of transfusion-associated sepsis is underestimated, thereby not reflecting the real risk. Based on data from Hong et al [58], a high proportion of transfusion-associated bacterial infections are not recognized. Active surveillance by platelet sample analysis at the time of release revealed a 10–40 times higher risk for platelet-associated bacterial transmission compared to passive surveillance.…”