Microbiological Screening of Platelet Concentrates in Europe

Abstract

The risk of transfusion-associated sepsis due to transmission of bacteria is a persistent problem in the transfusion field. Despite numerous interventions to reduce the risk, cases of bacterial sepsis following transfusion are repeatedly being reported. Especially platelet concentrates are highly susceptible to bacterial contaminations due to the growth-promoting storage conditions. In Europe, blood establishments and national authorities have implemented individual precaution measures to mitigate the risk of bacterial transmission. To obtain an overview of the different approaches, we compiled information from national authorities, blood establishments, and the current literature. Several aspects such as the shelf life of platelets, time of sampling and the applied control measures are compared between the member states. The analysis of the data revealed a broad heterogeneity of procedures on a national level ranging from platelet release without any safety testing up to mandatory screening of all platelet concentrates prior to transfusion. Despite the substantial progress made in recent years, several bacterial reports on transfusion-associated sepsis indicate that further efforts are needed to increase the safety of blood transfusions in the long term.

Keywords: Bacterial contamination; Blood safety; Infection; Pathogen inactivation; Platelet concentrates; Sepsis; Transfusion-associated infections.

Fig. 1

Strategies applied for risk reduction of transfusion-transmitted bacterial transmission via platelets in Europe. Green, routine-based screening; orange, routine-based pathogen inactivation; blue, only partial and/or quality control testing; white, no data available; dots, mini states. The map was generated with www.mapcharts.net.

Fig. 2

Detailed strategies of individual member states (MS) to prevent contaminated platelet concentrate (PC) transfusion. A) Shelf life reduction to 4 days with an extension to 5 days by additional testing with culture-based or rapid microbiological methods (dashed line). B) Implementation of a random quality control (QC) testing; release of platelets up to day 7 is possible in individual MS dependent on additional measures to detect bacteria (dashed lines). C) Routine culture-based screening with early sampling. A 2-bottle strategy (aerobic and anaerobic) is followed except for Denmark, where an aerobic culture bottle is used. Shelf life varies between 5 and 7 days among the respective MS. Ireland and UK allow additional testing on day 4 for shelf life extension to day 7. D) Routine culture-based screening with late sampling and a corresponding shelf life of 7 days. E) Implementation of pathogen reduction; red boxes indicate the sampling period.