Diagnostic Methods for Platelet Bacteria Screening: Current Status and Developments

Abstract

Bacterial contamination of blood components and the prevention of transfusion-associated bacterial infection still remains a major challenge in transfusion medicine. Over the past few decades, a significant reduction in the transmission of viral infections has been achieved due to the introduction of mandatory virus screening. Platelet concentrates (PCs) represent one of the highest risks for bacterial infection. This is due to the required storage conditions for PCs in gas-permeable containers at room temperature with constant agitation, which support bacterial proliferation from low contamination levels to high titers. In contrast to virus screening, since 1997 in Germany bacterial testing of PCs is only performed as a routine quality control or, since 2008, to prolong the shelf life to 5 days. In general, bacterial screening of PCs by cultivation methods is implemented by the various blood services. Although these culturing systems will remain the gold standard, the significance of rapid methods for screening for bacterial contamination has increased over the last few years. These new methods provide powerful tools for increasing the bacterial safety of blood components. This article summarizes the course of policies and provisions introduced to increase bacterial safety of blood components in Germany. Furthermore, we give an overview of the different diagnostic methods for bacterial screening of PCs and their current applicability in routine screening processes.

Microbiological Screening of Platelet Concentrates in Europe

“…Several systems are available on the market with different analytical sensitivities dependent on the detection principle. An overview of available methods and their test principles is provided by Störmer and Vollmer [44]. With regard to the time-to-result parameter, RMM are superior in comparison to culture-based methods.…”

Extension of the Storage Period of Platelet Concentrates in Germany to 5 Days by Bacterial Testing: Is it Worth the Effort?

“…NAT techniques are already accepted as one potential application. However, an easier approach regarding the technical equipment and required hands-on time [11] could be the application of rapidly interpreted cultural methods-combined sampling on day 3 or 4 of PC shelf life [9, 12]. This algorithm includes a defined minimum incubation time of sampled PCs, followed by extension of PC shelf life in case of negative results and continuous monitoring according to the negative-to-date concept.…”

Standardization of Diagnostics in Blood Safety

“…The maximum shelf life for platelets was reduced from 5 to 4 days in Germany to increase blood safety. Alternatively, rapid screening methods for bacterial detection in platelets have been optimized over the last decade and are now available for routine screening [7]. …”