Bacterial screening of apheresis platelets and the residual risk of septic transfusion reactions: the American Red Cross experience (2004‐2006)

Abstract

PLT contamination with bacteria that evade detection by QC culture remains a significant residual transfusion risk, in particular for older PLTs and skin-commensal bacteria in components collected by two-arm apheresis procedures during the study period.

Screening of platelet concentrates for bacterial contamination: spectrum of bacteria detected, proportionof transfused units, and clinical follow-up

“…The microbial spectrum is comparable to that of other studies which also performed aerobic and anaerobic cultures [3,4,7]. The high proportion of PCs contaminated with Propionibacteria is striking, accounting for 54% of confirmed positive PCs and 46% of potentially positive PCs.…”

“…Thus, if the Blood Service is notified on time of a suspected septic transfusion reaction (STR), it might be possible to block issues or recall other blood products prepared from the involved donations and thus prevent further STRs. Several blood donors services reported that PCs tested as false-negative by culture methods have caused 26 STRs, five of them fatal [4,7,10,17]. The deaths involved PCs contaminated with S. lugdunensis, S. aureus (two cases), S. marcescens, and K. pneumoniae.…”

“…A series of studies reports on the screening results of PCs with automated culture systems [3,4,6,7,[14][15][16][17]. Comparability of the results is limited.…”

“…If the six cases in this study in which follow-up revealed clinical reactions following the transfusion of potentially or confirmed contaminated PCs are considered unelucidated, 80 patients remain who were transfused with potentially positive PCs and 26 patients received confirmed positive [4,6,7,14,16,17]. However, it is noteworthy that none of the six cases of mild clinical reactions in our study was reported actively but was revealed only by solicited feedback after the treating physicians had been questioned in the study follow-up by the blood service.…”

“…In particular, platelet concentrates (PCs) that are stored at 20-24°C provide good bacterial growth conditions and are considered the main cause of bacterially induced transfusion disorders [5]. In the meantime, automated bacterial culture systems are used in some countries to screen PCs for bacterial contamination [6,7]. BacT/ALERT™ (bioMérieux, Durham, NC, USA) is the system most commonly employed [8].…”