Associated criteria used in investigating suspected septic transfusion reactions: A scoping review

BACKGROUND AND OBJECTIVES

Septic transfusion reactions (STRs) occur as a result of bacterial contamination of blood or blood products, resulting in sepsis. This scoping review aimed to identify, explore and map the available literature on the STR criteria triggering the investigation of STR.

MATERIALS AND METHODS

Four electronic databases (MEDLINE, Web of Science, Science Direct, Embase) were searched to retrieve scientific literature reporting such criteria, published from 1 January 2000 to 5 May 2022. Grey literature was also searched from open web sources.

RESULTS

Of 1052 references identified, 43 (21 peer-reviewed and 22 grey literature) met the eligibility criteria for inclusion and data extraction after full article screening. Of them, most (27/43, 62.79%) were found to report a single set of criteria, and only two reported four or more sets of criteria. The analysis of 66 sets of criteria collected from the selected references revealed 57 different sets. A few sets of criteria used only one sign and symptom (s/s) (12.12%, n = 8), whereas 16 sets used 7-15 s/s (n = 16/66; 24.24%). Of the total 319 occurrences of s/s associated with the 66 sets of criteria, post-transfusion hyperthermia, body temperature increase and hypotension were the most common s/s categories. Of all the literature available, only one study tested the diagnostic accuracy of the STR criteria.

CONCLUSION

This scoping review revealed a substantial variation in criteria used to identify suspected STR. Consequently, conducting further studies to enhance the diagnostic accuracy of these criteria, which trigger STR investigations, is imperative for advancing clinical practice.

Acquired platelet storage container leaks and contamination with environmental bacteria: A preventable cause of bacterial sepsis

Background

Apheresis platelets (AP) may be contaminated by environmental bacteria via container defects acquired during processing, transport, storage, or transfusion, as highlighted by a recent series of septic reactions related to Acinetobacter spp. and other bacterial strains.

Study design and methods

The frequency and nature of acquired container defect reports to one manufacturer were evaluated from January 2019 to July 2020. The published incidence of contamination and sepsis due to environmental bacteria with culture screened AP in the United States was reviewed for the period of 2010–2019.

Results

Review of a manufacturers' records showed 23 US reports of leaks involving 24 containers attributed to postmanufacturing damage, at a rate of 44 per million distributed storage containers. Analysis of returned containers showed evidence of scratches, impressions, and/or piercings. Literature review of US hemovigilance data revealed that environmental bacteria comprised 7% of confirmed positive primary bacterial culture screens, were responsible for 14%–16% of reported septic, and 8 of 28 (29%) fatal reactions with bacterial‐culture screened AP. Sepsis cases have been reported with culture screened, point‐of‐issue (POI) tested, or pathogen‐reduced AP.

Discussion

Environmental contamination of AP is rare but can cause sepsis. Container damage provides a pathway for contamination after culture screening, POI bacteria testing, or pathogen reduction. Blood collectors and transfusion services should have procedures to ensure proper inspection, handling, storage, and transport of AP to avoid damage and should enhance efforts to detect defects prior to release and to eliminate bacteria from all contacting surfaces to minimize the risk of contamination.

Limitations of current practices in detection of bacterially contaminated blood products associated with suspected septic transfusion reactions

BACKGROUND

In the setting of suspected septic transfusion reactions, bacterial culture of both the transfused patient and the residual blood component is recommended. Primary bacterial contamination can occur at the time of component collection. Clinically insignificant "secondary contamination" can occur during post-transfusion component discard, retrieval for culture, or manipulation of the bag at the time of culture sampling.

STUDY DESIGN AND METHODS

This retrospective, multi-center study analyzes positive residual component culture results and companion patient blood cultures from 15 hospitals, 1 blood center, and all cultured transfusion reactions within the province of Quebec, Canada, over a 5-year period. Imputability was assigned as "definite" (concordant growth), "possible" (discordant growth or lack of growth in patient culture), or "unable to assess" (patient not cultured).

RESULTS

There were 373 positive component cultures from 360 unique transfusion reactions, with 276 (76.7%) companion patient blood cultures performed, of which 10 (2.8%) yielded the pathogen detected in the positive component. Of these 10 definite pathogens, 7 (2 Staphylococcus aureus, 3 other staphylococci, and 1 Streptococcus pyogenes and 1 Bacillus sp.) were associated with platelet and 3 (Aeromonas veronii, Staphylococcus epidermidis, and Enterococcus faecalis) with RBC transfusions. RBC and plasma components comprised 70% of positive component cultures.

DISCUSSION

The process of performing residual component culture is vulnerable to secondary contamination. The significance of microorganisms recovered from component culture cannot be interpreted in isolation. In the context of low prevalence of primary contamination of blood components, the positive predictive value of a positive component culture result is very low.

Platelets treated with pathogen reduction technology: current status and future direction

Allogeneic platelets collected for transfusion treated with pathogen reduction technology (PRT), which has been available in some countries for more than a decade, are now increasingly available in the United States (US). The implementation of PRT-treated platelets, also known as pathogen-reduced platelets (PRPs), has been spurred by the need to further decrease the risk of sepsis associated with bacterial contamination coupled with the potential of this technology to reduce the risk of infections due to already recognized, new, and emerging infectious agents. This article will review available PRP products, examine their benefits, highlight unresolved questions surrounding this technology, and summarize pivotal research studies that have compared transfusion outcomes (largely in adult patients) for PRPs with non-PRT-treated conventional platelets (CPs). In addition, studies describing the use of PRPs in pediatric patients and work done on the association between PRPs and HLA alloimmunization are discussed. As new data emerge, it is critical to re-evaluate the risks and benefits of existing PRPs and newer technologies and reassess the financial implications of adopting PRPs to guide our decision-making process for the implementation of transfusing PRPs.